Virulence factors, Serotypes and Antimicrobial Suspectibility Pattern of Escherichia coli in Urinary Tract Infections

Purpose: To study the virulence factors, serotypes of uropathogenic Escherichia coli (UPEC) and antimicrobial suspectibility pattern. Methods: A total of 200 Escherichia coli from symptomatic cases of urinary tract infections and 50 stool samples from apparently healthy individuals were included. UPEC were screened for virulence factors namely haemolysin, mannose resistant, mannose sensitive haemagglutination (MRHA, MSHA) and serum resistance by recommended methods. Antimicrobial susceptibility testing done by Kirby Bauer disc diffusion method as per NCCLS guidelines. Results: Among 200 Escherichia coli 42(21%) were haemolytic, 60(30%) showed MRHA and 72(36%) MSHA, 99(49.5%) were serum resistant. In 50 controls 8(16%) were haemolytic, 2(4%) showed MRHA and 4(8%) MSHA, 16(32%) were serum resistant. The difference between cases and controls for MRHA and serum resistance were significant (p<0.001 and p<0.05) respectively. Majority of uropathogenic Escherichia coli belonged to serotype O20, O131, O25 and O101.Most 85%92% of the isolates were sensitive to Nitrofurantoin and Amikacin. Majority 70%-80% of the isolates were resistant to routinely used antibiotics.Conclusion: The present study revealed that 160(80%) Escherichia coli uroisolates exhibited one or the other virulence factors. Serotype O20 was isolated with maximum frequency followed by O131, O25 and O101 respectively.