An Increase of 63 kDa-Protein Present in the Cell Membranes of Staphylococcus aureus That Bears a Plasmid Mediating Inducible Resistance to Partial Macrolide and Streptogramin B Antibiotics

Abstract

A plasmid, pEP2104 (23.9 kilobase pairs), from Staphylococcus aureus carries a gene that specifies inducible resistance to 14-membered (erythromycin, EM, and oleandomycin, OL) and 16-membered macrolide (mycinamicin I and II), but not to all of the latter, and to streptogramin type B antibiotics (partial macrolide- and streptogramin- B-antibiotic resistance : PMS-resistance) (L. Janosi, E. Ban, Acta Microbiol. Acad. Sci. Hung., 29, 187 (1982) and Y. Nakajima et al., J. Pharmacobio-Dyn., 15, 319 (1992)). The induced cells of strain 8325(pEP2104) did not inactivate EM, OL, josamycin, rokitamycin or mikamycin B (MKM-B), and the cell-free extract of the strain did not inactivate EM or MKM-B, either. Ribosomes from the cells whose PMS-resistance was induced by EM were sensitive not only to EM or spiramycin, but also to MKM-B. A 63000-dalton protein increased to a great extent only in the cell membrane fractions of induced 8325(pEP2104), and may be involved in PMS-resistance.