Presence of virulence factor genes (gelE and esp) and biofilm formation in clinical Enterococcus faecalis and Enterococcus faecium isolated from urinary tract infection in Isfahan, Iran

Abstract

Background: The aim of present study was to determine the prevalence of two major virulence genes (gelE and esp) and biofilm-forming ability in Enterococcus faecalis and E. faecium isolated from patients with urinary tract infections (UTIs), and the correlation of selected virulence factors with biofilm formation. Methods: One hundred Enterococcus isolates were collected from urine of patients with urinary tract infections (UTIs) attending to Alzahra and Gharazi hospitals affiliated to Isfahan University of Medical Sciences. The isolates were confirmed by phenotypic and genotypic methods. Biofilm formation was determined by microtiter plate method and the frequency of gelE and esp genes was evaluated using PCR assay. Results: Of the 100 confirmed isolates, 83 and 17 were E. faecalis and E. faecium respectively. The capacity of biofilm formation was 91.5 and 58.7 in E. faecalis and E. faecium respectively. The prevalence of gel E and esp genes was 81.9 and 79.5 in E. faecalis and 76.5 and 58.8 in E. faecium, respectively. There was a significant correlation between biofilm formation and presence of both virulence genes (P < 0.05). Conclusions: In conclusion, we observed a high frequency of biofilm formation, esp and gelE genes in Enterococcoci strains isolated from UTIs. As an important result was a significant association between the presence of these two genes and biofilm production. Therefore, the new and more effective strategies should be applied to prevent and spread of these strains.