Abstract:

Salmonella is one of the most important gastrointestinal pathogens for human and animals. Approximately 70%－80% of bacterial food poisoning cases are caused by Salmonella in China. Therefore, food poisoning caused by Salmonella has become one of the most common and comparatively pernicious bacterial species. The contamination in raw milk from Tianjin and Shanxi regions in China was investigated by determining total bacterial count and coliform bacteria and Salmonella bacteria. The results indicated that the quality of raw milk from different sources in the two regions exhibited a great difference. The average total bacterial counts varied from 104 CFU/mL to 107 CFU/mL. Most of the tested samples could meet the quality standard and few of them were unqualified. However, coliforms bacterial count exhibited tremendous difference among samples from different sources. The quality of raw milk from Shanxi region was better than that from Tianjin region. The coliforms bacterial count was lower than 110 MPN/mL in the samples from Shanxi region. However, The coliforms bacterial count in the samples from Factory A were up to 1100 MPN/mL and from Factory B were no less than 11000 MPN/mL, respectively, although no Salmonella was detected. Therefore, the quality and safety issues of raw milk from the two regions can not be ignored.

Key words: raw milk, microorganism, total bacterial count, coliforms bacteria, Salmonella, contamination