ANIMAL INTESTINAL MICROBIOMES, FOODBORNE PATHOGENS, AND ANTIMICROBIALS
Location: Food Safety and Enteric Pathogens Research Unit
Title: Isolation of unique butyrate-producing bacteria from swine
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 22, 2012
Publication Date: May 20, 2012
Citation: Levine, U.Y., Looft, T.P., Allen, H.K., Stanton, T.B. 2012. Isolation of unique butyrate-producing bacteria from swine [abstract]. American Society for Microbiology General Meeting, June 16-19, 2012, San Francisco, California. Paper No. 3143.
Butyrate-producing bacteria in humans contribute to a healthy gastrointestinal tract and are known to be species from clostridial clusters IV, IX, XIVa, and XVI - with the community dominated by clusters XIVa and IV. However, the composition of the butyrate-producing bacterial community in swine is largely unknown. We hypothesize that if similar health benefits are conferred by butyrate producers to swine, then members of this functional group are targets for probiotic or prebiotic applications that may improve animal health. Therefore, in this study we investigated the butyrate-producing bacterial community in swine by isolating and screening 980 anaerobic isolates from swine fecal, tissue, or intestinal content samples for butyrate production (defined by greater than or less than 5mM production). Fifteen isolates were identified as butyrate producers, and full-length 16S rRNA gene sequences placed them within clostridial clusters IV, IX, XI, XIII, and XIVa. Within those clusters the isolates were found to belong to the following genera: Anaerostipes, Eubacterium, Megasphaera, Peptoniphilus, Roseburia, and clostridial strain 27-5-10 represents a previously uncultured genus. Megasphaera elsdenii (cluster IX) accounted for eight of the isolates, and the other seven isolates were all distantly related to previously cultured species (less than or greater than 97% sequence identity to their nearest cultured relatives). Three of the isolates (Eubacterium, Peptoniphilus, and strain 27-5-10) utilized O-linked glycans for carbon and energy, suggesting that they occupy niches associated with the mucosal lining. In functional assays for butyrate production, all isolates had measurable butyryl-CoA:acetate CoA-transferase (BCoAT, E.C. 220.127.116.11) activity. Nonetheless, only BCoAT genes from Clostridium clusters IV and XIVa isolates could be amplified with commonly used primers. Due to representation in clostridial clusters not found in humans, and unique species in those clusters that dominate humans, we conclude that the butyrate producing bacteria in swine are different from those in humans. Additional swine-specific studies with new probes are required to fully assess the butyrate-producing community and determine their potential for use in probiotic or prebiotic applications to benefit animal health.