Isolation of Bacteroides fragilis from the feces of diarrheic calves and lambs

Abstract
A selective medium was developed for the isolation of Bacteroides fragilis directly from ovine and bovine fecal samples. The medium (tryptose blood agar plus polymyxin B, triclosan (Irgasan), novobiocin, and nalidixic acid) permitted growth of B. fragilis and several other species of Bacteroides but inhibited growth of most other intestinal bacteria.