[Comparison of the sensitivity of Rhodococcus rubropertinctus R, S and M variants to antibiotic action]

Comparison of sensitivity of 63 clones of R, S and M variants of Rhodococcus rubropertinctus 104 to 6 antibiotics showed that sensitivity of the variants was similar only to erythromycin. Their sensitivity to penicillin, streptomycin, chlortetracycline, rifampicin and actinomycin C was different. Still, they preserved similar regularity: M cells were the most sensitive and R cells were the most resistant. There was a 1.5-3 fold difference in sensitivity of R and M variants to the antibiotics. The number and rate of chlortetracycline absorption by R cells were lower than those of S and especially M cells which must condition their higher resistance to the antibiotic.