The prevalence of plasmid-mediated AmpC beta-lactamases among clinical isolates of Klebsiella pneumoniae from four referral hospitals in Kerman, Iran

Introduction and Objectives: AmpC β-lactamases are clinically important cephalosporinases in the Enterobacteriaceae. They mediate resistance to beta-lactam antibiotics such as extended spectrum cephalosporins. In this study, we determined prevalence of plasmid-mediated AmpC beta-lactamases among clinical isolates of Klebsiella pneumoniae from four referral hospitals in Kerman, Iran.Material and methods: A total of 175 Klebsiella pneumoniae isolates were collected from hospitalized patients in hospitals in Kerman from 2015 to 2017. Presence of AmpC-beta-lactamases in cefoxitin resistant isolates confirmed by AmpC disk test method and plasmid-mediated AmpC beta-lactamases genes were detected by multiplex-PCR.Results: In this study, 64(36.6%) isolates of were resistant to cefoxitin. Among cefoxitin-resistant K. pneumoniae isolates 12 isolates (6.8%) were found to be AmpC β-lactamase producers. The prevalence of plasmid-mediated AmpC beta-lactamases genes including blaCMY, blaACC, blaACT and blaFOX was determined in 5 (2.85%), 1 (0.6%), 1 (0.6%) and 2 (1.1%), respectively.Conclusion: Our study has demonstrated the pAmpC β-lactamase-producing K. pneumoniae isolates from four referral hospitals in Kerman were mainly of CMY genotype, and the majorities were insusceptible to cefoxitin. Hence, continuous surveillance of the prevalence and evolution of AmpC beta-lactamase is important.

کلیدواژه ها:

AmpC beta-lactamase ، pAmpC ، Klebsiella pneumonia