Comparison of Schaedler Agar and Trypticase Soy-Yeast Extract Agar for the Cultivation of Anaerobic Bacteria

Schaedler agar (SA) and Trypticase soy-yeast extract agar (TSYEA), both supplemented with rabbit blood (5%, v/v) and menadione (0.5 mg/liter), were compared with respect to quantitative recovery, quality of growth, and rapidity of growth of selected anaerobic bacteria. The media were stored for 2 to 4 days prior to use in an anaerobic glove box, where all subsequent bacteriological procedures were performed. After 24 hr of incubation, colonies ofClostridium cadaveris (C. capitovale), C. haemolyticum, C. novyi A, andC. perfringens were larger on SA than on TSYEA, and the appearance ofC. novyi B colonies on SA at 24 hr antedated their appearance on TSYEA. Quantitative recovery ofC. novyi B was improved on SA; recovery of the other clostridia tested was comparable on the two media (inconclusive results were obtained withC. novyi A). Rough colonial types of some of the clostridia emerged on SA. No appreciable differences in results with the two media were noted forBacteroides fragilis, B. melaninogenicus, orFusobacterium fusiforme.