ceftazidime and Escherichia-coli-Infections

Extended-spectrum AmpC beta-lactamase (ESAC) Escherichia coli producers were investigated over a 5-year period. Eleven isolates presenting a strong ampC promoter and different strategic AmpC mutations, including two newly described modifications (A292V and an L-A-A insertion at 295), were characterized. All the isolates belonged to phylogenetic group A and to the ST23 complex.

Topics: Bacterial Proteins; beta-Lactam Resistance; beta-Lactamases; Cefepime; Cefotaxime; Ceftazidime; Cephalosporins; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; France; Hospitalization; Humans; Molecular Sequence Data; Mutation; Phylogeny; Promoter Regions, Genetic

All of the carbapenem-resistant Escherichia coli (CREC) isolates identified in our hospital from 2005 to 2008 (n = 10) were studied. CREC isolates were multidrug resistant, all carried bla(KPC-2), and six of them were also extended-spectrum beta-lactamase producers. Pulsed-field gel electrophoresis indicated six genetic clones; within the same clone, similar transferable bla(KPC-2)-containing plasmids were found whereas plasmids differed between clones. Tn4401 elements were identified in all of these plasmids.

Topics: Academic Medical Centers; Bacterial Proteins; Base Sequence; beta-Lactamases; Carbapenems; DNA Primers; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Humans; In Vitro Techniques; Israel; Microbial Sensitivity Tests; Molecular Epidemiology; Plasmids; Time Factors

From 2002 to 2008, there was a significant increase in extended-spectrum beta-lactamase (ESBL)-positive Escherichia coli isolates in European intra-abdominal infections, from 4.3% in 2002 to 11.8% in 2008 (P < 0.001), but not for ESBL-positive Klebsiella pneumoniae isolates (16.4% to 17.9% [P > 0.05]). Hospital-associated isolates were more common than community-associated isolates, at 14.0% versus 6.5%, respectively, for E. coli (P < 0.001) and 20.9% versus 5.3%, respectively, for K. pneumoniae (P < 0.01). Carbapenems were consistently the most active drugs tested.

Topics: Abdomen; Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Cross Infection; Escherichia coli; Escherichia coli Infections; Humans; Klebsiella Infections; Klebsiella pneumoniae

Topics: Anti-Bacterial Agents; beta-Lactamases; Cefoxitin; Escherichia coli; Escherichia coli Infections; Humans; Microbial Sensitivity Tests; Molecular Sequence Data; New Zealand; Plasmids

A combination of phenotypic and genotypic methods was used to investigate 70 unique Escherichia coli clinical isolates identified as producing extended-spectrum beta-lactamases (ESBLs) at a medical center in Pittsburgh, PA, between 2007 and 2008. Fifty-seven isolates (81%) produced CTX-M-type ESBLs, among which CTX-M-15 was predominant (n = 46). Isolates producing CTX-M-2, -9, -14, and -65 were also identified. One CTX-M-producing isolate coproduced CMY-2 cephalosporinase. Ten isolates (14%) produced SHV-type ESBLs, either SHV-5 or SHV-7. Two isolates produced only CMY-2 or -32. Pulsed-field gel electrophoresis revealed the presence of two major clusters of CTX-M-15-producing E. coli isolates, one in phylotype B2 (n = 15) and the other in phylotype A (n = 19). Of four phylotype B2 isolates that were able to transfer the bla(CTX-M-15)-carrying plasmids, three showed fingerprints related (>60%) to those of plasmids from phylotype A isolates. In phylotype B2, all CTX-M-15-producing isolates, as well as three isolates producing CTX-M-14, two producing SHV-5, and one producing SHV-7, belonged to the international epidemic clone defined by serotype O25:H4 and sequence type 131. The plasmids from eight of nine CTX-M-15-producing E. coli isolates of phylotype A that were examined were highly related to each other and were also found in two isolates belonging to phylotype D, suggesting horizontal transfer of this bla(CTX-M-15)-carrying plasmid between phylotypes. Our findings underscore the need to further investigate the epidemiology and virulence of CTX-M-producing E. coli in the United States.

Topics: beta-Lactamases; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Gene Transfer, Horizontal; Humans; Microbial Sensitivity Tests; Plasmids

Seven hundred fifty-one Escherichia coli clinical isolates collected from 140 Japanese hospitals between 2002 and 2006 were screened for the qepA and qnr genes. Two E. coli isolates (0.3%) harbored qepA, but no qnr was identified. The results suggested a low prevalence of E. coli harboring qepA or qnr in Japan.

