OBJECTIVES Widespread use of β-lactam antibiotics could cause resistance to this group of antibiotics in pathogenic bacteria through the production of the enzyme β-lactamases. The aim of this study is to determine the molecular detection of AmpC β-lactamases among clinical Escherichia coli isolated from Ilam hospitals in Ilam, Iran. METHODS One hundred and twelve clinical isolates of E. coli ...

BACKGROUND Enterobacteriaceae producing ESBL and AmpC enzymes can be associated with failure of antibiotic therapy and related morbidity and mortality. Their routine detection in microbiology laboratories is still a problem. The aim of this study was to compare the sensitivity of selected phenotypic methods. MATERIAL/METHODS A total of 106 strains of the Enterobacteriaceae family were tested,...

We tested 190 Klebsiella pneumoniae bloodstream isolates recovered from 189 patients in 30 U.S. hospitals in 23 states to determine the occurrence of extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase producers. Based on growth inhibition by clavulanic acid by disk and MIC test methods, 18 (9.5%) of the isolates produced ESBLs. Although the disk diffusion method with standard break...

In this prospective study all Enterobacteriaceae isolates (n = 2,129) recovered in the clinical microbiology laboratory during October 2009 to April 2010 were analyzed for AmpC production. Clinical and Laboratory Standards Institute (CLSI) cefoxitin and cefotetan susceptibility breakpoints and CLSI critical ESBL diameters were used to screen for potential AmpC producers. In total, 305 isolates ...

The aim of the present study was to investigate the resistance of plasmid-mediated AmpC β-lactamase in Pseudomonas aeruginosa, to detect and identify the AmpC genotype and to provide evidence for antibiotic applications in the clinic. Resistance phenotype in 108 strains of clinically isolated P. aeruginosa was determined by Kirby-Bauer disk test and cefoxitin three dimensional test in AmpC-posi...

OBJECTIVES To characterize the vectors involved in the dissemination of bla(CMY-2) genes in clinical isolates of Proteus mirabilis collected between 1999 and 2007. METHODS Plasmid analysis of 19 P. mirabilis carrying ampC genes was performed by PCR-based replicon typing, S1-PFGE and Southern hybridization with ampC and replicon probes. Isolates that could not be characterized were examined fo...

Extended-spectrum cephalosporin-resistant (ESCR) Enterobacteriaceae pose a serious infection control challenge for public health. The emergence of the ESCR phenotype is mostly facilitated by plasmid-mediated horizontal extended-spectrum β-lactamases (ESBLs) and AmpC gene transfer within Enterobacteriaceae. Current data regarding the plasmid contribution to this emergence within the Dutch human ...

There are few studies on the presence of extended-spectrum β-lactamases and AmpC β-lactamases (ESBL/AmpC) in bacteria that contaminate vegetables. The role of the production environment in ESBL/AmpC gene transmission is poorly understood. The occurrence of ESBL/AmpC in Escherichia coli (n = 46) from lettuce and irrigation water and the role of irrigation water in the transmission of resistant E...

background :   ampc β-lactamases are important cephalosporinases chromosomally encoded in many of enterobacteriaceae and a few other organisms where they mediate resistance to cephalothin, cefazolin, cefoxitin and penicillins. the six different families of plasmid-mediated ampc β-lactamases have been described, but no phenotypic test can discriminate among them. ampc multiplex pcr has been succ...