Objective To investigate the survival of Escherichia coli O157: H7 in eight kinds of food.
Methods Eight kinds of food were collected and contaminated by the bacterial suspension of EHEC O157: H7 933 strain, the count of contaminated bacteria was 7 log 10 cfu/ml·g. Then the survival of E.coli O157: H7 was observed experimentally at certain temperature(4, 25℃).
Results E.coli O157: H7 lived longer(> 70 days)in animal food than other food. The trend of bacterial survival number rose firstly and then dropped. The bacteria both proliferated 1-2 log 10 cfu/ml·g at two kinds of temperature and decreased logarithmically after reaching the peak. The bacterial count was still 3-6 log 10 cfu/ml·g after 42 days. The bacteria lived comparatively short(2-5 days in orange juice, 10-27 days in lactic drink).The bacterial count rapidly decreased to 0 when it cut down on 4 log 10 cfu/ml·g.E. coli O157: H7 was found intermittently in both the strawberry jam and the apple jam.
Conclusion E.coli O157: H7 had strong survival in ordinary food. The major measure to prevent and control its infection was to strengthen the sanitary administration of food, especially animal food, and beverage.