Topics: Anti-Bacterial Agents; Conjugation, Genetic; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fluoroquinolones; Hospitals; Humans; Japan; Microbial Sensitivity Tests; Plasmids; Prevalence

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae have rapidly spread worldwide and pose a serious threat for health care-associated (HA) infection. We conducted molecular detection and characterization of ESBL-related bla genes, including bla(TEM), bla(SHV), bla(CTX-M), bla(VEB), bla(OXA), bla(PER), and bla(GES), among 362 isolates of ESBL-producing E. coli (n = 235) and ESBL-producing K. pneumoniae (n = 127) collected from patients who met the definition of HA infection at two major university hospitals in Thailand from December 2004 to May 2005. The prevalence of ESBL-producing E. coli and ESBL-producing K. pneumoniae, patient demographics and the susceptibilities of these bacteria to various antimicrobial agents were described. A total of 87.3% of isolates carried several bla genes. The prevalence of bla(CTX-M) was strikingly high: 99.6% for ESBL-producing E. coli (CTX-M-14, -15, -27, -40, and -55) and 99.2% for ESBL-producing K. pneumoniae (CTX-M-3, -14, -15, -27, and -55). ISEcp1 was found in the upstream region of bla(CTX-M) in most isolates. Up to 77.0% and 71.7% of ESBL-producing E. coli and ESBL-producing K. pneumoniae, respectively, carried bla(TEM); all of them encoded TEM-1. ESBL-producing K. pneumoniae carried bla(SHV) at 87.4% (SHV-1, -2a, -11, -12, -27, -71, and -75) but only at 3.8% for ESBL-producing E. coli (SHV-11 and -12). bla genes encoding VEB-1 and OXA-10 were found in both ESBL-producing E. coli (8.5% and 8.1%, respectively) and ESBL-producing K. pneumoniae (10.2% and 11.8%, respectively). None of the isolates were positive for bla(PER) and bla(GES). Pulsed-field gel electrophoresis analysis demonstrated that there was no major clonal relationship among these ESBL producers. This is the first study to report CTX-M-3, CTX-M-27, CTX-M-40, SHV-27, SHV-71, and SHV-75 in Thailand and to show that CTX-M ESBL is highly endemic in the country.

Topics: Adult; Bacterial Proteins; beta-Lactamases; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Endemic Diseases; Escherichia coli; Escherichia coli Infections; Female; Humans; Klebsiella Infections; Klebsiella pneumoniae; Male; Middle Aged; Polymerase Chain Reaction; Sequence Analysis, DNA; Thailand

Two clinical strains of Escherichia coli (2138) and Enterobacter cloacae (7506) isolated from the same patient in France and showing resistance to extended-spectrum cephalosporins and low susceptibility to imipenem were investigated. Both strains harbored the plasmid-contained bla(TEM-1) and bla(KPC-2) genes. bla(KLUC-2), encoding a mutant of the chromosomal beta-lactamase of Kluyvera cryocrescens, was also identified at a plasmid location in E. cloacae 7506, suggesting the ISEcp1-assisted escape of bla(KLUC) from the chromosome. Determination of the KPC-2 structure at 1.6 A revealed that the binding site was occupied by the C-terminal (C-ter) residues coming from a symmetric KPC-2 monomer, with the ultimate C-ter Glu interacting with Ser130, Lys234, Thr235, and Thr237 in the active site. This mode of binding can be paralleled to the inhibition of the TEM-1 beta-lactamase by the inhibitory protein BLIP. Determination of the 1.23-A structure of a KPC-2 mutant in which the five C-ter residues were deleted revealed that the catalytic site was filled by a citrate molecule. Structure analysis and docking simulations with cefotaxime and imipenem provided further insights into the molecular basis of the extremely broad spectrum of KPC-2, which behaves as a cefotaximase with significant activity against carbapenems. In particular, residues 104, 105, 132, and 167 draw a binding cavity capable of accommodating both the aminothiazole moiety of cefotaxime and the 6 alpha-hydroxyethyl group of imipenem, with the binding of the former drug being also favored by a significant degree of freedom at the level of the loop at positions 96 to 105 and by an enlargement of the binding site at the end of strand beta 3.

Topics: Aged; Base Sequence; beta-Lactam Resistance; beta-Lactamases; beta-Lactams; Catalytic Domain; Cephalosporin Resistance; Crystallography, X-Ray; DNA Primers; DNA, Bacterial; Enterobacter cloacae; Enterobacteriaceae Infections; Escherichia coli; Escherichia coli Infections; France; Genes, Bacterial; Humans; Imipenem; Kinetics; Male; Models, Molecular; Mutation

One hundred twenty-one extended-spectrum beta-lactamse-producing enterobacterial clinical isolates were screened for the qepA gene. A single CTX-M-15-positive Escherichia coli isolate (0.8%) that produced the putative pump QepA2 was identified. This qepA2 gene was located onto a 90-kb mobilizable plasmid that conferred reduced susceptibility to hydrophilic fluoroquinolones.

