Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Actinomycinae, Family
Actinomycetaceae, Genus Actinomyces, Actinomyces georgiae Johnson, Moore, Kaneko and Moore, 1990.
Historical synonyms: Actinomyces D08.
Gram-positive swellings rods, shorter and even coccoid in broth medium without a
fermentable carbohydrate, occurring in pairs and short chains, branching is seldom
seen. Non-motile. Non-spore-forming.
Colonies are round with entire edges, pulvinate, translucent / opaque, white / beige,
shiny, smooth, 0.5-2.0 mm in diameter on blood agar incubated anaerobically.
Grows well in peptone-yeast extract-glucose-Tween 80 broth with/without turbidity and
smooth/flaky/granular sediment that occasionally adheres to the bottom of the tube.
Alpha-haemolysis may occur. Facultative anaerobic. Grows at 37 ºC, optimally.
Isolated from the gingival crevices and accounts for 1.4% of human healthy periodontal flora (1990).
Isolated from patients with gingivitis and periodontitis.
- 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 esculin hydrolysis, acid production from: fructose, glucose, glycogen, lactose, maltose, rhamnose, ribose, starch,
sucrose & xylose.
Negative results for catalase, starch hydrolysis, urease, acid production from: amygdalin, arabinose, cellobiose, esculin, melibiose,
melezitose, raffinose, salicin, sorbitol & trehalose.
Variable results for nitrate reduction, gelatin hydrolysis, acid production from: glycerol, inositol, mannitol & mannose.
(c) Costin Stoica