[Bacteriological studies on doxycycline (Bonnamycin 'Cipan') (author's transl)]

Bonnamycin which is a new tetracycline group antibiotic isolated from a variant strain of Streptomyces rimosus and is identified chemically as doxycycline was investigated, comparing with tetracycline. The results are as follows: (1) In in vitro studies of anti-bacterial spectrum, doxycycline is widely effective against standard strains kept in our department. (2) The distribution of susceptibility of 75 Staphylococci, 62 Salmonella and 64 Shigella strains isolated from clinical materials was similar to that of tetracycline. (3) As to the therapeutic experiment in acute infection of Klebsiella pneumoniae in mice, the drugs were equally effective and the ED50 was both 70.8 mcg. (4) Doxycycline administrated orally or subcutaneously in rats was distributed in kidneys, livers, lungs and spleens at relatively high concentration among organs.