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The oxidase test is used to determine whether an organism possesses the cytochrome c oxidase enzyme. The test is used as an aid for the differentiation of Neisseria, Moraxella, Campylobacter and Pasteurella species (oxidase positive). It is also used to differentiate pseudomonads from related species. [1]
Pseudomonas species also typically give a positive result to the oxidase test, the absence of gas formation from glucose, glucose is oxidised in oxidation/fermentation test using Hugh and Leifson O/F test, beta hemolytic (on blood agar), indole negative, methyl red negative, Voges–Proskauer test negative, and citrate positive. [citation needed]
However, H. influenzae isolated from cerebrospinal fluid or blood or joint fluid would indicate invasive H. influenzae infection. Microscopic observation of a Gram stained specimen of H. influenzae will show Gram-negative coccobacillus. The cultured organism can be further characterized using catalase and oxidase tests, both of which should be ...
In mixed cultures, it can be isolated as clear colonies on MacConkey agar (as it does not ferment lactose) which will test positive for oxidase. Confirmatory tests include production of the blue-green pigment pyocyanin on cetrimide agar and growth at 42 °C.
Moraxella catarrhalis is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system, and joints of humans. It causes the infection of the host cell by sticking to the host cell using trimeric autotransporter adhesins.
It is positive by the oxidase test and catalase test, but negative by the nitrate reductase test. It is alpha-hemolytic and requires oxygen. A. faecalis can be grown at 37 °C, and forms colonies that lack pigmentation. [1]
Inoculating the fluid from infected joints directly into blood culture vials can enhance the chances of an accurate culture, but extended culture times are not helpful. [2] The organism has also been known as Moraxella kingae. Kingella kingae is oxidase-positive, catalase-negative, and beta-hemolytic.
Campylobacter upsaliensis is a catalase negative species that can be further differentiated from other Campylobacter species by its inability to produce hydrogen sulfide on triple sugar iron as well as a positive oxidase test. [2] Additionally it cannot hydrolyze hippurate like other species and is considered sensitive to nalidixic acid. [4]