bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vitro Activities of Novel Oxapenems, Alone and in Combination with Ceftazidime, against Gram-Positive and Gram-Negative Organisms
Authors: Jamieson Conor E. , Lambert Peter A. , Simpson Iain N. 
Published: July 2003

ABSTRACT

Four novel oxapenem compounds (i.e., AM-112, AM-113, AM-114, and AM-115) were investigated for their β-lactamase inhibitory activity against a panel of isolated class A, C, and D enzymes, which included expanded-spectrum β-lactamase enzymes (ESBLs). The oxapenems were potent β-lactamase inhibitors. Activity varied within the group, with AM-113 and AM-114 proving to be the most active compounds. The 50% inhibitory concentrations for these agents were up to 100,000-fold lower than that of clavulanic acid against class C and D enzymes. As a group, the oxapenems were more potent than clavulanic acid against enzymes from all classes. The ability of these compounds to protect ceftazidime from hydrolysis by β-lactamase-producing strains was evaluated by MIC tests that combined ceftazidime and each oxapenem in a 1:1 or 2:1 ratio. The oxapenems markedly reduced the MICs for ceftazidime against class C hyperproducing strains and strains producing TEM- and SHV-derived ESBLs. There was little difference between the activity of 1:1 and 2:1 combinations of ceftazidime and oxapenem. The oxapenems failed to enhance the activity of ceftazidime against derepressed AmpC-producing
Pseudomonas aeruginosa
strains.
Oral Lactoferrin Treatment of Experimental Oral Candidiasis in Mice
Authors: Takakura Natsuko , Wakabayashi Hiroyuki , Ishibashi Hiroko , Teraguchi Susumu , Tamura Yoshitaka , Yamaguchi Hideyo , Abe Shigeru 
Published: July 2003

ABSTRACTWe assessed the potential of lactoferrin (LF), a multifunctional milk protein, for treatment of oral candidiasis with immunosuppressed mice, which have local symptoms characteristic of oral thrush. Oral administration of bovine LF in drinking water starting 1 day before the infection significantly reduced the number ofCandida albicansin the oral cavity and the score of lesions on the tongue on day 7 after the inoculation. The symptomatic effect of LF was confirmed by macroscopic and microscopic observations of the tongue's surface. Similar effects were also observed upon administration of LF pepsin hydrolysate, but not lactoferricin B, an antimicrobial peptide of LF. The anticandidal activity of LF was evident on administration either in drinking water or by intragastric intubation with a stomach tube. These results suggest that the effect of LF in this oral candidiasis model is not due to direct antifungal action. In conclusion, LF could have potential as a food component supporting antifungal drug treatment.
Entecavir Therapy Combined with DNA Vaccination for Persistent Duck Hepatitis B Virus Infection
Authors: Foster Wendy K. , Miller Darren S. , Marion Patricia L. , Colonno Richard J. , Kotlarski Ieva , Jilbert Allison R. 
Published: July 2003

ABSTRACT

This study was designed to test the efficacy of antiviral treatment with entecavir (ETV) in combination with DNA vaccines expressing duck hepatitis B virus (DHBV) antigens as a therapy for persistent DHBV infection in ducks. Ducks were inoculated with 10
9
DHBV genomes at 7 days of age, leading to widespread infection of the liver and viremia within 7 days, and were then treated orally with either ETV (0.1 mg/kg of body weight/day) or distilled water from 21 days posthatch for 244 days. Treatment with ETV caused a 4-log drop in serum DHBV DNA levels within 80 days and a slower 2- to 3-log drop in serum DHBV surface antigen (DHBsAg) levels within 120 days. Following withdrawal of ETV, levels of serum DHBV DNA and DHBsAg rebounded to match those in the water-treated animals within 40 days. Sequential liver biopsy samples collected throughout the study showed that ETV treatment reduced DHBV DNA replicative intermediates 70-fold in the liver, while the level of the stable, template form, covalently closed circular DNA decreased only 4-fold. ETV treatment reduced both the intensity of antigen staining and the percentage of antigen-positive hepatocytes in the liver, but the intensity of antigen staining in bile duct cells appeared not to be effected. Intramuscular administration of five doses of a DNA vaccine expressing the DHBV presurface, surface, precore, and core antigens, both alone and concurrently with ETV treatment, on days 50, 64, 78, 127, and 141 did not result in any significant effect on viral markers.
In Vitro Activities of 25 Quinolones and Fluoroquinolones against Liver and Blood Stage
Plasmodium
spp
Authors: Mahmoudi Nassira , Ciceron Liliane , Franetich Jean-François , Farhati Khemais , Silvie Olivier , Eling Wijnand , Sauerwein Robert , Danis Martin , Mazier Dominique , Derouin Francis 
Published: July 2003

