IDENTIFICATION OF A CLOSTRIDIUM-COCLEATUM STRAIN INVOLVED IN AN ANTI-CLOSTRIDIUM-DIFFICILE BARRIER EFFECT AND DETERMINATION OF ITS MUCIN-DEGRADING ENZYMES

We isolated Gram-positive circular bacterium HB1 from intestinal micro flora showing resistance to colonization by Clostridium difficile in m ice (Su et al., 1986a,b). We studied its enzymatic capacity to degrade mucin the first potential barrier to implantation of strains in the i ntestine. Its biochemical characteristics, terminal metabolites and th e electrophoretic profiles of proteins and DNA-DNA homology indicated that it was a strain of Clostridium cocleatum. This strain displayed n umerous glucosidase activities which were assumed to play a role in th e degradation of mucin oligosaccharide chains in the digestive tract. These enzymes included alpha- and beta-galactosidases, beta-glucosidas e, beta-N-acetylglucosaminidase, sialidase and alpha-N-acetylgalactosa minidase.