bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vitro Activities of Caspofungin Compared with Those of Fluconazole and Itraconazole against 3,959 Clinical Isolates of
Candida
spp., Including 157 Fluconazole-Resistant Isolates
Authors: Pfaller M. A. , Diekema D. J. , Messer S. A. , Hollis R. J. , Jones R. N. 
Published: February 2003

ABSTRACT

Caspofungin is an echinocandin antifungal agent with broad-spectrum activity against
Candida
and
Aspergillus
spp. The in vitro activities of caspofungin against 3,959 isolates of
Candida
spp. obtained from over 95 different medical centers worldwide were compared with those of fluconazole and itraconazole. The MICs of the antifungal drugs were determined by broth microdilution tests performed according to the NCCLS method using RPMI 1640 as the test medium. Caspofungin was very active against
Candida
spp. (MIC at which 90% of the isolates were inhibited [MIC
90
], 1 μg/ml; 96% of MICs were ≤2 μg/ml).
Candida albicans
,
C. dubliniensis
,
C. tropicalis
, and
C. glabrata
were the most susceptible species of
Candida
(MIC
90
, 0.25 to 0.5 μg/ml), and
C. guilliermondii
was the least susceptible (MIC
90
, >8 μg/ml). Caspofungin was very active against
Candida
spp., exhibiting high-level resistance to fluconazole and itraconazole (99% of MICs were ≤1 μg/ml). These results provide further evidence for the spectrum and potency of caspofungin activity against a large and geographically diverse collection of clinically important isolates of
Candida
spp.
High-Dose, Short-Duration, Early Valacyclovir Therapy for Episodic Treatment of Cold Sores: Results of Two Randomized, Placebo-Controlled, Multicenter Studies
Authors: Spruance Spotswood L. , Jones Terry M. , Blatter Mark M. , Vargas-Cortes Mauricio , Barber Judy , Hill Joanne , Goldstein Donna , Schultz Margaret 
Published: February 2003

ABSTRACT

Oral valacyclovir is better absorbed than oral acyclovir, increasing acyclovir bioavailability three- to fivefold. This provides the opportunity to explore whether high systemic acyclovir concentrations are effective in the treatment of cold sores (herpes labialis). Two randomized, double-blind, placebo-controlled studies were conducted. Subjects were provided with 2 g of valacyclovir twice daily for 1 day (1-day treatment), 2 g of valacyclovir twice daily for 1 day and then 1 g of valacyclovir twice daily for 1 day (2-day treatment), or a matching placebo and instructed to initiate treatment upon the first symptoms of a cold sore. In study 1, the median duration of the episode (primary endpoint) was reduced by 1.0 day (
P
= 0.001) with 1-day treatment and 0.5 days (
P
= 0.009) with 2-day treatment compared to placebo. Similarly, the mean duration of the episode was statistically significantly reduced by 1.1 days with 1-day treatment and 0.7 days with 2-day treatment compared to placebo. The proportion of subjects in whom cold sore lesion development was prevented and/or blocked was increased by 6.4% (
P
= 0.096) with 1-day treatment and 8.5% (
P
= 0.061) with 2-day treatment compared to placebo. The time to lesion healing and time to cessation of pain and/or discomfort were statistically significantly reduced with valacyclovir compared to placebo. In study 2, results similar to those in study 1 were obtained. AEs were similar across treatment groups. These studies provide evidence supporting a simple, 1-day valacyclovir treatment regimen for cold sores that is safe and effective. The 1-day valacyclovir regimen offers patients a unique and convenient dosing alternative compared to available topical therapies.
Use of the Microbial Growth Curve in Postantibiotic Effect Studies of
Legionella pneumophila
Authors: Smith Raymond P. , Baltch Aldona L. , Michelsen Phyllis B. , Ritz William J. , Alteri Richard 
Published: February 2003