ABSTRACT

The in vitro activities of 25 quinolones and fluoroquinolones against erythrocytic stages of
Plasmodium falciparum
and against liver stages of
Plasmodium yoelii yoelii
and
P. falciparum
were studied. All compounds were inhibitory for chloroquine-sensitive and chloroquine-resistant
P. falciparum
grown in red blood cells. This inhibitory effect increased with prolonged incubation and according to the logarithm of the drug concentration. Grepafloxacin, trovafloxacin, and ciprofloxacin were the most effective drugs, with 50% inhibitory concentrations of <10 μg/ml against both strains. Only grepafloxacin, piromidic acid, and trovafloxacin had an inhibitory effect against hepatic stages of
P. falciparum
and
P. yoelii yoelii
; this effect combined reductions of the numbers and the sizes of schizonts in treated cultures. Thus, quinolones have a potential for treatment or prevention of malaria through their unique antiparasitic effect against erythrocytic and hepatic stages of
Plasmodium
.
Comparison of Two Methods and Three End Points in Determination of In Vitro Activity of Micafungin against
Aspergillus
spp
Authors: Arikan Sevtap , Yurdakul Pınar , Hascelik Gulsen 
Published: July 2003

ABSTRACT

We investigated the in vitro activity of micafungin against clinical
Aspergillus
isolates (
n
= 37) (
Aspergillusfumigatus
[
n
= 21],
Aspergillusflavus
[
n
= 14], and
Aspergillus niger
[
n
= 2]) by using NCCLS M38A microdilution and an investigational disk diffusion assay. Microdilution assay results were evaluated by using the end points of a MIC-2 (measured in micrograms per milliliter) and minimum effective concentration (MEC, measured in micrograms per milliliter; the lowest concentration of micafungin that produces short and aberrant hyphal branchings microscopically). Disk diffusion results were interpreted by measuring the zone(s) of inhibition (ZOI, measured in millimeters). Micafungin proved to be similarly active against all
Aspergillus
species tested. At 24 h, MIC-2s and MECs were identical. At 48 h, however, MIC-2s increased unpredictably, leading to the loss of a consistent correlation between the two end points. MECs and ZOI remained consistent and correlated at both reading times, suggesting their use as relevant end points in susceptibility testing of micafungin against
Aspergillus
. All
Aspergillus
isolates yielded intrazonal growth on disk diffusion agar plates. The intrazonal colonies contained short, aberrant hyphal branchings microscopically. The in vivo significance of these findings remains to be further investigated.
In Vitro Activities of Tigecycline (GAR-936) and 12 Other Antimicrobial Agents against 90
Eikenella corrodens
Clinical Isolates
Authors: Cercenado Emilia , Cercenado Sonia , Bouza Emilio 
Published: July 2003

ABSTRACT

The activity of tigecycline was compared with those of other antimicrobials against 90 isolates of
Eikenella corrodens
. The MIC at which 90% of the isolates were inhibited was 2 μg/ml for tigecycline and 1, ≤0.5/0.25, 0.5, ≤0.12, ≤2, and 0.5 μg/ml for ampicillin, amoxicillin-clavulanate, cefotaxime, imipenem, chloramphenicol, and ciprofloxacin, respectively.
In Vitro Susceptibilities of SevenLeptospiraSpecies to Traditional and Newer Antibiotics
Authors: Hospenthal Duane R. , Murray Clinton K. 
Published: July 2003

