Abstract:
Bacteriophages are provided that infect strains of  Enterococcus faecalis , an opportunistic bacterial pathogen that causes human disease. Also provided are methods of treating  Enterococcus faecalis  by therapeutic administration of such bacteriophages.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The benefit of the filing date of U.S. Provisional Patent Application No. 61/804,922, filed Mar. 25, 2013, is hereby claimed. The entire disclosure of the aforesaid application is incorporated herein by reference. 
    
    
     REFERENCE TO GOVERNMENT GRANT 
     The invention was made with government support under grant no. 1R15DE021016-01 awarded by the National Institutes of Health. The government has certain rights in the invention. 
    
    
     SEQUENCE LISTING 
     The instant application contains a Sequence Listing which has been submitted in ASCII format via EFS-Web and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Mar. 21, 2014, is named 035926_0479_00_WO_SL.txt and is 256,052 bytes in size. 
     FIELD OF INVENTION 
     The invention relates to bacteriophages that infect strains of  Enterococcus faecalis , an opportunistic bacterial pathogen that causes human disease, and therapeutic uses thereof. 
     BACKGROUND OF THE INVENTION 
       E. faecalis , and closely related species, such as  E. faecium , have emerged as significant human pathogens, being major etiologic agents of infectious endocarditis, nosocomial infections, burn infections, urinary tract infections, meningitis, and surgical wound infections (Lerwis &amp; Zervos,  Eur J. Clin Microbiol Infect Dis  9(2): 111-117, 1990; Moellering Jr.,  Clin. Infect. Dis.  14(6): 1173-1176, 1992; Megran,  Clinical Infect. Dis.  15: 63-71, 1992; Emori &amp; Gaynes,  Clin. Microbiol. Rev.  6(4): 428-442, 1993; Jett et al., 1994; Edgeworth et al.,  Crit. Care Med.  28(8): 1421-1428, 1999; Richards et al.,  Infection Control Hosp. Epidemiol.  21(8): 510-515, 2000; NNIA System,  Am J Infect Control,  32: 470-485, 2004; Biedenbach et al.,  Diagn. Microbiol. Infect. Dis.  50: 59-69 2004; Linden,  Semin. Respir. Crit. Care Med.  28: 632-645, 2007). In terms of oral disease,  E. faecalis  is the most commonly isolated species from infected root canals of teeth that fail to heal following root canal therapy (Sundqvist et al.,  Oral Surg. Oral Med. Oral Pathol. Oral Radiol. And Endod.  85(1): 86-93, 1998; Peciuliene et al.,  J. Endod.  26(10): 593-595, 2000; Pinheiro et al.,  Int. Endod. J.  36: 1-11, 2003; Siqueira Jr. &amp; Rôças,  Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod.  97: 85-94, 2004; Stuart et al.,  J. Endod.  32(2): 93-98 2006; Zoletti et al.,  J Endod.  32(8): 722-726 2006). 
     The existing standard treatment for infections, including those due to enterococci, continues to involve the use of antibiotics. In the case of severe enterococcal infections, the regimen typically includes a cell wall active antibiotic, such as a penicillin or cephalosporin plus an aminoglycoside such as streptomycin (Megran,  CID  15:63-71, 1992; Noskin,  J Lab Clin Med  130:14-20, 1997). As resistance to these drugs became more common, vancomycin replaced these antibiotics as the drug of choice for treating these infections. 
     Complicating management of these infections is the development of resistance among many Enterococcal strains against many of the available, previously effective antibiotics, including vancomycin (Harvard et al.,  Br. Med. J.  1: 688-689, 1959; Murray &amp; Mederski-Samaroj, J. Clin.  Invest.,  72: 1168-1171, 1983; Uttley et al.,  Lancet , i: 57-58, 1988; Grayson et al.,  Antimicrob. Agents Chemother.,  35: 2180-2184, 1991; Bonten et al.,  Lancet Infect. Dis.  1: 314-325, 2001; Tenover &amp; McDonald,  Curr. Opin. Infect. Dis.  18: 300-305, 2005). With the appearance of vancomycin resistant enterococci (VREs) that were also resistant to the previously used antibiotics, combinations of vancomycin and quinolone type antibiotics, such as ciprofloxacin, were used, however, quinolone-resistant enterococcal strains also appeared. Although a modest number of new antibiotics, such as linezolid and daptomycin, have been developed to provide treatment alternatives in cases of infection by organisms that are resistant to all previously available antibiotics, there have been numerous reports of resistance by  E. faecalis  and  E. faecium  strains to these antibiotics as well (Eliopoulos et al.,  Antimicrob. Agents Chemother.,  45(5): 1088-1092, 1998; Prystowsky et al.,  Antimicrob. Agents Chemother.,  45(7): 2154-2156, 2001; Gonzales et al.,  Lancet  357(9263): 1179, 2002; Herrero et al.,  N Eng J Med  346: 867-860, 2002; Johnson et al.,  Int. J. Antimicrob. Agents  24: 315-319, 2004; Munoz-Price et al.,  Clin. Infect. Dis.,  41: 565-566, 2005; Kanafani et al.,  Scand. J. Infect. Dis.,  39(1): 75-77, 2007; Hidron et al.,  J Antimicrob. Chemother.,  61(6): 1394-1396, 2008; Marshall et al.,  Microbe,  4(5): 231-238, 2009; Kelesidis et al.,  Clin. Infect. Dis.,  52: 228-234, 2011; Ross et al.,  J. Chemother.,  23(2): 71-76, 2011; Ntokou et al.,  Antimicrob. Chemother.  67(8): 1819-1823, 2012). Therefore, alternative approaches to manage these infections are desired. 
     Bacteriophages are bacterial viruses that infect bacterial cells. During their infectious cycle within a host cell, the bacterial virus produces enzymes that will lead to the lysis of the cell and release of progeny virus particles. Harnessing this capacity of the bacteriophage to lyse and kill the host cell may provide a means of controlling antibiotic resistant bacterial infections. This approach, of using bacteriophages to treat and control bacterial infections has several advantages. Bacteriophages are highly specific in that they are only infectious for bacterial cells, and have no capacity for infecting cells of higher life forms such as mammals. In fact, they are so specific that the host range of any one bacteriophage is typically a single bacterial species, or at most, a few closely related bacterial species. Therefore, the effect of any one bacteriophage is limited to a very narrow portion of a mixed bacterial population. This provides an impact on the pathogenic bacteria while leaving the normal bacterial population unaffected. Both antibiotic sensitive and antibiotic resistant bacterial strains can be vulnerable to bacteriophage infection. In addition, in contrast to conventional antibiotics which decrease in concentration in the body after administration, bacteriophage titer can increase after administration, due to proliferation of the virus in the targeted host cell. 
     The therapeutic potential of bacteriophages was tested in 1919 by d&#39;Herelle, who showed that bacteriophage preparations could be used to successfully treat cases of dysentery (described in Chanishvili,  Advances in Virus Res.  83: 3-40, 2012). Further work continued, particularly in eastern Europe, on the use of bacteriophages (“phages”) to treat infectious diseases (Barrow,  J Chem Technol Biotechnol  76: 677-682, 2001; Duckworth and Gulig  Biodrugs,  16(1): 57-62, 2002, Petty et al.  TRENDS in Biotechnol.,  25(1): 7-15, 2006; Chanishvili, supra). With the advent of antibiotics in the 1940s, this line of research (phage therapy) fell by the wayside in the west since antibiotics were remarkably effective in combating many bacterial infections. However, in eastern Europe, where availability of antibiotics was limited, research into phage therapy continued, particularly in the Soviet Union, Georgia, and Poland. Here, the therapeutic use of phages became an accepted modality for treating a wide variety of bacterial infections. 
     Since the 1980s, as antibiotic resistance in pathogenic bacteria began to develop, and become more common in the West, there has been a resurgence in interest in using phages to treat human and animal infections (Summers,  Annu. Rev. Microbiol.  55: 437-451, 2001, Alisky et al.,  J. of Infec.  36: 5-15, 1998, Pirisi,  Lancet.  356: 1418, 2000; Ho,  Perspectives in Biology and Medicine,  44(1): 1-16, 2001; Merril et al.,  Naure Revs. Drug Disc.  2: 489-497, 2003; Bradbury,  Lancet.  363: 624-625, 2004; Dixon,  Lancet Infect Dis.  4: 186, 2004; Schoolnik et al.,  Nature  22(5): 505-506, 2004; Thiel,  Nature  22(1): 31-36, 2004; Skurnik and Strauch,  Int. J. Med. Microbiol.  296: 5-14, 2005). 
     Several recent studies report successful implementation of phage therapy (using either infectious bacteriophages or phage products) in modifying bacterial infections in animals by  Acinetobacter baumanii, Escherichia coli , group A streptococci,  Enterococcus faecium, Bacillus anthracis , and  Pseudomonas aeruginosa  (Soothill,  J. Med. Microbiol.  37: 258-261, 1992; Merril et al.,  Proc. Natl. Acad. Sci. USA.  93: 3188-3192, 1996; Nelson et al.,  Proc. Nat. Acad. Sci.  98(7): 4107-4112, 2001; Biswas et al.,  Infect. Immun.  70(1): 204-210, 2002; Schuch et al.,  Nature  418: 884-889, 2002; Watanabe et al.,  Antimicrob. Agents Chemother.  51: 446-452, 2007). In this regard, it is significant to note that in a study reported by Smith and Huggins,  J Gen Microbiol  128: 307-318 (1982), a single intramuscular (IM) dose of phage was more effective in protecting mice from normally lethal IM or intracerebral injections of  Escherichia coli  or  Salmonella enterica , than multiple IM injections of antibiotics such as tetracycline, ampicillin, chloramphenicol, or trimethoprim plus sulfisoxazole. In addition, in the first controlled trial of phage therapy in humans, it was shown that a cocktail of six  Pseudomonas aeruginosa  bacteriophages effectively treated antibiotic-resistant chronic otitis (Wright et al,  Clin. Otolaryngol.  34: 349-357, 2009). 
     In terms of phage therapy to treat  E. faecalis  infections, there has been relatively little reported. In 2004, Paisano et al.,  Oral Microbiol Immunol,  19: 327-330 reported that they could reduce the level of infection of a single  E. faecalis  strain in an infected dental root canal (in vitro), to an undetectable level, using a bacteriophage preparation. However, the bacteriophage used in this study was not characterized in any way (no morphological description, no genomic analysis). 
     Isolation of a bacterial virus (phage φEF24C) that could protect mice from otherwise lethal doses of  E. faecalis  has been reported (Uchiyama et al.,  FEMS Microbiol Lett.  278: 200-206, 2008; Uchiyama et al.,  Appl Environ Microbiol.  74(13): 4149-4163, 2008). This bacteriophage was reported to have a broad range of activity against many strains of  E. faecalis , and have no untoward effects on the mice. This phage was well characterized and could be described as follows: φEF24C has a contractile tail, giving it the morphology of a Myovirdae type bacteriophage. Its genome consisted of a linear, double stranded DNA, 142,072 by in length, with an estimated 221 ORFs and 5 tRNA genes. 
     Other strategies for exploiting bacteriophages for controlling  E. faecalis  infections involve the use of lytic enzymes produced by the viruses to lyse and kill the bacterial cells. The cell lysis produced by these enzymes is needed by the virus in order to allow the release of progeny viral particles from the infected cells. The strategy for exploiting these bacteriophage-specified lytic enzymes involves the cloning and expression of the genes for these enzymes, followed by the purification of the expressed proteins. One such lytic enzyme, active against strains of  E. faecalis  (as well as strains of  E. faecium , and several  Streptococcus  species), has reportedly been isolated from  E. faecalis  bacteriophage φ1 (Yoong et al.,  J Bacteria  186(145): 4808-4812, 2004). The bacteriophage source of this enzyme, phage φ1, was described as a Myoviridae morphotype; that is, a bacteriophage with a contractile tail. A second report of a bacteriophage lytic enzyme active against strains of  E. faecalis  came from Son et al.,  Appl. Microbiol.  108: 1769-1779 (2010). Here, the gene for a putative lytic enzyme specified by  E. faecalis  bacteriophage EFAP-1 was cloned, and expressed, and the gene product was purified. The purified phage protein was found to have lytic activity against numerous strains of  E. faecalis  and  E. faecium . Bacteriophage EFAP-1, the source of the lytic enzyme described by Son et al., had the non-contractile tail structure of a Siphovirdae morphotype. EFAP-1 had a 21,115 bp genome containing 24 ORFs. 
     Several other bacterial viruses that infect strains of  E. faecalis  have been reported. These include: Bacteriophages φFC1 (Yang et al.,  J. Bacteriol.  184: 1859-1864, 2002), F4 (Nigutova et al.,  Folio Microbiol.  53(3): 234-236, 2008), phages 31, 42, 54, and 70 (Mazaheri Nezhad Fard et al.,  Curr Microbiol.  60: 400-406, 2010), VD13 (Ackermann et al.,  Can. J. Microbiol.,  21: 571-574, 1975), phages 1 and 2 (Rogers and Sarles,  J. Bacteriol.  85: 1378-1385, 1963), SAP6 (Lee and Park,  J. Virol.  86(17): 9538-9539, 2012), BC-611 (Horiuchi et al.,  J. Virol.  86(17): 9538-9539, 2012), and phages φFL1A, φFL1B, φFL1C, φFL2A, φFL2B, φFL3A, φFL3B and φFL4A (Yasmin et al.,  J. Bacteriol.  192(4): 1122-1130, 2010). In addition several unnamed  E. faecalis  bacteriophages have been reported (Natkin,  Arch Oral Biol.  12(5): 669-680, 1967, Timperley et al.,  J. Pathol. Bacteriol.  9: 631-634, 1966, Follett et al.,  J. Gen. Virol.  1: 281-284, 1967, Letkiewicz et al.,  Folio Microbiol.  54: 457-461, 2009, and Bachrach et al.,  Lett. Appl. Microbiol.  36: 50-53, 2003). However, none of these have been proposed for use in phage therapy. 
     φEf11 is a temperate bacteriophage that was induced from a lysogenic root canal isolate of  Enterococcus faecalis  (Stevens et al.,  Oral Microbiol. Immunobiol.,  24: 278-284, 2009). φEf11 prophage is widely disseminated among strains of  E. faecalis . It is a member of the Siphoviridae family, with a long (130 nm) non-contractile tail and a small (41 nm diameter) spherical/icosahedral head. The phage produces small, turbid plaques in lawns of  E. faecalis  JH2-2. The φEf11 DNA has been sequenced and annotated, disclosing a genome of 42,822 base pairs encoding 65 Open Reading Frames (Stevens et al.,  FEMS Microbiol. Lett.,  317: 9-26, 2011, incorporated herein by reference; GenbankGQ452243.1, incorporated herein by reference). 
     The φEf11 genome is shown in  FIG. 10 . The numbered arrows indicate ORFs. The ORF numbering scheme in  FIG. 10  corresponds to the numbering system contained in Stevens et al., 2011, supra. ORFs 25-29 are involved in host cell lysis. 
     φEf11 possesses several characteristics making it a favorable candidate virus to be used in phage therapy: There are no toxin-related genes detected in the φEf11 genome, and it encodes several (4-6) genes encoding proteins with lysis-associated functions (Stevens et al., 2011, supra). However, as a temperate virus that has a very limited host range, and is difficult to propagate, wild-type φEf11 would not be suitable as a potential therapeutic agent. 
     Moreover, since φEf11 is a temperate bacteriophage, it possesses a module of genes that allows it to integrate its DNA into the host cell chromosome rather than initiating a productive infection and lysing the infected cell. The bacteriophage DNA can remain in this integrated state indefinitely, and the infected cell (a lysogen) will survive and continue to multiply. Furthermore, regulatory elements in the φEf11 genome whose activation is required for the development of a productive/lytic infection within the cell, are inactivated by a protein (repressor) produced by one of the lysogeny-related genes. Therefore, lysogenic cells producing this repressor are immune to super infection by φEf11, and would consequently survive exposure to this virus. This further limits the utility of φEf11 as therapeutic agent 
