bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbapenemases of
Chryseobacterium
(
Flavobacterium
)
meningosepticum
: Distribution of
blaB
and Characterization of a Novel Metallo-β-Lactamase Gene,
blaB3
, in the Type Strain, NCTC 10016
Authors: Woodford Neil , Palepou Marie-France I. , Babini Gioia S. , Holmes Barry , Livermore David M. 
Published: July 2002

ABSTRACT

Genes encoding carbapenemases in 15 reference strains of
Chryseobacterium
(
Flavobacterium
)
meningosepticum
from the United Kingdom National Collection of Type Cultures and in one recent clinical isolate were investigated. All the strains hydrolyzed imipenem, but their levels of resistance to carbapenems varied, with imipenem and meropenem MICs ranging from 2 to >32 μg/ml. The
blaB
gene, which encodes a molecular-class B carbapenemase, was detected in only six reference strains and in clinical isolate 97/P/5448. The gene from 97/P/5448 had 98% nucleotide identity with the published sequence of
blaB
(from strain NCTC 10585) and was designated
blaB2
. A distinct carbapenemase gene, designated
blaB3
, was cloned from the type strain of
C. meningosepticum
, NCTC 10016.
blaB3
had an open reading frame of 750 bp with 82% nucleotide identity to
blaB
and
blaB2
and encoded a β-lactamase of 249 amino acids, including the putative signal peptide. This β-lactamase showed 87.6 and 86.7% amino acid homology with BlaB and BlaB2, respectively.
blaB3
was detected in one other reference strain besides NCTC 10016, but the genetic basis of the carbapenemase activity detected in the other seven reference strains was not defined. Thus, neither
blaB
nor
blaB3
was ubiquitous in the strains of
C. meningosepticum
studied, indicating that the reference strains may represent more than one bacterial species, each with its own intrinsic metallo-β-lactamase. Further taxonomic studies of
C. meningosepticum
are necessary to resolve this topic.
Chryseobacterium
spp. are environmental organisms and occasional opportunist pathogens. They apparently represent a reservoir of diverse metallo-β-lactamases, which potentially spread to gram-negative bacteria of greater clinical significance.
In Vivo Activity of Evernimicin (SCH 27899) against Methicillin-Resistant
Staphylococcus aureus
in Experimental Infective Endocarditis
Authors: Boucher Helen W. , Thauvin-Eliopoulos Claudie , Loebenberg David , Eliopoulos George M. 
Published: July 2002

ABSTRACT

Currently, there exist few satisfactory alternatives to vancomycin for therapy of serious methicillin-resistant
Staphylococcus aureus
(MRSA) infections. We employed a rat model of aortic valve endocarditis to assess the potential efficacy of evernimicin (SCH 27899) compared with vancomycin against infection with a strain susceptible to both agents (MICs of 0.25 and 0.50 μg/ml, respectively). Infected animals were assigned to one of three groups: controls (no treatment), evernimicin at 60 mg/kg of body weight by intravenous (i.v.) infusion once daily, or vancomycin at 150 mg/kg of body weight per day by continuous i.v. infusion. Therapy was administered for 5.5 days. At the start of therapy, colony counts in vegetations were 6.63 ± 0.44 log
10
CFU/g. In both treatment groups, bacterial density within vegetations was significantly reduced in comparison with control animals that had not been treated. Final colony counts were as follows (mean ± standard deviation): controls, 10.12 ± 1.51 log
10
CFU/g of vegetation; evernimicin, 7.22 ± 2.91 log
10
CFU/g of vegetation; vancomycin, 5.65 ± 1.76 log
10
CFU/g of vegetation. The difference between the evernimicin and vancomycin groups was not significant. These results confirmed the bacteriostatic activity of evernimicin in vivo in an experimental model of severe MRSA infection.
In Vitro and In Vivo Efficacies of T-3811ME (BMS-284756) against
Mycoplasma pneumoniae
Authors: Takahata Masahiro , Shimakura Masako , Hori Ritsuko , Kizawa Kazuo , Todo Yozo , Minami Shinzaburo , Watanabe Yasuo , Narita Hirokazu 
Published: July 2002

