5. Conclusions

Furthermore, connection between sensitivity to antimicrobial drugs of E. faecalis and its biological properties was identified. It was found that uropathogenic enterococci characterized with proteolytic activity are resistant to antibacterial agents with different action mechanisms. In the work, it was found that E. faecalis, resistant to linezolid and chloramphenicol drugs that suppress protein synthesis at the level of the 50S subunit of the bacterial ribosome, possess a

Interesting data were obtained with regard to the sensitivity of uropathogenic E. faecalis to the reserve drug linezolid, recommended for treatment of infections caused by strains, which are resistant to vancomycin, aminoglycosides, and betalactams. In Primorsky Krai, E. faecalis cultures were found resistant and intermediate sensitivity to linezolid. However, in Russia in the period from 2005 to 2013, there were isolated single enterococcal strains with reduced sensi-

This way, the mentioned variability of biochemical and fermentation activity of factors related to pathogenicity demonstrated phenotypic heterogeneity of enterococci and might have a

Pathogenicity factors of bacteria are genetically determined by properties which are localized in genome of microorganisms in the form of "pathogenicity islands" [17]. These genetic elements can contain various sets of virulence genes, which are important for the development of the enterococcal infectious process, including genes of antibiotics resistance [17, 24]. At the present stage, the association of antibiotic resistance of E. faecalis with pathogenic factors is actively studied. It is known that strains of enterococci resistant to ampicillin, ciprofloxacin, and gentamicin, but sensitive to vancomycin and nitrofurantoin have more pathogenicity factors (hemolysin, gelatinase, hyaluronidase, form biofilms) than vancomycin resistant [2, 28]. E. faecalis having the asa1 gene are more resistant to fluoroquinolones (norfloxacin, ciprofloxacin, and levofloxacin) than isolates lacking this gene. Resistance to ciprofloxacin is significantly higher in E. faecalis having the genes cylL and cylS than in strains with their absence [23, 28]. esp gene-positive E. faecalis are more resistant to doxycycline than esp gene-negative cultures [3]. Among the strains

with multidrug resistance, a high prevalence of genes asa1 and esp was observed [23, 36].

proves their involvement in certain stages of the infectious process.

physiologic mechanism of infectious and inflammatory diseases.

The research implemented using PCR method enabled to characterize in greater detail the structure of E. faecalis population isolated from children with UTI from Primorsky region. In our research, significant variability in occurrence frequency of the studied genes was found. Two of them—efaA (coding the surface antigen A (EfaA), which initiates the infectious process) and eep (coding Eep protein, which conduces to formation of a biofilm, making it resistant to various biological stress factors) were found in all studied uropathogenic E. faecalis, which

MLST analysis conducted earlier revealed eight sequence types, five of which were character-

This way, clinically significant E. faecalis strains have a complex of virulent properties, which allow the bacteria to materialize their pathogenic potential on all stages of the inflammation process in urinary system. This makes further research of the listed factors in clinical E. faecalis necessary to estimate objectively the contribution of these properties of the agent into patho-

high pathogenic potential. These results require further research in this direction.

94 Microbiology of Urinary Tract Infections - Microbial Agents and Predisposing Factors

tivity to linezolid.

certain diagnostic significance.

ized by multidrug resistant.

