Authors : Mohaddeseh Namjoo, S. Ali Taheri and Fatemeh Taheri
Abstract: Escherichia coli is the most important species in the Escherichia genus. In the recent years, haemorrhagic colitis has been associated with a strain called E. coli O157:H7. This strain is known as causative agent of bloody diarrhea and predominant cause of Haemolytic Uremic Syndrome (HUS). The aim of this study was to determine the effect of milk fermented by Bifidobacterium angulatum as a probiotic on infection induced by E. coli O157:H7 in mice. In this study, 45 mice of 6-8 weeks age were randomly divided into 5 groups, each containing 9 mice. These groups consisted of control group A, infected group B, non-infected group fed by probiotic C, pre-infected group fed by probiotic D and post-infected group fed by probiotic E. Each mouse in groups B, D and E received 1.5x108 cfu mL-1 of E. coli O157:H7 through intra gastric tube (gavage). Group C mice fed with 0.5 mL of B. angulatum fermented milk daily for 14 days, group D mice fed with 0.5 mL of B. angulatum fermented milk daily for 7 days post-infection and group E mice fed as mentioned earlier for 7 days prior to infection. Mice stools were studied for E. coli O157:H7 before getting infected and on days 2, 4 and 7 after infection. MacConkey sorbitol agar was used to identify E. coli O157:H7 and specific antiserum against E. coli O157 was used for confirmation. Alive E. coli O157:H7 was not isolated in mice of control group A and non-infected group fed with the probiotic C. Statistical analysis showed significant differences between group C, B and D (p<0.01). Results showed that consumption of milk fermented by B. angulatum could shorten the duration and reduce the severity of the illness caused by B. angulatum. Further studies are needed on humans.
Mohaddeseh Namjoo, S. Ali Taheri and Fatemeh Taheri, 2012. Fermented Milk by Bifidobacterium angulatum and Infection Induced by Escherichia coli O157:H7 in Mice. Research Journal of Biological Sciences, 7: 285-289.