A bacteria that belongs to the order Actinomycetales: Some of the actinomycetes are pathogenic for animals and humans.

Two types of actinomycetes are the eubacteria and the true bacteria which are in a large group of bacteria that have rigid wall cells or, flagella when they are motile.

The actinomycetes comprise a broad group of bacteria that grow slowly as branched filaments, as the ray fungus.