Survival test and haemolysin activity of Escherichia coli in raw fresh and pasteurized milk produced in Negeri Sembilan / Farra Amira Mohamed

Demand for milk has increased in Malaysia due to the increased in awareness of healthy foods consumption. Hence, research of milk is crucial to ensure that it is not contaminated with Escherichia coli. This study evaluated the survival of E. coli at different temperature and haemolysin activity of E. coli on blood agar. A total of 8 samples of raw fresh and pasteurized milk were collected from nearby farm and market in Negeri Sembilan, Malaysia. The bacteriological test of milk was evaluated for the presence of Escherichia coli. Overall, all raw fresh milk exceeded the acceptable limit of bacterial count which is 1 x 105 CFU/ml. Raw fresh milk recorded the highest at 35°C with 4.4 x 107 CFU/ml and the lowest at 0°C with 8.3 x 104 CFU/ml. The presence of E. coli was detected in 7/20(35%) of the raw fresh milk samples. All pasteurized milk showed no presence of E. coli due to the effectiveness of heat treatment. Haemolysin test showed no haemolytic activity. Milk contaminated with E. coli can cause diarrheal, gastrointestinal diseases and urinary infection. Hence, it is important to study the survival rate of E. coli and its pathogenicity in milk to ensure public safety.