ABSTRACT

Using the standard Craig and Gudmundsson method (W. A. Craig and S. Gudmundsson, p. 296-329,
in
V. Lorian, ed.,
Antibiotics in Laboratory Medicine
, 1996) as a guideline for determination of postantibiotic effects (PAE), we studied a large series of growth curves for two strains of
Legionella pneumophila
. We found that the intensity of the PAE was best determined by using a statistically fitted line over hours 3 to 9 following antibiotic removal. We further determined the PAE duration by using a series of observations of the assay interval from hours 3 to 24. We determined that inoculum reduction was not necessarily the only predictor of the PAE but that the PAE was subject to the type and dose of the drug used in the study. In addition, there was a variation between strains. Only levofloxacin at five and ten times the minimum inhibitory concentration (MIC) resulted in a PAE duration of 4 to 10 h for both strains of
L. pneumophila
tested. Ciprofloxacin at five and ten times the MIC and azithromycin at ten times the MIC caused a PAE for one strain only. No PAE could be demonstrated for either strain with erythromycin or doxycycline. Using the presently described method of measuring PAE for
L. pneumophila
, we were able to detect differences in PAE which were dependent upon the
L. pneumophila
strain, the antibiotic tested, and the antibiotic concentration. We suggest the use of mathematically fitted curves for comparison of bacterial growth in order to measure PAE for
L. pneumophila
.
Activities of Moxifloxacin against, and Emergence of Resistance in,
Streptococcus pneumoniae
and
Pseudomonas aeruginosa
in an In Vitro Pharmacokinetic Model
Authors: MacGowan Alasdair P. , Rogers Chris A. , Holt H. Alan , Bowker Karen E. 
Published: February 2003

ABSTRACT

The pharmacodynamics of moxifloxacin against
Streptococcus pneumoniae
and
Pseudomonas aeruginosa
were investigated in a pharmacokinetic infection model. Three strains of
S. pneumoniae
, moxifloxacin, and two strains of
P. aeruginosa
were used. Antibacterial effect and emergence of resistance were measured for both species over a 72-h period using an initial inoculum of about 10
8
CFU/ml. At equivalent area under the curve (AUC)/MIC ratios,
S. pneumoniae
was cleared from the model while
P. aeruginosa
was not. For
S. pneumoniae
, the area under the bacterial kill curve up to 72 h could be related to AUC/MIC ratio using an inhibitory maximum effect (
E
max
) model (concentration required for 50%
E
max
[EC
50
], 45 ± 22;
r
2
, 0.97). For
P. aeruginosa
even at the highest AUC/MIC ratio (427), bacterial clearance was insufficient for the EC
50
to be calculated. Emergence of resistance occurred with
P. aeruginosa
but not to any significant extent with
S. pneumoniae
. Emergence of resistance in
P. aeruginosa
as measured by population analysis profile (PAP-AUC) was dependent on drug exposure and time of exposure. In weighted least-squares regression analysis AUC/MIC ratio was predictive of PAP-AUC. When emergence of resistance was measured by the time for the colony counts on media containing antibiotic to increase by 2 logs, again AUC/MIC was the best predictor of emergence of resistance. However, for both experiments using
S. pneumoniae
and
P. aeruginosa
the correlation between all the pharmacodynamic parameters was high. These data indicate that for a given fluoroquinolone the magnitude of the AUC/MIC ratio for antibacterial effect is dependent on the bacterial species. Emergence of resistance is dependent on (i) species, (ii) duration of drug exposure, and (iii) drug exposure. A single AUC/MIC ratio magnitude is not adequate to predict antibacterial effect or emergence of resistance for all bacterial species.
Mechanism of Fluoroquinolone Resistance Is an Important Factor in Determining the Antimicrobial Effect of Gemifloxacin against
Streptococcus pneumoniae
in an In Vitro Pharmacokinetic Model
Authors: MacGowan Alasdair P. , Bowker Karen E. 
Published: February 2003