ABSTRACT

T-3811, the free base of T-3811ME (BMS-284756), a new des-F(6)-quinolone, showed a potent in vitro activity (MIC at which 90% of the isolates tested are inhibited [MIC
90
], 0.0313 μg/ml) against
Mycoplasma pneumoniae
. The MIC
90
of T-3811 was 4-fold higher than that of clarithromycin but was 4- to 8-fold lower than those of trovafloxacin, gatifloxacin, gemifloxacin, and moxifloxacin and was 16- to 32-fold lower than those of levofloxacin, ciprofloxacin, and minocycline. In an experimental
M. pneumoniae
pneumonia model in hamsters, after the administration of T-3811ME (20 mg/kg of body weight as T-3811, once daily, orally) for 5 days, the reduction of viable cells of
M. pneumoniae
in bronchoalveolar lavage fluid was greater than those of trovafloxacin, levofloxacin, and clarithromycin (20 and 40 mg/kg, orally) (
P
< 0.05).
In Vitro Pharmacodynamic Studies of Activities of Ketolides HMR 3647 (Telithromycin) and HMR 3004 against Extracellular or Intracellular
Helicobacter pylori
Authors: Gustafsson I. , Engstrand L. , Cars O. 
Published: July 2002

ABSTRACT

The pharmacodynamic properties of the ketolides HMR 3647 (telithromycin) and HMR 3004 were studied against
Helicobacter pylori
. Both ketolides showed a pronounced concentration-dependent killing, a significant postantibiotic effect, a long postantibiotic sub-MIC effect, and a reduction of intracellular
H. pylori
.
Selection and Genetic Characterization of
Streptococcus pneumoniae
Mutants Resistant to the Des-F(6) Quinolone BMS-284756
Authors: Hartman-Neumann Sandra , DenBleyker Kenneth , Pelosi Lenore A. , Lawrence Laura E. , Barrett John F. , Dougherty Thomas J. 
Published: July 2002

ABSTRACT

Existing quinolones are known to target the type II topoisomerases in bacteria. In order to determine which of these targets are of key importance in
Streptococcus pneumoniae
treated with BMS-284756 (T-3811ME), a novel des-F(6) quinolone, resistant mutants were selected in several steps of increasing resistance by plating pneumococci on a series of blood agar plates containing serial twofold-increasing concentrations of drug. After incubation, colonies that arose were selected and passaged twice on antibiotic-containing media at the selection level. Mutants generally showed increases in resistance of four- to eightfold over the prior level of susceptibility. Mutants in the next-higher level of resistance were selected from the previous round of resistant mutants. Subsequently, chromosomal DNA was prepared from parental (R6) pneumococci and from at least three clones from each of four levels of increasing antibiotic resistance. Using PCR primers, 500- to 700-bp amplicons surrounding the quinolone resistance determining regions (QRDR) of
gyrA
,
gyrB
,
parC,
and
parE
genes were prepared from each strain. Internal primers were used to sequence both DNA strands in the regions of approximately 400 bp centered on the QRDR. Mutations identified with increasing levels of resistance included changes in GyrA at Ser-81 and Glu-85 and changes in ParC at Ser-79 and Asp-83. Changes in GyrB and ParE were not observed at the levels of resistance obtained in this selection. The resistance to comparator quinolones (levofloxacin, ciprofloxacin, and moxifloxacin) also increased in four- to eightfold steps with these mutations. The intrinsically greater level of antibacterial activity and thus lower MICs of BMS-284756 observed at all resistance levels in this study may translate to coverage of these resistant pneumococcal strains in the clinic.
TEM-89 β-Lactamase Produced by a
Proteus mirabilis
Clinical Isolate: New Complex Mutant (CMT 3) with Mutations in both TEM-59 (IRT-17) and TEM-3
Authors: Neuwirth Catherine , Madec Stephanie , Siebor Eliane , Pechinot Andre , Duez Jean-Marie , Pruneaux Michele , Fouchereau-Peron Martine , Kazmierczak Antoine , Labia Roger 
Published: July 2002

