Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Actinomycinae, Family
Actinomycetaceae, Genus Actinomyces, Actinomyces johnsonii Henssge, Do, Radford, Gilbert, Clark and Beighton, 2009.
Historical synonyms: Actinomyces naeslundii genospecies WVA 963 Johnson et al., 1990 (Thompson and Lovested 1951);
Actinomyces naeslundii serotype WVA 963 Johnson et al., 1990 (Thompson and Lovested 1951).
Gram-positive diphtheroid rods, sometimes occurring in curved or branched filaments.
Non-motile. Non-spore-forming. Non-acid-fast.
Colonies are flat, round with entire edges, small after 24 h on BHI agar; after 7-14 days
the colonies are 1-3 mm in diameter, convex, smooth or finely granular, white and soft.
In BHI broth grows as a flocculent mass to the top with discreet soft granules below.
Alpha-haemolysis may occur. Facultative anaerobic. Grows at 35-37 ºC, optimally. No
growth at 25 ºC.
Isolated from the gingival crevice of healthy children and gingival crevice of an adult with progressive periodontitis.
Undetermined.
- 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.
- Henssge U., Do T., Radford D.R., Gilbert S.C., Clark D. and Beighton D., 2009. Emended description of Actinomyces naeslundii
and descriptions of Actinomyces oris sp. nov. and Actinomyces johnsonii sp. nov., previously identified as Actinomyces naeslundii
genospecies 1, 2 and WVA 963. Int J Syst Evol Microbiol. 59, 509-516.
- 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.
Decription is based on API Rapid ID 32A results.
Positive results for alpha-fucosidase, alpha- and beta-galactosidase, alpha- and beta-glucosidase, leucine arylamidase, methyl red,
nitrate reduction, acid production from: fructose, glucose, inositol, maltose, melibiose, raffinose and sucrose.
Negative results for arginine dihydrolase, catalase, esculin hydrolysis, gelatin hydrolysis, hippurate hydrolysis, indole production,
beta-glucuronidase, N-acetyl-beta-glucosaminidase, pyrrolidonyl arylamidase, starch hydrolysis, Voges-Proskauer test, acid
production from: amygdalin, arabinose, mannitol, melezitose, rhamnose and xylose.
Variable results for alkaline phosphatase, urease, acid production from: cellobiose, esculin, glycogen, lactose, mannose, ribose,
salicin, sorbitol, starch and trehalose.
(c) Costin Stoica