130. Miro JM, Cervera C, Garcia-de-la-Maria C, Del Rio A, Armero Y, Mestres CA, et al. Success of ampicillin plus ceftriaxone rescue therapy for a relapse of Enterococcus faecalis native-valve endocarditis and in vitro data on double beta-lactam activity. Scand J Infect Dis 2008; 40:968-72; PMID:18767002; http://dx.doi.org/10. 1080/00365540802398945 131. Euba G, Lora-Tamayo J, Murillo O, Pedrero S, Cabo J, Verdaguer R, et al. Pilot study of ampicillin- ceftriaxone combination for treatment of orthopedic infections due to Enterococcus faecalis. Antimicrob Agents Chemother 2009; 53:4305-10; PMID: 19667290; http://dx.doi.org/10.1128/AAC.00444-09 132. Tascini C, Doria R, Leonildi A, Martinelli C, Menichetti F. Efficacy of the combination ampicillin plus ceftriaxone in the treatment of a case of enterococcal endocarditis due to Enterococcus faecalis highly resistant to gentamicin: efficacy of the “ex vivo” synergism method. J Chemother 2004; 16:400-3; PMID:15332717 133. Farina C, Russello G, Chinello P, Pasticci MB, Raglio A, Ravasio V, et al. Italian Infective Endocarditis Study Group (SEI). In vitro activity effects of twelve antibiotics alone and in association against twenty- seven Enterococcus faecalis strains isolated from Italian patients with infective endocarditis: high in vitro synergistic effect of the association ceftriaxone-fosfo- mycin. Chemotherapy 2011; 57:426-33; PMID: 22122863; http://dx.doi.org/10.1159/000330458 134. Brandt CM, Rouse MS, Laue NW, Stratton CW, Wilson WR, Steckelberg JM. Effective treatment of multidrug-resistant enterococcal experimental endo- carditis with combinations of cell wall-active agents. J Infect Dis 1996; 173:909-13; PMID:8603970; http:// dx.doi.org/10.1093/infdis/173.4.909 135. Pasticci MB, Mencacci A, Moretti A, Palladino N, Maria Lapalorcia L, Bistoni F, et al. In vitro Antimicrobial Activity of Ampicillin-Ceftriaxone and Ampicillin-Ertapenem Combinations Against Clinical Isolates of Enterococcus faecalis with High Levels of Aminoglycoside Resistance. Open Microbiol J 2008; 2:79-84; PMID:19088915; http://dx.doi.org/10. 2174/1874285800802010079 136. Moellering RC, Linden PK, Reinhardt J, Blumberg EA, Bompart F, Talbot GH, Synercid Emergency-Use Study Group. The efficacy and safety of quinupristin/ dalfopristin for the treatment of infections caused by vancomycin-resistant Enterococcus faecium. J Antimicrob Chemother 1999; 44:251-61; PMID: 10473233; http://dx.doi.org/10.1093/jac/44.2.251 137. Chong YP, Lee SO, Song EH, Lee EJ, Jang EY, Kim SH, et al. Quinupristin-dalfopristin versus linezolid for the treatment of vancomycin-resistant Enterococcus faecium bacteraemia: efficacy and development of resistance. Scand J Infect Dis 2010; 42:491-9; PMID:20524781; http://dx.doi.org/10.3109/00365541003699623 138. Bérenger R, Bourdon N, Auzou M, Leclercq R, Cattoir V. In vitro activity of new antimicrobial agents against glycopeptide-resistant Enterococcus faecium clinical isolates from France between 2006 and 2008. Med Mal Infect 2011; 41:405-9; PMID:21550192; http:// dx.doi.org/10.1016/j.medmal.2010.12.013 139. Arias CA, Torres HA, Singh KV, Panesso D, Moore J, Wanger A, et al. Failure of daptomycin monotherapy for endocarditis caused by an Enterococcus faecium strain with vancomycin-resistant and vancomycin- susceptible subpopulations and evidence of in vivo loss of the vanA gene cluster. Clin Infect Dis 2007; 45: 1343-6; PMID:17968832; http://dx.doi.org/10.1086/ 522656 140. Baltch AL, Ritz WJ, Bopp LH, Michelsen PB, Smith RP. Antimicrobial activities of daptomycin, vancomy- cin, and oxacillin in human monocytes and of daptomycin in combination with gentamicin and/or rifampin in human monocytes and in broth against Staphylococcus aureus. Antimicrob Agents Chemother 2007; 51:1559-62; PMID:17283190; http://dx.doi. org/10.1128/AAC.00973-06 141. Cilli F, Aydemir S, Tunger A. In vitro activity of daptomycin alone and in combination with various antimicrobials against Gram-positive cocci. J Chemother 2006; 18:27-32; PMID:16572890 142. Snydman DR, McDermott LA, Jacobus NV. Evaluation of in vitro interaction of daptomycin with gentamicin or beta-lactam antibiotics against Staphylococcus aureus and Enterococci by FIC index and timed-kill curves. J Chemother 2005; 17:614-21; PMID:16433191 143. Pankey G, Ashcraft D, Patel N. In vitro synergy of daptomycin plus rifampin against Enterococcus fae- cium resistant to both linezolid and vancomycin. Antimicrob Agents Chemother 2005; 49:5166-8; PMID:16304195; http://dx.doi.org/10.1128/AAC. 49.12.5166-5168.2005 144. Entenza JM, Moreillon P. Tigecycline in combination with other antimicrobials: a review of in vitro, animal and case report studies. Int J Antimicrob Agents 2009; 34:8-, e1-9; PMID:19162449; http://dx.doi.org/10. 1016/j.ijantimicag.2008.11.006 145. Jacqueline C, Caillon J, Le Mabecque V, Miègeville AF, Ge Y, Biek D, et al. In vivo activity of a novel anti- methicillin-resistant Staphylococcus aureus cephalos- porin, ceftaroline, against vancomycin-susceptible and -resistant Enterococcus faecalis strains in a rabbit endocarditis model: a comparative study with linezolid and vancomycin. Antimicrob Agents Chemother 2009; 53:5300-2; PMID:19752276; http://dx.doi. org/10.1128/AAC.00984-09 146. Kak V, You I, Zervos MJ, Kariyama R, Kumon H, Chow JW. In-vitro synergistic activity of the com- bination of ampicillin and arbekacin against vancomy- cin-and high-level gentamicin-resistant Enterococcus faecium with the aph(2'')-Id gene. Diagn Microbiol Infect Dis 2000; 37:297-9; PMID:10974585; http:// dx.doi.org/10.1016/S0732-8893(00)00155-3 www.landesbioscience.com Virulence 433