COMPARATIVE STUDY OF BIOFILM PRODUCING AND NON-PRODUCING Escherichia coli ISOLATED FROM URINE SAMPLES OF PATIENTS VISITING A TERTIARY CARE HOSPITAL OF MORANG, NEPAL

Abstract

Escherichia coli is the normal flora found in the intestines of warm blooded animals including humans and birds. It has been reported that E. coli is responsible for more than 80-85% of UTI cases. Several studies suggest that the prevalence of MDR E. coli is increasing day by day which is a matter of concern for the clinical therapies. The urine sample was inoculated onto the CLED agar and was incubated at 37°C for 24 hours. E. coli colonies were counted. The positive isolates of E. coli were identified by different biochemical tests such as indole test, methyl red test, Voges-Proskauer, citrate utilization test, TSIA, carbohydrate fermentation tests and starch hydrolysis test. This study reported 15% prevalence of E. coli out of 400 urine samples. All isolated strains of E. coli were tested for antibiotic susceptibility testing by using Kirby Bauer disk diffusion method. 100% of E. coli isolates showed resistance to both Ampicillin and Amoxicillin while 100% were sensitive to Chloramphenicol. This analysis also showed 70% (42/60) as MDR E. coli isolates. The maximum isolates (75%) were found to be Biofilm producers. Similarly, microtitre plate method was considered to be the most efficient screening method as compared to tube and congo red agar method. Similarly, resistance to other antibiotics such as Nalidixic acid (71.11% vs 46.66%), Norfloxacin (53.33% vs 46.66%), Cotrimoxazole (42.22% vs 26.66%) was comparatively higher among biofilm producers than non-biofilm producers.There was a significant correlation (P<0.05) between biofilm and MDR. Hence, the antibiotic resistance shown by biofilm producers was comparatively higher than non-biofilm producers.