     SUMMARY OF THE INVENTION 
     Provided is a bacteriophage capable of infecting and lysing an  Enterococcus faecalis bacterium, said bacteriophage having a genome comprising: 
     (A) the following ORFs with the corresponding Protein ID Numbers from Genbank Accession Number GQ452243.1 , or having the following nucleic acid sequence: 
     (a) ORF 2, encoding the amino acid sequence of SEQ ID NO: 28, corresponding to Protein ID Number YP 003358792.1; 
     (b) ORF 3, encoding the amino acid sequence of SEQ ID NO: 29, corresponding to Protein ID Number YP 003358793.1; 
     (c) ORF 4, encoding the amino acid sequence of SEQ ID NO: 30, corresponding to Protein ID Number YP 003358794.1; 
     (d) ORF 5, encoding the amino acid sequence of SEQ ID NO: 31, corresponding to Protein ID Number YP 003358795.1; 
     (e) ORF 6, encoding the amino acid sequence of SEQ ID NO: 32, corresponding to Protein ID Number YP 003358796.1; 
     (f) ORF 7, encoding the amino acid sequence of SEQ ID NO: 33, corresponding to Protein ID Number YP 003358797.1; 
     (g) ORF 8, encoding the amino acid sequence of SEQ ID NO: 34, corresponding to Protein ID Number YP 003358798.1; 
     (h) ORF 9, encoding the amino acid sequence of SEQ ID NO: 35, corresponding to Protein ID Number YP 003358799.1; 
     (i) ORF 10, encoding the amino acid sequence of SEQ ID NO: 36, corresponding to Protein ID Number YP 003358800.1; 
     (j) ORF 11, encoding the amino acid sequence of SEQ ID NO: 37, corresponding to Protein ID Number YP 003358801.1; 
     (k) ORF 12, encoding the amino acid sequence of SEQ ID NO: 38, corresponding to Protein ID Number YP 003358802.1; 
     (l) ORF 13, encoding the amino acid sequence of SEQ ID NO: 39, corresponding to Protein ID Number YP 003358803.1; 
     (m) ORF 14, encoding the amino acid sequence of SEQ ID NO: 40, corresponding to Protein ID Number YP 003358804.1; 
     (n) ORF 15, encoding the amino acid sequence of SEQ ID NO: 41, corresponding to Protein ID Number YP 003358805.1; 
     (o) ORF 16, encoding the amino acid sequence of SEQ ID NO: 42, corresponding to Protein ID Number YP 003358806.1; 
     (p) ORF 17, encoding the amino acid sequence of SEQ ID NO: 43, corresponding to Protein ID Number YP 003358807.1; 
     (q) ORF 18, encoding the amino acid sequence of SEQ ID NO: 44, corresponding to Protein ID Number YP 003358808.1; 
     (r) ORF 19, encoding the amino acid sequence of SEQ ID NO: 45, corresponding to Protein ID Number YP 003358809.1; 
     (s) ORF 20, encoding the amino acid sequence of SEQ ID NO: 46, corresponding to Protein ID Number YP 003358810.1; 
     (t) ORF 21, encoding the amino acid sequence of SEQ ID NO: 47, corresponding to Protein ID Number YP 003358811.1; 
     (u) ORF 22, encoding the amino acid sequence of SEQ ID NO: 48, corresponding to Protein ID Number YP 003358812.1; 
     (v) ORF 23, encoding the amino acid sequence of SEQ ID NO: 49, corresponding to Protein ID Number YP 003358813.1; 
     (w) ORF 24, encoding the amino acid sequence of SEQ ID NO: 50, corresponding to Protein ID Number YP 003358814.1; 
     (x) ORF 25, encoding the amino acid sequence of SEQ ID NO: 51, corresponding to Protein ID Number YP 003358815.1; 
     (y) ORF 26, encoding the amino acid sequence of SEQ ID NO: 52, corresponding to Protein ID Number YP 003358816.1; 
     (z) ORF 27, encoding the amino acid sequence of SEQ ID NO: 53, corresponding to Protein ID Number YP 003358817.1; 
     (aa) ORF 28, encoding the amino acid sequence of SEQ ID NO: 54, corresponding to Protein ID Number YP 003358818.1; 
     (bb) ORF 29, encoding the amino acid sequence of SEQ ID NO: 55, corresponding to Protein ID Number YP 003358819.1; 
     (cc) ORF 30, encoding the amino acid sequence of SEQ ID NO: 56, corresponding to Protein ID Number YP 003358820.1; 
     (dd) ORF 37, encoding the amino acid sequence of SEQ ID NO: 63, corresponding to Protein ID Number YP 003358827.1; 
     (ee) ORF 38, encoding the amino acid sequence of SEQ ID NO: 64, corresponding to Protein ID Number YP 003358828.1; 
     (ff) ORF 39, encoding the amino acid sequence of SEQ ID NO: 65, corresponding to Protein ID Number YP 003358829.1; 
     (gg) ORF 40, encoding the amino acid sequence of SEQ ID NO: 66, corresponding to Protein ID Number YP 003358830.1; 
     (hh) ORF 41, encoding the amino acid sequence of SEQ ID NO: 67, corresponding to Protein ID Number YP 003358831.1; 
     (ii) ORF 42, encoding the amino acid sequence of SEQ ID NO: 68, corresponding to Protein ID Number YP 003358832.1; 
     (jj) ORF 43, encoding the amino acid sequence of SEQ ID NO: 69, corresponding to Protein ID Number YP 003358833.1; 
     (kk) ORF 44, encoding the amino acid sequence of SEQ ID NO: 70, corresponding to Protein ID Number YP 003358834.1; 
     (ll) ORF 45, encoding the amino acid sequence of SEQ ID NO: 71, corresponding to Protein ID Number YP 003358835.1; 
     (mm) ORF 46, encoding the amino acid sequence of SEQ ID NO: 72, corresponding to Protein ID Number YP 003358836.1; 
     (nn) ORF 47, encoding the amino acid sequence of SEQ ID NO: 73, corresponding to Protein ID Number YP 003358837.1; 
     (oo) ORF 48, encoding the amino acid sequence of SEQ ID NO: 74, corresponding to Protein ID Number YP 003358838.1; 
     (pp) ORF 49, encoding the amino acid sequence of SEQ ID NO: 75, corresponding to Protein ID Number YP 003358839.1; 
     (qq) ORF 50, encoding the amino acid sequence of SEQ ID NO: 76, corresponding to Protein ID Number YP 003358840.1; 
     (rr) ORF 51, encoding the amino acid sequence of SEQ ID NO: 77, corresponding to Protein ID Number YP 003358841.1; 
     (ss) ORF 52, encoding the amino acid sequence of SEQ ID NO: 78, corresponding to Protein ID Number YP 003358842.1; 
     (tt) ORF 53, encoding the amino acid sequence of SEQ ID NO: 79, corresponding to Protein ID Number YP 003358843.1; 
     (uu) ORF 54, encoding the amino acid sequence of SEQ ID NO: 80, corresponding to Protein ID Number YP 003358844.1; 
     (vv) ORF 55, encoding the amino acid sequence of SEQ ID NO: 81, corresponding to Protein ID Number YP 003358845.1; 
     (ww) ORF 56, encoding the amino acid sequence of SEQ ID NO: 82, corresponding to Protein ID Number YP 003358846.1; 
     (xx) ORF 57, encoding the amino acid sequence of SEQ ID NO: 83, corresponding to Protein ID Number YP 003358847.1; 
     (yy) ORF 58, encoding the amino acid sequence of SEQ ID NO: 84 corresponding to Protein ID Number YP 003358848.1; and 
     (zz) ORF 59, encoding the amino acid sequence of SEQ ID NO: 85, corresponding to Protein ID Number YP 003358849.1; 
     (aaa) ORF 60, encoding the amino acid sequence of SEQ ID NO: 86, corresponding to Protein ID Number YP 003358850.1; 
     (bbb) a portion of ORF 1, having the nucleic acid sequence of SEQ ID NO: 170; 
     (B) an inducible or constitutive promoter immediately upstream of ORF 37; and 
     (C) the following ORFs from bacteriophage ΦFL1C: 
     (a) ORF 40 encoding the amino acid sequence of SEQ ID NO: 158; 
     (b) ORF 41 encoding the amino acid sequence of SEQ ID NO: 159; 
     (c) ORF 42 encoding the amino acid sequence of SEQ ID NO: 160; 
     (d) ORF 43 encoding the amino acid sequence of SEQ ID NO: 161; 
     (e) ORF 44 encoding the amino acid sequence of SEQ ID NO: 162. 
     In some embodiments, the bacteriophage has a genome comprising: 
     (A) the following ORFs having the corresponding Gene ID Numbers from Genbank Accession Number GQ452243.1, or having the following nucleic acid sequence: 
     (a) ORF 2, the nucleic acid sequence of SEQ ID NO: 94, corresponding to Gene ID Number 8683900; 
     (b) ORF 3, the nucleic acid sequence of SEQ ID NO: 95, corresponding to Gene ID Number 8683888; 
     (c) ORF 4, the nucleic acid sequence of SEQ ID NO: 96, corresponding to Gene ID Number 8683893; 
     (d) ORF 5, the nucleic acid sequence of SEQ ID NO: 97, corresponding to Gene ID Number 8683933; 
     (e) ORF 6, the nucleic acid sequence of SEQ ID NO: 98, corresponding to Gene ID Number 8683946; 
     (f) ORF 7, the nucleic acid sequence of SEQ ID NO: 99, corresponding to Gene ID Number 8683941; 
     (g) ORF 8, the nucleic acid sequence of SEQ ID NO: 100, corresponding to Gene ID Number 8683932; 
     (h) ORF 9, the nucleic acid sequence of SEQ ID NO: 101, corresponding to Gene ID Number 8683887; 
     (i) ORF 10, the nucleic acid sequence of SEQ ID NO: 102, corresponding to Gene ID Number 8683904; 
     (j) ORF 11, the nucleic acid sequence of SEQ ID NO: 103, corresponding to Gene ID Number 8683926; 
     (k) ORF 12, the nucleic acid sequence of SEQ ID NO: 104, corresponding to Gene ID Number 8683911; 
     (l) ORF 13, the nucleic acid sequence of SEQ ID NO: 105, corresponding to Gene ID Number 8683923; 
     (m) ORF 14, the nucleic acid sequence of SEQ ID NO: 106, corresponding to Gene ID Number 8683914; 
     (n) ORF 15, the nucleic acid sequence of SEQ ID NO: 107, corresponding to Gene ID Number 8683916; 
     (o) ORF 16, the nucleic acid sequence of SEQ ID NO: 108, corresponding to Gene ID Number 8683884; 
     (p) ORF 17, the nucleic acid sequence of SEQ ID NO: 109, corresponding to Gene ID Number 8683912; 
     (q) ORF 18, the nucleic acid sequence of SEQ ID NO: 110, corresponding to Gene ID Number 8683919; 
     (r) ORF 19, the nucleic acid sequence of SEQ ID NO: 111, corresponding to Gene ID Number 8683929; 
     (s) ORF 20, the nucleic acid sequence of SEQ ID NO: 112, corresponding to Gene ID Number 8683927; 
     (t) ORF 21, the nucleic acid sequence of SEQ ID NO: 113, corresponding to Gene ID Number 8683928; 
     (u) ORF 22, the nucleic acid sequence of SEQ ID NO: 114, corresponding to Gene ID Number 8683935; 
     (v) ORF 23, the nucleic acid sequence of SEQ ID NO: 115, corresponding to Gene ID Number 8683908; 
     (w) ORF 24, the nucleic acid sequence of SEQ ID NO: 116, corresponding to Gene ID Number 8683924; 
     (x) ORF 25, the nucleic acid sequence of SEQ ID NO: 117, corresponding to Gene ID Number 8683907; 
     (y) ORF 26, the nucleic acid sequence of SEQ ID NO: 118, corresponding to Gene ID Number 8683925; 
     (z) ORF 27, the nucleic acid sequence of SEQ ID NO: 119, corresponding to Gene ID Number 8683889; 
     (aa) ORF 28, the nucleic acid sequence of SEQ ID NO: 120, corresponding to Gene ID Number 8683944; 
     (bb) ORF 29, the nucleic acid sequence of SEQ ID NO: 121, corresponding to Gene ID Number 8683920; 
     (cc) ORF 30, the nucleic acid sequence of SEQ ID NO: 122, corresponding to Gene ID Number 8683896; 
     (dd) ORF 37, the nucleic acid sequence of SEQ ID NO: 129, corresponding to Gene ID Number 8683921; 
     (ee) ORF 38, the nucleic acid sequence of SEQ ID NO: 130, corresponding to Gene ID Number 8683898; 
     (ff) ORF 39, the nucleic acid sequence of SEQ ID NO: 131, corresponding to Gene ID Number 8683895; 
     (gg) ORF 40, the nucleic acid sequence of SEQ ID NO: 132, corresponding to Gene ID Number 8683940; 
     (hh) ORF 41, the nucleic acid sequence of SEQ ID NO: 133, corresponding to Gene ID Number 8683917; 
     (ii) ORF 42, the nucleic acid sequence of SEQ ID NO: 134, corresponding to Gene ID Number 8683897; 
     (jj) ORF 43 the nucleic acid sequence of SEQ ID NO: 135, corresponding to Gene ID Number 8683894; 
     (kk) ORF 44, the nucleic acid sequence of SEQ ID NO: 136, corresponding to Gene ID Number 8683883; 
     (ll) ORF 45, the nucleic acid sequence of SEQ ID NO: 137, corresponding to Gene ID Number 8683903; 
     (mm) ORF 46, the nucleic acid sequence of SEQ ID NO: 138, corresponding to Gene ID Number 8683943; 
     (nn) ORF 47, the nucleic acid sequence of SEQ ID NO: 139, corresponding to Gene ID Number 8683913; 
     (oo) ORF 48, the nucleic acid sequence of SEQ ID NO: 140, corresponding to Gene ID Number 8683910; 
     (pp) ORF 49, the nucleic acid sequence of SEQ ID NO: 141, corresponding to Gene ID Number 8683937; 
     (qq) ORF 50, the nucleic acid sequence of SEQ ID NO: 142, corresponding to Gene ID Number 8683915; 
     (rr) ORF 51, the nucleic acid sequence of SEQ ID NO: 143, corresponding to Gene ID Number 8683885; 
     (ss) ORF 52, the nucleic acid sequence of SEQ ID NO: 144, corresponding to Gene ID Number 8683890; 
     (tt) ORF 53, the nucleic acid sequence of SEQ ID NO: 145, corresponding to Gene ID Number 8683886; 
     (uu) ORF 54, the nucleic acid sequence of SEQ ID NO: 146, corresponding to Gene ID Number 8683909; 
     (vv) ORF 55, the nucleic acid sequence of SEQ ID NO: 147, corresponding to Gene ID Number 8683902; 
     (ww) ORF 56, the nucleic acid sequence of SEQ ID NO: 148, corresponding to Gene ID Number 8683931; 
     (xx) ORF 57, the nucleic acid sequence of SEQ ID NO: 149, corresponding to Gene ID Number 8683930; 
     (yy) ORF 58, the nucleic acid sequence of SEQ ID NO: 150 corresponding to Gene ID Number 8683899; and 
     (zz) ORF 59, the nucleic acid sequence of SEQ ID NO: 151, corresponding to Gene ID Number 8683936; 
     (aaa) ORF 60, the nucleic acid sequence of SEQ ID NO: 152, corresponding to Gene ID Number 8683942; 
     (bbb) a portion of ORF 1, having the nucleic acid sequence of SEQ ID NO: 170; 
     (B) an inducible or constitutive promoter immediately upstream of ORF 37; and 
     (C) the following ORFs from bacteriophage ΦFL1C: 
     (a) ORF 40 having the nucleic acid sequence of SEQ ID NO: 163; 
     (b) ORF 41 having the nucleic acid sequence of SEQ ID NO: 164; 
     (c) ORF 42 having the nucleic acid sequence of SEQ ID NO: 165; 
     (d) ORF 43 having the nucleic acid sequence of SEQ ID NO: 166; 
     (e) ORF 44 having the nucleic acid sequence of SEQ ID NO: 167. 
     In some embodiments the bacteriophage has the genome of the bacteriophage ΦEf11 from Genbank Accession Number GQ452243.1, corresponding to SEQ ID NO: 92: 
     (A) wherein the following ORFs have been deleted: 
     (a) a portion of ORF  1  having the nucleic acid sequence of SEQ ID NO: 169; 
     (b) ORF 31, encoding the amino acid sequence of SEQ ID NO: 57, corresponding to Protein ID Number YP 003358821.1; 
     (c) ORF 32, encoding the amino acid sequence of SEQ ID NO: 58, corresponding to Protein ID Number YP 003358822.1; 
     (d) ORF 33, encoding the amino acid sequence of SEQ ID NO: 59, corresponding to Protein ID Number YP 003358823.1; 
     (e) ORF 34, encoding the amino acid sequence of SEQ ID NO: 60, corresponding to Protein ID Number YP 003358824.1; 
     (f) ORF 35, encoding the amino acid sequence of SEQ ID NO: 61, corresponding to Protein ID Number YP 003358825.1; 
     (g) ORF 36, encoding the amino acid sequence of SEQ ID NO: 62, corresponding to Protein ID Number YP 003358826.1; 
     (h) ORF 61, encoding the amino acid sequence of SEQ ID NO: 87, corresponding to Protein ID Number YP 003358851.1; 
     (i) ORF 62, encoding the amino acid sequence of SEQ ID NO: 88, corresponding to Protein ID Number YP 003358852.1; 
     (j) ORF 63, encoding the amino acid sequence of SEQ ID NO: 89, corresponding to Protein ID Number YP 003358853.1; 
     (k) ORF 64, encoding the amino acid sequence of SEQ ID NO: 90, corresponding to Protein ID Number YP 003358854.1; 
     (l) ORF 65, encoding the amino acid sequence of SEQ ID NO: 91 corresponding to Protein ID Number YP 003358855.1;
     (B) wherein the P CRO  promoter between ORFs 36 and 37 has been replaced with an inducible promoter or a constitutive promoter; and   (C) comprising the following ORFs from bacteriophage ΦFL1C:   

