Differential Diagnosis of Pseudomonas-Like Microorganisms in the Clinical Laboratory

Abstract

Three new laboratory tests are currently available for the identification of Pseudomonas aeruginosa isolated from clinical specimens. None of these procedures are specific for P. aeruginosa and cannot be used to differentiate between species within the genus. However, since P. aeruginosa is the only known human pathogen it is the only member of this genus that usually will be encountered in clinical specimens. All three tests are based on the oxidative characteristics of the organisms. Haynes (1951) suggested

DIFFERENTIAL TECHNIQUES AND METHODS OF ISOLATION OF PSEUDOMONAS

“…Klinge (1959~) reviewed the modifications of this method and discussed the results obtained by their use. Schultze (1910) , Kramer (1912), Loele (1929), Frei, Riedmiiller & Almasy (1934), Gordon & McLeod (1928), Kovacs (1956), Gaby & Hadley (1957), Gaby & Free (1958) and Klinge (1959a) obtained a positive oxidase or cytochrome oxidase reaction with Pseudomonas. Lutz, Schaeffer & Hofferer (1958) and Kohler (1959) obtained negative results in some cases and felt that the test was not reliable.…”

“…When the reagent is dropped on to colonies grown on the surface of solid media the composition ofthe medium does not influence the oxidase reaction. The procedure described by Kovacs (1956) consists in smearing the bacteria to be tested on filter paper previously soaked with the reagent : but as also found by Gaby & Free (1958) this method is too sensitive, probably because of the rapid autoxidation of the reagent.…”

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

“…The usefulness of the oxidation of gluconate to keto-gluconate in differentiating P. aeruginosa from other pseudomonads has been established (8). Positive (14) and variable (28) gluconate oxidation has been reported for P. fluorescens.…”

“…Studies performed. The tests, media, and references to procedures employed included: acid production from 1% glucose, OF Basal Medium [Difco, (16)]; acid production from 10% lactose, Purple Agar Base [Difco, (1)]; acid production from glucose, fluorescein production, nitrogen gas production, and anaerobic growth in the presence of nitrate, Sellers' Differential Agar [Difco, (23)]; dihydrolase and decarboxylase activity, Decarboxylase Base Moller [Difco, (20)]; deoxyribonuclease activity, DNase Test Agar [Difco, (6)]; gluconate oxidation, Gluconate Substrate [Key Scientific Products, (8)]; malonate utilization, Malonate Broth [Difco 0395, (17)]; tyrosinase activity, Trypticase Soy Agar (TSA; BBL) with 1% 1-tyrosine (4); starch hydrolysis, TSA with 1% starch (19); lipase activity, Sierra medium with 1% polyethylene sorbitan monooleate [Tween 80,(24)]; aesculin hydrolysis, TSA with 0.1% aesculin and 0.05% ferric citrate (4); growth on cetrimide, Pseudosel Agar [BBL, (3)]; growth on triphenyl tetrazolium chloride (TTC), TSA with 1% TTC (3); growth on cadmium, TSA with 0.04% cadmium sulfate (28); growth at pH 5.6, Sabouraud Dextrose Agar (Difco); sodium chloride tolerance, TSA adjusted to NaCl concentrations of 2.5% and 6.5%; and utilization of glucose and acetamide as sole sources of carbon and energy in a basal mineral medium previously described (11).…”

REISOLATION AND EMENDATION OF DESCRIPTION OFVIBRIO MARINUS(RUSSELL) FORD

“…Other tests which were performed included: hydrogen sulfide formation (Colwell and Quadling, 1962); trimethylamine oxide reduction (Wood and Baird, 1943); production of acid from carbohydrates (Hugh and Leifson, 1953); production of 2-keto gluconic acid (Gaby and Free, 1958); lipolytic activity (Sierra, 1957); digestion of chitin (Benton, 1935;Pohja, 1960); growth and production of pyocyanine or fluorescein, or both, on Sabouraud maltose agar, Sabouraud dextrose agar, Burton's medium (Burton, Campbell, and Eagles, 1948), and King's medium (King, Campbell, and Eagles, 1948); production of acetic acid from ethanol; dihydroxyacetone from glycerol; production of carbonates on calcium lactate medium (Shimwell, Carr, and Rhodes, 1950); presence of oxidase (Kovacs, 1956;Ewing and Johnson, 1960; Gaby and Free, 1958); and casein hydrolysis (Demeter, 1943).…”