Isolation and identification of clostridia from the intestine of laboratory animals

Quantitative and qualitative examination of faecal clostridia from laboratory mice, rats, hamsters and rabbits was carried out by using selective as well as nonselective culture techniques. The 364 isolates were identified where possible, to species level on the basis of physiological and biochemical characteristics. Most isolates from mice and rabbits were identified, i.e. 79.4% and 76.5%, respectively, while only 25.4% and 28.6% of isolates from rats and hamsters were characterized as described species. The most common species of the 16 identified were: C. coccoides, C. cocleatum and C. innocuum from mice; C. cocleatum, C. cochlearium and C. irregularis from rats; C. cocleatum and C. irregularis from hamsters; and C. aminovalericum and C. irregularis from rabbits. Unidentified Clostridium spp. were isolated from each animal species tested and were tentatively classified into 26 groups. None of these groups was found in more than one animal species in this study.