ABSTRACT

TEM-89 (CMT-3) is the first complex mutant β-lactamase produced by a clinical strain of
Proteus mirabilis
(strain Pm 631). This new enzyme, which has a pI of 6.28, is derived from TEM-3 and has a single amino acid substitution also encountered in TEM-59 (inhibitor-resistant TEM β-lactamase IRT-17): Ser-130 to Gly. TEM-89 hydrolyzed penicillins to the same extent that TEM-3 did but lost almost all hydrolytic activity for cephalosporins and, like TEM-59, was highly resistant to inhibitors.
Novel Scintillation Proximity Assay for Measuring Membrane-Associated Steps of Peptidoglycan Biosynthesis in
Escherichia coli
Authors: Chandrakala B. , Elias Bertha C. , Mehra Upasana , Umapathy N. S. , Dwarakanath P. , Balganesh T. S. , deSousa Sunita M. 
Published: July 2002

ABSTRACT

We have developed a novel, high-throughput scintillation proximity assay to measure the membrane-associated steps (stages 2 and 3) of peptidoglycan synthesis in
Escherichia coli
. At least five enzymes are involved in these two stages, all of which are thought to be essential for the survival of the cell. The individual enzymes are difficult to assay since the substrates are lipidic and difficult to isolate in large quantities and analysis is done by paper chromatography. We have assayed all five enzymes in a single mixture by monitoring synthesis of cross-linked peptidoglycan, which is the final product of the pathway.
E. coli
membranes are incubated with the two sugar precursors, UDP–
N
-acetyl muramylpentapeptide and UDP–[
3
H]-
N
-acetylglucosamine. The radiolabel is incorporated into peptidoglycan, which is captured using wheat germ agglutinin-coated scintillation proximity assay beads. The assay monitors the activity of the translocase (MraY), the transferase (MurG), the lipid pyrophosphorylase, and the transglycosylase and transpeptidase activities of the penicillin-binding proteins. Vancomyin, tunicamycin, nisin, moenomycin, bacitracin, and penicillin inhibit the assay, and these inhibitors have been used to validate the assay. The search for new antimicrobial agents that act via the late stages of peptidoglycan biosynthesis can now be performed in high throughput in a microtiter plate.
Diversity of Tn
1546
Elements in Clinical Isolates of Glycopeptide-Resistant Enterococci from Scottish Hospitals
Authors: Brown A. R. , Townsley A. C. , Amyes S. G. B. 
Published: July 2002

ABSTRACT

The Tn
1546
-related elements of 48 Van glycopetide-resistant enterococci were compared. Ten distinct Tn
1546
types were identified with variation primarily due to IS
1542
and IS
1216V
-like insertions. Clonal isolates frequently differed in their Tn
1546
type, indicating instability of Tn
1546
-related elements. A putative hybrid promoter was identified, generated upstream of
vanR
by the insertion of IS
1542
. The presence of this hybrid promoter was associated with constitutive expression of the
van
genes and elevated teicoplanin resistance.
Salmonella Excretion after Cessation of Tosufloxacin Therapy in Acute Nontyphoid Salmonella Enterocolitis
Authors: Ohnishi Kenji , Kimura Kyoko 
Published: July 2002

ABSTRACT
Symptomatic nontyphoid salmonella enterocolitis patients were treated with tosufloxacin (TFLX) at oral doses of 150 mg three times a day for 5 to 7 days, but bacterial relapse without symptoms occurred in 85% of the patients within 15 days after the cessation of therapy. Our study indicates that TFLX may not be an ideal drug against symptomatic salmonella enterocolitis from a bacteriological point of view.
Azasordarins: Susceptibility of Fluconazole-Susceptible and Fluconazole-Resistant Clinical Isolates of
Candida
spp. to GW 471558
Authors: Cuenca-Estrella Manuel , Mellado Emilia , Dı́az-Guerra Teresa M. , Monzón Araceli , Rodrı́guez-Tudela Juan L. 
Published: July 2002

