Corynebacterium riegelii appear as club-shaped Gram-positive rods in clusters or singly. The colonies are generally white in color, slightly sticky, and glistening. Growth is best in the presence of 5% CO2 after 48 hours of incubation on blood agar. This organism does not ferment glucose but will ferment ribose, trehalose, and is slow to ferment maltose. C. riegelii also has strong urease production.
Isolates are usually recovered in urinary tract infections primarily from women. The strong urease reaction is thought to contribute to the pathogenicity of the organism.
19. CDC. "This photograph depicts the results of a urease test, based on the process involving the hydrolysis of urea..." CDC Public Health Image Library (PHIL). Public domain. 1976. Accessed July 28, 2023. https://phil.cdc.gov/Details.aspx?pid=6711
