Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Actinomycinae, Family
Actinomycetaceae, Genus Actinomyces, Actinomyces gerencseriae Johnson, Moore, Kaneko and Moore, 1990.
Historical synonym: Actinomyces israelii serotype II.
Gram-positive filamentous cells with swellings; sometimes branching cells.
Non-motile. Non-spore-forming.
Colonies are slightly irregular to circular, translucent/opaque, white, lumpy, 0.2-2.0 mm
in diameter on blood agar incubated 48 h anaerobic. Alpha-haemolytic. Excellent
growth in peptone-yeast extract-glucose-broth. Facultative anaerobic or obligate
anaerobic. Grows at 37 ºC.
Isolated from the gingival crevices, parotide abscess and various other clinical specimens, and accounts for 1.2% of human healthy
periodontal flora (1990).
Isolated from mandibular abscess, cervicofacial actinomycosis, retroperitoneal abscesses, hand abscesses and other clinical
specimens and accounts for 1.5% of periodontal flora 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, lactose, maltose, mannitol, mannose, raffinose,
ribose, sucrose, salicin, trehalose and xylose.
Negative results for catalase, gelatin hydrolysis, lecithinase, lipase, starch hydrolysis, urease, acid production from: L-arabinose,
glycerol, glycogen and sorbitol.
Variable results for nitrate reduction, acid production from: amygdalin, cellobiose, esculin, inositol, melezitose, melibiose, rhamnose
and starch.
(c) Costin Stoica