ABSTRACTHuman leptospirosis is generally treated with penicillin or doxycycline. We studied the susceptibilities of 11 serovars (seven species) ofLeptospirato 14 antibiotics. With the exception of chloramphenicol, all tested agents were at least as potent as penicillin and doxycycline, with the macrolide and ketolide drugs producing the lowest MICs (and minimal bactericidal concentrations).
Reduced Release of Pneumolysin by
Streptococcus pneumoniae
In Vitro and In Vivo after Treatment with Nonbacteriolytic Antibiotics in Comparison to Ceftriaxone
Authors: Spreer Annette , Kerstan Holger , Böttcher Tobias , Gerber Joachim , Siemer Alexander , Zysk Gregor , Mitchell Timothy J. , Eiffert Helmut , Nau Roland 
Published: July 2003

ABSTRACT

Pneumolysin, a virulence factor of
Streptococcus pneumoniae
with cytotoxic and proinflammatory activities, occurs at concentrations from 0.85 to 180 ng/ml in cerebrospinal fluid (CSF) of meningitis patients. In pneumococcal cultures and in a rabbit meningitis model, the concentrations of pneumolysin in supernatant and CSF were lower after addition of nonbacteriolytic bactericidal antibiotics (rifampin and clindamycin) than after incubation with ceftriaxone.
Efficacy of Linezolid plus Rifampin in an Experimental Model of Methicillin-Susceptible
Staphylococcus aureus
Endocarditis
Authors: Dailey Charlene F. , Pagano Paul J. , Buchanan Lewis V. , Paquette Jennifer A. , Haas Joseph V. , Gibson John K. 
Published: July 2003

ABSTRACT

The efficacy of linezolid, alone or in combination with rifampin, against methicillin-susceptible
Staphylococcus aureus
in rabbits with experimental endocarditis was investigated. Linezolid (50 or 75 mg/kg of body weight), rifampin, and linezolid (25, 50, or 75 mg/kg) plus rifampin produced statistically significant reductions in bacterial counts compared with those in untreated controls. Plasma or valvular vegetation levels of linezolid in the groups treated with the linezolid-rifampin combination were similar to those in the respective linezolid-only treatment groups. At therapeutic levels of linezolid, rifampin resistance was not observed. The results from this experimental model of endocarditis suggest that while rifampin did not provide synergy to the linezolid dosing, it did not antagonize the efficacy of linezolid.
Polymyxin B Nephrotoxicity and Efficacy against Nosocomial Infections Caused by Multiresistant Gram-Negative Bacteria
Authors: Ouderkirk John P. , Nord Jill A. , Turett Glenn S. , Kislak Jay Ward 
Published: July 2003

ABSTRACT

Reported rates of nephrotoxicity associated with the systemic use of polymyxins have varied widely. The emergence of infections due to multiresistant gram-negative bacteria has necessitated the use of systemic polymyxin B once again for the treatment of such infections. We retrospectively investigated the rate of nephrotoxicity in patients receiving polymyxin B parenterally for the treatment of infections caused by multiresistant gram-negative bacteria from October 1999 to September 2000. Demographic and clinical information was obtained for 60 patients. Outcome measures of interest were renal toxicity and clinical and microbiologic efficacy. Renal failure developed in 14% of the patients, all of whom had normal baseline renal function. Development of renal failure was independent of the daily and cumulative doses of polymyxin B and the length of treatment but was significantly associated with older age (76 versus 59 years,
P
= 0.02). The overall mortality was 20%, but it increased to 57% in those who developed renal failure. The organism was cleared in 88% of the patients from whom repeat specimens were obtained. The use of polymyxin B to treat multiresistant gram-negative infections was highly effective and associated with a lower rate of nephrotoxicity than previously described.
Efficacy of Single-Dose Azithromycin in Treatment of Acute Otitis Media in Children after a Baseline Tympanocentesis
Authors: Dunne Michael W. , Khurana Chandra , Mohs Adriano Arguedas , Rodriguez Adib , Arrieta Antonio , McLinn Samuel , Krogstad Judy A. , Blatter Mark , Schwartz Richard , Vargas Sergio L. , Emparanza Paz , Fernandez Pilar , Gooch Willis M. , Aspin Mary , Podgore John , Roine Irmeli , Blumer Jeffrey L. , Ehrlich Garth D. , Chow Jean 
Published: July 2003

