Activity of trospectomycin against Bacteroides fragilis and other Bacteroides species.

The in vitro activity of trospectomycin (U-63366; 6'-n-propyl spectinomycin pentahydrate sulfate) was evaluated against 189 clinical isolates of the Bacteroides fragilis group and 65 Bacteroides species isolates. At less than or equal to 8 micrograms/ml, the activity of trospectomycin compared favorably with those of clindamycin and cefoxitin against B. fragilis, Bacteroides distasonis, and Bacteroides vulgatus, and there was no cross resistance to these three drugs among the strains of the B. fragilis group. All the Bacteroides species were susceptible to trospectomycin. The results of this in vitro study indicate that trospectomycin possesses excellent activity against Bacteroides species.