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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Microbiol. | doi: 10.3389/fmicb.2019.01669

Molecular epidemiology of multidrug-resistant Klebsiella pneumoniae isolates in a Brazilian tertiary hospital

  • 1Federal University of Paraná, Brazil
  • 2Instituto de Pesquisa Pelé Pequeno Príncipe, Brazil
  • 3Institute of Biomedical Sciences, University of São Paulo, Brazil
  • 4Hospital Universitário Professor Polydoro Ernani de São Thiago, Brazil
  • 5Universidade Estadual do Norte Fluminense Darcy Ribeiro, Brazil

Multidrug-resistant (MDR) Klebsiella pneumoniae (Kp) is a major bacterial pathogen responsible for hospital outbreaks worldwide, mainly via the spread of high-risk clones and epidemic resistance plasmids. In this study, we evaluated the molecular epidemiology and β-lactam resistance mechanisms of MDR-Kp strains isolated in a Brazilian academic care hospital. We used whole-genome sequencing to study drug resistance mechanisms and their relationships with a Klebsiella pneumoniae carbapenemase-producing (KPC) Kp outbreak. Forty-three Kp strains were collected between 2003 and 2012. Antimicrobial susceptibility testing was performed for 15 antimicrobial agents, and polymerase chain reaction (PCR) was used to detect 32 resistance genes. Mutations in ompk35, ompk36, and ompk37 were evaluated by PCR and DNA sequencing. Pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were carried out to differentiate the strains. Based on distinct epidemiological periods, six Kp strains were subjected to whole-genome sequencing. β-lactamase coding genes were widely distributed among isolates. Almost all isolates had mutations in porin genes, particularly ompk35. The presence of blaKPC promoted a very high increase in carbapenem minimum inhibitory concentration only when ompk35 and ompk36 were interrupted by insertion sequences. A major cluster was identified by PFGE analysis and all isolates from this cluster belonged to clonal group (CG) 258. We have also identified a large repertoire of resistance genes in the sequenced isolates. A blaKPC-2-bearing plasmid (pUFPRA2) was also identified, which was very similar to a plasmid previously described in the first Brazilian KPC-Kp (2005). We found high-risk clones (CG258) and an epidemic resistance plasmid throughout the duration of the study (2003 to 2012), emphasizing a persistent presence of MDR-Kp strains in the hospital setting. Finally, we found that horizontal transfer of resistance genes between clones may have played a key role in the evolution of the outbreak.

Keywords: Brazil, Klebsiella pneumoniae, Molecular Epidemiology, Multidrug resistance (MDR) bacteria, clonal group 258, Whole-genome sequencing (WGS)

Received: 03 Jul 2018; Accepted: 08 Jul 2019.

Edited by:

Gilberto Igrejas, University of Trás-os-Montes and Alto Douro, Portugal

Reviewed by:

Hong-Yu OU, Shanghai Jiao Tong University, China
Alberto Antonelli, University of Florence, Italy
Lalitagauri Deshpande, JMI Laboratories, United States  

Copyright: © 2019 Palmeiro, De Souza, Schörner, Araujo, Grazziotin, Vidal, Venancio and Dalla Costa. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
PhD. Jussara K. Palmeiro, Federal University of Paraná, Curitiba, Brazil, jukasuko@gmail.com
Prof. Thiago M. Venancio, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Brazil, thiago.venancio@gmail.com
PhD. Libera M. Dalla Costa, Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil, lmdallacosta@gmail.com