Prevalence of E. Coli in Commonly Consumed Food in and Around Meerut

Abstract

Food borne diseases are a major public health problem in both developed and developing countries in recent years and have caused major economic losses. It has been proved that in industrialized countries almost one third of the population is affected by food borne diseases each year, and the problem in developing countries is probably more. There are several opportunities for microorganisms to contaminate foods, if the food is prepared, processed, handled, and stored under unhygienic conditions. Escherichia coli is a Gram negative, oxidase negative, rod- shaped bacterium from the family Enterobacteriaceae. It is a common bacterium that normally inhabits the intestinal tracts of humans and animals, but can cause infection in other parts of the body, especially the urinary tract. The involvement of E. coli in human illness has been recognized virtually since its discovery in 1885. Therefore, this study is planned out to evaluate the prevalence of pathogenic E. coli in commonly consumed food from the examined samples of foods (milk & milk products, chicken) which were collected from different areas of Modipuram region of Meerut. The samples were inoculated into the enrichment broth and incubated at 37°C in a bacteriological incubator for 24 hrs followed by streaking on MacConkey agar plates and then on EMB agar plates followed by biochemical characterization. Total 27 samples out of 48 samples found to be positive for E. coli infection as they show lactose fermenting colonies on MacConkey agar plates and on TSI slants and metallic green sheen colonies on EMB agar. A series of biochemical test was performed, results of these test confirm the presence of E. coli in the samples. After confirmation of E. coli isolates, seven isolates were serotyped. E. coli serovars found after serotyping were O135, O8 and O11. O8 is Uro-pathogenic E. coli whereas O135 is Entero-invasive E. coli and O11 belongs to Shiga toxin-producing E. coli (STEC) which can cause food borne disease such as hemorrhagic colitis, HUS in humans. Antibiotic sensitivity test of E. coli was performed by Hi-media Octa disc containing Ciprofloxacin (CIP), Ofloxacin (OF), Norfloxacin (NX), etc. Antibiogram shows that there are different zones among all the isolates. All the isolates were found resistant to antibiotic Nitrofurantoin and Co- Trimoxazole. E. coli shows highest degree of sensitivity to antibiotic Levofloxacin.