Study of uropathogenic escherichia coli with special reference to virulence factors and antibiotic susceptibility pattern in a tertiary care hospital

Escherichia coli is the most common pathogen causing UTI. Various virulence factors play role in pathogenesis of uropathogenic E. coli. The common virulence factors include surface hydrophobicity, colonization factor, capsule, serum resistance, resistance to phagocytosis, hemolysin, enterotoxin, siderophore production, fimbriae and hemagglutination. Multidrug resistance is increasing in E. coli and production of various beta lactamases pose a major problem for clinical therapeutics and contributes to the virulence. Method: In the present study various virulence factors of UPEC like serum resistance, hemolysin, protease (gelatinse) and hemagglutination was detected. Antibiotic susceptibility profile and detection of ESBL, carbapenemase, Metallo-beta-lactamase, AmpC beta lactamase production by phenotypic methods was done. Result: 75 UPEC isolates with significant colony count were included in the study. Hemolysis was seen in 32% of the isolates; Hemagglutination in 40% of the isolates, 24% of the isolates were MSHA and 16% of the isolates were MRHA; 47% of the isolates were showing serum resistance and 13% of the isolates produced gelatinase. 32(43%) of them had more than one virulence factors. Maximum sensitivity was seen with Imipenem (92%), Nitrofurantoin (85%) Amikacin (80%) and least with Ampicillin (2.6%) and Amoxicillin- Clavulanate (6%). 53% of the isolates were ESBL producers, 8% of the isolates produced AmpC beta lactamase. 65% of the isolates having virulence factors were ESBL and/or AmpC beta lactamase producers. None of the isolates were Carbapenamase or MBL positive by phenotypic methods. Conclusion: Presence of virulence factors help in the pathogenesis of E. coli causing UTI. And along with it production of beta lactamases possess major problem in treatment.