The Effect of Bifidobacterium Angulatum Fermented Milk on Escherichia Coli O157:H7 Infection in Mice

E. coli O157:H7 strain is known cause of bloody diarrhea and haemolytic uremic syndrome (HUS). The aim of this study was to determine the effect of milk fermentation by Bifidobacterium angulatum as a probiotic on infection induced by E. coli O157:H7 in mice. In this study 45 female mice, 6-8 weeks age were randomly divided into 5 groups, each containing 9 mice. Control group (A), Infected group (B), non-infected group feeded by probiotic (C), pre-infected group feeded by probiotic (D) and post-infected group feeded by probiotic (E). Each of the mouse in groups (B, D) and (E) received 1.5×108 CFU of E. coli O157: H7 by intra gastric tube. Group (C) feeded with 0.5 ml of B. angulatum fermented milk daily for 14 days, group (D) and group (E) were feeded with 0.5ml of B. angulatum fermented milk daily for 7 days before and after infection respectively. Stools of the mice were examed for E. coli O157:H7 before getting infected and on days 3, 5, 7 and 9 after getting infected. For identification of E. coli O157:H7 we used MacConkey sorbitol agar medium. Specific antiserum also was used for more confirmation. Alive E. coli O157:H7 was not isolated in control group (A), and non-infected group feeded with the probiotic (C). Statistical analysis showed significant differences between groups B (11.53±2.81) ×105 and D (2.67±0.56) ×105 cfug-1 (P<0.01) and B (11.53±2.81) ×105 and E (1.47±0.57) × 105 cfug-1 (P<0.01). Consumption of milk fermented by B. Angulatum shortens the duration of E. coli O157:H7 and reduces the severity of the illness.