ABSTRACT

Children with acute otitis media underwent tympanocentesis and were given a single dose of 30 mg of azithromycin/kg of body weight. At day 28, the overall clinical cure rate was 206 of 242 (85%). Clinical cure rates for patients infected with
Streptococcus pneumoniae
(67 of 76; 88%) and
Haemophilus influenzae
(28 of 44; 64%) were consistent with historical rates for the 5-day dosing regimen.
α-Defensin 1 (Human Neutrophil Protein 1) as an Antichemotactic Agent for Human Polymorphonuclear Leukocytes
Authors: Grutkoski P. S. , Graeber C. T. , Lim Y. P. , Ayala A. , Simms H. H. 
Published: July 2003

ABSTRACTMedium conditioned by tumor necrosis factor alpha (TNF-α)-stimulated polymorphonuclear leukocytes (PMN) (CM-TNF) suppresses PMN migration. Therefore, we wished to identify the agent(s) in CM-TNF that mediated antichemotactic activity. CM-TNF was fractionated by high-performance liquid chromatography, and one fraction with antichemotactic activity contained the bactericidal protein human neutrophil protein 1 (HNP-1). We showed that HNP-1 suppresses PMN migration to formyl-methionyl-leucyl-phenylalanine but not to interleukin 8.
Molecular and Biochemical Characterization of a Novel Class A β-Lactamase (HER-1) from
Escherichia hermannii
Authors: Beauchef-Havard Anne , Arlet Guillaume , Gautier Valerie , Labia Roger , Grimont Patrick , Philippon Alain 
Published: July 2003

ABSTRACT

Escherichia hermannii
showed a low level of resistance to amoxicillin and ticarcillin, reversed by clavulanate, and a moderate susceptibility to piperacillin but was susceptible to all cephalosporins. A
bla
gene was cloned and encoded a typical class A β-lactamase (HER-1, pI 7.5), which shares 45, 44, 41, and 40% amino acid identity with other β-lactamases, AER-1 from
Aeromonas hydrophila
, MAL-1/Cko-1 from
Citrobacter koseri
, and TEM-1 and LEN-1, respectively. No
ampR
gene was detected. Only penicillins were efficiently hydrolyzed, and no hydrolysis was observed for cefuroxime and broad-spectrum cephalosporins. Sequencing of the
bla
gene in 12 other strains showed 98 to 100% identity with
bla
HER-1
.
Dinucleotide Analogues as Novel Inhibitors of RNA-Dependent RNA Polymerase of Hepatitis C Virus
Authors: Zhong Weidong , An Haoyun , Barawkar Dinesh , Hong Zhi 
Published: July 2003

