Sir, In Gram-negative bacteria, extended-spectrum b-lactamases (ESBLs) are widespread enzymes conferring resistance to most b-lactams, including third-generation cephalosporins but with the exception of carbapenems and cephamycins. In animals, the blaCTX-M-1 gene is one of the most frequently reported ESBL-encoding genes; in contrast, in humans the blaCTX-M-15 gene is highly prevalent. Plasmids...

Enterobacteriaceae-associated blaCTX-M genes have become globally widespread within the past 30 years. Among isolates from Washington State cattle, Escherichia coli strains carrying blaCTX-M (CTX-M E. coli strains) were absent from a set of 2008 isolates but present in a set of isolates from 2011. On 30 Washington State dairy farms sampled in 2012, CTX-M E. coli prevalence was significantly hig...

To study molecular epidemiology of CTX-M-55-carrying Escherichia coli isolates from urinary tract infections (UTIs) in China. 111 blaCTX-M-55-positive E.coli isolates from UTIs patients in China were studied. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to analyze the homologies among the strains. Conjugation experiments, S1nuclease PFGE and PCR analys...

Sir, CTX-M enzymes include more than 60 variants belonging to five different clusters (CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9 and CTX-M-25) according to their amino acid sequence. In recent years, CTX-M enzymes have become the most prevalent extended-spectrum b-lactamases (ESBLs), both in nosocomial and in community settings. Different genetic elements might be involved in the mobilization of blaCT...

OBJECTIVES blaCTX-M and blaPER are two genes that encode class A extended-spectrum β-lactamases (ESBLs) and can be responsible for therapeutic problems. This study was carried out to evaluate the molecular properties of these genes in clinical isolates of Enterobacteriaceae by polymerase chain reaction (PCR), restriction digestion and sequencing. MATERIALS AND METHODS During six months, start...

OBJECTIVE To investigate CTX-M genotypes among extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) isolated from patients with community-onset and hospital-onset infections in China, their clonality and the distribution of CTX-M variants in different specimens of community-onset and hospital-onset infections. METHODS ESBL-EC isolates were collected from general hospitals from 2...

objective(s):blactx-mand blaper are two genes that encode class a extended-spectrum β-lactamases (esbls) and can be responsible for therapeutic problems. this study was carried out to evaluate the molecular properties of these genes in clinical isolates of enterobacteriaceae by polymerase chain reaction (pcr), restriction digestion and sequencing. materials and methods: during six months, start...

The Escherichia coli sequence type (ST) 131 C2/H30Rx clade with the blaCTX-M-15 gene had been most responsible for the global dissemination of extended-spectrum β-lactamase (ESBL)-producing E. coli. ST131 C1/H30R with blaCTX-M-27 emerged among ESBL-producing E. coli in Japan during the late 2000s. To investigate the possible expansion of a single clade, we performed whole-genome sequencing for ...

This is the first report regarding the detection of blaCTX-M genes encoding CTX-M-1, CTX-M-15, and CTX-M-2 cefotaximases in clinical isolates of enterobacteria collected in hospitals in Bogotá, Colombia. During a period of 4 months in 2005, 117 isolates of enterobacteria having extended spectrum beta-lactamase (ESBL) phenotype were collected from nine third-level hospitals in Bogotá, Colombia. ...