the following information is not yet verified
Taxonomy
Family: Cardiobacteriaceae
Natural habitats
The oral cavity and nasopharynx but possibly also the gastrointestinal and urogenital tract of humans.
Clinical significance
Human disease is mainly endocarditis (HACEK), on rare occasions, they have been isolated from other body sites
the following information is not yet verified
Pleomorphic or straight Gram negative rods,
0.5-0.75 x 1.0-3.0 µm
with rounded ends and long filaments may occur.
They are arranged singly, in pairs, in short chains and in rosette clusters
Parts of the cell can stain Gram positive
Facultative anaerobic
5% CO2 improves the growth
BA: growth on blood agar is very poor.
After incubation for two days, colonies are 1 mm, circular, smooth and opaque, and may pit the agar.
Slight α-haemolysis
Addition of yeast extract to the medium (e.g., chocolate agar) seems to abolish this pleomorphism
McConkey: no growth
BBAØ: growth
James Versalovic et al.(2011) Manual of Clinical Microbiology 10th Edition
Karen C. Carrol et al (2019) Manual of Clinical Microbiology, 12th Edition