The acetylation of 6'-amino group of amikacin by a new enzyme prepared from serratia sp.

It was found that Serratia marcescens 43, Serratia proteamaculans 48 and Serratia sp. 45, all of which were clinically isolated, produced a new type of aminoglycoside acetyltransferase which acetylated amikacin at the 6'-amino group. 1-N-[(S)-3-Amino-2-hydroxypropionyl]-gentamicin B (HAPA-B, SCH 21420) and gentamicin C2 were hardly inactivated by the enzymes and had effective antimicrobial activities against these strains both in vitro and in vivo. This kind of aminoglycoside acetyltransferase should be classified into a new group other than previously reported AAC(6') enzymes.