Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Actinomycinae, Family
Actinomycetaceae, Genus Actinomyces, Actinomyces radingae WUst, Stubbs, Weiss, Funke and Collins 1995, emend. Vandamme,
Falsen, Vancanneyt, Esbroeck, Van de Merwe, Bergmans, Schouls and Sabbe, 1998.
Historical synonyms: CDC coryneform group E, Actinomyces pyogenes-like, Arcanobacterium haemolyticum-like.
Gram-positive coccoid rods (coccobacilli); pseudobranching is rare. Non-motile.
Colonies are convex, opaque, grey, small, with a glistening surface and butyrous
consistency after 48 h of incubation, 5% CO2, on sheep blood agar. Grows better with
addition of 5% rabbit or horse serum in broth. Alpha-haemolysis is produced.
Facultative anaerobic. Grows at 37 ºC; variable at 43 ºC; slow growth at 30 ºC. No
growth at 25 ºC. CAMP test is negative.
Isolated from various infections in humans.
Susceptible to penicillin, oxacillin, erythromycin, cefazolin, amoxicillin/clavulanic acid , erythromycin, cotrimoxazol, phosphomycin and
Isolated from human perineal abscess, pilonidal cyst, pleural empyema, axillar hydradenitis, pilonidal sinus infection, penis and knee
fluid. Doesn't seem to cause typical actinomycosis.
- Vandamme P., Falsen E., Vancanneyt M., Van Esbroeck M., Van de Merwe D., Bergmans A., Schouls L. and Sabbe L., 1998.
Characterisation of Actinomyces turicensis and Actinomyces radingae. Int. J. Syst. Bacteriol. Vol. 48, 503-510.
- 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.
Description is based on API CORYNE tests.
Positive results for esculin hydrolysis, alpha- and beta-galactosidase, alpha- and beta-glucosidase, N-acetyl-beta-glucosaminidase,
acid production from: D-glucose, lactose (with 5% horse serum in API gallery macrotubes), maltose, salicin & sucrose (saccharose).
Negative results for alkaline phosphatase, catalase, gelatin hydrolysis, beta-glucuronidase, indole production, nitrate reduction,
leucine arylamidase, pyrrolidonyl arylamidase, urease, acid production from mannitol.
Variable results for pyrazinamidase.
(c) Costin Stoica