     (a) ORF 40 encoding the amino acid sequence of SEQ ID NO: 158; 
     (b) ORF 41 encoding the amino acid sequence of SEQ ID NO: 159; 
     (c) ORF 42 encoding the amino acid sequence of SEQ ID NO: 160; 
     (d) ORF 43 encoding the amino acid sequence of SEQ ID NO: 161; 
     (e) ORF 44encoding the amino acid sequence of SEQ ID NO: 162. 
     In yet further embodiments the bacteriophage has the genome of the ΦEf11bacteriophage that is comprised by  Enterococcus faecalis  NRRL Deposit Number NRRL B-50832, deposited on March 22, 2013:
     (A) wherein the following ORFs have been deleted, which have the following nucleic acid sequence, or the following amino acid sequences, corresponding to the following Protein ID Numbers from Genbank Accession Number GQ452243.1:   

     (a) a portion of ORF 1 having the nucleic acid sequence of SEQ ID NO: 169; 
     (b) ORF 31, encoding the amino acid sequence of SEQ ID NO: 57, corresponding to Protein ID Number YP 003358821.1; 
     (c) ORF 32, encoding the amino acid sequence of SEQ ID NO: 58, corresponding to Protein ID Number YP 003358822.1; 
     (d) ORF 33, encoding the amino acid sequence of SEQ ID NO: 59, corresponding to Protein ID Number YP 003358823.1; 
     (e) ORF 34, encoding the amino acid sequence of SEQ ID NO: 60, corresponding to Protein ID Number YP 003358824.1; 
     (f) ORF 35, encoding the amino acid sequence of SEQ ID NO: 61, corresponding to Protein ID Number YP 003358825.1; 
     (g) ORF 36, encoding the amino acid sequence of SEQ ID NO: 62, corresponding to Protein ID Number YP 003358826.1; 
     (h) ORF 61, encoding the amino acid sequence of SEQ ID NO: 87, corresponding to Protein ID Number YP 003358851.1; 
     (i) ORF 62, encoding the amino acid sequence of SEQ ID NO: 88, corresponding to Protein ID Number YP 003358852.1; 
     (j) ORF 63, encoding the amino acid sequence of SEQ ID NO: 89, corresponding to Protein ID Number YP 003358853.1; 
     (k) ORF 64, encoding the amino acid sequence of SEQ ID NO: 90, corresponding to Protein ID Number YP 003358854.1; 
     (l) ORF 65, encoding the amino acid sequence of SEQ ID NO: 91, corresponding to Protein ID Number YP 003358855.1;
     (B) wherein the P CRO  promoter between ORFs 36 and 37 has been replaced with an inducible promoter or a constitutive promoter; and   (C) comprising the following ORFs from bacteriophage ΦFL1C:   

     (a) ORF 40 encoding the amino acid sequence of SEQ ID NO: 158; 
     (b) ORF 41 encoding the amino acid sequence of SEQ ID NO: 159; 
     (c) ORF 42 encoding the amino acid sequence of SEQ ID NO: 160; 
     (d) ORF 43 encoding the amino acid sequence of SEQ ID NO: 161; 
     (e) ORF 44 encoding the amino acid sequence of SEQ ID NO: 162. 
     In some embodiments of the previous embodiment, for the following ORFs from bacteriophage ΦFL1C: 
     (a) ORF 40 has the nucleic acid sequence of SEQ ID NO: 163; 
     (b) ORF 41 has the nucleic acid sequence of SEQ ID NO: 164; 
     (c) ORF 42 has the nucleic acid sequence of SEQ ID NO: 165; 
     (d) ORF 43 has the nucleic acid sequence of SEQ ID NO: 166; 
     (e) ORF 44 has the nucleic acid sequence of SEQ ID NO: 167. 
     In further embodiments the bacteriophage comprises the genome of the bacteriophage ΦEf11 from Genbank Accession Number GQ452243.1 corresponding to SEQ ID NO: 92:
     (A) wherein nucleotides 39671-42813 and nucleotides 1-336 have been deleted and replaced by nucleotides 14600-17836 from bacteriophage ΦFL1C; and   (B) wherein the P CRO  promoter between ORFs 36 and 37 of the genome of bacteriophage ΦEf11 have been replaced with an inducible promoter or a constitutive promoter.   

     In further embodiments the bacteriophage is φEf11 (vir) PnisA  and is comprised by  Enterococcus faecalis  NRRL Deposit Number NRRL B-50833. 
     In further embodiments, the bacteriophage is a variant of the bacteriophage φEf11(vir) PnisA  comprised by  Enterococcus faecalis  NRRL Deposit Number NRRL B-50833, wherein the nisin promoter present in said deposited bacteriophage is replaced by a constitutive promoter, and wherein the erythromycin resistance gene present in said deposited bacteriophage is deleted. 
     In some embodiments the promoter is a constitutive promoter. In further embodiments the constitutive promoter is the Tu promoter having the nucleic acid sequence of SEQ ID NO: 168. 
     In some embodiments the inducible promoter is the nisin promoter. 
     Also provided is a bacteria comprising the bacteriophage of any one of the preceding bacteriophage embodiments. In some bacteria embodiments, the bacteria is a strain of  Enterococcus faecalis.    
     Provided is a composition for prevention and treatment of  Enterococcus faecalis  or  Enterococcus faecium  infection comprising the bacteriophage of any one of the preceding embodiments, provided that the inducible promoter is not a promoter that utilizes a toxic inducer (e.g., the promoter is not the nisin promoter); and a pharmaceutically acceptable carrier. 
     Also provided is a method for prevention or treatment of  Enterococcus faecalis  or  Enterococcus faecium  infection comprising administering to a subject in need of such treatment or prevention the composition of the preceding embodiment. In some embodiments the composition is administered orally, optically, subcutaneously, peritoneally, intravenously, topically, intradentally or parenterally. In further embodiments the composition is administered to a root canal. In yet further embodiments the infection is resistant to at least one antibiotic. In yet further embodiments the infection is in an immunocompromised patient. 
     As envisioned in the present invention with respect to the disclosed compositions of matter and methods, in one aspect the embodiments of the invention comprise the components and/or steps disclosed herein. In another aspect, the embodiments of the invention consist essentially of the components and/or steps disclosed herein. In yet another aspect, the embodiments of the invention consist of the components and/or steps disclosed herein. 
     ABBREVIATIONS 
     AGE means agarose gel electrophoresis. 
     ORF means open reading frame. 
    
