Study on occurrence and antibiogram pattern of Escherichia coli from raw milk samples in Anand, Gujarat, India

Aim: The study was carried out with aim to isolate Escherichia coli from raw milk samples and determine antibiogram pattern of E. coli isolates. Materials and Methods: During 6 months duration of study a total of 100 raw milk samples were collected from different places in and around Anand city such as individual household, cattle farms, milk collection centres of Co-operative milk dairies and milk vendors. All raw milk samples were enriched in peptone water and inoculated on selective media and various biochemical tests were performed for confirmation of isolates. Antibiogram pattern of E.coli to antimicrobial agents was evaluated by disk diffusion method. E. coli isolates were sent to National Salmonella and Escherichia Centre, Central Research Institute, Kasauli, Himachal Pradesh for serotyping. Results: The result of present study revealed that out of 100 samples, 38 samples were found contaminated with E.coli. Antibiogram pattern revealed high resistance against ampicillin (100 %), whereas moderate resistance was observed for streptomycin (57.89 %), oxytetracycline (47.37 %) and amoxy-clav (42.11 %). Also lesser percentage of resistance was observed for co-trimoxazole (13.16 %) and chloramphenicol (5.26 %). Serotypes detected were O24 (7 isolates), followed by O36 (1 isolate), O89 (1 isolate), O91 (1 isolate) and O153(1 isolate). Conclusions: Results suggested a possibility of potential public health threat of E.coli originating from raw milk sources. [Vet World 2012; 5(9.000): 556-559