ABSTRACT

Antibacterial effect and emergence of resistance to gemifloxacin and levofloxacin were studied in an in vitro pharmacokinetic model of infection. A panel of
Streptococcus pneumoniae
strains with known mechanisms of resistance were used; two strains had no known resistance mechanism, two had efflux pumps, three had
gyrA
plus
parC
mutations, and one had only a
parC
mutation. Gemifloxacin MICs were in the range of 0.016 to 0.25 mg/liter, and levofloxacin MICs ranged from 1 to 16 mg/liter. Antimicrobial effect was measured by area under the bacterial-kill curve up to 72 h, and emergence of resistance was determined by population analysis profile before and during drug exposure. The area under the curve (AUC)/MIC ratios for gemifloxacin and levofloxacin were 35 to 544 and 3 to 48, respectively. As expected on the basis of these AUC/MIC ratio differences, antibacterial effect was much greater for gemifloxacin than levofloxacin. In the gemifloxacin simulations, mechanism of resistance as well as MIC determined the antibacterial effect, as indicated by gemifloxacin’s greater effect against efflux strains compared to those with
gyrA
or
parC
mutations despite similar MICs. This was not true of levofloxacin. Emergence of resistance was not easily demonstrated with either agent, and mechanism of resistance did not have any impact on it.
Aminoglycoside Efflux in
Pseudomonas aeruginosa
: Involvement of Novel Outer Membrane Proteins
Authors: Jo James T. H. , Brinkman Fiona S. L. , Hancock Robert E. W. 
Published: February 2003

ABSTRACT

The expression of tripartite multidrug efflux pumps such as MexA-MexB-OprM in
Pseudomonas aeruginosa
contributes to intrinsic resistance to a wide variety of antimicrobials, including β-lactams, chloramphenicol, macrolides, quinolones, and tetracycline. The MexX-MexY linker-pump combination has been shown to be involved in intrinsic resistance to aminoglycosides, but the identity of the cognate outer membrane channel component remains under debate. Fourteen uncharacterized OprM homologs identified in the genome of
P. aeruginosa
were examined as candidates for this role by assessing the minimum inhibitory concentrations (MICs) of aminoglycosides in
P. aeruginosa
strain PAK knockout mutants lacking the corresponding genes. Insertional inactivation of OpmG, OpmI, and OpmH resulted in decreases of various degrees in the MICs of streptomycin, kanamycin, and gentamicin. When reintroduced into
P. aeruginosa
on multicopy plasmids, OpmG was able to complement the susceptibility of an
opmG
::miniTn
5
mutant; however, cloned
opmH
, the proposed ortholog of
Escherichia coli tolC
according to our phylogenetic analysis, was able to only partially complement the
opmH
::miniTn
5
mutant. Mini-microarray hybridization analysis demonstrated that
opmG
disruption does not affect expression of OpmI or OpmH (ruling out such indirect effects on aminoglycoside resistance); however,
opmH
disruption did have possible effects on expression of OpmG and OpmI. Based on the data, we propose that OpmG is a major outer membrane efflux channel involved in aminoglycoside efflux in
P. aeruginosa
PAK and that OpmI, its most related paralog, may share an overlapping function.
Erythromycin and Clindamycin Resistance and Telithromycin Susceptibility in
Streptococcus agalactiae
Authors: Betriu C. , Culebras E. , Gómez M. , Rodríguez-Avial I. , Sánchez B. A. , Ágreda M. C. , Picazo J. J. 
Published: February 2003

ABSTRACT

The rates of resistance to erythromycin and clindamycin among
Streptococcus agalactiae
strains isolated in our hospital increased from 4.2 and 0.8% in 1993 to 17.4 and 12.1%, respectively, in 2001. Erythromycin resistance was mainly due to the presence of an Erm(B) methylase, while the M phenotype was detected in 3.8% of the strains. Telithromycin was very active against erythromycin-resistant strains, irrespective of their mechanisms of macrolide resistance.
Mercury Resistance Determinants Related to Tn
21
, Tn
1696
, and Tn
5053
in Enterobacteria from the Preantibiotic Era
Authors: Essa Ashraf M. M. , Julian Daniel J. , Kidd Stephen P. , Brown Nigel L. , Hobman Jon L. 
Published: February 2003

ABSTRACT

Three
mer
transposons from the Murray collection of preantibiotic enterobacteria show >99% sequence identity to current isolates. Tn
5073
is most closely related to Tn
5036
and Tn
1696
, and Tn
5074
is most closely related to Tn
5053
. Tn
5075
is most closely related to Tn
21
but lacks integron In2 and is flanked by insertion elements.
A Point Mutation in the 14α-Sterol Demethylase Gene
cyp51A
Contributes to Itraconazole Resistance in
Aspergillus fumigatus
Authors: Diaz-Guerra T. M. , Mellado E. , Cuenca-Estrella M. , Rodriguez-Tudela J. L. 
Published: February 2003

