Clostridium coccoides, a New Species from the Feces of Mice

Clostridium coccoides sp. nov. is described on the basis of 12 strains isolated from a number of fecal specimens from mice fed a high-lactose diet. The isolates are obligately anaerobic, gram-positive, sporeforming, nonmotile, coccobacillary to rod-shaped cells which occur singly, in pairs, and sometimes in chains. They differ from other clostridia principally in morphology; the nearly spherical form of the cells, particularly on agar media, is rather distinctive. The guanine plus cytosine (G+C) contents of the deoxyribonucleic acids of the new strains are 43 to 45 mol%, values similar to those of clostridia with high G+C contents, such as Clostridium sphenoides, C. oroticum, C. indolis, C. innocuum, C. barkeri, and C. nexile; however, C. coccoides can be clearly differentiated from these organisms by numerous biochemical characteristics and/or fermentation products. The type strain of C. coccoides is CLC-1 (= ATCC 29236 = NCTC 11035).