[Plasmidic resistance of "Haemophilus sp." to aminoglycoside antibiotics: isolation and study of a new phosphotransferase (author's transl)].

Plasmid mediated phosphorylating activities have been found in Haemophilus sp. strains resistant to some aminoglycoside antibiotics. The enzymes responsible for this phenomenon have been purified and studied. They belong to the group of aminoglycoside phosphotransferases which are able to phosphorylate these antibiotics on the 3'- or 5"-hydroxyl group. The first enzyme studied is closely related to APH(3')I whereas the second one is different from the former on the basis of substrate specificities and physicochemical properties. We propose to call this second enzyme APH(3')Ib as compared to APH(3')I which will be called APH(3')Ia.