    
     
       DESCRIPTION OF THE FIGURES 
         FIG. 1  is a schematic representation of the construction of plasmid pΔ31-36PnisA, the vector used to delete ORFs 31-36, and replace P cro  with P nisA  in the φEf11(Δ61-1, φFL1C40-44) prophage. The sequence comprising the two component nisin sensor system (nisR/nisK) is marked “A”. The fragment representing the nisin promoter (P nisA ) is marked “B”. The segment representing an erythromycin resistance marker (erm) is marked “C”. Fragments immediately upstream (pre31) and downstream (post 36) of the φEf11 genomic region targeted for allelic exchange are marked “D”. 
         FIGS. 2A-2F  show the results of a plaque assay of φEf11 wild type (WT), spontaneous recombinant [(φEf11(φ61-1, φFL1C40-44)], and virulent mutant [φEf11(vir) PnisA ]: ( 2 A) WT after incubation for 1 day, ( 2 B) WT after incubation for 2 days, ( 2 C) spontaneous recombinant after incubation for 1 day, ( 2 D) spontaneous recombinant after incubation for 4 days, ( 2 E) virulent mutant after incubation for 1 day, ( 2 F) virulent mutant after incubation for 4 days. 
         FIGS. 3A-3B  show the results of an agarose gel electrophoresis analysis of ethidium bromide-stained NdeI restriction fragments of φEf11 and φEf11(φ61-1, φFL1C 40-44) DNA. ( 3 A) Lanes 1 and 2: DNA molecular length standards (values on left are DNA lengths in kilobase pairs); 3: intact (undigested) φEf11 DNA; 4: NdeI-digested φEf11 DNA. ( 3 B) Lane 1: DNA molecular length standards (values on left are DNA lengths in kilobase pairs); 2: NdeI-digested φEf11(φ61-1, φFL1C 40-44) DNA. Note that fragment 6, seen in gel containing Ndel fragments of φEf11 DNA, is missing in the gel containing the NdeI-digested φEf11(φ61-1, φFL1C 
         FIG. 4  shows a Ndel restriction site analysis of the φEf11 DNA. The φEf11 DNA is 42,822 in length and is oriented as described in Stevens et al., 2011. supra), with the genes arranged with ORF 1 at the extreme left end and ORF 65 at the extreme right end. Ndel restriction sites (bp coordinates) are indicated the boxes. The Ndel restriction fragments, as visualized in agarose gel electrophoresis analysis AGE, are labeled 1-12. The first Ndel site is located 1.036 kbp from the left terminus of the DNA (coordinate 1036), and the Ndel site is located 1.754 kbp from the right terminus of the DNA (coordinate 41,068). The combined length of these two fragments (2,7980 kbp) is equal to the size estimated from Ndel fragment 6 observed in AGE analysis. 
         FIG. 5  presents an overview of the regions of φEf11 (top) and φFL1C (bottom) that recombined to yield recombinant φEf11(Δ61-1, φFL1C 40-44) (middle). Non-bolded line portions indicate φEf11 sequences, bolded lines indicate φFL1C sequences. 
         FIG. 6  shows the PCR detection of φFL1C genes in  E. faecalis  JH2-2. Template DNA, lanes: 1-3: φEf11(Δ61-1, φFL1C40-44); 4-6:  E. faecalis  JH2-2; 7-9: φEf11 wildtype. Primers, lanes: 1, 4, 7: φFL1C gp40 internal primers (FL1A35F/FL1A35R); 2, 5, 8: φFL1C gp44 internal primers (FL1A37F/FL1A38R); 3, 6, 9: φEf11 ORF44 internal primers (EF44F/EF44R); M: DNA marker. 
         FIG. 7  shows a one-step growth curve for phage φEf11 (wild type), φEf11(Δ61-1, φFL1C40-44) (spontaneous recombinant), and φEf11(vir)P nisA  (virulent variant). Log phase broth cultures of  E. faecalis  JH2-2 were infected with a phage stock. After adsorption for 30 minutes, the cells were collected by centrifugation, washed, and incubated at 37° C. At various time points aliquots of the suspension were centrifuged to remove the cells, and the supernatants were plaque assayed for phage titer (pfu/ml) using JH2-2 indicator cells. (-●- φEf11 titer (pfu/ml); -▪- φEf11(Δ61-1, φFL1C40-44) titer (pfu/ml); -▴- φEf11 (vir)P nisA  titer (pfu/ml). 
         FIG. 8  represents a φEf11 (wild type) and φEf11(vir) PnisA  sequence comparison. The virulent mutant, φEf11(vir) PnisA , genes ORF30-ORF36 as well as the cro promoter were allelically exchanged for the Nisin promoter cassette, and OR61-ORF1 were allelically exchanged with gp40-gp44 of φFL1C. 
         FIG. 9  shows a PCR analysis of the φEf11(vir) PnisA  genome demonstrating absence of φEf11 ORFs 31 and 36, and the presence of nisR, P nisA , φFL1C ORFs gp40 and gp44. PCR products were separated by electrophoresis in 2% agarose gels and detected by ethidium bromide staining. Numbers to the left of the gel indicate DNA fragment size (kbp). Template DNA for PCR reactions: φEf11(vir) PnisA  (vir/lanes 1-4 and 7-8); φEf11 (wt/lanes 5-6 and 9-10). Primers used in the PCR reactions (see  FIG. 8  for primer binding sites): Primer set EF31UUF/RK5R spanning ORF 29 to nisR (lane 1), primers PNISaF/37DDR spanning P nisA  to ORF 38 (lane 2); primers EF31MF/EF31MR within ORF 31 (lanes 3 and 5); primers EF36MF/EF36MR within ORF 36 (lanes 4 and 6); primers FL1A35F/FL1A35R within φFL1C ORF gp40 (lanes 7 and 9), primers FL1A37F/FL1A38R within φFL1C ORF gp44 (lanes 8 and 10). Lane M: molecular weight markers (BenchTop 1 kb ladder, Promega). 
         FIG. 10  shows the φEf11 genome. The numbered arrows indicate ORFs. The ORF numbering scheme in  FIG. 10  corresponds to the numbering system contained in Stevens et al., 2011, supra. ORFs 25-29 are involved in host cell lysis. 
         FIGS. 11A-11E  show a nucleotide sequence alignment of phages φEf11, φFL1C, and spontaneous recombinant phage [φEf11(Δ61-1, φFL1C 40-44)] in the region of recombination (φEf11 ORFs 60/61-1 and φFL1C ORFs 39/40-44). Non-bolded text indicates φEf11 sequences, boldface text indicates φFL1C sequences. Spontaneous recombinant is abbreviated as Sp. Genomic coordinates are indicated to right of each row of sequence. Sites of sequence identity between φEf11 and φEf11(Δ61-1, φFL1C 40-44) are indicated by *****. The figures show φEf11 sequence from 39307 to 41213 (SEQ ID NO: 171) (within ORF60) and from 1 through 451 (SEQ ID NO:172) (within ORF1), and φFL1C sequence from 14237 to 16206 (SEQ ID NO: 173) (within ORF39) and from 1672 to 17451 (SEQ ID NO: 174) (within ORF44). The segment of the φEf11 sequence that has been replaced by the φFL1C sequence to form the φEf11(Δ61-1, φFL1C 40-44) recombinant is indicated as enclosed by the hashed brackets. The figures shows the nucleotide sequence of the spontaneous recombinant phage [φEf11(Δ61-1, φFL1C 40-44)] from 1772 to 3740 (SEQ ID NO: 175) and from 4527 to 5006 (SEQ ID NO: 176). NdeI restriction site in φEf11 sequence is indicated. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     According to the present invention, engineered  Enterococcus faecalis  bacteriophages are provided that are virulent, highly lytic, incapable of lysogeny, insensitive to repressor, and capable of an extended host infectivity range. These characteristics make the recombinant phages useful as therapeutic agents in treatment and prevention of  Enterococcus faecalis  infections. 
     A recombinant bacteriophage, designated φEf11(vir) PnisA , has been derived from φEf11. A lysogenic  Enterococcus faecalis  strain harboring phage φEf11(vir) PnisA  was deposited in the Agricultural Research Service Culture Collection (NRRL), National Center for Agricultural Utilization Research Agricultural Research Service, USDA, 1815 North University Street Peoria, Illinois 61604-3999 on March 22, 2013 under accession number NRRL B-50833. The wild type phage φEf11 was deposited in the same depository on March 22, 2013 under accession number NRRL B-50832. 
     φEf11 is a temperate bacteriophage that was induced from a lysogenic root canal isolate of  Enterococcus faecalis  (Stevens et al.,  Oral Microbiol. Immunol.,  24: 278-284, 2009). Passage of φEf11 in  E. faecalis  JH2-2 has yielded the recombinant variant, φEf11(Δ61-1, φFL1C40-44), which provides elevated phage titers in broth cultures compared to the φEf11 wild type. The recombinant bacteriophage also produces much larger, clearer zones of lysis in lawns of  E. faecalis  cells, than does the wild type φEf11. Genetic analysis of the cloned virus producing the large plaques revealed that the variant was a recombinant between φEf11 and a defective φFL1C-like prophage located in the  E. faecalis  JH2-2 chromosome. The recombinant possessed 5 ORFs of the defective φFL1C-like prophage in place of 6 ORFs of the φEf11 genome. Deletion of ORFs 31-36 and replacement of the putative cro promoter from the recombinant phage genome with an exogenous regulatory element (inducible promoter) resulted in no loss of virus infectivity. Deletion of all lysogeny-related genes has resulted in a recombinant no longer having the capacity to form lysogens. 
     It was found that ORFs 31-36 are completely dispensable for lytic cycle function, since deletion of these genes did not prevent productive infection by the virus. Infection of lawns of host cells by the mutant virus lacking these genes produced clear plaques. Furthermore, surviving (presumptive lysogenic) cells from the plaques produced by the mutant virus lacking ORFs 31-36 could not be recovered. This confirms that deleting these genes from the viral genome, results in an φEf11 mutant that is incapable of lysogeny. 
     Regulatory elements in the φEf11 genome whose activation is required for the development of a productive/lytic infection within the cell, are inactivated by a protein (repressor) produced by ORF 36, one of the lysogeny-related genes. Lysogenic cells producing this repressor are thus immune to super infection by φEf11, and would consequently survive exposure to this virus. 
     Accordingly, a stem-loop structure surrounded by P L  and P R  promoter sequences in the φEf11 genome lying between a putative cI repressor gene and a putative cro gene was replaced with an exogenous regulatory element that is not susceptible to inactivation by the repressor. This P CRO  region lies between ORFs 36 and 37. Specifically, the native promoter sequence was replaced with a nisin-inducible promoter, generating a virus that was capable of productively infecting  E. faecalis  (φEf11) lysogens, in the presence of the φEf11 cI repressor protein. Accordingly, replacement of the φEf11 wild type regulatory element with an exogenous regulatory element that is not susceptible to inactivation by the repressor, as provided herein, allows the variant bacteriophage to productively infect and lyse lysogenic cells that harbor a previously integrated φEf11 genome. 
     Surprisingly, spontaneous recombinational replacement of 5 genes (ORFs 61-65) of the DNA replication/modification module and 1 gene (ORF 1/terminase A) of the packaging module by 5 genes (ORFs 40-44) of  E. faecalis  phage φFL1C also had an effect on the virulence properties of the virus. While this genetic recombination had no effect upon host range, it did markedly alter the lytic properties observed during infection of either broth cultures or soft agar overlay lawns of susceptible host cells. Broth cultures rapidly and more thoroughly cleared, after infection by the recombinant phage φEf11(Δ61-1, φFL1C40-44), as compared to infection by the wild type φEf11 virus. Similarly, plaques produced by the recombinant phage φEf11(Δ61-1, φFL1C40-44) appeared as large, extensively spreading lytic zones with a clearer center, compared to those formed by the wild type φEf11 virus. Without wishing to be bound by any theory, the replacement (φFL1C) genes may contribute to a more robust, more productive lytic infection by increasing the efficiency of either phage DNA synthesis or packaging, or both. The results of one step growth experiments for wild type φEf11 and recombinant φEf11(Δ61-1, 95FL1C40-44) phages appear to bear out this hypothesis in that recombination of φEf11 with the φFL1C genes results in a greatly (&gt;100 fold) enhanced production of progeny virus. 
     The recombination that occurred resulted in the deletion of a portion of ORF 1 of φEf11 corresponding to the nucleic acid sequence of SEQ ID NO: 169. The portion of ORF 1 of φEf11 corresponding to the nucleic acid sequence of SEQ ID NO: 170 was retained in the spontaneous recombinant phage φEf11 (Δ61-1, φFL1C40-44). The region upstream of the recombined ORF 1 sequence is an intergenic sequence between ORFs 65 and ORF 1. 
     In addition, the source of the φFL1C genes (i.e., the  E. faecalis  JH2-2chromosome) was unexpected, since previous studies reported that this  E. faecalis  strain was susceptible to φFL1C infection, and in fact, could form φFL1C lysogens following φFL1C infection, suggesting that this strain did not initially harbor a φFL1C prophage (Yasmin et al.,  J. Bacteria  192(4):1122-1130, 2010). PCR analysis failed to reveal other regions of the φFL1C genome that could be detected in JH2-2, suggesting that the φFL1C sequence that was detected was part of a defective (incomplete) prophage, or was the only φFL1C-like portion of a complete prophage. 
     A genetic construct incorporating all the afore-mentioned φEf11 genomic modifications has resulted in the generation of a variant, designated φEf11(vir) PnisA , that is incapable of lysogeny and insensitive to repressor, rendering it virulent and highly lytic, with a notably extended host-range in comparison with the wild type virus φEf11. Compared to the wild type φEf11, the recombinant virus produces a more robust infection of  E. faecalis  cells and a greater degree of lysis of the host  E. faecalis  cells. 
     The φEf11(vir) PnisA  virus has been constructed, in part, by replacing the repressor-sensitive cro promoter of the wild type φEf11 virus with the repressor-insensitive, nisin-inducible promoter system to drive phage lytic infection functions. This replacement has proved to be a very effective and useful strategy in making genetic modifications in the virus, and allows the φEf11(vir) PnisA  virus to function as a useful intermediate in the preparation of derivative virus containing the desirable features discussed above. It may be appreciated, however, that to provide a therapeutic phage for managing Enterococcal infections would require replacement of the nisin-inducible promoter system of φEf11(vir) PnisA  with an alternative inducible promoter responsive to a non-toxic inducer, or with a constitutive promoter. 
     One such promoter is the following constitutive promoter Tu derived from an  E. faecalis  strain: 
     
