Brevibacterium is a genus of bacteria of the order Actinomycetales. This order is comprised of radial fungi.They are bacilli(rod-shaped), and in some phases of life they are, more particularly, club-shaped. They are Gram-positive soil organisms that occur commonly in nature in the soil, water, plants, and food products.
They are widely distributed in nature in the microbiota of animals and are mostly innocuous. They can cause disease in humans, most notably through diphtheria. Though not usually pathogenic, Brevibacterium ammoniagenes can occasionally opportunistically capitalize on atypical access to tissues (via wounds) or weakened host defenses.
Brevibacterium ammoniagenesare of low pathogenicity and are considered secondary invaders. They generally require a major break in the host’s immunological defenses to cause significant infection. In such cases, diphtheria, is the most prominent condition.