Propionibacterium

A genus of nonmotile, non–spore-forming, anaerobic to aerotolerant bacteria (family Propionibacteriaceae) containing Gram-positive rods that are usually pleomorphic, diphtheroid, or club shaped, with one end rounded, the other tapered or pointed. Some cells may be coccoid, elongate, bifid, or even branched. The cells usually occur singly, in pairs, in V and Y configurations, short chains, or clumps in “Chinese character” arrangement. The metabolism of these organisms is fermentative, and the products of fermentation include combinations of propionic and acetic acid s. These organisms occur in dairy products, on human skin, and in the intestinal tracts of humans and other animals. They may be pathogenic. The type species is P. freudenreichii.

- P. acnes a species of bacteria commonly found in acne pustules, although it occurs in other types of lesions in humans and even as a saprophyte in the intestine, skin, hair follicles, and in sewage.

- P. freudenreichii a bacterial species found in raw milk, Swiss cheese, and other dairy products; it is the type species of the genus P..

- P. jensenii a bacterial species found in dairy products, silage, and occasionally in infections.

- P. propionicus SYN: Arachnia propionica.

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pro·pi·oni·bac·te·ri·um .prō-pē-.än-ə-bak-'tir-ē-əm n

1) cap a genus (the type of the family Propionibacteriaceae) of gram-positive nonmotile usu. anaerobic bacteria that form propionic acid by fermenting lactic acid, carbohydrates, and polyalcohols and that include forms found esp. on human skin and in dairy products

2) pl -ria -ē-ə any bacterium of the genus Propionibacterium

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Pro·pi·on·i·bac·te·ri·um (pro″pe-on″ĭ-bak-tērґe-əm) [pro- + Gr. piōn fat + baktērion little rod] a genus of bacteria of the family Propionibacteriaceae, made up of non–spore-forming, anaerobic or aerotolerant, gram-positive rods. The organisms are found as saprophytes in animals and in dairy products, and occasionally cause soft tissue infections.