ABSTRACT

Replication of hepatitis C virus (HCV) RNA is catalyzed by the virally encoded RNA-dependent RNA polymerase NS5B. It is believed that the viral polymerase utilizes a de novo or primer-independent mechanism for initiation of RNA synthesis. Our previous work has shown that dinucleotides were efficient initiation molecules for NS5B in vitro (W. Zhong, E. Ferrari, C. A. Lesburg, D. Maag, S. K. Ghosh, C. E. Cameron, J. Y. Lau, and Z. Hong, J. Virol.
74:
9134-9143, 2000). In this study, we further demonstrated that dinucleotide analogues could serve as inhibitors of de novo initiation of RNA synthesis directed by HCV NS5B. Both mononucleotide- and dinucleotide-initiated RNA syntheses were affected by dinucleotide analogues. The presence of the 5′-phosphate group in the dinucleotide compounds was required for efficient inhibition of de novo initiation. Optimal inhibitory activity also appeared to be dependent on the base-pairing potential between the compounds and the template terminal bases. Because the initiation process is a rate-limiting step in viral RNA replication, inhibitors that interfere with the initiation process will have advantages in suppressing virus replication. The use of dinucleotide analogues as inhibitor molecules to target viral replication initiation represents a novel approach to antiviral interference.
In Vitro Bactericidal Activities of Daptomycin against
Staphylococcus aureus
and
Enterococcus faecalis
Are Not Mediated by Inhibition of Lipoteichoic Acid Biosynthesis
Authors: Laganas Valerie , Alder Jeffrey , Silverman Jared A. 
Published: July 2003

ABSTRACT

Previous studies have suggested that lipoteichoic acid biosynthesis inhibition is the mechanism of action of daptomycin. In this investigation, daptomycin inhibited all macromolecular synthesis in
Staphylococcus aureus
,
Enterococcus faecalis
, and
Enterococcus hirae
without kinetic or dose specificity for lipoteichoic acid. Daptomycin remained bactericidal in the absence of ongoing lipoteichoic acid synthesis. Inhibition of lipoteichoic acid synthesis is apparently not the mechanism of action of daptomycin in these pathogens.
Thiosemicarbazole (Thiacetazone-Like) Compound with Activity against
Mycobacterium avium
in Mice
Authors: Bermudez Luiz E. , Reynolds Robert , Kolonoski Peter , Aralar Pricilla , Inderlied Clark B. , Young Lowell S. 
Published: July 2003

ABSTRACT

In vitro screening of thiacetazone derivatives indicated that two derivatives, SRI-286 and SRI-224, inhibited a panel of 25
Mycobacterium avium
complex (MAC) isolates at concentrations of 2 μg/ml or lower. In mice, SRI-224 and thiacetazone had no significant activity against the MAC in livers and spleens, but treatment with SRI-286 resulted in significant reduction of bacterial loads in livers and spleens. A combination of SRI-286 and moxifloxacin was significantly more active than single drug regimens in liver and spleen.
Bovine Lactoferrin Inhibits Adenovirus Infection by Interacting with Viral Structural Polypeptides
Authors: Pietrantoni Agostina , Di Biase Assunta Maria , Tinari Antonella , Marchetti Magda , Valenti Piera , Seganti Lucilla , Superti Fabiana 
Published: July 2003

ABSTRACTWe recently demonstrated that lactoferrin, an antimicrobial glycoprotein, can inhibit adenovirus infection by competing for common glycosaminoglycan receptors. This study further characterizes the antiadenovirus activity of the protein, thus demonstrating that lactoferrin neutralizes infection by binding to adenovirus particles and that its targets are viral III and IIIa structural polypeptides.
Fluoroquinolone-Resistant
Streptococcus pneumoniae
in Spain: Activities of Garenoxacin against Clinical Isolates Including Strains with Altered Topoisomerases
Authors: Morosini María-Isabel , Loza Elena , del Campo Rosa , Almaraz Felisa , Baquero Fernando , Cantón Rafael 
Published: July 2003

