Resistance to the expanded-spectrum cephalosporins has become a worldwide problem. Such resistance occurs primarily in members of the family Enterobacteriaceae via the production of extendedspectrum β-lactamases (ESBLs), which are capable of hydrolyzing the oxyimino-cephalosporins and monobactams (Bush et al., 2001; Pitout et al., 2004). It has recently been shown that the CTX-M β-lactamases ar...

Background Extended spectrum beta-lactamases (ESBLs) are enzymes produced by some gram negative bacilli that mediate resistance to extended-spectrum cephalosporins and aztreonam. ESBLs are commonly recognized in a variety of Enterobacteriaceae and Pseudomonas aeruginosa isolates. This study focused on the prevalence of ESBL producing strains from diabetes patients and their antimicrobial correl...

Extended spectrum beta-lactamases (ESBLs) confer resistance to clinically relevant antibiotics. Often, the resistance genes are carried by conjugative plasmids which are responsible for dissemination. Five IncI1 plasmids carrying ESBLs from commensal and clinical Escherichia coli isolates were completely sequenced and annotated along with a non-ESBL carrying IncI1 plasmid.

Extended-spectrum β-lactamases (ESBL) producing bacteria have been increasingly reported in both hospital and community patients. Production of ESBLs is the major mechanism of resistance to oxymino-cephalosporins and aztreonam in Gram-negative bacteria. Recently a new family of ESBLs with predominant activity against cefotaxime (CTX-M β-lactamases) has been reported. Over 80 CTX-M enzymes have ...

This study was performed to assess the prevalence and genotypes of plasmid-borne extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases in Escherichia coli in Korea. A total of 576 isolates of E. coli was collected from 12 Korean hospitals during May and July 2007. A phenotypic confirmatory test detected ESBLs in 82 (14.2 %) of the 576 E. coli isolates. The most common types of ESBL...

To determine the prevalence and genotypes of extended-spectrum beta-lactamases (ESBLs) among clinical isolates of Klebsiella pneumoniae and Escherichia coli, we performed antibiotic susceptibility testing, pI determination, induction testing, transconjugation, and DNA sequencing analysis. Among the 509 isolates collected from 13 university hospitals in Korea, 39.2% produced ESBLs. ESBL-producin...

Respiratory isolates of Klebsiella pneumoniae in Korea during 2002-2003 were studied to determine the prevalence and types of extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated AmpC beta-lactamases (PABLs). ESBL-production was tested by double-disk synergy, and genotypes of beta-lactamases were determined by PCR and sequencing. ESBLs were detected in 28.4% of 373 isolates, and the m...

Many clinical laboratories have problems detecting extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated AmpC beta-lactamases. Confusion exists about the importance of these resistance mechanisms, optimal test methods, and appropriate reporting conventions. Failure to detect these enzymes has contributed to their uncontrolled spread and sometimes to therapeutic failures. Although Natio...

Three hundred sixty Enterobacteriaceae and nonfermenting gram-negative bacilli, isolated during one week in May 2004 at five hospitals in Amsterdam, The Netherlands, were evaluated for the presence of extended-spectrum beta-lactamases (ESBLs). A prevalence of 7.8% was found, in contrast to the 1% observed in 1997. CTX-M ESBLs dominated, and four types were identified in 18 isolates.