Altered chicken cecal microbial communities affect Salmonella colonization

Altering the diets of chicken and other poultry shows promise as a mean for controlling and preventing Salmonellosis. However, it is not known whether alteration of the gut microbiota from changes in diet in turn changes the colonization of Salmonella. The current study describes an investigation of the effects of medium composition on chicken cecal microbiota and subsequent colonization of Salmonella in vitro. Both batch fermentation and chemostat systems were used to compare the effects on bacterial community by different culture media, which were either rich in starch and peptone (Veal Infusion medium, VI) or rich in simple sugars and hydrolyzed peptide (Viande-Levure medium, VL). Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) and quantitive real-time PCR (qPCR) were used to ascertain that the growth of chicken cecal microbiota in VL medium resulted in a Bacteroides-enriched community that was closer to the initial cecal inoculum. However, VI medium produced a microbiota represented mainly by Lactobacillus and Bifidobacterium. A time-dependent reduction of Salmonella was observed only in VI microbiota and the decrease was correlated with a marked increase in the proportion of Lactobacillus and Bifidobacterium relative to other species. Supernatant from lactic-acid bacteria (LAB) isolates from VI microbiota showed lactic acid-independent bacteriocidal activity on Salmonella. Animal challenge experiment also showed that LAB isolates have the function of decrease S. pullorum colonization in vivo. In summary, our results suggest that in vitro enriched microbiota with probiotic compositions can reduce colonization by Salmonella. [Yin Y, Lei F, Fang D, et al. Altered chicken cecal microbial communities affect Salmonella colonization. Life Sci J 2015;12(2):14-25]. (ISSN:1097-8135). http://www.lifesciencesite.com. 3