Evaluating etiological significance of Enterococcus faecalis isolated from children with urinary tract infection

Aim. To conduct comprehensive evaluation of microbiological properties of Enterococcus faecalis, isolated from urine in children with urinary system infections (UTI), to determine their etiological significance.Materials and methods. The study employed clinical isolates E. faecalis (n = 51) from the urine of children aged 3 days to 17 years who were treated for urinary tract infection between 2013 and 2017. The biological properties of enterococci were evaluated by means of classical microbiological and up-to-date molecular genetic methods. Statistical processing of digital data was carried out using non-parametric methods.Results. Phenotypic and genetic heterogeneity of microbiological properties of the studied urinary enterococci isolates was revealed. Using statistical methods of analysis, the authors established significant correlations between pathogenicity genes, antibiotic resistance and phenotypic manifestations of biological properties in urinary isolates E. faecalis. The results of evaluating the phenotypic manifestations of biological properties and the presence of certain genes enabled the enterococci to be classified into groups that correlated with certain sequence types (ST). Based on the revealed relationships of some biological properties of urinary isolates E. faecalis with certain sequence types, the authors developed an algorithm for assessing etiologically significant and highly virulent E. faecalis isolated from the urine of children with UTI.Conclusions. A comprehensive determination of some, potentially relevant biological properties, of the pathogen – enzymatic activity associated with pathogenicity and biochemical activities, antibiotic resistance (not only at the phenotypic, but also at the genetic level) – allows for assessing the diagnostic value of urostams E. faecalis, isolated from the urine of children with UTI, which will contribute to a personalized approach to treatment of these patients.