IDENTIFICATION OF VIRULENCE FACTORS AMONG ESBL-PRODUCING ESCHERICHIA COLI CLINICAL ISOLATES FROM GAZA STRIP, PALESTINE

Virulence Genes among ESBL-producing E.coli

Abstract

This study was done to assess the occurrence of virulence factors and correlation of phylogenetic grouping in ESBLs producing E. coli isolates from Palestine.

Twenty-seven ESBLs producing E. coli isolates were collected between April and June 2013 from three hospitals in Gaza. Detection of genes encoding virulence factors, pathogenicity associated island marker (PAI) and phylogenetic groups were studied by PCR. The correlation of E. coli phylogenetic grouping with the virulence factors in the isolates was studied. The clonal relationships between the isolates were tested by pulsed-field gel electrophoresis (PFGE).

Overall, 44.4% of the 27 E. coli isolates belonged to phylogroup B2, 44.4% to D and 11.2% to A. Among the isolates, fimH, traT and fimA were the most frequent virulence genes and were found over 85% of the isolates. PAIs was found in 8 isolates while the tcpC gene was detected in one isolate. The overall prevalence of PAI was higher in group B2 as compared to groups A and D (p<0.043). A clonal diversity was confirmed among our isolates (27 unrelated PFGE profiles). We report for the first time the prevalence of tcpC as a new virulence marker and PAI in clinical ESBLs-producing E. coli in Palestine.

This study indicates that most of the ESBL- positive isolates showed virulence genes and most strains belonged to phylogenetic groups B2 and D. The study suggested that high number of virulence genes in studied strains may be important factors in the infections development.