Molecular characterization of multidrug-resistant (MDR) Pseudomonas aeruginosa isolated in a burn center

Burns. 2017 Feb;43(1):137-143. doi: 10.1016/j.burns.2016.07.002. Epub 2016 Aug 29.

Abstract

Objective: The aim of this study was to characterize molecularly multidrug-resistant (MDR) Pseudomonas aeruginosa isolates collected from burn center (BC) patients and environment in a hospital localized in Rio de Janeiro city, RJ, Brazil.

Methods: Thirty-five P. aeruginosa isolates were studied. The antimicrobial resistance was tested by disk diffusion method as recommended by CLSI. The assessment of virulence (exoS and exoU) and resistance (blaPER-1, blaCTX-M, blaOXA-10, blaGES-1, blaVIM, blaIMP, blaSPM-1, blaKPC, blaNDM and blaSIM) genes were achieved through PCR and biofilm forming capacity was determined using a microtiter plates based-assay, as described previously. Genotyping was performed using Multilocus sequence typing (MLST).

Results: High rate of P. aeruginosa (71.4%; 25/35) were classified as MDR, of them 64% (16/25) were related to clone A, the most prevalent clone found in the BC studied. A total of eight carbapenems resistant isolates were detected; three belonging to clone A and five carrying the exoU virulence gene. In addition, clone A isolates were also biofilm producers. Two new sequence types (ST) were detected in this study: ST2236, grouped in to clone A; and ST2237, classified in the different clones, displaying carbapenem resistance and exoU virulence gene.

Conclusion: The high prevalence of biofilm producers and multiresistant P. aeruginosa isolates in BC indicates that prevention programs need to be implemented to avoid infection in highly susceptible patients.

Keywords: Biofilm; Carbapenem resistant; Multidrug resistant; Pseudomonas aeruginosa; Wound burn.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins
  • Biofilms
  • Brazil
  • Burn Units
  • Burns / microbiology*
  • Carbapenems
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Genotype
  • Humans
  • Microbial Sensitivity Tests
  • Multilocus Sequence Typing
  • Polymerase Chain Reaction
  • Pseudomonas Infections / microbiology*
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / growth & development
  • beta-Lactam Resistance / genetics*
  • beta-Lactamases / genetics*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Carbapenems
  • pseudomonas exoprotein A protein, Pseudomonas aeruginosa
  • GES-1 beta-lactamase
  • beta-lactamase OXA-10
  • beta-lactamase PER-1
  • beta-lactamase SPM-1, Pseudomonas aeruginosa
  • beta-Lactamases