Evaluation of Media for Differentiating Nonfermenting Gram-negative Bacteria of Medical Significance

Abstract

An evaluation was made of media and tests used for differentiating nonfermenting gram-negative bacteria encountered in medical bacteriology in order to determine those diagnostic procedures most useful in identifying these bacteria. The organisms examined included Alcaligenes faecalis, A. odorans var. viridans, Moraxella duplex (Mima polymorpha var. oxidans), Acinetobacter anitratum (Herellea vaginicola), A. Iwoffi (Mima polymorpha), Pseudomonas fluorescens, P. putida, P. maltophilia, P. pseudomallei, P. stutzeri, P. alcaligenes, and atypical strains of P. aeruginosa. The media and tests evaluated included Sellers' medium; Hugh and Leifson's OF medium; acid production from 10% lactose infusion agar; gluconate oxidation; starch, aesculin, and Tween 80 hydrolysis; lysine decarboxylase, arginine dihydrolase, deoxyribonuclease, and tyrosinase activity; tolerance to triphenyl tetrazolium chloride, cetrimide, cadmium sulfate, 2.5% and 6.5% sodium chloride, and pH 5.6; utilization of glucose, acetamide, and malonate. An evaluation was made of diagnostic procedures for examining nonfermenting gramnegative bacteria in order to determine those methods most useful in the identification of these bacteria. The organisms examined included representative species of Pseudomonas, Alcaligenes, Moraxella, and Acinetobacter. This paper reports on those findings. MATERIALS AND METHODS Cultures. The strains of Pseudomonas pseudomallei were obtained from the American Type Culture Collection (ATCC 11668

The effects of hyperosmosis or high pH on a dual‐species biofilm of Enterococcus faecalis and Pseudomonas aeruginosa: an in vitro study

“…This was expected because bacterial species respond differently to environmental stresses. It was reported that P. aeruginosa does not tolerate 6.5% NaCl (Gilardi 1969) whilst E. faecalis was reported to be more resistant to NaCl (Lee 1972, Faklam 1973).…”