Abstract
Two clindamycin-erythromycin resistance transfer factors of Bacteroides fragilis, pBF4 and pBFTM10, were analyzed for regions of DNA homology. Although the plasmids were derived from different clinical isolates of B. fragilis and have different sizes, they showed homology in the clindamycin-erythromycin resistance region; no homology could be detected outside of this region.