Effect of consumption of fermented milk with Lactobacillus Casei and Lactobacillus Plantarum isolated from Ligvan Cheese against E. Coli O157:H7 Induced Infections in BALB/C Mice

In the recent years, association of E. coli O157:H7 with hemorrhagic Colitis has been reported and this strain is known as causative agent of bloody diarrhea and predominant cause of hemolytic uremic syndrome (HUS). The aim of present study was to assess prevention role of fermented milk on E. coli O157:H7 infection which prepared by adding isolated L. plantarum (MLp) and L. casei (MlLc) from local Ligvan cheese either with only one probiotic or combined form of them (MLpc). In this study, 40 male mice (BALB/c strain) with an average of 6-8 weeks old were categorized in 4 groups. During a week, 1 (MLp), 2 (MLc), and 3 (MLpc) test groups were prescribed daily by 0.5 ml milk that were fermented by one of probiotic, the last group, was control group with normal nutrition. All of groups were fed by Escherichia coli O157:H7 equal 0.5 McFarland standards by using gavages, after 24 h from last treatments. The stool samples were taken from all of the group in days 1, 3, 5, and 7 in order to assess the excretion rate of Escherichia coli O157:H7. Five mice from each group were autopsied in 3rd and 7th day for evaluation of the colonization rate. So, 5cm of large intestine of mice were cut and serial dilutions of stool samples were prepared and cultured in Sorbitol Mac Conkey agar. White colonies (Sorbitol negative) in Sorbitol Mac Conkey agar were counted. Based on the statistical tests, there were significant difference (P<0.05) between test groups. The results of present study were shown that the consumption of fermented milk by probiotics could reduce significantly the exertion and colonization of Escherichia coli O157:H7 in the intestine of the mice. [Hamid Mirzaei, Hamed Shahirfar, Haedeh Mobaiyen. Effect of consumption of fermented milk with Lactobacillus Casei and Lactobacillus Plantarum isolated from Ligvan Cheese against E. Coli O157:H7 Induced Infections in BALB/C Mice. Life Sci J 2012;9(4):5895-5898] (ISSN:1097-8135). http://www.lifesciencesite.com. 882