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...

1. Bonnet, R. (2003). Growing group of extended-spectrum blactamases: the CTX-M enzymes. Antimicrobial Agents and Chemotherapy 48, 1–14. 2. Mushtaq, S., Woodford, N., Potz, N. et al. (2003). Detection of CTX-M-15 extended-spectrum b-lactamase in the United Kingdom. Journal of Antimicrobial Chemotherapy 52, 528–9. 3. Baraniak, A., Fiett, J., Hryniewicz, W. et al. (2002). Ceftazidimehydrolysing C...

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 ...

OBJECTIVES High levels of β-lactamase production can impact treatment with a β-lactam/β-lactamase inhibitor combination. Goals of this study were to: (i) compare the mRNA and protein levels of CTX-M-15- and CTX-M-14-producing Escherichia coli from 18 different STs and 10 different phylotypes; (ii) evaluate the mRNA half-lives and establish a role for chromosomal- and/or plasmid-encoded factors;...