Antibiotic sensitivity of ribosomes from wild-type and clindamycin resistant Bacteroides vulgatus strains.

The sensitivity to different antibiotics of in-vitro polyuridylic acid-dependent polypeptide synthesizing system from Bacteroides vulgatus RYC18F6 and two clindamycin-resistant derivatives was studied. The ribosomes from the resistant strains were not affected by concentrations of up to 0.1 mM clindamycin and lincomycin. In contrast, streptogramin B was found to cause strong stimulation of the clindamycin-resistant polymerizing systems. The modified ribosomes from the resistant strains were more sensitive to other antibiotics like sparsomycin and chloramphenicol. The data indicate that resistance in these B. vulgatus mutant strains is due to alteration of the ribosome structure.