ABSTRACT

The genes encoding 14α-sterol demethylases (
cyp51A
and
cyp51B
) were analyzed in 12 itraconazole (ITC)-resistant and three ITC-susceptible clinical isolates of
Aspergillus fumigatus
. Six ITC-resistant strains exhibited a substitution of another amino acid for glycine at position 54, which is located at a very conserved region of the Cyp51A protein. The
cyp51A
gene from the
A. fumigatus
wild-type strain (CM-237) was replaced with the mutated
cyp51A
gene copy of an ITC-resistant strain (AF-72). Two transformants exhibited resistance to ITC, both of which had incorporated the mutated copy of the
cyp51A
gene.
PCR-Restriction Fragment Length Polymorphism Analysis for Detection of Point Mutations Associated with Macrolide Resistance in
Campylobacter
spp
Authors: Vacher Sylvie , Ménard Armelle , Bernard Elisabeth , Mégraud Francis 
Published: February 2003

ABSTRACT

A 23S rRNA gene fragment in domain V was sequenced from 30 clinical isolates of
Campylobacter
spp., including 22 resistant to macrolides. Two point mutations associated with erythromycin resistance were identified at positions 2074 and 2075 on the 23S rRNA gene (homologous to A2142C and A2143G mutations in
Helicobacter pylori
) in which an adenine residue is also replaced with a cytosine and a guanine residue, respectively. A combined PCR-restriction fragment length polymorphism technique was developed to detect these mutations by using the
Bsa
I and
Bce
AI enzymes.
ABT-773: Pharmacokinetics and Interactions with Ranitidine and Sucralfate
Authors: Pletz M. W. , Preechachatchaval V. , Bulitta J. , Allewelt M. , Burkhardt O. , Lode H. 
Published: February 2003

ABSTRACT

We assessed the pharmacokinetics and interaction of ABT-773 in 12 volunteers receiving ABT-773 alone or concomitantly with ranitidine or sucralfate. Data for 150 mg of ABT-773 were as follows: the maximum concentration of the drug in plasma (
C
max
) was 318 ng/ml, its half-life was 5.66 h, and its area under the plasma concentration-time curve from 0 h to ∞ (AUC
0-∞
) was 1,662 ng · h/ml. Coadministration of ranitidine, reduced the
C
max
(−25.7%) and AUC
0-∞
(−15.8%) significantly. Sucralfate had no impact on the bioavailability of ABT-773.
In Vitro Bactericidal Activities of ABT-773 against
ermB
Strains of
Streptococcus pneumoniae
Authors: Neuhauser Melinda M. , Prause Jennifer L. , Danziger Larry H. , Pendland Susan L. 
Published: February 2003

ABSTRACT

The bactericidal activities of ABT-773, a new ketolide, were compared to those of cefuroxime and amoxicillin-clavulanate against 10 strains of
Streptococcus pneumoniae
containing the
ermB
gene. MICs and time-kill curves were determined in duplicate per NCCLS guidelines with cation-adjusted Mueller-Hinton broth with 3% lysed horse blood. Viable counts were done at 0, 2, 6, and 24 h. Antibiotic concentrations tested were two and eight times the MIC. ABT-773 MICs ranged from 0.008 to 1.0 μg/ml. Bactericidal activity was observed with ABT-773 at eight times the MIC against 4 of 10 strains at 24 h compared to 10 of 10 strains with the beta-lactam antibiotics.
In Vitro Activities of Rifamycin Derivatives ABI-1648 (Rifalazil, KRM-1648), ABI-1657, and ABI-1131 against
Chlamydia trachomatis
and Recent Clinical Isolates of
Chlamydia pneumoniae
Authors: Roblin Patricia M. , Reznik Tamara , Kutlin Andrei , Hammerschlag Margaret R. 
Published: February 2003

