IN VITRO AND LN VIVO ANTITUBERCULOUS ACTION OF NEOCIDIN, A NEW ANTIBIOTIC PRODUCED BY A NUMBER OF THE BACILLUS SUBTILIS-GROUP

Abstract

Neocidin, a new, basic and water-soluble antibiotic extracted from bacterial cells of a number of the Bacillus subtilis-group has been demonstrated to exhibit in vitro and in vivo antituberculous action against Mycobacterium tuberculosis var, hominis (H37Rv) and Mycobacterium avium (Jucho). The antibiotic has been effective against experimental tuberculosis in mice infected with Mycobacterium tuberculosis var. hominis (H37Rv). The activity of this antibiotic was reduced by the presence of egg and agar in the medium. It was also demonstrated that there is no significant cross resistance of Mycobacterium avium (Jucho) to neocidin and other known antituber-culous agents, and that the appearance of neocidin resistance in Mycobacterium avium (Jucho) occurs in a step-wise manner.