Reduced imipenem susceptibility in Klebsiella pneumoniae clinical isolates with plasmid-mediated CMY-2 and DHA-1 beta-lactamases co-mediated by porin loss

Lee, Kyungwon, Yong, Dongeun, Choi, Yeong Seon, Yum, Jong Hwa, Kim, June Myung, Woodford, Neil, Livermore, David M and Chong, Yunsop (2007) Reduced imipenem susceptibility in Klebsiella pneumoniae clinical isolates with plasmid-mediated CMY-2 and DHA-1 beta-lactamases co-mediated by porin loss. International Journal of Antimicrobial Agents, 29 (2). pp. 201-206. ISSN 1872-7913

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Abstract

We investigated the resistance mechanisms and clonality among 42 imipenem-non-susceptible Klebsiella pneumoniae isolated at a tertiary care hospital in Korea. Two isolates had bla(VIM-2) alleles, whereas bla(CMY-2)- and bla(DHA-1)-like alleles were detected in 24 and 16 isolates, respectively, with these enzymes confirmed by sequencing for representative isolates. Transfer of bla(CMY-2) and bla(DHA-1) was achieved by conjugation. Addition of 300 mg/L 3-aminophenylboronic acid (APB) reduced the minimum inhibitory concentration for 90% of the organisms (MIC(90)) of imipenem and meropenem eight- and four-fold, respectively, for the bla(CMY-2)- and bla(DHA-1)-positive isolates, confirming the role of these enzymes in resistance. SDS-PAGE of outer membrane proteins for representative isolates showed lack or greatly diminished expression of OmpK35 and OmpK36 porins. Pulsed-field gel electrophoresis of XbaI-restricted genomic DNA revealed two closely related clusters among 23 bla(CMY-2)-positive isolates, whereas those with bla(DHA-1) were more heterogeneous. In conclusion, reduced imipenem susceptibility among K. pneumoniae at this Korean hospital was largely co-mediated by production of plasmid-mediated AmpC beta-lactamases along with lack or greatly diminished expression of OmpK35 and OmpK36 porins.

Item Type: Article
Uncontrolled Keywords: anti-bacterial agents,bacterial outer membrane proteins,bacterial proteins,electrophoresis, gel, pulsed-field,electrophoresis, polyacrylamide gel,humans,imipenem,isoelectric focusing,klebsiella pneumoniae,microbial sensitivity tests,plasmids,porins,beta-lactamases
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Related URLs:
Depositing User: Rhiannon Harvey
Date Deposited: 07 Jul 2011 11:24
Last Modified: 21 Apr 2020 19:16
URI: https://ueaeprints.uea.ac.uk/id/eprint/33452
DOI: 10.1016/j.ijantimicag.2006.09.006

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