Physiological and molecular characteristics of carbapenem resistance in Klebsiella pneumoniae and Enterobacter aerogenes

  • Rito Santo Pereira Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
  • Vanessa Cordeiro Dias Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
  • Alessandra Barbosa Ferreira-Machado Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
  • Juliana Alves Resende Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
  • André Netto Bastos Cortes Villela Clinical Laboratory, Juiz de Fora, Minas Gerais, Brazil
  • Lucas Quinet Andrade Bastos Cortes Villela Clinical Laboratory, Juiz de Fora, Minas Gerais, Brazil
  • Victor Quinet Andrade Bastos Cortes Villela Clinical Laboratory, Juiz de Fora, Minas Gerais, Brazil
  • Ricardo Villela Bastos Cortes Villela Clinical Laboratory, Juiz de Fora, Minas Gerais, Brazil
  • Vânia Lúcia da Silva Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
  • Cláudio Galuppo Diniz Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
Keywords: Carbapenemases, enterobacteria, antimicrobial resistance, biocide tolerance

Abstract

Introduction: Bacterial resistance is a growing concern in the nosocomial environment in which Klebsiella pneumoniae and Enterobacter aerogenes play an important role due to their opportunism and carbapenemase-production. This work aimed to evaluate physiological and molecular characteristics of carbapenem-resistant K. pneumoniae and E. aerogenes isolated in a Brazilian tertiary hospital.

Methodology: In total, 42 carbapenem-resistant bacteria isolated from clinical specimens were included (21 K. pneumoniae and 21 E. aerogenes). Drug-sensitive K. pneumoniae (n = 27) were also included. Antimicrobial susceptibility and biocide tolerance patterns, hemolytic activity, tolerance to oxidative stress, and aggregative ability were assessed. Genetic markers related to carbapenem resistance, or ESBL-production were screened by PCR.

Results: Compared to drug-sensitive strains, carbapenem-resistant K. pneumoniae were more tolerant to biocides and to oxidative stress, and they displayed an increase in biofilm formation. The genetic markers blaKPC (95.2%) and blaTEM (90.5%) were the most frequent. Among the carbapenem-resistant E. aerogenes strains, blaKPC, and blaTEM were detected in all bacteria. Drug-sensitive E. aerogenes were not isolated in the same period. blaSHV, blaVIM, and blaCTX markers were also observed among carbapenem-resistant bacteria.

Conclusions: Results suggest that carbapenemase-producing enterobacteria might show peculiar characteristics regarding their physiology associated with their environmental persistency, virulence, and multidrug resistance. The observed phenomenon may have implications not only for antimicrobial chemotherapy, but also for the prognosis of infectious diseases and infection control.

Published
2016-06-30
How to Cite
1.
Pereira RS, Dias VC, Ferreira-Machado AB, Resende JA, Bastos AN, Andrade Bastos LQ, Andrade Bastos VQ, Bastos RV, da Silva VL, Diniz CG (2016) Physiological and molecular characteristics of carbapenem resistance in Klebsiella pneumoniae and Enterobacter aerogenes. J Infect Dev Ctries 10:592-599. doi: 10.3855/jidc.6821
Section
Original Articles