ABSTRACT

The in vitro activity of the azasordarin GW 471558 was compared with those of amphotericin B, flucytosine, itraconazole, and ketoconazole against 177 clinical isolates of
Candida
spp. GW 471558 showed potent activity against
Candida albicans
,
Candida glabrata
, and
Candida tropicalis
, even against isolates with decreased susceptibility to azoles.
Candida krusei, Candida parapsilosis, Candida lusitaniae,
and
Candida guilliermondii
are resistant to GW 471558 in vitro (MICs, >128 μg/ml).
Prevalence of Macrolide Resistance Genes in Clinical Isolates of the
Streptococcus anginosus
(“
S. milleri
”) Group
Authors: Jacobs Jan A. , van Baar Gilles J. , London Nancy H. H. J. , Tjhie Jeroen H. T. , Schouls Leo M. , Stobberingh Ellen E. 
Published: July 2002

ABSTRACT

Twenty-two unrelated erythromycin-resistant anginosus group strains (3.2% resistance rate) were assessed for mechanisms of resistance.
Streptococcus anginosus
accounted for 16 of the 22 isolates. Fifteen isolates harbored the
erm
(B) gene. The
erm
(TR) and the
mef
(E) genes were carried by two isolates each. In three isolates, none of these resistance genes was detected by PCR.
Interactions of Quinupristin-Dalfopristin with Eight Other Antibiotics as Measured by Time-Kill Studies with 10 Strains of
Staphylococcus aureus
for Which Quinupristin-Dalfopristin Alone Was Not Bactericidal
Authors: Fuchs Peter C. , Barry Arthur L. , Brown Steven D. 
Published: July 2002

ABSTRACT

Quinupristin-dalfopristin (Q-D) and eight other antimicrobial agents were tested alone and in combination with Q-D in time-kill studies against 10 strains of macrolide-lincosamide-streptogramin B-resistant
Staphylococcus aureus
. Although Q-D is normally a bactericidal drug, it was only bacteriostatic for these isolates. Gentamicin alone was bactericidal against 7 of the 10 strains, and Q-D did not alter that killing effect. However, when vancomycin, cefepime, ceftazidime, imipenem, piperacillin-tazobactam, and ciprofloxacin were bactericidal when tested alone, the killing rates were reduced when combined with Q-D. The clinical significance of this in vitro antagonism is unknown at this time, and more studies are needed.
In Vitro Activities of BMS-284756 against
Chlamydia trachomatis
and Recent Clinical Isolates of
Chlamydia pneumoniae
Authors: Malay Sheila , Roblin Patricia M. , Reznik Tamara , Kutlin Andrei , Hammerschlag Margaret R. 
Published: July 2002

ABSTRACT

The in vitro activities of BMS-284756 (a novel des-fluoroquinolone), levofloxacin, moxifloxacin, and clarithromycin were tested against 5 strains of
Chlamydia trachomatis
and 20 isolates of
Chlamydia pneumoniae
. The MIC at which 90% of the isolates were inhibited and the minimal bactericidal concentration at which 90% of the isolates were killed by BMS-284756 for all isolates of
C. pneumoniae
and
C. trachomatis
was 0.015 μg/ml (range, 0.015 to 0.03 μg/ml). BMS-284756 was the most active quinolone tested.
In Vitro Antibacterial Activities of DQ-113, a Potent Quinolone, against Clinical Isolates
Authors: Tanaka Mayumi , Yamazaki Emi , Chiba Megumi , Yoshihara Kiyomi , Akasaka Takaaki , Takemura Makoto , Sato Kenichi 
Published: July 2002