       
         
               
             
           
               
                 (SEQ ID NO: 168) 
               
               
                 TCTAGATITTTCCTTGAGAATAAAAGGTTTGTTTTTAGAACTATCCTTT 
               
               
                   
               
               
                 TTTCAAGATTTCGTGTAAAATAGCTTATGATGATCAGACGATTTTTAGT 
               
               
                   
               
               
                 AACGTCTATCACATATAAAACAAACAATAAAATTTATATTTTTAGGAGG 
               
               
                   
               
               
                 AACATTCAAA  
               
             
          
         
       
     
     φEf11(vir) PnisA  was engineered to include the property of antibiotic (erythromycin) resistance in order to assist in the selection of transformant lysogen clones containing prophages with the desired genotype. The skilled artisan would recognize that this feature would be omitted from a therapeutic phage, without prejudice to the desirable characteristics discussed above. 
     The bacteriophages of the present invention have been exemplified by preparation of φEf11 (vir) PnisA  Further variants may be prepared by utilizing φEf11 as a template and carrying out the following genetic modifications as described in detail in the Example: (i) deletion of lysogeny ORFs 31-36; (i) replacement of the repressor-sensitive cro promoter of the wild type φEf11 virus with a repressor-insensitive inducible promoter system or constitutive promoter system to drive phage lytic infection functions; (iii) replacement of 5 genes (ORFs 61-65) of the wild type DNA replication/modification module and 1 gene (ORF 1/terminase A) of the wild type packaging module by five genes (ORFs 40-44) of  E. faecalis  phage φFL1C. Utilization of the nisin-inducible promoter system as described in the Example, and provision for erythromycin resistance results in the φEf11(vir) PnisA  phage, may be omitted. 
     Alternatively, variants of phage φEf11 (vir) PnisA  may be prepared by utilizing φEf11(vir) PnisA  phage as a starting material, and optionally removing the erythromycin resistance gene and optionally substituting the nisin-inducible promoter system of φEf11(vir) PnisA  with either an inducible promoter system that does not rely on a toxic inducer, or with a constitutive promoter system, e.g., the constitutive Tu promoter of SEQ ID NO: 168. 
     Indications 
     The bacteriophages used in the methods and compositions of the present invention may be used to prevent and treat  Enterococcus faecalis  and  Enterococcus faecium  infections. Non-limiting sites of infection include, for example, the urinary tract, bloodstream, abdomen, biliary tract, burn wounds, indwelling catheters, infected root canals and the heart (e.g. endocardium). 
     The bacteriophages used in the methods and compositions of the present invention may be used to prevent and treat antibiotic-resistant  Enterococcus faecalis  and  Enterococcus faecium  infections, as well as infections that may be antibiotic-sensitive, to augment the antibiotic treatment regimen. The bacteriophages may also be used to treat immunocompromised patients and patients suffering from opportunistic hospital infections. Especially advantageous indications for the present invention may be as a treatment for root canal infections, infectious endocarditis, nosocomial infections, burn infections, urinary tract infections, meningitis and surgical wound infections. 
     Administration 
     The bacteriophages used in the methods and compositions of the present invention may be administered by any route, including orally, optically, subcutaneously, peritoneally, intravenously, topically, intradentally or parenterally. Also contemplated within the scope of the invention is the instillation of bacteriophage in the body of the patient in a controlled formulation, with systemic or local release of the drug to occur at a later time. For example, the bacteriophage may be localized in a depot for controlled release to the circulation, or for release to a local site of  Enterococcus  infection. 
     The bacteriophage may be placed on or imbedded within a wound dressing, e.g., a surgical wound dressing, to treat or prevent  Enterococcus  infection of the wound. The bacteriophage may be applied to the wound in this fashion alone or in combination with other antibacterial agents that do not interfere with antibacterial action of the bacteriophage. For example, the bacteriophage may be contained in a composition impregnated in a wound dressing, e.g. a cotton wool dressing, for topical administration to a wound site. 
     The specific dose of bacteriophage to obtain therapeutic benefit for treatment of an  Enterococcus  infection will, of course, be determined by the particular circumstances of the individual patient including, the size, weight, age and sex of the patient, the stage of the disease, the aggressiveness of the disease, and the route of administration of the bacteriophage. 
     The daily dose of the bacteriophage may be given in a single dose, or may be divided, for example into two, three, or four doses, equal or unequal, but preferably equal, that comprise the daily dose. When given intravenously, such doses may be given as a bolus dose injected over, for example, about 1 to about 4 hours. 
     The bacteriophages used in the methods of the present invention may be administered in the form of a pharmaceutical composition, in combination with a pharmaceutically acceptable carrier. The active ingredient in such formulations may comprise from 0.1 to 99.99 weight percent. By “pharmaceutically acceptable carrier” is meant any carrier, diluent or excipient which is compatible with the other ingredients of the formulation and not deleterious to the recipient. 
     The bacteriophage is preferably administered with a pharmaceutically acceptable carrier selected on the basis of the selected route of administration and standard pharmaceutical practice. The active agent may be formulated into dosage forms according to standard practices in the field of pharmaceutical preparations. See Alphonso Gennaro, ed.,  Remington&#39;s Pharmaceutical Sciences,  18th Ed., (1990) Mack Publishing Co., Easton, Pa. Suitable dosage forms may comprise, for example, tablets, capsules, solutions, parenteral solutions, troches, suppositories, or suspensions. 
     The compositions of the present invention can include pharmaceutically acceptable carriers such as lactose, dextrose, sucrose, sorbitol, mannitol, starch, acacia rubber, calcium phosphate, alginate, gelatin, calcium silicate, micro-crystalline cellulose, polyvinyl pyrrolidone, cellulose, water, syrup, methyl cellulose, methylhydroxybenzoate, propylhydroxybenzoate, talc, magnesium stearate and mineral oil, but not always limited thereto. The composition of the present invention can additionally include lubricants, wetting agents, sweetening agents, flavors, emulsifiers, suspensions and preservatives. 
     The composition of the present invention contains bacteriophage as an active ingredient. The bacteriophage may be included at the concentration of 1×10 1  pfu/ml-1×10 15  pfu/ml or 1×10 1  pfu/g-1×10 15  pfu/g, and more preferably at the concentration of 1×10 4  pfu/ml-1×10 9  pfu/ml or 1×10 4  pfu/g-1×10 9  pfu/g. Other concentrations may be envisioned by the skilled artisan. 
     For parenteral administration, the bacteriophage may be mixed with a suitable carrier or diluent such as water, an oil (particularly a vegetable oil), ethanol, saline solution, aqueous dextrose (glucose) and related sugar solutions, glycerol, or a glycol such as propylene glycol or polyethylene glycol. Solutions for parenteral administration preferably contain a water soluble salt of the active agent. Stabilizing agents, antioxidant agents and preservatives may also be added. Suitable antioxidant agents include sulfite, ascorbic acid, citric acid and its salts, and sodium EDTA. Preservatives may be included, but must be selected so as not to inactivate or otherwise impact the bacteriophage. The composition for parenteral administration may take the form of an aqueous or nonaqueous solution, dispersion, suspension or emulsion. 
     For oral administration, the bacteriophage may be combined with one or more solid inactive ingredients for the preparation of tablets, capsules, pills, powders, granules or other suitable oral dosage forms. For example, the bacteriophage may be combined with at least one excipient such as fillers, binders, humectants, disintegrating agents, solution retarders, absorption accelerators, wetting agents absorbents or lubricating agents. According to one tablet embodiment, the bacteriophage may be combined with carboxymethylcellulose calcium, magnesium stearate, mannitol and starch, and then formed into tablets by conventional tableting methods. 
     The pharmaceutical composition is preferably in unit dosage form. In such form the preparation is divided into unit doses containing appropriate quantities of the active component. The unit dosage form can be a packaged preparation, the package containing discrete quantities of preparation, such as packeted tablets, capsules, and powders in vials or ampoules. Also, the unit dosage form can be a capsule, tablet, cachet, or lozenge itself, or it can be the appropriate number of any of these in packaged form. 
     The pharmaceutical compositions of the present invention may be used for the prevention and treatment of  Enterococcus faecalis  and  Enterococcus faecium  infections. 
     The practice of the invention is illustrated by the following non-limiting example. 
     EXAMPLE 
     A. Materials and Methods 
     1. Bacterial Strains and Growth Conditions 
     TUSoD11 is a lysogenic  E. faecalis  strain, harboring a φEf11 prophage, which was previously isolated from an infected root canal (Stevens et al.,  Oral Microbiol. Immunol.,  24:278-284 (2009). Following curing, the non-lysogenic variant of this strain was designated  E. faecalis  TUSoD11 (ΔφEf11). 
     JH2-2 is a Fus r , Rif r  mutant of a clinical  E. faecalis  isolate (Jacob &amp; Hobbs,  J. Bacteriol.  117(2):360-372, 1974) that was generously provided to us by Dr. Nathan Shankar. In the course of this study, it was found that this strain harbored a φFL1C-type prophage element (Yasmin et al.,  J. Bacteriol.  192(4):1122-1130, 2010), indicating that this strain was a lysogen with a defective prophage. Other  E. faecalis  strains used in this study are listed in Table 1. 
     All strains were grown in brain heart infusion (BHI) broth (or on brain heart infusion agar, with appropriate antibiotics).  Escherichia coli  one shot mach-T1® (Invitrogen) was used in cloning plasmids as describe below. The cells were grown in LB medium supplemented with the appropriate antibiotics. Additional bacterial species used as negative controls in PCR experiments are also listed in Table 1. 
     
