Clinical isolation and characterization of aminoglycoside-resistant small colony variants of enterobacter aerogenes

Small colony variants of Enterobacter aerogenes, as well as the parental large colony type, grew in blood drawn for cultures on three separate days from a patient who had received suboptimal gentamicin therapy. Minimum inhibitory concentrations of four aminoglycoside antibiotics were eight to more than 16 times higher for small colony variants than for the normal large colony type. Small colony variants had defective catalase activity, which …