Effect of some probiotics on Salmonella paratyphi during associated growth in milk
Subject Areas : Veterinary Clinical Pathology
حمید Mirzaei
1
(Associate Professor Department of Food Hygiene, Faculty of Veterinary Medicine, Islamic Azad University- Tabriz Branch, Tabriz,)
افشین Javadi
2
(Associate Professor Department of Food Hygiene, Faculty of Veterinary Medicine, Islamic Azad University- Tabriz Branch, Tabriz,)
یوسف Angouri
3
(Graduate of Veterinary Medicine, Faculty of Veterinary Medicine, Islamic Azad University- Tabriz Branch, Tabriz, Iran)
Keywords: Milk, probiotics, Salmonella paratyphi, associated growth,
Abstract :
The aim of this study is to determine the effects of Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium angulatom and Bifidobacterium bifidum on salmonella paratyphi in associated condition in milk. At first a quantity of 1.5 × 108 cfu/ml activated S. paratyphi was added to 500 ml of sterile milk and after homogenization distributed equally in five erlene meyers. The first erlene meyer was considered as individual culture and in to the second, third, fourth and fifth erlene meyer a quantity of 1.5×108 cfu/ml of the above probiotic was inoculated respectively and after 24-48 hours of incubation at 37 oC, pH was measured by pH meter and S. paratyphi count was determined by pour plate method in SSA medium. This procedure was repeated 10 times and the mean of pH and number of S. paratyphi in one ml of individual culture and with probiotic cultures was compared using statistical analysis. According to statistical tests of ANOVA and Tukey at α=0.05, in 24 and 48 hour incubation of associated growth of L. acidophilus, L. casei and B. bifidum had significant inhibitory effect on S. paratyphi growth (p<0.01). However, in similar condition associated growth of L. angulatum did not show significant inhibitory effect on S. paratyphi growth. Meanwhile, in 24 and 48 hour incubation of associated growth of L. acidophilus, L. casei and B. bifidum reduced the mean of pH of milk samples compared to control sample significantly (p<0.01). These results show the consumption of probiotic products containing B. angulatom, B. bifidum, L. acidophilus and L. casei could have beneficial effects in prevention of Salmonella paratyphi infection. Although further research especially at in vivo condition in this aspect should be carried out.