Ac.ti.no.my'ces. Gr. fem. n.
aktis, aktinos
ray; Gr. masc. n.
mukês
fungus; N.L. masc. n.
Actinomyces
ray fungus referring to the radial arrangement of filaments in
Actinomyces bovis
sulfur granules.
Actinobacteria / Actinobacteria / Actinomycetales / Actinomycetaceae / Actinomyces
Straight or slightly curved rods
, 0.2–1.0 µm in diameter, which vary considerably in shape and size, and
slender filaments
, 1 µm or less in width and 10–50 µm or more in length,
with true branching. Short rods
(0.5–5.0 µm in length)
with or without clubbed ends
are frequently seen and
may occur singly, in pairs with diphtheroidal arrangements
(Y, V, T forms and palisades),
in short chains or in small clusters.
Longer (5.0–10.0 µm in length) branched rods are also common. Several members of the genus appear chiefly or exclusively as
coccobacillary or even coccoid elements. Filaments
which may predominate in certain species
are either straight or wavy
, show varying degrees of
branching
and may have
swollen, clubbed, or clavate ends. Gram‐stain‐positive
, but irregular staining giving rise to a beaded or barred appearance frequently occurs, and two species may be Gram‐stain‐variable.
Non‐acid‐fast, nonmotile, and non‐endospore‐forming.
Conidia are not produced.
DNA G+C content (mol%)
: 55–71 (
T
m
, HPLC).
Type species
:
Actinomyces bovis
Harz 1877, 133
AL
.