Molecular characterization and genetic relatedness of clinically XDR Acinetobacter baumannii isolates obtained from Sina hospital, Tabriz, in terms of genes associated with carbapenemase, biofilm, virulence, surface motility and typing by AB-PBRT schemes, 1397

Abstract

Acinetobacter baumannii, by virtue of its heightened expression of virulence factors, aptitude to form biofilm and acquisition of multifactorial antibiotic resistance mechanisms, is increasingly associated with serious infections among hospitalized patients. We assessed AB-PBRT (A. baumannii PCR-based replicon typing) system to investigate the distribution and epidemiology of intrasplasmid (Rep) genes in A. baumannii and elucidated the potential relationship with other traits. Method: Thirty extensive drug-resistance (XDR) A. baumannii were investigated for the presence of genes encoding carbapenemase resistance, biofilm, autoinducer synthase, virulence and surface motility by polymerase chain reaction (PCR). Later, the isolates were typed by AB-PBRT and trilocus sequence typing. Results: All XDR A. baumannii strains displayed genes related to surface motility (Type I fimbriae, PilT), autoinducer synthase (abaI), virulence determinant (omp), and biofilm (bfmSR, csuE, pgaA, and pgaD), except PER and bap genes, the frequency of which was 83.3% and 76.6%, respectively. The trilocus sequence-typing scheme distinguished predominant SG I (European clone II) sequence type. AB-PBRT scheme displayed highest frequency of rep6 and rep2, with frequency of 75% and 65%, respectively.