CLOSTRIDIUM-DIFFICILE - ISOLATION AND CHARACTERISTICS

C. difficile can be grown readily in Reinforced Clostridial Medium (RCM) containing 0.1-0.4% of o-, m- or p-cresol, or phenol; 0.2% of phenol or p-cresol in RCM for the [diagnostic] isolation of this organism is recommended. The characteristic cornfield growth in RCM in 25-ml Universal containers is described. Glucose, fructose, galactose, mannose, raffinose, esculin and mannitol are fermented with production of acid and gas; maltose, sucrose, glycogen, soluble starch and sorbitol are fermented with production of acid only. Lactose and rice starch are not fermented by any strain, and DL-methionine is not attacked. Nitrate is reduced to nitrite. H2S and indole are not produced. Gelatin is attacked by all strains, but in some cases prolonged incubation is required. Hyaluronidase is produced, but not DNase. A lethal toxin [for guinea pigs] appears to be produced. Strains possess shared and strain-specific antigens.