The molecular-genetic characteristics of uropathogenic Escherichia coli isolated from pregnant women with asymptomatic bacteriuria

Abstract

Introduction. Uropathogenic Escherichia coli (UPEC) are the dominant bacterial pathogens of urinary tract infections (UTIs). UPEC belong to different phylogenetic groups and have many virulence factors, the study of which, in conjuction with the assessment of their relationship with clinical forms of UTI, is necessary for a better understanding of the pathogenesis of UTI and the development of new diagnostic algorithms. Aim: determination of the molecular genetic characteristics of uropathogenic Escherichia coli isolated from pregnant women with asymptomatic bacteriuria. Materials and methods. Clinical isolates of uropathogenic E. coli (n = 70) from pregnant women with asymptomatic bacteriuria were included in the study. The PCR method was used to determine the belonging to phylogenetic groups and detect 15 virulence markers — genes associated with adhesion (fimH, papC, sfa, afa, focG); toxin synthesis (cnf 1, hlyA, sat, vat, usp); siderophores (fyuA, iroN, iuc); capsular antigen (kpsMII). To assess the statistical significance of differences, Fisher's exact test was used. Differences were considered statistically significant at a confidence interval of 95% (p 0.05). Results. Most of the UPEC isolates belonged to phylogroup B2 (51,4%) and were characterized by the detection of all UPEC-associated virulence factors included in this study; genes associated with adhesion (sfa, focG), invasins (ibeA), synthesis of toxins (hlyA, cnf1, vat, usp) and capsule (kpsMII), siderophores (fyuA, iroN, hlyA) were detected significantly more frequently (p 0.05). Two or more virulence determinants were detected in 93% of isolates. Conclusion. The identification of key determinants of virulence and/or a combination of virulence genes can be a prognostic marker for predicting the course of UTI, especially in pregnant women, and will expand diagnostic capabilities taking into account the virulent properties of the uropathogen.

Keywords

• urinary tract infections
• asymptomatic bacteriuria
• uropathogenic escherichia coli
• phylogenetic characteristics
• virulence factors