background beta-lactam resistance in gram-negative bacteria, especially escherichia coli, is a main clinical problem. it is often caused by the co-production of β-lactamases, particularly extended-spectrum β-lactamases (esbls) and ampc enzymes. it may lead to a problem for diagnosis via recommended phenotypic tests by the clinical and laboratory standards institute (clsi). conversely, β-lactama...

background clinical significance of extended-spectrum beta-lactamases (esbls) production in enterobacter spp. has not well been established. objectives this study was conducted to investigate the prevalence of esbls produced by enterobacter spp. in clinical isolates. materials and methods this descriptive cross-sectional study was performed during may 2010 to april 2012 in the city of sanandaj,...

objective(s) resistance to the new generation of cephalosporins which is mediated by extended-spectrum beta-lactamases (esbls) has been found among escherichia coli isolates throughout the world. these resistance genes and their producers, the micro-organisms carrying beta-lactamases, are responsible for serious clinical and therapeutic problems among inpatients and it is necessary to pay more ...

abstract background: pseudomonas aeruginosa is one of the most common gram negative bacteria involved in nosocomial infections. presence of extended-spectrum beta-lactamases (esbls) genes, play an important role in induction of resistance in beta-lactamase producing species to beta lactam antibiotics. frequency of resistance to these antibiotics is increasing. in this study, antibiotic sensitiv...

conclusions the levels of resistance to ceftazidime were remarkably variable among ctx-mproducers. this study provides further evidences of the global dissemination of ctx-m type esbls and emphasized on the need for their epidemiological monitoring. results in phenotypic confirmatory test, 154 (44%) out of 350 clinical isolates were esbl positive. using molecular assay, 154 strains potentially ...

Beta-lactamase enzymes (BLs) have become the most worrisome mediators of antimicrobial resistance expressed by gram-negative bacteria (GNB). The multiple families of BLs have in common the ability to hydrolyze the -lactam rings of one or more members of the penicillins, cephalosporins, cephamycins, carbapenems, and monobactams. Extended-spectrum -lactamases (ESBLs) are a subset of BLs that conf...