IDENTIFICATION OF UROVIRULENT MARKERS IN UROPATHOGENIC ESCHERICHIA COLI

Context: Escherichia coli is the most frequent urinary pathogen isolated from uncomplicated urinary tract infection. These isolates express chromosomally encoded virulence markers. Aims: The present study was designed to determine the urovirulence factors of E.coli isolated from the patients of urinary tract infection and to study their antimicrobial susceptibility pattern. Methods and Material: The study was conducted in the department of microbiology, Rangaraya Medical College, Kakinada, Andhra Pradesh, from October 2010 to September 2011.One hundred and fifty E.coli strains isolated from urine samples and fifty faecal isolates were studied for 1) alpha haemolysin on 5% sheep blood agar, 2) mannose resistant haemagglutination,3) cell surface hydrophobicity,4) antibiotic susceptibility testing by Kirby-Bauyer's disc diffusion method. Results: Among 150 E.coli isolates from urine tested 82 (54%) and out of 50 E.coli isolates from stool (control), 10 (20%) were positive for virulence markers. In the urinary isolates, the most common virulent marker was Haemolysin 59 (39%), followed by Mannose Resistant Haemagglutination (MRHA) 47(31%) and Cell Surface Hydrophobicity (CSH) 43 (28%). In control group, the occurrence of Haemolysin was 3 (6%), MRHA 6 (12%), CSH 9(18%). The difference between cases and controls for Haemolysin and MRHA were significant. (p