Aminoglycoside-O-phosphotransferase (APH (3'')) activity in a clinical isolate of Acinetobacter calcoaceticus

An isolate of Acinetobacter calcoaceticus var. anitratus containing an aminoglycoside-aminocyclitol antibiotic-modifying enzyme, which phosphorylates streptomycin at the 3" position, is described. The enzyme, APH(3"), was identified on the basis of its substrate specificity; in particular, its ability to phosphorylate streptomycin but not streptidine.