ABSTRACT

ABI-1648 (rifalazil) is a semisynthetic rifamycin with potent bactericidal activity against intracellular respiratory bacteria, including
Mycobacterium tuberculosis
, and a long half-life (∼60 h) and thus can be administered once weekly. We therefore tested the in vitro activities of ABI-1648, its derivatives ABI-1657 and ABI-1131, azithromycin, and levofloxacin against 10 strains of
Chlamydia trachomatis
and 10 recent clinical isolates of
Chlamydia pneumoniae
. The MICs at which 90% of the isolates were inhibited and the minimal bactericidal concentration at which 90% of the isolates were killed for ABI-1648, ABI-1657, and ABI-1131 were 0.0025 μg/ml for
C. trachomatis
and 0.00125 to 0.0025 μg/ml for
C. pneumoniae
. ABI-1648, ABI-1657, and ABI-1131 were 10- to 1,000-fold more active than azithromycin and levofloxacin.
In Vitro Susceptibilities of
Shigella flexneri
and
Streptococcus pyogenes
to Inner Gel of
Aloe barbadensis
Miller
Authors: Ferro Valerie A. , Bradbury Fiona , Cameron Pamela , Shakir Eisin , Rahman Sabita R. , Stimson William H. 
Published: February 2003

ABSTRACT

Aloe barbadensis
Miller (or
Aloe vera
) has widespread use in health products, and despite numerous reports on the whole plant, little work has been performed on the inner gel, which has been used extensively in these products. This report describes the in vitro susceptibilities of two bacteria to this component.
Postantibiotic Effects of Garenoxacin (BMS-284756) against 12 Gram-Positive or -Negative Organisms
Authors: Pankuch G. A. , Jacobs M. R. , Appelbaum P. C. 
Published: February 2003

ABSTRACT

Conventional in vitro methods were used to determine the postantibiotic effects (PAEs), sub-MIC effects (SMEs), and postantibiotic sub-MIC effects (PA-SMEs) of garenoxacin for a range of organisms. The mean PAEs of garenoxacin for pneumococci, staphylococci, and enterococci were 0.3 to 2.2 h. For
Escherichia coli
and
Pseudomonas aeruginosa
, the PAEs were 0.9 to 1.6 h. The mean PA-SMEs (0.4 times the MIC) for pneumococci, staphylococci, and enterococci were 3.0 to >10 h, 1.8 to >10.7 h, and 5.8 h, respectively, while those for
E. coli
and
P. aeruginosa
were 7.6 and 4.4 h, respectively.
Antianaerobe Activity of RBX 7644 (Ranbezolid), a New Oxazolidinone, Compared with Those of Eight Other Agents
Authors: Ednie Lois M. , Rattan Ashok , Jacobs Michael R. , Appelbaum P. C. 
Published: February 2003

ABSTRACT
The activity of ranbezolid (RBX 7644), a new oxazolidinone, against 306 anaerobes was compared with those of 11 other agents. The MICs at which 50% of the isolates tested are inhibited and those at which 90% of the isolates tested are inhibited (in micrograms per milliliter) were as follows: ranbezolid, 0.03 and 0.5; linezolid, 2 and 4; vancomycin, >16 and >16; teicoplanin, 1 and >16; quinupristin-dalfopristin, 1 and >8; amoxicillin-clavulanate, 0.5 and 2; imipenem, 0.125 and 1; clindamycin, 0.25 and 8; metronidazole, 1 and 4; gatifloxacin, 0.5 and 4; and moxifloxacin, 0.5 and 2, respectively. Ranbezolid had very good in vitro activity against both gram-negative and -positive anaerobes.
Antipneumococcal and Antistaphylococcal Activities of Ranbezolid (RBX 7644), a New Oxazolidinone, Compared to Those of Other Agents
Authors: Hoellman Dianne B. , Lin Gengrong , Ednie Lois M. , Rattan Ashok , Jacobs Michael R. , Appelbaum Peter C. 
Published: February 2003

ABSTRACT

For 260 pneumococcal and 266 staphylococcal strains, ranbezolid MICs ranged from ≤0.06 to 4 μg/ml. The MICs for pneumococci were similar irrespective of the strains' β-lactam, macrolide, or quinolone susceptibilities, and ranbezolid MICs for coagulase-negative staphylococci were lower than those for
Staphylococcus aureus
. Ranbezolid was bacteriostatic against pneumococci. Ranbezolid MICs were similar to or lower than those of linezolid. Vancomycin and quinupristin-dalfopristin were also very active.
Lack of Synergy of Erythromycin Combined with Penicillin or Cefotaxime against
Streptococcus pneumoniae
In Vitro
Authors: Lin Eugene , Stanek Ronald J. , Mufson Maurice A. 
Published: February 2003

