Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Actinomycinae, Family
Actinomycetaceae, Genus Actinomyces, Actinomyces odontolyticus Batty 1958.
Gram-positive irregular, diphtheroid or branched rods, occurring filaments. Non-motile.
Colonies are small, smooth, may have dense center and occasional may be
filamentous, like those of A. israelii, after 24-48 h on BHI agar; the colonies are up to 1
mm, circular to irregular, low convex and smooth to slightly granular on blood agar
and may produce a green area around them, like alpha-streptococci. After 7-14 days
the colonies are 1-2 mm in diameter on BHI agar, convex or umbonate, circular to
irregular, raised, opaque, white, soft and smooth or granular. Colonies of some
strains may have “molar-tooth” aspect, like those of A. israelii. After 2-14 days on
blood agar, the colonies are dark red in transmitted light and may be difficult to
subculture. Growth is turbid, sometimes flocculent, in BHI broth. Most strains are
serophilic. Facultative anaerobic. Grows best in presence of CO2. Grows at 35-37 ºC,
optimally. Alpha haemolysis may occur.
Oral cavity of man is normal habitat. There are two serotypes.
Isolated from deep dentinal caries in man.
- Slack J.M., 1975. Genus Actinomyces Harz 1877 . In: Buchanan R.E. and Gibbons N.E. (Editors), Bergey’s Manual of
Determinative Bacteriology, Eight Edition, The Williams & Wilkins Company, Baltimore, 660-667.
- Johnson J.L., Moore L.V.H., Kaneko B. and Moore W.E.C., 1990. Actinomyces georgiae sp. nov. , Actinomyces gerencseriae sp.
nov. , Designation of Two Genospecies of Actinomyces naeslundii, and Inclusion of A. naeslundii serotypes II and III and
Actinomyces viscosus serotype II in A. naeslundii Genospecies 2. Int J Syst Bacteriol Vol. 40, No. 3, 273-286.
Positive results for H2S production, methyl red, nitrate reduction, acid production from: fructose, glucose, glycerol & sucrose
Negative results for catalase, gelatin hydrolysis, indole production, starch hydrolysis, urease, Voges-Proskauer test, acid production
from: amygdalin, cellobiose, dulcitol, esculin, inositol, inulin, mannitol, mannose, melibiose, melezitose, raffinose, sorbitol &
Variable results for esculin hydrolysis, acid production from: adonitol, arabinose, glycogen, lactose, maltose, rhamnose, ribose,
salicin, starch & xylose.
(c) Costin Stoica