Identification of nonfermentative gram-negative bacteria in the clinical laboratory

Abstract

A simplified, concise scheme was developed for the identification of nonfermentative, gram-negative bacteria which have most frequently been reported in the literature as definite or possible agents of human disease. These organisms included apyocyanogenic Pseudomonas aeruginosa, P. fluorescens, P. putida, P. stutzeri, P. maltophilia, P. putrefaciens, P. cepacia, P. alcaligenes, FLAVOBACTERIUM SPECIES, Bordetella bronchiseptica, Acinetobacter anitratum (Herellea vaginicola), A. Iwoffi (Mima polymorpha), Moraxella species, Alcaligenes odorans and Alcaligenes species. The tests used for identification included production of cytochrome oxidase, amylase, deoxyribonuclease, gelatinase, urease and Beta-galactosidase; motility; oxidation of one per cent glucose and ten per cent lactose; fluorescence; indole, hydrogen sulfide and nitrogen gas production; denitrification of nitrites; growth at 42C; penicillin sensitivity and production of an aromatic odor and greenish discoloration on blood agar. Using this scheme, 85 per cent of 243 isolates (unknowns and reference strains) were identified to genus and species. Of the 15 per cent remaining, 11 per cent were identified as alkaline organisms and four per cent were unidentifiable.