       
         
               
             
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Bacterial strains 
               
             
          
           
               
                   E .  faecalis  strain 
                 Characteristics 
                 Source 
               
               
                   
               
               
                 TUSoD11 
                 Lysogenic root canal isolate harboring 
                 1 
               
               
                   
                 φEfll prophage 
                   
               
               
                 JH2-2 
                 Rif r , Fus r , clinical isolate harboring 
                 2, 3 
               
               
                   
                 defective φFL1C prophage 
                   
               
               
                 OG1RF 
                 Rif r , Fus r   
                 3,4 
               
               
                 MMH594 
                 Gen r   
                 3 
               
               
                 OG1SSp 
                 Str r , Spc r   
                 5 
               
               
                 ER3/2s, ER5/1 
                 root canal isolates 
                 6, 7 
               
               
                 E1, E2, E3, E4, E5, E6, E7, E8, E10, E11 
                 oral isolates 
                 6, 8 
               
               
                 GS1, GS2, GS3, GS4, GS5, GS6, GS7, GS8,  
                 root canal isolates 
                 9 
               
               
                 GS9, GS10, GS12, GS13, GS14, GS15, GS16, 
                   
                   
               
               
                 GS17, GS18, GS19, GS21, GS22, GS23, GS24, 
                   
                   
               
               
                 GS25, GS26, GS27, GS28, GS29, GS30, GS31, 
                   
                   
               
               
                 GS32, GS33 
                   
                   
               
               
                 GS34 
                 tongue 
                 6, 7 
               
               
                 OS25 
                 oral isolate 
                 6, 10 
               
               
                 AA-OR3, AA-OR4, AA-OR26, AA-OR34 
                 oral isolates 
                 6, 11 
               
               
                 AA-T4, AA-T26 
                 tongue 
                 6, 11 
               
               
                 V583 
                 Van r , clinical isolate 
                 6, 12 
               
               
                 OS16 
                 oral isolate 
                 6, 10 
               
               
                 TUSoD1, TUSoD2, TUSoD3 
                 Lysogenic root canal isolate 
                 1 
               
               
                 TUSoD9, TUSoD10, TUSoD12 
                 root canal isolates 
                 1 
               
               
                 TUSoD15, TUSoD17, TUSoD18 
                   
                   
               
               
                 Non-Enterococcal spp: 
                   
                   
               
               
                   Streptococcus mutans  10449 
                 grown in BHI broth 
                 ATCC 
               
               
                   Streptococcus sanguis  43055 
                 grown in BHI broth 
                 ATCC 
               
               
                   Fingoldia  ( Peptostreptococcus ) 
                 grown in chopped meat broth 
                 ATCC 
               
               
                   magna  ( magnus ) 
                   
                   
               
               
                   Clostridium perfringens  13124 
                 grown in modified PY broth 
                 ATCC 
               
               
                   Actinomyces israelii  10049 
                 grown in BHI broth 
                 ATCC 
               
               
                   Eubacterium lentum  43033 
                 grown in chopped meat broth 
                 ATCC 
               
               
                   
               
               
                   1 Stevens et al.,  Oral Microbiol .  Immunol ., 24: 278-284 (2009); 
               
               
                   2 Jacobs and Hobbs,  J .  Bacteriol . 117(2): 360-372 (1974); 
               
               
                   3 Dr. Nathan Shankar; 
               
               
                   4 Dunny et al,  Plasmid , 2: 454-465 (1979); 
               
               
                   5 Dunny,  Plasmid , 2: 454-465 (1979); 
               
               
                   6 Dr. Christine Sedgley; 
               
               
                   7 Johnson et al.,  J .  Endod  32: 946-950 (2006); 
               
               
                   8 Sedgley et al.,  Oral Microbiol Immunol . 19: 95-102(2004); 
               
               
                   9 Sedgely et al.,  Oral Microbiol Immunol  20: 10-19 (2005a); 
               
               
                   10 Sedgley et al.,  Archs oral Biol . 50(8): 575-583 (2005); 
               
               
                   11 Sedgley et al.,  J .  Endod  32(2): 104-111 (2006); 
               
               
                   12 Sahm et al.,  Antimicrob Agents Chemother  33: 1588-1591 (1989). 
               
             
          
         
       
     
     2. Construction of Recombinant Plasmids 
     The allelic exchange plasmid pΔ31-36 P nisA  was prepared as follows. 
     The Nisin promoter (P nisA ) cassette containing an erythromycin selection marker (erm) was PCR-amplified using the AccuPrime DNA Taq Polymerase High Fidelity kit (Invitrogen) with primer set PNISaF/PNISR (see Table 2 for primer specifications) from plasmid pMSP3535 (Bryan et al.  Plasmid,  44:183-190, 2000), a kind gift from Dr. B. Buttaro. PCRs were performed in 30 μl reaction mixtures containing 2 μl template DNA, 2 μl (20 pmol) forward primer, 2 μl (20 pmol) reverse primer, 21.5 μl dH 2 0, 2 μl buffer (provided by manufacturer), and 0.5 μl AccuPrime DNA Taq Polymerase. The PCR program used was: 95° C. for 2 min, followed by 35 cycles of (i) 95° C. for 45 sec, (ii) 55° C. for 45 sec, and (iii) 72° C. for 2 min. This was followed by an additional 5 min extension at 72° C. Following PCR, the amplicons were detected by agarose gel electrophoresis and ethidium bromide staining. 
     The allelic exchange plasmid pΔ31-36 P nisA  was then constructed as follows, as shown in  FIG. 1 . The amplicons generated by the above procedure were cloned into pCR8/GW/TOPO vector (Life Technologies) to create pErm-PnisA. The two-component Nisin sensor system (nisR/nisK) that controls the activation of P nisA  by Nisin, was also amplified from pMSP3535 by PCR, using primer set RKnpF/RKaxR, and cloned into pCR8/GW/TOPO to create pRK. The P nisA  fragment plus the erythromycin selection marker was digested from pErm-PnisA with AatII and SphI, and inserted into pRK to create pRK-Erm-PnisA. A fragment (pre31) of 1088 bp from nucleotide coordinates 24585 to 25672 of φEf11 (upstream of ORF31, the first gene of the putative lysogeny module) and a fragment (post36) of 1090 bp from 28588 to 29577 of φEf11 (immediately upstream of the putative cro gene, ORF37) were PCR-amplified using primer sets EF31UF/EF31UR and EF37DF/EF37DR, respectively, and cloned into pCR8/GW/TOPO to create pPre31 and pPost36. The post36 fragment was cut out from the pPost 36 with BamHI and SphI and inserted into pRK-Erm-PnisA, to create pPost36-RK-PnisA. The pPre31 was first digested with EcoRI and blunt-ended with the Klenow fragment of DNA polymerase I (Promega), then digested with PstI. Following this, the digested pre31 fragment was cloned into pPost36-RK-PnisA to create the allelic exchange plasmid pΔ31-36 P nisA . 
     3. Isolation of Spontaneous Phage φEf11/φFL1C-Like Recombinant [φEf11(φ61-1, φFL1C40-44)] and the Creation of a Lysogen Harboring the Recombinant Prophage. 
     A log phase BHI broth culture of  E. faecalis  JH2-2 was inoculated with phage φEf11. After incubation at 37° C. for 1 hr, the culture was centrifuged (17,000×g for 3 min) and the supernatant was filtered (0.45 μm) before being plaque-assayed. After overnight incubation at 37° C., the plates were examined, and several large, extensively-spreading plaques were noticed among a background of small, turbid plaques. These large plaques were picked, and the virus in these large plaques was cloned by successive plaque purifications. The genomic DNA from the cloned virus was sequenced by Sanger di-deoxy sequencing reactions as described previously (Stevens et al.,  FEMS Microbiol. Lett.,  317: 9-26, 2011). 
     To create a lysogen harboring a φEf11(Δ61-1, φFL1C40-44) prophage, JH2-2 cells from surviving colonies in the center of the large plaques produced by this virus were cloned and screened for the presence of the recombinant phage genome. This was done by PCR using primers (EF60F/FL1A35R) that recognized φEf11 ORF 60 at the 5′ end and φFL1C ORF 40 at the 3′ end (see Table 2 for primer specifications). The lysogen harboring this recombinant prophage was designated  E. faecalis  JH2-2[φEf11(Δ61-1, φFL1C40-44)]. In addition, virus spontaneously released from this lysogen was detected by plaque assay, and also confirmed to be recombinant by PCR analysis. 
     
       
         
               
             
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Primers 
               
             
          
           
               
                 Primer 
                 Sequence (5′→3′) 
                 Use 
               
               
                   
               
               
                 EF31UF 
                 GATAGTTCTTGTTTCGACAAATCAC  
                 Amplify upstream 
               
               
                   
                 (SEQ ID NO: 1) 
                 of φEf11 Orf31 
               
               
                   
               
               
                 EF31UR 
                 CTGTCGACGTTCCTGCAGAGCTCTAAATAAATATGG 
                 Amplify upstream 
               
               
                   
                 CAAGTA (SEQ ID NO: 2) 
                 of φEf11 Orf31 
               
               
                   
               
               
                 EF37DF 
                 CTGGATCCATGTGCTATGATTACTCAAAATTAGCAG  
                 Amplify downstream of 
               
               
                   
                 (SEQ ID NO: 3) 
                 φEf11 Orf36 
               
               
                   
               
               
                 EF37DR 
                 CTGCATGCCCTTTACCAGTAATTTTCGGCGT  
                 Amplify downstream of 
               
               
                   
                 (SEQ ID NO: 4) 
                 φEf11 Orf36 
               
               
                   
               
               
                 RKnpF 
                 CTCCATGGTCTCTCCTGCAGATAGAATTCTCATGTTT 
                 Amplify nisR and nisK 
               
               
                   
                 GACAGCTTATCA (SEQ ID NO: 5) 
                   
               
               
                   
               
               
                 RKaxR 
                 CTGCATGCTCTCTCGACGTCGCCAGTTAATAGTTTGC  
                 Amplify nisR and nisK 
               
               
                   
                 CGAA (SEQ ID NO: 6) 
                   
               
               
                   
               
               
                 PNISaF 
                 CTGACGTCACAAAAGCGACTCATAGAATTATTTCCTC  
                 Amplify Erm-P nisA   
               
               
                   
                 C (SEQ ID NO: 7) 
                   
               
               
                   
               
               
                 PNISR 
                 GCTTATCGAAATTAATACGACTCACTATAGG  
                 Amplify Erm- PnisA   
               
               
                   
                 (SEQ ID NO: 8) 
                   
               
               
                   
               
               
                 EF31UUF 
                 AAGAGCACCTCAAATTCCAGT (SEQ ID NO: 9) 
                 Detection of φEf11 
               
               
                   
                   
                 ΔOrf31-36 (upstream) 
               
               
                   
               
               
                 RK5R 
                 TGATAAGCTGTCAAACATGAGAATTCT  
                 Detection of φEf11 
               
               
                   
                 (SEQ ID NO: 10) 
                 ΔOrf31-36 (upstream) 
               
               
                   
               
               
                 37DDR 
                 TGTGATTTGCATGTAGACATCTCCT  
                 Detection of φEf11 
               
               
                   
                 (SEQ ID NO: 11) 
                 ΔOr131-36 (downstream) 
               
               
                   
               
               
                 PNIS3F 
                 TTGTAAAACAGGAGACTCTGCATG  
                 Detection of φEf11 
               
               
                   
                 (SEQ ID NO: 12) 
                 ΔOrf31-36 (downstream) 
               
               
                   
               
               
                 EF31MF 
                 AAGTTGTTTCCGTGTCAACGTGGC  
                 Detection of φEf11 Orf31 
               
               
                   
                 (SEQ ID NO: 13) 
                 deletion 
               
               
                   
               
               
                 EF31MR 
                 GTGTCCATCATGGTCGTTTAGCAG  
                 Detection of φEf11 Orf31 
               
               
                   
                 (SEQ ID NO: 14) 
                 deletion 
               
               
                   
               
               
                 EF36MF 
                 TTATCAGGGTCTGGTGAATGCG  
                 Detection of φEf11 Orf36 
               
               
                   
                 (SEQ ID NO: 15) 
                 deletion 
               
               
                   
               
               
                 EF36MR 
                 GCAACTTATGAGTGAGCGCAA  
                 Detection of φEf11 Orf36 
               
               
                   
                 (SEQ ID NO: 16) 
                 deletion 
               
               
                   
               
               
                 φEF11F 
                 GAGAGTGGAAGTGGA TTCAATG (SEQ ID NO: 17) 
                 Detection of φEf11 Orf43 
               
               
                   
               
               
                 φEf11R 
                 GCACTTTCATCTAAACTCTCG (SEQ ID NO: 18) 
                 Detection of φEf11 Orf43 
               
               
                   
               
               
                 EF44F 
                 ACCAAGATTTGACGCAGAAGTTGCC (SEQ ID NO: 19) 
                 Detection of φEf11 Orf44 
               
               
                   
               
               
                 EF44R 
                 TGGCCATCGTCGTCTTTATCTGCT (SEQ ID NO: 20) 
                 Detection of φEf11 Orf44 
               
               
                   
               
               
                 EF60F 
                 AGACGTTTGGACCGAATAGCTGGT (SEQ ID NO: 21) 
                 Detection of φEf11 Orf60 
               
               
                   
               
               
                 EF60R 
                 TGCGGTAAGCTTCTGCGAATTCAA (SEQ ID NO: 22) 
                 Detection of φEf11 Orf60 
               
               
                   
               
               
                 Fl1A35F 
                 GGGAACTAGCAGTTGAAGAATCGC (SEQ ID NO: 23) 
                 Detection of φFL1C gp40 
               
               
                   
               
               
                 Fl1A35R 
                 TTCCTTTGTACTATCTTGATCTCCA (SEQ ID NO: 24) 
                 Detection of φFL1C gp40 
               
               
                   
               
               
                 Fl1A37F 
                 GAGCGTTTAGATAAGTCGGATTGG (SEQ ID NO: 25) 
                 Detection of φFL1C gp44 
               
               
                   
               
               
                 Fl1A38R 
                 CCAAGTTTCTTTAGCCTGGTCACG (SEQ ID NO: 26) 
                 Detection of φFL1C gp44 
               
               
                   
               
             
          
         
       
     
