شناسايي ملكولي و سروتايپينگ O در سويه هاي اشريشيا كلي مولد ورو توكسين در عفونت هاي ادراري در شهر تهران

Molecular Characterization and O- Serotyping in Verocytotoxin- Producing Escherichia coli Isolates from Urinary Tract Infection in Tehran

Background and Objectives: Verocytotoxin-producing: Escherichia coli strains are important human pathogens. Here we studied the prevalence of virulence genes and O stereotyping in strains isolated from urine samples.Materials and Methods: In this study, 300 urine samples from individuals with urinary tract infections E. coli was isolated using enterobacteriase diagnostic kit .The strains were examined with polyvalent and monovalant antiserum for O-serotyping. Verocytotoxin-producing E. coliv strains were characterized by polymerase chain reaction. 0157 groups were distinguished from non 0157 groups by culturing in sorbitol macconkey agar. Rapid Passive Latex Agglutination (RPLA) technique was performed in order to find the expression of vtxl and vtxl genes.Results: From total number of 300 urine samples, 180 samples had positive culture result for E. coli of these, 158 strains had virulence genes and all of them showed a toxic effect after applying Rapid Passive Latex Agglutination technique. Twenty four percent of samples were classified as 0157 group and 76% as non 0157 group. The most prevalent virulence genes were found in 026 strains containing vtxl genes.Conclusion: Our findings showed that non~0157 verocytotoxin-producing E.Coli is more prevalent than 0157 strains in our study.