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...

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...

defined by susceptibility to all of ciprofloxacin, co-trimoxazole and gentamicin) isolates was low (2.9%, 5/175). PCR and sequencing showed that the only extended-spectrum b-lactamase (ESBL)-producing O25b-ST131 isolate had blaCTX-M-14. Our results showed that O25b-ST131 exhibited a wide range of susceptibility patterns. Similar to previous studies, our findings showed that O25b-ST131 isolates ...

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...

OBJECTIVE To investigate the molecular characteristics of extended-spectrum cephalosporin (ESC)-resistant Enterobacteriaceae collected during a cross-sectional study examining the prevalence and risk factors for faecal carriage of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in humans living in areas with high or low broiler density. METHODS ESC-resistant Enterobacteriace...

We constructed a phylogenetic analysis of class A beta-lactamases and found that the blaCTX-Ms have been mobilized to plasmids approximately 10 times more frequently than other class A beta-lactamases. We also found that the blaCTX-Ms are descended from a common ancestor that was incorporated in ancient times into the chromosome of the ancestor of Kluyvera species through horizontal transfer. C...

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...

OBJECTIVES Several studies on faecal carriage of extended-spectrum β-lactamase (ESBL)/AmpC-producing Escherichia coli have been performed in cattle, but little is known about faecal carriage in veal calves. This study describes the prevalence and molecular characteristics of ESBL/AmpC genes in E. coli isolated from faecal samples of veal calves from 1997 to 2010. METHODS Pooled faecal samples...

2 3 Background: A high rate of resistance to 3 rd generation cephalosporins among Enterobacteriaceae 4 isolates from Egypt has been previously reported. This study aims to characterize the resistance 5 mechanism (s) to extended spectrum cephalosporins among resistant clinical isolates at a medical 6 institute in Cairo, Egypt. 7 Methods: Nonconsecutive Klebsiella pneumoniae (Kp), Enterobacter cl...