Genotypic analysis of plasmid-mediated β-lactamases amongst Enterobacteriaceae other than Escherichia spp. and Klebsiella spp. that are non-susceptible to a broad-spectrum cephalosporin

Abstract

Enterobacteriaceae other than Escherichia spp. and Klebsiella spp. are recognisable for their increasing resistance. Plasmid-mediated β-lactamases, including extended-spectrum β-lactamases (ESBLs), plasmid-mediated AmpC β-lactamases (pAmpCs) and the newly emerged KPC, play an important role in β-lactam resistance. In this study, we investigated the genetic characteristics of plasmid-mediated β-lactamases amongst non-Escherichia, non-Klebsiella Enterobacteriaceae that were non-susceptible to at least a broad-spectrum cephalosporin. A total of 143 (23.9%) of 598 isolates during the 6-month study period met the screening criteria, amongst which 142 (99.3%) and 99 (69.2%) isolates carried ESBL and pAmpC genes, respectively. Resistance genotypes were described. blaKPCwas not detected in isolates with reduced susceptibility to carbapenems. This study provides an insight into plasmid-mediated resistance determinants amongst cephalosporin-non-susceptible Enterobacteriaceae other than Escherichia spp. and Klebsiella spp. © 2010 Elsevier B.V. and the International Society of Chemotherapy.