<原著>〔第 1 篇〕Capreomycin の試験管内抗結核菌作用及び結核マウスに対する Capreomycin の延命効果に関する研究(Capreomycin の抗結核作用に関する基礎的検討, 特に Kanamycin 及び Viomycin との交叉耐性に関する研究)

Abstract

Experimental studies on capreomycin, a new antibiotics, were made. The minimum inhibitory concentration of capreomycin against Mycobacterium tuberculosis H37Rv strain was approximately 1 to 2mcg. per ml. in liquid media and Kirchner's agar, but 10 to 20mcg. per ml. in egg medium. The tuberculostatic activity was considerably reduced in proportion as the pH of medium was changed to acid, the inoculum size was strengthened, and/or the serum concentration in medium was increased. No cross resistance existed between capreomycin and other antituberculous drugs excluding kanamycin, and viomycin (neomycin did not be studied). Among kanamycin, capreomycin, and viomycin, one way or reciprocal cross resistance was observed. High degree resistant strain to kanamycin was relatively resistant to capreomycin, but sensitive to viomycin. Low degree as same as high degree resistant strains to capreomycin were resistant to both kanamycin and viomycin. Low degree resistant strain to viomycin was sensitive to kanamycin but resistant in some extent to capreomycin, while the high degree resistant strain was resistant to both kanamycin and capreomycin. Some increases of tuberculostatic activity in vitro were shown when capreomycin was combined with isoniazid, p-aminosalicylate, kanamycin, or ethionamide. No antagonistic effect was demonstrated between capreomycin and the other drugs. Although tuberculocidal activity of capreomycin was evidently observed, it seemed to be less potent than kanamycin. Therapeutic effect of capreomycin against experimental tuberculosis in mice was studied. The mean survival times were prolonged by the treatment of capreomycin, both in single use and in combined use with cycloserine. The effects of capreomycin for the mouse tuberculosis were compared to kanamycin. In summary : According to the antituberculous activity, capreomycin will be placed in second class along with streptomycin, kanamycin, viomycin, ethionamide, and ethambutol. In the clinical use, careful thought should be given for the cross resistance among kanamycin, capreomycin, and viomycin.