ABSTRACT
The genus Actinomyces encompasses a large number of gram-positive, nonspore-forming, anaerobic, or facultatively anaerobic bacterial species belonging to the family Actinomycetaceae, order Actinomycetales, phylum Actinobacteria, domain Bacteria. While individual Actinomyces bacteria are rods of <1 µm in diameter, Actinomyces colonies on nutrient medium are irregular in form with radiant edges, consisting of fungus-like branched networks of hyphae.
