Differentiation of nonfermentative gram-negative bacilli in the clinical laboratory

A rapid and simplified system for the differentiation of nonfermentative Gram-negative bacilli, encountered frequently in clinical specimens, is presented for use in the clinical laboratory. Nonfermentative bacteria can be grouped initially by the motility, oxidase and OF glucose reactions. This grouping simplifies the choice of additional tests for further identification. The additional tests included Gram stain, acid production from 10% lactose agar, nitrate reduction, arginine dihydrolase activity, fluorescein production, deoxyribonuclease activity, hydrolysis of aesculin, growth at 42 degrees C, gelatinase activity and susceptibility to antibiotics.