ANTIMICROBIAL ACTIVITY OF DKB AND MECHANISM OF ITS RESISTANCE AGAINST PSEUDOMONAS AERUGINOSA

Abstract

We compared the antibacterial activity of DKB (3', 4'-dideoxykanamycin B) and that of gentamicin on 355 strains of Pseudomonas aeruginosa, and the mechanism of resistancl to DKB was studied.
1) The newly introduced semisynthetic aminoglycoside antibiotics, i. e., 3', 4'-dideoxykanamycin B (DKB), 6'-N-methyl DKB (6'-Me-DKB) and amikacin have been found to be effective against Pseudomonas aeruginosa which are resistant to the known aminoglycoside antibiotics.
2) DKB resistant Pseudomonas aeruginosa strains were isolated from clinical specimens before DKB was used.
3) The strain resistant to DKB and 6'-Me-DKB disclosed that the enzyme catalyzing inactivation of both DKB and 6'-Me-DKB was mediated by an R factor.
4) Enzymatic studies of inactivation reaction and chemical studies of the inactivated products indicated that DKB and 6'-Me-DKB were inactivated by acetylation of the 6' amino group of the drugs.