Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Corynebacterinae, Family
Corynebacteriaceae, Genus Corynebacterium, Corynebacterium urealyticum Pitcher, Soto, Soriano and Valero-Guillen 1992.
Historical synonym: CDC coryneform group D-2.
Gram-positive rods (may appear coccoidal after prolonged incubation), 0.5-1.0 µm in
diameter, arranged in V forms or palisades. Nonsporing.
Colonies are convex, whitish, smooth, pinpoint after 48 h of incubation at 25-42 ºC on
sheep blood agar under CO2; they grow in 7% CO2 as tiny, creamy-white colonies on
chocolate agar and as greyish-white colonies on cystine lactose electrolyte-deficient
agar. It is fastidious, and slow-growing. Good growth on cystine lactose
electrolyte-deficient agar growth is stimulated by Tween 80. Strict aerobe. Growth
temperature: 25-42 ºC. Hemolysis is not produced. CAMP reaction is negative.
Source: human urine, skin and blood. It is a frequent colonizer of the skin of hospitalized pacients with or without UTIs.
It is one of the more frequently isolated clinically significant corynebacteria from clinical specimens.
Susceptible to vancomycin. Resistant to penicillins, aminoglycosides , beta-lactams. Often multiresistant to antibiotics.
Strongly implicated in urinary tract infections (UTI), primarily in association with alkali-encrusted cystitis. Bacteriuria occurs mainly in
patients hospitalized, immunocompromised, urologically manipulated and elderly. Recovery from urine does not always signify UTI but
is significantly associated with an alkaline pH and the presence of struvite crystals.
May be transmitted by air.
It cause acute or chronic infections of the lower urinary tract if underlying renal or bladder disease is present.
May cause infection in the upper part of the urinary tract, resulting in pyelonephritis or pyeloureteritis, especially in
immunocompromised or post-renal-transplant patients with surgical complications.
It is an infrequent cause of infections other than UTI: endocarditis, bacteremia, osteomyelitis, soft tissue infection and wound infection.
- Funke G., von Graevenitz A., Clarridge III J.E., and Bernard K.A., 1997. Clinical Microbiology of Coryneform Bacteria. Clinical
Microbiology Rewiews Vol. 10, No. 1, p. 125-159.
- 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.
- Pitcher D., Soto A., Soriano F. and Valero-Guillen P., 1992. Classification of Coryneform Bacteria Associated with Human Urinary
Tract Infection (Group D2) as Corynebacterium urealyticum sp. nov. IJSB Vol. 42, No.1, p. 178-181.
Oxidative metabolism. Not acid fast.
Positive results for catalase, leucine aminopeptidase, lipophilism, pyrazinamidase, Tween 80 hydrolysis & urease (strong reaction!).
Negative results for esculin hydrolysis, gelatin hydrolysis, nitrate reduction, oxidase, acid production from: arabinose, glucose,
glycogen, inulin, lactose, maltose, mannitol, raffinose, ribose, starch, sorbitol, sucrose, trehalose & xylose.
Variable results for: alkaline phosphatase, hippurate hydrolysis & Voges-Proskauer reaction.
(c) Costin Stoica