ABSTRACT

We investigated a possible synergistic effect of a macrolide and β-lactams against
Streptococcus pneumoniae
strains with different resistance profiles. Checkerboard and time-kill assays of erythromycin combined with penicillin or cefotaxime essentially showed indifference, suggesting that these antibiotics in combinations in vitro act substantially as individuals in their activity against
S. pneumoniae
.
Vancomycin Resistance Is Maintained in Enterococci in the Viable but Nonculturable State and after Division Is Resumed
Authors: Lleò Maria del Mar , Bonato Barbara , Signoretto Caterina , Canepari Pietro 
Published: February 2003

ABSTRACT
Stressed vancomycin-resistant enterococci (VRE) can activate a survival strategy known as the viable but nonculturable (VBNC) state and are able to maintain vancomycin resistance. During restoration of division they continue to express the vancomycin resistance trait. We suggest that VBNC enterococci may constitute further reservoirs of VRE and therefore represent an additional risk for human health.
Activities of Temporin Family Peptides against the Chytrid Fungus (Batrachochytrium dendrobatidis) Associated with Global Amphibian Declines
Authors: Rollins-Smith Louise A. , Carey Cynthia , Conlon J. Michael , Reinert Laura K. , Doersam Jennifer K. , Bergman Tomas , Silberring Jerzy , Lankinen Hilkka , Wade David 
Published: February 2003

ABSTRACTTemporin A and structurally related peptides produced in amphibian dermal granular glands and in wasp venom were tested for growth inhibition ofBatrachochytrium dendrobatidis, a pathogen associated with global amphibian declines. Two natural amphibian temporins, a wasp temporin, and six synthetic analogs effectively inhibited growth. Differences in potency due to amino acid substitution suggest that ability to penetrate membranes and form an α-helical structure is important for their effectiveness against this pathogen.
In Vitro Effects of Ciprofloxacin and Roxithromycin on Apoptosis of Jurkat T Lymphocytes
Authors: Jun Yong-Taek , Kim Hee-Jung , Song Min-Jin , Lim Ji-Hyang , Lee Dong-Gun , Han Kyung-Ja , Choi Su-Mi , Yoo Jin-Hong , Shin Wan-Shik , Choi Jung-Hyun 
Published: February 2003

ABSTRACTCiprofloxacin (CPFX) and roxithromycin (RXM) induced apoptosis of activated Jurkat T cells in vitro. CPFX showed concentration-dependent acceleration of apoptosis of activated Jurkat T cells by enhancing the expression of FasL and activities of caspase-3 and -8. RXM accelerated cell death, enhanced expression of FasL and caspase-3 but not caspase-8, and did not show the concentration dependency.
Imipenem Resistance in
Salmonella enterica
Serovar Wien Related to Porin Loss and CMY-4 β-Lactamase Production
Authors: Armand-Lefèvre L. , Leflon-Guibout V. , Bredin J. , Barguellil F. , Amor A. , Pagès J. M. , Nicolas-Chanoine M.-H. 
Published: February 2003

ABSTRACT

Two multidrug-resistant
Salmonella enterica
serovar Wien strains (SW468 and SW1107) were isolated in 2001 in Tunis. Both strains produced the β-lactamases TEM-1, SHV-2a, and CMY-4, whereas strain SW1107 also produced the β-lactamase CTX-M-3. The imipenem-resistant strain (SW468) was totally devoid of the OmpF-immunorelated porin. Imipenem resistance was shown as being related to porin loss and CMY-4 β-lactamase production.
A New Sulfonamide Resistance Gene (
sul3
) in
Escherichia coli
Is Widespread in the Pig Population of Switzerland
Authors: Perreten Vincent , Boerlin Patrick 
Published: February 2003

ABSTRACT

A new gene,
sul3
, which specifies a 263-amino-acid protein similar to a dihydropteroate synthase encoded by the 54-kb conjugative plasmid pVP440 from
Escherichia coli
was characterized. Expression of the cloned
sul3
gene conferred resistance to sulfamethoxazole on
E. coli
. Two copies of the insertion element IS
15
Δ
/26
flanked the region containing
sul3
. The
sul3
gene was detected in one-third of the sulfonamide-resistant pathogenic
E. coli
isolates from pigs in Switzerland.