Actinomyces odontolyticus

RANK: Species

TAXONOMY: Terrabacteria group -> Actinobacteria -> Actinobacteria -> Actinomycetales -> Actinomycetaceae -> Actinomyces -> Actinomyces odontolyticus


Actinomyces odontolyticus is an anaerobic, facultative capnophilic, gram-positive, nonsporulating, non–acid fast, non-motile, irregularly staining bacterium. Sometimes short or medium-sized rods resembling diphtheroids are seen. Shorter rods resembling propionibacteria are frequently seen with A. odontolyticus and may be arranged in palisades as well as other diphtheroidal arrangements. On blood agar, the bacteria develop as small, irregular, whitish colonies that are smooth to slightly granular and show a dark red pigment when mature (2–14 days). This pigmentation is most obvious when the cultures are left standing in air at room temperature after primary anaerobic isolation. The organism also grows well on CNA and Brucella agar. Clinical disease in patients with A. odontolyticus closely resembles disease caused by A. israelii and other actinomyces species. Similar to A. israelii infections, those caused by A. odontolyticus primarily involve the cervicofacial regions, the chest, abdomen, and pelvis with rare involvement of the central nervous system, bones, and joints. Additional similarities include a more frequent occurrence in men than women and a peak incidence in the middle decades of life. Clinical features in 97% of 181 patients with actinomycosis including the following: mass or swelling, pulmonary disease, draining abscesses, abdominal disease, dental disease, and intracranial infection . See: as a constituent of the oral microbiome by Human Oral Microbiome Database.

This species has been identified as a resident in the human gastrointestinal tract based on the phylogenetic framework of its small subunit ribosomal RNA gene sequences.[PMC 4262072]

Gut associated
Oral microbiome