Evaluation of contamination rate of pasteurized milk with Escherichia coli in different seasons in Myaneh City

Milk is one of the main sources which can be contaminated with microbial agents. Escherichia coli is one of the most important indicators of the food microbial examinations. In this study, the contamination of pasteurized milk with E. coli during different seasons in Myaneh city is investigated. A total of 96 pasteurized milk samples were collected by cluster random sampling method in 2010. E. coli was found in 19 samples (19.79%) including 3 samples in spring, 8 samples in summer, 4 samples in autumn and 4 samples in winter of the total 24 examined samples caught in each season were contaminated. According the results, the contamination rate of pasteurized milk in summer is more than other seasons which may be due to the higher temperature in this season and also mesophilic nature of E. coli.