In vitro activity of BU-2313B against anaerobic bacteria

The antimicrobial efficacy of BU-2313B, a new antibiotic, was evaluated in comparison with clindamycin, chloramphenicol and cefoxitin against 265 clinical anaerobic isolates. BU-2313B inhibited 88% of 66 isolates of Bacteroides fragilis tested at 2 micrograms/ml, whereas clindamycin, chloramphenicol and cefoxitin inhibited 98, 97 and 92% of them at 2, 8 and 16 micrograms/ml, respectively. BU-2313B was severalfold more effective than chloramphenicol and cefoxitin, but it was eight times less effective than clindamycin.