Antimicrobial resistance in relation to virulence determinants and phylogenetic background among uropathogenic Escherichia coli in Lebanon. (c2007)

Abstract

Escherichia coli is the most common causative agent of recurrent, uncomplicated urinary tract infections. Screening of antimicrobial resistance among urinary tract pathogens is very crucial and useful for proper empirical treatment. The aim of this study was to assess how resistance to antimicrobial agents relates to virulence potential and phylogenetic background of clinical E. coli isolates in Lebanon. Triplex PCR assays and the disc diffusion method were used to determine and correlate E. coli phylogenetic group, three virulence-associated genes and antimicrobial resistance among 100 uropathogens collected from two major hospitals in Lebanon. Group 132 represented 58% of the tested isolates, followed and in equal proportions by group A and D, while none of tl1e isolates belonged to group 131. Isolates witl1 highest percentage of susceptibility to all used antimicrobial agents were within 132 phylogenetic group, whereas resistant isolates mainly exhibited shifts to non-B2 groups. The majority of the isolates resistant to SXT were from g1•0Up B2 (52.7°1<1) and 45% of t11em were posi6ve for the three tested virulence determinant genes (eftt, fop and picU) encoded by the PAT IT CFf073. However, ciprofloxacin resistance mainly occurred in t11e low-virulence E. coli group A (41.4%resistant). 'TI1ese findings suggest that virulence and antimicrobial resistance are not always mutually exclusive in E. coli clinical isolates. The relationship between virulence and antimicrobial varies according to the particular resistance phenotype.