ABSTRACT

The antibacterial activity of DQ-113, formerly D61-1113, was compared with those of antibacterial agents currently available. MICs at which 90% of the isolates tested are inhibited (MIC
90
s) of DQ-113 against clinical isolates of methicillin-susceptible and -resistant
Staphylococcus aureus
and methicillin-susceptible and -resistant coagulase-negative staphylococci were 0.03, 0.008, 0.03, and 0.06 μg/ml, respectively. Moreover, DQ-113 showed the most potent activity against ofloxacin-resistant and methicillin-resistant
S. aureus
, with a MIC
90
of 0.25μg/ml. DQ-113 inhibited the growth of all strains of
Streptococcus pneumoniae
, including penicillin-resistant strains, and
Streptococcus pyogenes
at 0.06 μg/ml, and DQ-113 was more active than the other quinolones tested against
Enterococcus faecalis
and
Enterococcus faecium
with MIC90s of 0.25 and 2 μg/ml, respectively. Against vancomycin-resistant enterococci, DQ-113 showed the highest activity among the reference compounds, with a MIC range from 0.25 to 2 μg/ml. DQ-113 also showed a potent activity against
Haemophilus influenzae
, including ampicillin-resistant strains (MIC90, 0.015 μg/ml), and
Moraxella catarrhalis
(MIC90, 0.03 μg/ml). The activity of DQ-113 was roughly comparable to that of levofloxacin against all species of
Enterobacteriaceae
. The MICs of DQ-113 against ofloxacin-susceptible
Pseudomonas aeruginosa
ranged from 0.25 to 2 μg/ml, which were four times higher than those of ciprofloxacin. From these results, DQ-113 showed the most potent activity against gram-positive pathogens among antibacterial agents tested.
Effects of Compounds Found in Propolis onStreptococcus mutansGrowth and on Glucosyltransferase Activity
Authors: Koo Hyun , Rosalen Pedro L. , Cury Jaime A. , Park Yong K. , Bowen William H. 
Published: July 2002

ABSTRACTPropolis, a resinous bee product, has been shown to inhibit the growth of oral microorganisms and the activity of bacterium-derived glucosyltransferases (GTFs). Several compounds, mainly polyphenolics, have been identified in this natural product. The present study evaluated the effects of distinct chemical groups found in propolis on the activity of GTF enzymes in solution and on the surface of saliva-coated hydroxyapatite (sHA) beads. Thirty compounds, including flavonoids, cinnamic acid derivatives, and terpenoids, were tested for the ability to inhibit GTFs B, C, and D fromStreptococcus mutansand GTF fromS. sanguinis(GTF Ss). Flavones and flavonols were potent inhibitors of GTF activity in solution; lesser effects were noted on insolubilized enzymes. Apigenin, a 4′,5,7-trihydroxyflavone, was the most effective inhibitor of GTFs, both in solution (90.5 to 95% inhibition at a concentration of 135 μg/ml) and on the surface of sHA beads (30 to 60% at 135 μg/ml). Antibacterial activity was determined by using MICs, minimum bactericidal concentrations (MBCs), and time-kill studies. Flavanones and some dihydroflavonols, as well as the sesquiterpenett-farnesol, inhibited the growth ofS. mutansandS. sobrinus;tt-farnesol was the most effective antibacterial compound (MICs of 14 to 28 μg/ml and MBCs of 56 to 112 μg/ml).tt-Farnesol (56 to 112 μg/ml) produced a 3-log-fold reduction in the bacterial population after 4 h of incubation. Cinnamic acid derivatives had negligible biological activities. Several of the compounds identified in propolis inhibit GTF activities and bacterial growth. Apigenin is a novel and potent inhibitor of GTF activity, andtt-farnesol was found to be an effective antibacterial agent.
Outbreak of Infections Caused by
Enterobacter cloacae
Producing the Integron-Associated β-Lactamase IBC-1 in a Neonatal Intensive Care Unit of a Greek Hospital
Authors: Kartali Georgia , Tzelepi Eva , Pournaras Spyros , Kontopoulou Constantina , Kontos Fanourios , Sofianou Danai , Maniatis Antonios N. , Tsakris Athanassios 
Published: July 2002