     4. Deletion of the Lysogeny Module and Replacement of Cro Promoter with P nisA  by Allelic Exchange 
     Cells of  E. faecalis  lysogen JH2-2[φEf11(Δ61-1, 4FL1C40-44)] were made competent using the procedures described by Shepard &amp; Gilmore,  Methods Mol Biol.  47:217-226 (1995). Briefly, the cells were grown in SGM17 medium (37.25 g/L M17, 0.5M sucrose and 8% glycine) for 48 hours at 37° C. The cells were then harvested by centrifugation, washed twice with EB buffer (0.5M sucrose and 10% glycerol), and finally resuspended in EB buffer. Plasmid pΔ31-36 P nisA  was linearized with XhoI and then electroporated into the competent JH2-2 lysogens using the BioRad MicroPulser System. Following electroporation, 1 ml of SGM17MC medium (SGM17 plus 10 mM MgCl 2  and 10 mM CaCl 2 ) was added to the electroporation cuvette, which was then incubated for 2 hours. Transformants were selected on BHI agar containing erythromycin (30 μg/ml). Presumptive transformant colonies were screened for deletion of the lysogeny module genes (φEf11 ORFs 31-36) and replacement of P cro  by P nisA  by PCR using primers EF31UUF/RK5R, PNIS3F/37DDR, EF31MF/EF31MR and EF36MF/EF36MR. In addition, control of lytic functions in the prophage by the P nisA  was demonstrated by measuring phage induction in the presence or absence of Nisin (40 ng/ml). The phage recovered from the induced lysogens lacking ORFs 31-36 and P cro , but containing the P nisA  promoter, was designated φEf11 (vir) PnisA . 
     5. Screening for the Presence of φEf11 Prophages in  E. faecalis  Strains 
     Primers specific to φEf11 were designed from φEf11 ORF 43 (GenBank accession number GQ452243.1, Gene ID number 8683894). This sequence (ORF 43) of the φEf11 genome was chosen since searches of all available data bases failed to disclose any homologous sequences to this gene. The forward (φEf11F) and reverse (φEf11R) primers for amplification of a 165 bp amplicon of this gene are specified in Table 2, above. Template DNA was prepared as follows: 10 ml broth cultures of each strain to be screened were pelleted by centrifugation, washed in 4 ml of wash solution [20 mM Tris-HCl (pH 8.5), 0.85% NaCl], resuspended in 2 ml of lysis buffer [1% Triton X-100, 20 mM Tris-HCl (pH 8.5), 2 mM EDTA], and heated to 95°-100° C. for 10 min. The suspension was then centrifuged and the supernatants were collected and frozen away at −80° C. until being used in PCR assays (Goncharoff et al., 1993,  Oral Microbiol Immunol  8:105-110). Extracts from  E. faecalis  TUSoD11 (lysogenic for φEf11) were used as positive controls, and extracts from  E. faecalis  JH2-2 (non-lysogenic for φEf11) and numerous unrelated species (see Table 1) were used as negative controls. Reaction mixtures (Σ=40 μl) for PCR contained 5 μl of template DNA, 5 μl (50 pmol) of forward primer, 5 μl (50 pmol) of reverse primer, 5 μl dH 2 O, and 20 μl 2X Go Taq green PCR master mix (Promega). The PCR program used was 97° C. for 1 min, followed by 26 cycles of (i) 97° C. for 1 min, (ii) 50° C. for 45 sec, and (iii) 72° C. for 1 min. This was followed by an additional 4 min at 72° C. Following PCR, amplification products were detected by agarose (2%) gel electrophoresis and ethidium bromide staining. 
     6. Preparation of Cured  E. faecalis  TUSoD11 
     Cells of  E. faecalis  TUSoD11 were made competent for electroporation as described above. After electroporation with the allelic exchange vector pΔ31-36 PnisA, erythromycin-resistant colonies were screened for homologous recombination-mediated deletion of the lysogeny module genes (ORFs 31-36) in the genome of  E. faecalis  TUSoD11. Strains exhibiting deletion of ORFs 31-36 were further tested by PCR for the presence of φEf11 genes outside of the lysogeny module. In addition to clones containing φEf11 genes other than ORFs 31-36, a few rare clones were identified that lacked any of the φEf11 genes. Such clones could not be induced, but could now be infected by phage φEf11. These cured clones were designated  E. faecalis  TUSoD11(ΔφEf11). 
     7. Testing Adsorption of φEf11 and φEf11(Δ61-1, 4FL1C40-44) to Lysogenic and Non-Lysogenic  E. faecalis  Strains 
       E. faecalis  strains JH2-2, TUSoD11 and the cured strain, TUSoD11 (ΔφEf11) were grown in BHI medium to log phase. 100 μl of φEf11 or φEf11(Δ61-1, φFL1C40-44) preparations were added to 1 ml  E. faecalis  strains. After incubation at 37° C. for 10 minutes the mixtures were centrifuged at 17,000 g for 3 minutes, the supernatants were filtered through 0.45 μm filters, and filtrates containing any unabsorbed phage, were plaque-assayed, using JH2-2 indicator cells, to determine residual phage titers. 
     8. One Step Growth Curve 
     The cells of a log phase BHI broth culture (2 ml) of  E. faecalis  JH2-2 were collected by centrifugation, resuspended in 1 ml of BHI broth, and inoculated with 100 μl of a stock culture of either phage φEf11, φEf11(Δ61-1, φFL1C40-44) or φEf11(vir) PnisA . After incubation for 30 minutes to allow phage adsorption, the cells were recovered by centrifugation, washed 3 times in BHI broth, and finally resuspended in 10 ml of BHI broth. Aliquots (500 μl) of the suspension were made, and each was incubated at 37° C. At various time points, an aliquot was centrifuged to remove the cells, and the supernatant was plaque-assayed, using fresh JH2-2 indicator cells, for phage titer. 
     9. Host range determination for φEf11, φEf11(Δ61-1, φFL1C40-44), and φEf11(Vir) PnisA . 
     Plaque assays and spot tests were conducted with wild type phage φEf11 and recombinant phages φEf11(Δ61-1, φFL1C40-44) and φEf11(vir) PnisA  using a panel of 66  E. faecalis  strains as indicators. The  E. faecalis  panel included both lysogenic and non-lysogenic strains. Lytic infection by each phage was detected by plaque assay with each  E. faecalis  indicator strain. 
     B. Results and Discussion 
     1. Isolation of Spontaneous φEf11/φFL1C Recombinant 
     Repeated propagation and plaque assay of phage φEf11 on host strain  E. faecalis  JH2-2, revealed that variants of the wild type virus were being generated. Whereas wild type φEf11 produced small, turbid plaques in lawns of JH2-2 ( FIG. 2A ), approximately 0.02% of the plaques appeared as large, extensively spreading, somewhat clearer zones of lysis. Interestingly, incubation of plaque assays of clones obtained by plaque purification of the virus producing these larger plaques resulted in continued expansion of the plaques to the extent that virtually the entire JH2-2 lawn was lysed ( FIGS. 2C-2D ). In contrast, wild type plaques typically disappeared after extended incubation, presumably due to growth of surviving lysogens within the plaques ( FIG. 2B ). 
     AGE analysis of the NdeI restriction fragments of the DNA from the virus producing these large plaques revealed that it was missing one of the fragments (fragment 6, 2.79 kbp) that was present in the NdeI DNA digestion of the original φEf11 isolate ( FIG. 3B ). In addition, it was also noticed that another one of the NdeI fragments (fragment 2, approx. 9.4 kbp) from the DNA of the virus producing the large plaques, had increased in size (compared to the NdeI fragment 2 from the original φEf11 DNA) ( FIG. 3A ) by an amount approximately equal to the size of the missing NdeI fragment 6 ( FIG. 3B ). 
       FIG. 4  shows the NdeI restriction site analysis of the φEf11 DNA. The φEf11 DNA is 42,822 in length and is oriented as described in Stevens et al.,  FEMS Microbiol. Lett.,  317: 9-26 (2011), with the genes arranged with ORF 1 at the extreme left end and ORF 65 at the extreme right end. NdeI restriction sites (bp coordinates) are indicated the boxes. The NdeI restriction fragments, as visualized in agarose gel electrophoresis analysis AGE, are labeled 1-12. 
     Inspection of the φEf11 NdeI restriction map ( FIG. 4 ) and the φEf11 NdeI restriction digest summary (Table 3), revealed that NdeI fragment 6 was composed of the two extreme ends of the genome (fragment coordinates 0-1,036 plus 41,068-42,822), and that in a circularly permuted genome, this fragment is immediately adjacent to NdeI fragment 2 (coordinates 33,692-41,068) ( FIG. 4 ). 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 NdeI restriction digest summary for φEf11 genome 
               
             
          
           
               
                   
                 Fragment Number 
                   
                   
               
               
                   
                 (as seen in gel) 
                 Fragment Length 
                 Fragment Coordinates 
               
               
                   
               
             
          
           
               
                   
                 1 
                 12,126 
                  9,349-21,475 
               
               
                   
                 2 
                 7,376 
                 33,692-41,068 
               
               
                   
                 3 
                 5,029 
                 26,948-31,977 
               
               
                   
                 4 
                 4,660 
                 22,288-26,948 
               
               
                   
                 5 
                 4,247 
                 3,065-7,312 
               
               
                   
                 6 
                 2,790 
                 0-1,036 + 41,068-42,822 
               
               
                   
                 7 
                 2,037 
                 7,312-9,349 
               
               
                   
                 8 
                 1,818 
                 1,248-3,065 
               
               
                   
                 9 
                 1,715 
                 31,977-33,682 
               
               
                   
                 10 
                 547 
                 21,741-22,288 
               
               
                   
                 11 
                 266 
                 21,475-21,741 
               
               
                   
                 12 
                 212 
                 1,036-1,248 
               
               
                   
               
             
          
         
       
     
