STUDIES ON THE ANTIBIOTICS FROM STREPTOMYCES SPINICHROMOGENES VAR. KUJIMYCETICUS. V

Two neutral macrolide antibiotics, kujimycin A (desacetyl lankamycin) and kujimycin B (lankamycin) inhibited the growth of certain macrolide resistant strains of staphylococci. The antimicrobial activities of kujimycins A and B against the strains of clinically isolated staphylococci which were resistant to other antibiotics were examined. Kujimycins A and B inhibited the growth of strains resistant to penicillin (PC), tetracycline (TC), streptomycin (SM), kanamycin (KM) and chloramphenicol (CP) as well as strains of an unknown type of staphylococcus resistant to erythromycin (EM) and oleandomycin (OM) constitutively. Kujimycins A and B did not inhibit the growth of group A strains (EM, OM, leucomycin (LM), spiramycin (SPM) resistant or EM, OM, LM, SPM, lincomycin (LCM) resistant), group B strains (EM, OM-resistant) and group C strains (EM, OM, LM, SPM, LCM-resistant) carrying induced resistance. Kujimycins A and B were found to be capable of inducing macrolide resistance as do EM and OM in inducible resistant strains. Staphylococcus aureus TPR-4B, a laboratory-developed strain, was constitutively resistant to LM and SPM at the concentration of 100 mcg/ml or more but it was sensitive to kujimycins A and B at the concentration of 12.5 mcg/ml. The minimal inhibitory concentrations of kujimycins A and B against Staphylococcus aureus FDA209P did not change at the range of pH 5.8-8.2.