Pathogenic features of urinary Escherichia coli strains causing asymptomatic bacteriuria during pregnancy

Abstract

Urinary tract infection (UTI) during pregnancy is often correlated with complications. As the main objective of this study, we investigated the prevalence of antimicrobial susceptibility, resistance genes, virulence genes and its relationship with different phylogenetic groups among Uropathogenic E. coli strains isolated from pregnant women with asymptomatic bacteriuria who referred to Hafez hospital, Shiraz, Iran. Our results revealed that among 300 urine samples, 105 (35) were positive for E. coli. The data demonstrated that the highest and the lowest resistance rates were observed against nalidixic acid (82.1), and imipenem (2.8), respectively. The frequency of ESBLs and AmpC-beta-lactamase, in the Uropathogenic E. coli isolates was 41 and 9.5 respectively. blaCTXM was the commonest genotype (93). Phylogenetic group distribution was as follow: B1 2.8, A 14.2, B2 61.9 and D 4.6. Our result showed that most of the virulence genes belonged to group B2 and also several virulence genes such as hlyA, cnf-1 and papGII genes were positively associated with group B2. Among E. coli strains isolated from patients with UTIs, different features phylogroups, with special virulence factors, could cause severe infection. Awareness about the virulence patterns distribution among phylogenetic groups of UPEC could greatly aid in confine and prevent the development of lethal infection caused by these strains.