What is the Gram stain of Moraxella catarrhalis?
Moraxella (Branhamella) catarrhalis, formerly called Neisseria catarrhalis or Micrococcus catarrhalis, is a gram-negative, aerobic diplococcus frequently found as a commensal of the upper respiratory tract (124, 126; G.
Does Moraxella catarrhalis have a capsule?
Although M. catarrhalis does not possess a polysaccharide capsule, it does have a number of surface adhesins. Examples of important adhesins include the outer membrane proteins, lipooligosaccharide, and ubiquitous surface protein A (UspA) proteins.
What color is Moraxella catarrhalis?
grey-white
catarrhalis produces distinctive grey-white, medium to large, raised or dome-shaped, dry, and brittle colonies which can be easily lifted off the medium with a wire loop. In the clinical laboratory, isolates of M.
Does Moraxella catarrhalis grow on blood agar?
catarrhalis appears as extracelluar, kidney-shaped diplococci, measuring 0.5 – 1.5µm in diameter on Gram stained clinical specimens. They grow well on blood agar as well as chocolate agar but not on MacConkey agar.
What is the shape of Moraxella catarrhalis?
kidney-shaped
M. catarrhalis is a large, kidney-shaped, Gram-negative diplococcus. It can be cultured on blood and chocolate agar plates after an aerobic incubation at 37 °C for 24 hours. Cultures revealed gray-white hemispheric colonies about 1 mm in diameter.
What media does Moraxella grow?
Moraxella organisms are small, gram-negative bacteria that grow well on blood or chocolate agar. They are catalase and oxidase positive.
How do you test for Moraxella catarrhalis?
Confirmation of the diagnosis of M catarrhalis infection is based on isolation of the organism in culture. Cultures can be taken from middle ear effusion, the nasopharynx, sputum, sinus aspirates, transtracheal or transbronchial aspirates, blood, peritoneal fluid, wounds, or urine.
Is Catarrhalis DNAse positive?
A variety of biochemical tests can distinguish M. catarrhalis from Neisseria. M. catarrhalis produce oxidase, catalase, and DNAse (detected using DNAse test agar with methyl green); reduce nitrate and nitrite; and hydrolyze tributyrin.
Is Moraxella gram-positive?
Members of the genus Moraxella are Gram-negative, aerobic, asaccharolytic bacteria that can be pleomorphic, resistant to Gram-stain decolorization, and occur predominantly in pairs or short chains.