       FIGS. 5 and 11A-11E  show the nucleotide sequence alignment of phages φEf11, φFL1C, and spontaneous recombinant phage [φEf11(Δ61-1, φFL1C 40-44)] in the region of recombination (φEf11 ORFs 60/61-1 and φFL1C ORFs 39/40-44).  FIG. 5  presents an overview of the regions of φEf11 and φFL1C that recombined to yield recombinant φEf11(Δ61-1, φFL1C 40-44).  FIGS. 11A-11E  show φEf11 sequence from 39307 (within ORF60) through 451 (within ORF1), and φFL1C sequence from 14236 (within ORF39) to 17451 (within ORF44). Non-bolded text indicates φEf11 sequences, boldface text indicates φFL1C sequences. Spontaneous recombinant is abbreviated as Sp. Genomic coordinates are indicated to right of each row of sequence. Sites of sequence identity between φEf11 and φEf11(Δ61-1, φFL1C 40-44) are indicated by *****. 
     Sequencing this region of the genome thus disclosed that ORFs 60 through 65 and 1 of φEf11 (coordinates 39671-42822 and 1-336), were replaced by ORFs 40 through 44 (coordinates 14600-17336) of  E. faecalis  phage φFL1C ( FIGS. 5 and 11 ). NdeI restriction site at coordinate 41,068 which divides NdeI fragment 2 from NdeI fragment 6 in the φEf11 DNA is absent in the φFL1C DNA and consequently in the DNA of the recombinant virus ( FIGS. 11A-11E ). No other modifications of the genome were detected. Consequently, this φEf11/φFL1C recombinant was designated phage φEf11(Δ61-1, φFL1C40-44). 
     Since the JH2-2 genome was the only possible source of the φFL1C genes,  E. faecalis  JH2-2 was screened for the φFL1C prophage. φFL1C (ORFs 40-44)-specific primers (Table 2) were used in PCR with JH2-2 extracts, prepared as described previously. As seen in  FIG. 6 , φFL1C-specific amplicons were generated from the JH2-2 templates and the φFL1C-specific primers, confirming the presence of (at least a portion of) a φFL1C prophage in the JH2-2 chromosome. PCR, using JH2-2 template DNA and primers specific for regions of the φFL1C genome other than ORFs 40-44, failed to produce any amplicons (data not shown). 
     2. Deletion of the Lysogeny Module and Replacement of Cro Promoter in φEf11(Δ61-1, φFL1C40-44) by Allelic Exchange 
     A one-step growth curve was generated as follows for phage φEf11 (wild type), φEf11(Δ61-1, φFL1C40-44) (spontaneous recombinant), and φEf11(vir)P nisA  (virulent variant). Log phase broth cultures of  E. faecalis  JH2-2 were infected with a phage stock. After adsorption for 30 minutes, the cells were collected by centrifugation, washed, and incubated at 37° C. At various time points aliquots of the suspension were centrifuged to remove the cells, and the supernatants were plaque assayed for phage titer using JH2-2 indicator cells. The results are shown in  FIG. 7  (-●- φEf11 titer (pfu/ml); -▪- φEf11 (Δ61-1, φFL1C40-44) titer; -▴- φEf11 (vir)P nisA  titer. The φEf11(Δ61-1, φFL1C40-44) recombinant exhibited enhanced lytic activity (compared to wild type virus) as judged by the extensively enlarged plaques it forms in lawns of host cells ( FIG. 2C ), and the elevated titers it achieved in productive infection ( FIG. 7 ). These variants of phage φEf11 could be subject to repression due to superinfection immunity, and be limited in lytic infection due to the possibility of entering into lysogeny, rather than generating a productive infection. Accordingly, all lysogeny-related genes were deleted and regulatory genetic elements were rendered insensitive to repressor control, as follows. 
     Clones of JH2-2[φEf11(Δ61-1, φFL1C40-44)] transformed with plasmid pΔ31-36 PnisA, were selected on erythromycin-containing media. PCR analysis and sequencing of these erythromycin-resistant JH2-2[φEf11(Δ31-36, ΔP CRO , P nisA , erm, nisR/K, Δ61-1, φFL1C40-44)] clones demonstrated that they lacked φEf11 ORFs 31-36, and the φEf11 cro promoter, but contained the nisin promoter (P nisA ) and nisR/nisK ( FIG. 8  and  FIG. 9 ). In the analysis, PCR products were separated by electrophoresis in 2% agarose gels and detected by ethidium bromide staining. Numbers in  FIG. 9  to the left of the gel indicate DNA fragment size (kbp). Template DNA for PCR reactions: φEf11(vir) PnisA  (vir/lanes 1-4 and 7-8); φEf11 (wt/lanes 5-6 and 9-10). For the primers used in the PCR reactions, see  FIG. 8  for primer binding sites: Primer set EF31UUF/RK5R spanning ORF 29 to nisR (lane 1), primers PNISaF/37DDR spanning P nisA  to ORF 38 (lane 2); primers EF31MF/EF31MR within ORF 31 (lanes 3 and 5); primers EF36MF/EF36MR within ORF 36 (lanes 4 and 6); primers FL1A35F/FL1A35R within φFL1C ORF gp40 (lanes 7 and 9), primers FL1A37F/FL1A38R within φFL1C ORF gp44 (lanes 8 and 10). In  FIG. 9 , lane M shows molecular weight markers (BenchTop 1 kb ladder, Promega). 
     Exposure of a population of this lysogenic clone, harboring a mutant prophage containing the nisin promoter (P nisA ) in place of the wild type cro promoter/operator (P CRO ), to nisin (40 ng/ml) resulted in the induction of phage, yielding a titer of 6.82×10 7  pfu/ml (±0.31×10 7 ). In the absence of nisin, a similar population of these lysogens spontaneously released phage, producing a titer of 5.57×10 5  pfu/ml (±0.31×10 5 ). In contrast, phage induction from lysogens [JH2-2{φEf11(Δ61-1, φFL1C40-44)}] containing a prophage with the wild type cro promoter/operator did not appear to be affected by the presence of nisin: In the presence of nisin (40 ng/ml), these cells produced a phage titer of 3.36×10 5  pfu/ml (±0.25×10 5 ), whereas the same cells produced a titer of 3.31×10 5  pfu/ml (±0.38×10 5 ) in the absence of nisin. These data indicate that productive infection was now under control of the nisin-sensitive promoter (P nisA ), albeit somewhat leaky. 
     The virus obtained, phage [φEf11(Δ31-36, ΔP CRO , P nisA , erm, nisR/KΔ61-1, φFL1C40-44)], by Nisin induction of the JH2-2[φEf11(Δ31-36, ΔP CRO , P nisA , erm, nisR/KΔ61-1, φFL1C40-44)] lysogens produced large, clear plaques ( FIG. 2E-2F ), and was designated φEf11 (vir) PnisA . As will be shown below, this derivative of temperate phage φEf11 had all the characteristics of a virulent virus. 
     3. Isolation of Cured  E. faecalis  TUSoD11 
     After electroporation of  E. faecalis  TUSoD11 with the gene exchange vector pΔ31-36 PnisA, erythromycin-resistant colonies were screened by PCR for deletion of ORF31-ORF36. Unexpectedly, a few colonies were found with deletions of not only the intended ORF31-ORF36 lysogeny module, but also all other phage genes outside this region. These clones may have been generated by the homologous recombination between the gene exchange vector and a permutated and terminally redundant prophage DNA that may have positioned the ORF30 and ORF37 regions at either end of the φEf11 prophage within the host  E. faecalis  TUSoD11 chromosome. These  E. faecalis  clones, lacking any detectable φEf11 genes, were designated TUSoD11(φEf11), and were further tested for phage induction. No phage could be induced from these cells. 
     4. Restoration of Adsorption of φEf11 and φEf11(Δ61-1, φFL1C40-44) by a Cured  E. faecalis  Strain 
     Phage suspensions were incubated with each of the  E. faecalis  strains indicated in Table 4 for 10 minutes, whereupon the cultures were centrifuged and filtered to remove the cells along with all adsorbed phage. The cell-free filtrates were then assayed for residual phage titer. The values shown in Table 4 represent the mean of triplicate assays ±standard deviation. 
     
       
         
               
             
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 Phage adsorption by lysogenic and non-lysogenic  E .  faecalis  strains. 
               
             
          
           
               
                   
                 Phage titer 
                 Residual phage titer after adsorption with: 
               
             
          
           
               
                   
                 before 
                 Lysogen 
                 Non-lysogen 
                 Non-lysogen 
               
               
                 Phage 
                 adsorption 
                 TUSoD11 
                 JH2-2 
                 Cured TUSoD11 
               
               
                   
               
               
                 φEf11 
                  1.2 × 10 5   
                 1.17 × 10 5  ±  
                  3.2 × 10 2  ±  
                 2.74 × 10 2  ±  
               
               
                   
                   
                 0.16 × 10 5   
                 0.25 × 10 2   
                 0.16 × 10 2   
               
               
                 φEf11(Δ61-1, ΦFL1C40-44) 
                 5.58 × 10 7   
                 5.23 × 10 7  ± 0.2  
                 4.79 × 10 2  ±  
                 3.82 × 10 2  ±  
               
               
                   
                   
                   3 × 10 7   
                 0.23 × 10 2   
                 0.17 × 10 2   
               
               
                   
               
             
          
         
       
     
     As shown in Table 4, neither φEf11 nor φEf11(Δ61-1, φFL1C40-44) could produce a viable infection on the lysogenic TUSoD11 strain due to superinfection immunity. It was interesting that incubation of either φEf11 or φEf11 (Δ61-1, φFL1C40-44) with a cell suspension of lysogenic  E. faecalis  strain TUSoD11 failed to result in phage adsorption to the cells. In contrast, cell suspensions of either strain JH2-2 (non-lysogenic with respect to φEf11) or TUSoD11(φEf11), a cured  E. faecalis  strain, effectively adsorbed both virus strains. 
     5. Host Range of φEf11(Vir) PnisA    
     Plaque assays and spot tests were conducted with wild type phage φEf11 and recombinant phages φEf11(Δ61-1, φFL1C40-44) and φEf11 (vir) PnisA  using a panel of 66  E. faecalis  strains as indicators. The  E. faecalis  panel included both lysogenic and non-lysogenic strains. Lytic infection by each phage was detected by plaque assay with each  E. faecalis  indicator strain. The results are shown in Table 5. It can be seen that whereas wild type φEf11 productively infected only 4 (6%) of the 67  E. faecalis  strains tested, productive infection occurred in 33 (49%) of these strains inoculated with phage φEf11(vir) PnisA . The panel of  E. faecalis  strains was also screened by PCR for the presence of a prophage, using φEf11-specific primers. Among the strains tested, 14 were found to be φEf11 lysogens (data not shown). Of these 14 φEf11 lysogens, none were susceptible to wild type φEf11, however, 4 of these lysogenic strains (strains GS2, GS8, GS22 and GS25) could be productively infected by φEf11(vir) PnisA . Furthermore, the presence of the φEf11 repressor gene (cI/ORF-36) was confirmed in these φEf11(vir) PnisA -susceptible lysogenic strains by PCR (data not shown). 
     
       
         
               
             
               
               
             
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 Host range of  E. faecalis  phages 
               
             
          
           
               
                   
                 Phage 
               
             
          
           
               
                   
                   
                 φEf11 (Δ61-1,  
                 φEf11(Δ31-36, 
               
               
                   
                   
                 φFL1C39-44 
                 ΔP cro , P nisA , Δ611, 
               
               
                 
                   E. faecalis  
                 
                 φEf11  
                 (spontaneous 
                 φFL1C39-44) 
               
               
                 strain 
                 (wild type) 
                 recombinant) 
                 (virulent mutant) 
               
               
                   
               
               
                 OG1RF 
                 − 
                 − 
                 − 
               
               
                 ER3/2s 
                 − 
                 − 
                 − 
               
               
                 ER5/1 
                 − 
                 − 
                 + 
               
               
                 E1 
                 + 
                 + 
                  +* 
               
               
                 E2 #   
                 − 
                 − 
                 − 
               
               
                 E3 #   
                 − 
                 − 
                 − 
               
               
                 E4 #   
                 − 
                 − 
                 − 
               
               
                 E5 #   
                 − 
                 − 
                 − 
               
               
                 E6 
                 − 
                 − 
                 − 
               
               
                 E7 #   
                 − 
                 − 
                 − 
               
               
                 E8 
                 − 
                 − 
                 + 
               
               
                 E10 
                 − 
                 − 
                 + 
               
               
                 E11 
                 − 
                 − 
                 + 
               
               
                 GS1 
                 − 
                 − 
                 − 
               
               
                 GS2 #   
                 − 
                 − 
                 + 
               
               
                 GS3 
                 − 
                 − 
                 + 
               
               
                 GS4 
                 − 
                 − 
                 − 
               
               
                 GS5 
                 − 
                 − 
                 − 
               
               
                 GS6 
                 − 
                 − 
                 + 
               
               
                 GS7 
                 − 
                 − 
                 + 
               
               
                 GS8 #   
                 − 
                 − 
                 + 
               
               
                 GS9 #   
                 − 
                 − 
                 − 
               
               
                 GS10 
                 − 
                 − 
                 − 
               
               
                 GS12 
                 − 
                 − 
                 − 
               
               
                 GS13 
                 − 
                 − 
                 + 
               
               
                 GS14 
                 − 
                 − 
                  +* 
               
               
                 GS15 
                 − 
                 − 
                 + 
               
               
                 GS16 
                 − 
                 − 
                 + 
               
               
                 GS17 
                 − 
                 − 
                 − 
               
               
                 GS18 
                 − 
                 − 
                 − 
               
               
                 GS19 
                 − 
                 − 
                 + 
               
               
                 GS21 
                 − 
                 − 
                 − 
               
               
                 GS22 #   
                 − 
                 − 
                 + 
               
               
                 GS23# 
                 − 
                 − 
                 − 
               
               
                 GS24 
                 − 
                 − 
                 + 
               
               
                 GS25 #   
                 − 
                 − 
                 + 
               
               
                 GS26 
                 − 
                 − 
                 + 
               
               
                 GS27 
                 − 
                 − 
                 + 
               
               
                 GS28 
                 − 
                 − 
                 − 
               
               
                 GS29 #   
                 − 
                 − 
                 − 
               
               
                 GS30 
                 − 
                 − 
                  +* 
               
               
                 GS31 
                 − 
                 − 
                 − 
               
               
                 GS32 
                 − 
                 − 
                 − 
               
               
                 GS33 #   
                 − 
                 − 
                 − 
               
               
                 GS34 
                 − 
                 − 
                 − 
               
               
                 OS25 
                 − 
                 − 
                 + 
               
               
                 AA-OR3 
                 − 
                 − 
                 + 
               
               
                 AA-OR4 
                 − 
                 − 
                 + 
               
               
                 AA-OR26 
                 − 
                 − 
                  +* 
               
               
                 AA-OR34 #   
                 − 
                 − 
                 − 
               
               
                 AA-T4 
                 − 
                 − 
                 + 
               
               
                 AA-26 
                 − 
                 − 
                  +* 
               
               
                 V583 
                 − 
                 − 
                 + 
               
               
                 OS16 
                 − 
                 − 
                 + 
               
               
                 TUSoD1 
                  +* 
                  +* 
                 + 
               
               
                 TUSoD2 
                 − 
                 − 
                 − 
               
               
                 TUSoD3 
                 − 
                 − 
                 − 
               
               
                 TUSoD9 
                 − 
                 − 
                 + 
               
               
                 TUSoD10 
                 − 
                 − 
                 − 
               
               
                 TUSoD12 
                 − 
                 − 
                 − 
               
               
                 TUSoD15 
                 − 
                 − 
                 − 
               
               
                 TUSoD17 
                 − 
                 − 
                 − 
               
               
                 TUSoD18 
                  +* 
                 − 
                 − 
               
               
                 MMH594 
                 − 
                 − 
                 − 
               
               
                 OG1SSP 
                 − 
                 − 
                 + 
               
               
                 DG16 
                 − 
                 − 
                 − 
               
               
                 JH2-2 
                 + 
                 + 
                 + 
               
               
                 Cumulative 
                 6.0% 
                 4.5% 
                 49.3% 
               
               
                   
               
               
                 + = Sensitive to phage (plaque assay) 
               
               
                 +* = Sensitive to phage (spot test) 
               
               
                 − = Not sensitive to phage 
               
               
                   # = Lysogenic E. faecalis strain containing ∅Ef11 prophage 
               
             
          
         
       
     
     The disclosures of each and every patent, patent application, and publication cited herein are hereby incorporated herein by reference in their entirety. One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. While the invention has been disclosed with reference to specific embodiments, it is apparent that other embodiments and variations of this invention may be devised by others skilled in the art without departing from the true spirit and scope used in the practice of the invention. The appended claims are intended to be construed to include all such embodiments and equivalent variations.