A genus of nonmotile, nonsporeforming, facultatively anaerobic bacteria (family Actinomycetaceae) containing Gram-positive, non-acid-fast, branched, Primarily propionic and acetic acids are produced from glucose. Catalase is not produced. The cell wall contains diaminopimelic acid but not arabinose. These organisms are pathogenic for man, causing lacrimal canaliculitis and typical actinomycosis. The type species is Arachnia propionica.

Arachnia propionica