PLoS ONE (Jan 2017)

Molecular epidemiological survey of bacteremia by multidrug resistant Pseudomonas aeruginosa: the relevance of intrinsic resistance mechanisms.

  • Raquel Cristina Cavalcanti Dantas,
  • Rebecca Tavares E Silva,
  • Melina Lorraine Ferreira,
  • Iara Rossi Gonçalves,
  • Bruna Fuga Araújo,
  • Paola Amaral de Campos,
  • Sabrina Royer,
  • Deivid William da Fonseca Batistão,
  • Paulo Pinto Gontijo-Filho,
  • Rosineide Marques Ribas

DOI
https://doi.org/10.1371/journal.pone.0176774
Journal volume & issue
Vol. 12, no. 5
p. e0176774

Abstract

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The bacterial factors associated with bacteremia by multidrug-resistant and extensively drug-resistant P. aeruginosa, including overexpression of efflux pumps, AmpC overproduction, and loss/alteration of the OprD porin in isolates that are non-Metallo-β-Lactamase producing were analyzed in a retrospective study. Molecular analyses included strain typing by Pulsed Field Gel Electrophoresis and identification of key genes via qualitative and quantitative PCR-based assays. Previous use of carbapenems and tracheostomy was independently associated with the development of bacteremia by extensively drug-resistant and multidrug-resistant strains of P. aeruginosa. A high consumption of antimicrobials was observed, and 75.0% of the isolates contained amplicons with the blaSPM-1 and blaVIM genes. Of the 47 non-Metallo-β-Lactamase isolates, none had another type of carbapenemase. However, the isolates exhibited high rates of hyperproduction of AmpC, loss of the OprD porin (71.4%) and the presence of MexABOprM (57.1%) and MexXY (64.3%). This study suggests that in non-Metallo-β-Lactamase isolates, the association of intrinsic resistance mechanisms could contributes to the expression of multidrug-resistant/extensively drug-resistant phenotypes.