ABSTRACT

Nineteen of 27 ceftazidime-resistant
Enterobacter cloacae
isolates from a neonatal intensive care unit in Thessaloniki, Greece, had genes coding for the novel extended-spectrum β-lactamase IBC-1; 18 of those 19 harbored similar conjugative plasmids and belonged to two distinct genetic lineages. A synergy test with ceftazidime and imipenem enabled us to identify five unrelated
bla
IBC-1
-carrying
E. cloacae
isolates from other wards of the hospital. It seems that this integron-associated gene is capable of dispersing both by clonal spread and by gene dissemination.
High Prevalence of High-Level Ciprofloxacin Resistance in
Neisseria gonorrhoeae
in Tel Aviv, Israel: Correlation with Response to Therapy
Authors: Dan Michael , Poch Francesca , Sheinberg Bracha 
Published: July 2002

ABSTRACT

A survey of the drug susceptibilities of gonococcal isolates from 100 consecutive patients attending clinics in the Tel Aviv area of Israel during the period from February to September 2000 has shown a 61% rate of ciprofloxacin resistance (MICs, ≥1 μg/ml); 51 isolates were highly resistant (MICs, ≥4 μg/ml). Ciprofloxacin-resistant strains were more prevalent among isolates with chromosomally mediated resistance to penicillin and tetracycline. Therapeutic failures with ciprofloxacin correlated with MICs of ≥1 mg/ml (
P
< 0.01). The high rate of ciprofloxacin resistance coinciding with a sharp rise in the incidence of gonorrhea precludes the use of fluoroquinolone drugs for the empirical treatment of gonococcal infections acquired in Israel.
Phylogeny of All Recognized Species of Ammonia Oxidizers Based on Comparative 16S rRNA and
amoA
Sequence Analysis: Implications for Molecular Diversity Surveys
Authors: Purkhold Ulrike , Pommerening-Röser Andreas , Juretschko Stefan , Schmid Markus C. , Koops Hans-Peter , Wagner Michael 
Published: July 2002

ABSTRACT

The current perception of evolutionary relationships and the natural diversity of ammonia-oxidizing bacteria (AOB) is mainly based on comparative sequence analyses of their genes encoding the 16S rRNA and the active site polypeptide of the ammonia monooxygenase (AmoA). However, only partial 16S rRNA sequences are available for many AOB species and most AOB have not yet been analyzed on the
amoA
level. In this study, the 16S rDNA sequence data of 10
Nitrosomonas
species and
Nitrosococcus mobilis
were completed. Furthermore, previously unavailable 16S rRNA sequences were determined for three
Nitrosomonas
sp. isolates and for the gamma-subclass proteobacterium
Nitrosococcus halophilus
. These data were used to revaluate the specificities of published oligonucleotide primers and probes for AOB. In addition, partial
amoA
sequences of 17 AOB, including the above-mentioned 15 AOB, were obtained. Comparative phylogenetic analyses suggested similar but not identical evolutionary relationships of AOB by using 16S rRNA and AmoA as marker molecules, respectively. The presented 16S rRNA and
amoA
and AmoA sequence data from all recognized AOB species significantly extend the currently used molecular classification schemes for AOB and now provide a more robust phylogenetic framework for molecular diversity inventories of AOB. For 16S rRNA-independent evaluation of AOB species-level diversity in environmental samples,
amoA
and AmoA sequence similarity threshold values were determined which can be used to tentatively identify novel species based on cloned
amoA
sequences. Subsequently, 122
amoA
sequences were obtained from 11 nitrifying wastewater treatment plants. Phylogenetic analyses of the molecular isolates showed that in all but two plants only nitrosomonads could be detected. Although several of the obtained
amoA
sequences were only relatively distantly related to known AOB, none of these sequences unequivocally suggested the existence of previously unrecognized species in the wastewater treatment environments examined.