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. 2009 Apr;53(4):1652-6.
doi: 10.1128/AAC.00822-08. Epub 2009 Jan 21.

Occurrence of efflux mechanism and cephalosporinase variant in a population of Enterobacter aerogenes and Klebsiella pneumoniae isolates producing extended-spectrum beta-lactamases

Que-Tien Tran  1 , Myrielle Dupont, Jean-Philippe Lavigne, Jacqueline Chevalier, Jean-Marie Pagès, Albert Sotto, Anne Davin-Regli
Affiliations

Occurrence of efflux mechanism and cephalosporinase variant in a population of Enterobacter aerogenes and Klebsiella pneumoniae isolates producing extended-spectrum beta-lactamases

Que-Tien Tran et al. Antimicrob Agents Chemother. 2009 Apr.

Abstract

We investigated the occurrence of multidrug resistance in 44 Enterobacter aerogenes and Klebsiella pneumoniae clinical isolates. Efflux was involved in resistance in E. aerogenes isolates more frequently than in K. pneumoniae isolates (100 versus 38% of isolates) and was associated with the expression of phenylalanine arginine beta-naphthylamide-susceptible active efflux. AcrA-TolC overproduction in E. aerogenes isolates was noted. An analysis of four E. aerogenes isolates for which cefepime MICs were high revealed no modification in porin expression but a new specific mutation in the AmpC beta-lactamase.

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Figures

FIG. 1.
FIG. 1.
Effect of the EPI on the intracellular accumulation of [14C]chloramphenicol. The assays were carried out in the presence or absence of CCCP. Values (expressed as counts per minute per unit of optical density [OD]) were obtained from duplicate independent experiments.
FIG. 2.
FIG. 2.
(A and B) Immunodetection of porins (A) and internal loop 3 (B) in E. aerogenes and K. pneumoniae strains. (C and D) Immunoblots of whole-cell extracts with polyclonal antibodies against AcrA (C) or TolC (D). Only the relevant parts of the gels are shown. MW, molecular weight marker; SM, size marker.
See this image and copyright information in PMC

References

    1. Ardanuy, C., J. Linares, M. A. Dominguez, S. Hernandez-Alles, V. J. Benedi, and L. Martinez-Martinez. 1998. Outer membrane profiles of clonally related Klebsiella pneumoniae isolates from clinical samples and activities of cephalosporins and carbapenems. Antimicrob. Agents Chemother. 42:1636-1640. - PMC - PubMed
    1. Barnaud, G., Y. Benzerara, J. Gravisse, L. Raskine, M. J. Sanson-Le Pors, R. Labia, and G. Arlet. 2004. Selection during cefepime treatment of a new cephalosporinase variant with extended-spectrum resistance to cefepime in an Enterobacter aerogenes clinical isolate. Antimicrob. Agents Chemother. 48:1040-1042. - PMC - PubMed
    1. Charrel, R. N., J. M. Pagès, P. De Micco, and M. Malléa. 1996. Prevalence of outer membrane porin alteration in beta-lactam-antibiotic-resistant Enterobacter aerogenes. Antimicrob. Agents Chemother. 40:2854-2858. - PMC - PubMed
    1. Chevalier, C., C. Mulfinger, E. Garnotel, P. Nicolas, A. Davin-Regli, and J.-M. Pagès. 2008. Identification and evolution of drug efflux pump in clinical Enterobacter aerogenes strains isolated in 1995 and 2003. PloS ONE 3:e3203. - PMC - PubMed
    1. Davin-Regli, A., J. M. Bolla, C. E. James, J. P. Lavigne, J. Chevalier, E. Garnotel, A. Molitor, and J.-M. Pagès. 2008. Membrane permeability and regulation of drug “influx and efflux” in enterobacterial pathogens. Curr. Drug Targets 9:750-759. - PubMed

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