Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Corynebacterinae, Family
Corynebacteriaceae, Genus Corynebacterium, Corynebacterium nigricans Shukla, Bernard, Harney, Frank and Reed 2004.
Historical synonym: C. nigricans it is a later heterotypic synonym of C. aurimucosum Yassin et al. 2002 emend. Daneshvar et al. 2004.
Gram-positive, coccobacillary to rod-shaped, 1.25-2.5 µm. Nonspore-forming.
Colonies are small, dry, granular, pitted, with a strong adhesion to agar, up to 2-3 mm
after 48 h. Produce black pigmentation on hem-containing sheep blood agar,
colistin-naladixic acid agar, chocolate agar, and non-hem-containing BHI agar after
24 to 48 h of incubation; these could be the criteria to distinguish this coryneform from
other coryneforms. The pigment is not water soluble. Colonies also turn black on
trypticase soy agar after 4 to 5 days. Haemolysis and CAMP test are negative. Aerobic;
grows well in air saturated with 5% CO2 and poorly in anaerobic conditions.
Isolated from the human female urogenital tract. Four of the six source patients had complications of pregnancy, including
spontaneous abortion, preterm labor, and low amniotic fluid volume at the time of the pathogen isolation. One isolate was recovered
from a vaginal ulcer.
Susceptible to O/129, tetracycline and clindamycin. Resistant to beta-lactams.
Four of the six source patients had complications of pregnancy, including spontaneous abortion, preterm labor, and low amniotic fluid
volume at the time of the pathogen isolation. One isolate was recovered from a vaginal ulcer.
- 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.
- Daneshvar M.I. et al., 2004. Identification of Some Charcoal-Black-Pigmented CDC Fermentative Coryneform Group 4 Isolates as
Rothia dentocariosa and Some as Corynebacterium aurimucosum: Proposal of Rothia dentocariosa emend. Georg and Brown
1967, Corynebacterium aurimucosum emend. Yassin et al. 2002, and Corynebacterium nigricans Shukla et al. 2003 pro synon.
Corynebacterium aurimucosum. J.Clin.Microbiol. Vol. 42, No.9, 4189-4198.
Positive results for catalase, hippurate hydrolysis, tyrosine hydrolysis, acid production from: fructose, glucose, maltose, mannose &
Negative results for casein hydrolysis, DNA-hydrolysis, esculin hydrolysis, indole production, lipophilism, nitrate reduction, citrate,
gelatinase, oxidase, starch hydrolysis, urease, acid production from: lactose, mannitol & xylose.
Variable results for alkaline phosphatase, pyrazinamidase, acid production from: glycogen & ribose.
(c) Costin Stoica