<原著>〔I〕低温下の抗菌力 / 〔II〕ガス曝露下の抗菌力(第 4 編 結核菌の発育に不適当な条件と R. P. の抗菌力)(Griselimycine の半合成誘導体 27753RP の抗結核作用に関する試験管内実験的検討)

Abstract

(I) Antituberculous activities of R. P under low temperature. The antituberculous activities of R. P against Mycobacterium tuberculosis H37Rv strain at 4℃ or 25℃ were investigated using SSC method. 1. Bacteriostatic effect When the cultures were incubated at 4℃ or 25℃, there was no growth of tubercle bacilli. But at 37℃, the MIC of R.P was 0.156mcg/ml; SM, 1.563mcg/ml; RFP, 0.078mcg/ml, respectively. The bacteriostatic effect of R. P. was inferior than that of RFP, but it was superior to that of SM. 2. Bactericidal effect At 37℃, the MBC of R. P was 0.313mcg/ml; SM, 12.5mcg/ml; RFP, 0.313mcg/ml, respectively. Bactericidal effect of R. P was inferior to that of RFP, but superior to that of SM. There was no difference of the bactericidal effect of R. P between at 37℃ and at 25℃, so the bactericidal effect of R. P was fairly potent. (II) Anituberculous Activities of R. P in Vitro under Several Kinds of Gas Exposures. The antituberculous activities of R. P to tubercle bacilli (H37Rv strain) were evaluated in vitro by replacing the air with N_2 and CO_2 gases. The experiments were performed by using SSC method with Kirchner's liquid medium. The results obtained are as follows : 1. There was no growth of tubercle bacilli in any sample, regardless of the kind of drug or gas during continuous exposure for four weeks. 2. With the CO_2 gas exposure, R. P, SM, and RFP showed remarkably strong bactericidal effects. The bactericidal effects of R. P was superior to that of SM, and similar to that of RFP. 3. Under N_2 gas exposure, the bactericidal effects of R. P and SM were less than those under CO_2 gas exposure. With the increase of drug concentrations, the bactericidal effects of these drugs increased under N_2 and CO_2 gas exposures.