Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Actinomycinae, Family
Actinomycetaceae, Genus Actinomyces, Actinomyces gerencseriae Johnson, Moore, Kaneko and Moore, 1990.
Historical synonyms: Actinomyces israelii serotype II.
Gram-positive filamentous cells with swellings; sometimes branching cells.
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 (1990)
- 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 & xylose.
Negative results for catalase, gelatin hydrolysis, lecithinase, lipase, starch hydrolysis, urease, acid production from: L-arabinose,
glycerol, glycogen & sorbitol.
Variable results for nitrate reduction, acid production from: amygdalin, cellobiose, esculin, inositol, melezitose, melibiose, rhamnose
(c) Costin Stoica