OBJECTIVES To characterize plasmids encoding extended-spectrum β-lactamases (ESBLs) from a recent UK collection of clinical Escherichia coli isolates. METHODS The isolates comprised 118 ESBL producers referred from 54 laboratories. Plasmids were transferred by electroporation, and their incompatibility groups, associated addiction systems and resistance genes with the flanking genetic environ...

CTX-M-15 type β-lactamase has the ability to hydrolyse cefotaxime, a third generation cephalosporin. The infections caused by multidrug resistant strains, especially CTX-M-15 producing strains are being treated with carbapenem group of β-lactam antibiotics. The objective of the study was to know if cefotaxime in combination with doripenem (carbapemen antibiotic) at very low concentration, inhib...

CTX-M-type beta-lactamases are increasing among US Enterobacteriaceae isolates. Of 2,165 non-Typhi Salmonella isolates submitted in 2007 to the National Antimicrobial Resistance Monitoring System, 100 (4.6%) displayed elevated MICs (≥2 mg/L) of ceftriaxone or ceftiofur. Three isolates (serotypes Typhimurium, Concord, and I 4,5,12:i:-) contained bla(CTX-M-5), bla(CTX-M-15), and bla(CTX-M-55/57),...

INTRODUCTION The aim of this study was to detect the prevalence of the extended-spectrum beta-lactamase (ESBL)-encoding CTX-M gene in Escherichia coliisolates. METHODS Phenotypic screening of 376 E. coli isolates for ESBL was conducted using disk diffusion. ESBL-producing isolates were tested using PCR and specific primers. The bla(CTX-M) cluster was identified using the RFLP method, and its ...

Twelve isolates of Enterobacteriaceae (1 of Klebsiella pneumoniae, 8 of Escherichia coli, 1 of Proteus mirabilis, and 2 of Proteus vulgaris) classified as extended-spectrum beta-lactamase (ESBL) producers according to the ESBL screen flow application of the BD-Phoenix automatic system and for which the cefotaxime MICs were higher than those of ceftazidime were collected between January 2001 and...

OBJECTIVES CTX-M extended-spectrum beta-lactamases (ESBLs) are emerging worldwide. Fast and reliable detection techniques may become mandatory for implementing proper treatment and infection control measures. Here, a bla(CTX-M)-specific LightCycler real-time PCR (LC-PCR) assay based on hybridization probes was developed. METHODS Urine samples positive for Gram-negative bacilli as revealed by ...

CTX-M enzymes, the plasmid-mediated cefotaximases, constitute a rapidly growing family of extended-spectrum β-lactamases (ESBLs) with significant clinical impact. CTX-Ms are found in at least 26 bacterial species, particularly in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. At least 109 members in CTX-M family are identified and can be divided into seven clusters based on thei...

This study determined the phylogenetic groups and virulence factors of 37 Escherichia coli isolates producing types of CTX-M compared with those of 19 isolates producing different types of extended-spectrum beta-lactamases (ESBLs) in a well-defined North American population. Most CTX-M-14 producers (97%) were from phylogenic group D; 67% of the CTX-M-15 producers were from group B2. A single CT...

conclusions the results of this study phenotypically and genotypically confirmed the high frequency of esbl-producing strains, such as the ctx-m and ctx-m-1 genes, among enterobacteriaceae isolates in our region. therefore, use of antibiotic susceptibility testing for the detection of esbl isolates prior to the prescription of beta-lactam antibiotics is recommended. this could help prevent the ...