Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Corynebacterinae, Family
Corynebacteriaceae, Genus Corynebacterium, Corynebacterium riegelii Funke, Lawson and Collins 1998.
Gram-positive, typical club-shaped rods that occur as single cells, in pairs or in small
clusters. Nonspore-forming. Nonmotile.
Colonies are whitish, glistening, convex, creamy or a slightly sticky consistency and
up to 1.5 mm in diameter after 48 h of incubation at 37 ºC on sheep blood agar in a
5% CO2-enriched atmosphere. CAMP test is negative. Anaerobic growth is weak.
Isolated, mainly, from females (urine) with urinary tract infections.
Susceptible to penicillin, cephalotin, tetracyclines, vancomycin, ciprofloxacin, gentamicin, and rifampin. Resistant to cefetamet,
ceftibuten, and fosfomycin.
Isolated from females (urine) with urinary tract infections the strong urease activity may be a pathogenicity factor.
- Funke G., 2006. Corynebacteria and rare coryneforms. In: Topley & Wilson’s Microbiology & Microbial Infections, 10th Edition,
Edited by Borriello S.P., Murray P.R. and Funke G., Edward Arnold (Publishers) Ltd., Bacteriology, volume 2.
- Funke G., Lawson P.A. and Collins M.D., 1998. Corynebacterium riegelii sp. nov., an Unusual Species Isolated from Female
Patients with Urinary Tract Infections. J. Clin. Microb. Vol. 36, No. 3, p. 624-627.
Most results are based on API CORYNE and API 50CH tests.
Positive results for catalase, esterase (C4), esterase lipase (C8), urease (strong
reaction), acid production from: 5-ketogluconate, maltose (slow), ribose, tagatose & trehalose.
Negative results for esculin hydrolysis, beta-galactosidase, beta-glucuronidase, alpha-glucosidase, lipophilism, nitrate reduction,
acid production from: N-acetylglucosamine, adonitol, amygdalin, arabinose, arabitol, arbutin, cellobiose, dulcitol, erythritol, fructose,
fucose, galactose, beta-gentiobiose, gluconate, 2-ketogluconate, glucose (!), glycerol, glycogen, inositol, inulin, lactose, lyxose,
mannitol, melezitose, melibiose, raffinose, rhamnose, salicin, sorbitol, sorbose, sucrose, turanose, xylitol & xylose.
Variable results for alkaline phosphatase & pyrazinamidase.
(c) Costin Stoica