ABSTRACT

The activity of garenoxacin was assessed against 412
Streptococcus pneumoniae
isolates (49.3% from the adult population). Overall penicillin, erythromycin, and ciprofloxacin (MIC, ≥4 μg/ml) resistance was 51.7, 35.4, and 1.5%, respectively. For all isolates, the garenoxacin MIC was ≤1 μg/ml. Amino acid replacements in GryA (Ser81→Phe or Tyr), ParC (Ser79→Phe or Tyr; Asp83→Gly; Lys137→Asn), and ParE (Ile460→Val; Asp435→Asn), alone or in combination, were ascribed to the reduced garenoxacin susceptibility (MIC range, 0.5 to 1 μg/ml) found in four isolates. The low impact of these mutations on garenoxacin activity envisages the possible coverage of
S. pneumoniae
populations resistant to preexisting quinolones.
Quinupristin-Dalfopristin Resistance in
Streptococcus pneumoniae
: Novel L22 Ribosomal Protein Mutation in Two Clinical Isolates from the SENTRY Antimicrobial Surveillance Program
Authors: Jones Ronald N. , Farrell David J. , Morrissey Ian 
Published: July 2003

ABSTRACT

Resistance to quinupristin-dalfopristin (Q/D) among gram-positive cocci has been very uncommon. Two clinical isolates among 8,837 (0.02%)
Streptococcus pneumoniae
isolates were discovered in 2001 to 2002 with Q/D MICs of 4 μg/ml. Each had a 5-amino-acid tandem duplication (RTAHI) in the L22 ribosomal protein gene (
rplV
) preventing synergistic ribosomal binding of the streptogramin combination. Similar gene duplication has been reported in Q/D-resistant
Staphylococcus aureus
.
Antimicrobial Susceptibility and Macrolide Resistance Inducibility of
Streptococcus pneumoniae
Carrying
erm
(A),
erm
(B), or
mef
(A)
Authors: Syrogiannopoulos George A. , Grivea Ioanna N. , Ednie Lois M. , Bozdogan Bülent , Katopodis George D. , Beratis Nicholas G. , Davies Todd A. , Appelbaum Peter C. 
Published: July 2003

ABSTRACT

Erythromycin-resistant
Streptococcus pneumoniae
isolates from young carriers were tested for their antimicrobial susceptibility; additionally, inducibility of macrolide and clindamycin resistance was investigated in pneumococci carrying
erm
(A),
erm
(B), or
mef
(A). Of 125 strains tested, 101 (81%) were multidrug resistant. Different levels of induction were observed with erythromycin, miocamycin, and clindamycin in
erm
(B) strains; however, in
erm
(A) strains only erythromycin was an inducer. Induction did not affect macrolide MICs in
mef
(A) strains.
In Vitro Activities of Florfenicol against Bovine and Porcine Respiratory Tract Pathogens
Authors: Priebe Saskia , Schwarz Stefan 
Published: July 2003

ABSTRACT

Florfenicol in vitro activities for a total of 756 bacterial isolates from respiratory tract infections of cattle and swine were comparatively investigated by the agar diffusion method and the microdilution broth method. Florfenicol showed high in vitro activity against
Pasteurella multocida
,
Mannheimia haemolytica
,
Actinobacillus pleuropneumoniae
, and
Streptococcus suis
, with all of the isolates inhibited by ≤2 μg of florfenicol per ml.
In Vivo Efficacy of the Ketolide ABT-773 (Cethromycin) against Enterococci in a Mouse Peritonitis Model
Authors: Pai Suresh R. , Singh Kavindra V. , Murray Barbara E. 
Published: July 2003

ABSTRACT

Using six
Enterococcus faecalis
and five
Enterococcus faecium
strains, the ketolide ABT-773 (ABT), now known as cethromycin, was found to have in vivo efficacy against both erythromycin (ERY)-susceptible (Ery
s
) and -intermediate (Ery
i
) enterococci (ABT 50% protective doses [PD
50
s], 0.5 to 4.1 and 10.3 to 16.2 mg/kg of body weight, respectively). Against four highly Ery-resistant (Ery
r
) strains for which ABT MICs were low, ABT showed much greater activity (PD
50
, 6.3 to 32.5 mg/kg) than ERY (PD
50
, >200 mg/kg) but was not protective for strains for which ABT MICs were high. In conclusion, ABT-773 showed in vivo efficacy and considerably greater activity than ERY in a mouse peritonitis model.