GENETIC DIVERSITY OF ENTEROCOCCUS FAECALIS ISOLATES FROM CHILDREN WITH URINARY TRACT INFECTION IN PRIMORSKY KRAI OF RUSSIA

Abstract

Background: Escherichia coli is the most common cause of urinary tract infections (UTI). However, Enterococcus faecalis has been shown to be the most common causative agent of UTI among children and newborns in Primorsky Krai of Russia warranting further research. Aim: To study the occurrence of pathogenicity factor genes in the E. faecalis isolates from children with UTI in the Primorsky Krai of the Russian Far East. Methods: Forty-two E. faecalis clinical isolates from children under the age of 16 with UTI identified in 2013-2017 were studied. Phylogenetic diversity of the strains was assessed by the ultilocus sequence typing. Six genes, namely, cylA, aggA, efaA, eep, gelE, esp were tested in the isolates by polymerase chain reaction . Results: CylA, aggA, efaA, eep, gelE and esp genes occurred in 50.0 %, 80.95 %, 100 %, 100 %, 76.2 % and 71.4 % of the isolates, respectively. Eleven different gene variants were detected for the combination of pathogenicity factor genes. The most common gene variants were (aggA, cylA, efaA, eep, gelE, esp) and (aggA, efaA, eep, gelE). Among the uropathogenic E. faecalis. Fourteen sequence-types were identified (ST6, ST16, ST21, ST25, ST40, ST41, ST64, ST116, ST133, ST151, ST179, ST480, ST537, ST774), with ST179, ST774, ST6 being the most common. Conclusions: The identified diversity of sequence-types indicates the genetic heterogeneity of uropathogenic enterococci isolated in the Primorsky Krai. The detection of a large amount of pathogenicity factors and their combinations causes the predominance of E. faecalis in the region as a clinically relevant etiological agent of UTI among children. The identification of highly virulent sequence types such as E. faecalis ST6, ST179 and ST774 warrants further research to determine the population structure of enterococci.