The study of virulence factor production in escherichia coli causing urinary tract infections

Urinary tract infection is one of the most common cause of bacterial infections and Escherichia coli is the predominant urinary pathogen isolated from community based and hospitalized patients.1,2 Uropathogenic strains of E.coli are consistently associated with UTI exhibiting various virulence factors like serum resistance, cell surface hydrophobicity and hemolysin.2 The treatment has been posing as a challenge due to the emergence of multidrug resistant E .coli especially in nosocomial infections. The present study is undertaken to evaluate association of virulence factors of E. coli in comparison to antimicrobial resistance. Total of 100 E.coli isolates from clinically suspected UTI cases from patients attending Victoria hospital & Vani Vilas hospital attached to BMC & RI, Bangalore were studied from October 2010 to September 2012. Mid stream urine samples were collected after taking informed consent from all patients and were processed. All samples were cultured by semi quantitative method. The identification of E.coli was done using standard biochemical tests. E.coli thus identified were screened for Virulence factors like Serum resistance, Cell surface hydrophobicity and α hemolysin production and studied for the drug resistance patterns. Out of the 100 E.coli isolated from UTI cases 45 isolates were from male and 55 from female. Amongst these isolates 48.3% showed Serum resistance, 39.3% showed Haemolysin production and 24.7% showed cell surface hydrophobicity. The antibiotic sensitivity testing showed maximum sensitivity to Amikacin and least to Ampicillin with 87% and 10% respectively.71% of the isolates were resistant to Cefotaxime. Considering high morbidity in UTI the occurrence of virulence markers in Uropathogenic E.coli (UPEC) strains strengthens the association with pathogenecity. Hence the screening of above mentioned virulence factors can be routinely done in clinical laboratory.