Abstract

In this investigation, the effects of Lactobacillus acidophilus, Lactobacillus casei,Bifidobacterium angulatom and Bifidobacterium bifidum on Salmonella typhi was evaluated in associated growth condition in milk. According to statistical tests, in 24 and 48 h incubation of associated growth, L. acidophilus, L. casei and B. bifidum had significant inhibitory effect on the growth of S. typhi (p<0.01). But in similar condition, associated growth of B. angulatum did not show significant inhibitory effect on S. typhigrowth. Meanwhile, in 24 and 48 h incubation of associated growth, L. acidophilus, L. casei and B. bifidum significantly reduced (p<0.01) the mean pH of milk samples compared to the control sample. These results demonstrate that the consumption of probiotic products containing B. bifidum, L. acidophilus and L. casei could have benefical effects in prevention of S. typhi caused infections. Though, further research especially at in vivo condition should be carried out in this field.

Key words: Salmonella typhi, probiotics, associated growth, milk.