Relationship of biofilm formation with csg, afa, kpsMT II and fyuA virulence genes in uropathogenic Escherichia coli isolates from southwestern Iran

Introduction and Objectives: Urinary tract infection (UTI), an inflammatory disease occurs to a high multiplication of pathogenic microbes in the urinary system. Escherichia coli (E. coli) are the most frequent cause of UTI. The virulence factors responsible for pathogenesis outside of the gastrointestinal tract belong to various functional groups. The formation of biofilm one is pathogenic mechanism, allowing E. coli to persist in the genitourinary tract and hindering the eradication of microorganisms. Biofilms are group of microorganisms which are embedded within a self-produced matrix of extracellular polymeric substance which adhere to each other. This study was conducted to analysis the relationship of virulence genes with biofilm forming E. coli isolated from patients with suspected UTI Collected from the medical diagnostic laboratories of Yasuj city in southwestern Iran. Materials and Methods: A total of 130 E. coli isolates isolated from patients with UTI were collected and characterized by routine bacteriological methods. Biofilm detection by Congo red agar (CRA) and Microtitre plate method (MTP) and and the presence of csg, afa, kpsMT II and fyuA virulence genes was examined by polymerase chain reaction (PCR) assay. Data analysis was performed using SPSS 16.0 software. Results: From 130 isolates of E. coli isolated from UTIs, the biofilm formation rate by MTP and CRA was 75.38% and 86.92%, respectively. About 28.46% (37 of 130) of the isolates harbor afa gene. csgA gene was found in 100% (130) isolate, fyuA was found in 85.38% (111 isolate) and kpsMT II genes were found in 84.61% (110) isolate. In this study, the frequency of virulence genes csg, fyuA, kpsMT II and afa in isolates that were able to produce strong biofilms were 100%, 78.6%, 85.7% and 14.3%, respectively, in isolates with moderate biofilms of 100%, 93.5 %, 90.3% and 22.6%, respectively, and isolated in weak biofilms were 100%, 86.8%, 84.9% and 34%, respectively. There is no significant relationship between the presence of fyuA, kpsMT II and afa virulence genes with biofilm formation. (P<0.307, P<0.609, P<0.421). Conclusion: PCR molecular method was more reliable for the detection of biofilm forming UPEC as compared to phenotypic methods MCRA and MTP methods. The results of this study show the importance of virulence genes in the isolates of the biofilm producing uropathogenic E. coli. All the positive biofilm producer strains could be expressed in the csg gene. The results also indicate a high prevalence of virulence genes of csg, fyuA and kpsMT II among uropathogenic E. coli (UPEC) isolates from patients with UTI in Yasuj, southwest of Iran. There was no statistically significant correlation between presences of virulance genes with biofilm formation.

کلیدواژه ها:

Antibiotic resistance ، Biofilm ، Virulence ، genes ، Uropathogenic ، E. coli ، Urinary Tract Infection