Topics: Aged; Base Sequence; DNA Primers; DNA, Bacterial; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Fluoroquinolones; France; Genes, Bacterial; Humans; Models, Genetic; Molecular Sequence Data; Plasmids

beta-Lactamases produced by urine isolates from patients in long-term care facilities (LTCFs), outpatient, clinics, and one hospital in a U.S. community were characterized. A total of 1.3% of all Escherichia coli and Klebsiella pneumoniae isolates collected from patients in 30 LTCFs and various outpatient clinics produced extended-spectrum beta-lactamases (ESBLs) and/or imported AmpC beta-lactamases.

Topics: Bacterial Proteins; beta-Lactamases; Community-Acquired Infections; Disease Reservoirs; Escherichia coli; Escherichia coli Infections; Humans; Klebsiella Infections; Klebsiella pneumoniae; Population Surveillance; United States

Among 144 ciprofloxacin-resistant Escherichia coli isolated in Brazil, one (0.69%) QnrA1-producing isolate was detected. The qnrA1 gene was associated with ISCR1. The QnrA1 determinant was carried on a 41-kb conjugative plasmid, which also carried a FOX-type cephalosporinase encoding gene and a class 1 integron with the aadB and catB3 cassettes. This is the first report of a qnrA-carrying isolate in a Latin American country.

Topics: Anti-Bacterial Agents; Ciprofloxacin; Conjugation, Genetic; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Integrons; Latin America; Molecular Sequence Data; Plasmids

Of the 181 unduplicated Escherichia coli strains isolated in nine different hospitals in three Portuguese regions, 119 were extended-spectrum beta-lactamase (ESBL)-CTX-M producers and were selected for phenotype and genotype characterization. CTX-M producer strains were prevalent among community-acquired infections (56%), urinary tract infections (76%), and patients >/=60 years old (76%). In MIC tests, all strains were resistant to cefotaxime, 92% were resistant to ceftazidime, 93% were resistant to quinolones, 89% were resistant to aminoglycoside, and 26% were resistant to trimethoprim-sulfamethoxazole; all strains were sensitive to carbapenems, and 92% of the strains had a multidrug resistance phenotype. Molecular methods identified 109 isolates harboring a bla(CTX-M-15) gene, 1 harboring the bla(CTX-M-32) gene (first identification in the country), and 9 harboring the bla(CTX-M-14) gene. All isolates presented the ISEcp1 element upstream from the bla(CTX-M) genes; one presented the IS903 element (downstream of bla(CTX-M-14) gene), and none had the IS26 element; 85% carried bla(TEM-1B), and 84% also carried a bla(OXA-30). Genetic relatedness analysis based on pulsed-field gel electrophoresis defined five clusters and indicated that 76% of all isolates (from cluster IV) corresponded to a single epidemic strain. Of the 47 strains from one hospital, 41 belonged to cluster IV and were disseminated in three main wards. CTX-M-producing E. coli strains are currently a problem in Portugal, with CTX-M-15 particularly common. This study suggests that the horizontal transfer of bla(CTX-M) genes, mediated by plasmids and/or mobile elements, contributes to the dissemination of CTX-M enzymes to community and hospital environments. The use of extended-spectrum cephalosporins, quinolones, and aminoglycosides is compromised, leaving carbapenems as the therapeutic option for severe infections caused by ESBL producers.

Topics: Aged; Anti-Bacterial Agents; beta-Lactamases; Community-Acquired Infections; Cross Infection; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Middle Aged; Portugal

Topics: Aged, 80 and over; Anti-Bacterial Agents; beta-Lactamases; Conjugation, Genetic; Escherichia coli; Escherichia coli Infections; Humans; Male; Microbial Sensitivity Tests; Plasmids; Recombination, Genetic

This work identifies an ISCR1-related bla(CTX-M-14) gene, which has never been reported before, from a clinical isolate of Escherichia coli. The bla(CTX-M-14) gene was preceded by an ISCR1 element that was followed by a class 1 integron containing three different insert gene cassettes, i.e., dfrA12, orfF, and aadA2.

Topics: Adult; Anti-Bacterial Agents; Base Sequence; beta-Lactamases; DNA Transposable Elements; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Integrons; Male; Microbial Sensitivity Tests; Molecular Sequence Data; Pneumonia, Bacterial; Sequence Analysis, DNA