Propionibacterium Infections

Updated: Feb 12, 2018
  • Author: Sajeev Handa, MBBCh, BAO, LRCSI, LRCPI; Chief Editor: Mark R Wallace, MD, FACP, FIDSA  more...
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Propionibacterium species are nonsporulating, gram-positive anaerobic bacilli that are considered commensal bacteria on the skin. They are usually nonpathogenic and are common contaminants of blood and body fluid cultures. These species are slow-growing and require at least 6 days for growth in culture. [1]

Propionibacterium species belong to the genera of coryneforms and are the best studied because of their association with acne vulgaris. Propionibacterium species, however, can also cause numerous other types of infections, including endocarditis, postoperative shoulder infections, and neurosurgical shunt infections. These are discussed later in the article and are classified as ”endovascular”, ”orthopedic”, ”neurosurgical”, and ”other” infections.

Propionibacterium acnes is found briefly on the skin of neonates, but true colonization begins during the 1-3 years prior to sexual maturity. During this time, numbers of P acnes rise from fewer than 10/cm2 to about 106/cm2, chiefly on the face and upper thorax. P acnes grows in the lipid-rich microenvironment of the hair follicle. In acne vulgaris, P acnes produces inflammatory mediators that result in acne papules, pustules, and nodulocystic lesions.

Propionibacterium granulosum is found in the same areas but at numbers about one hundredth of those of P acnes.

Both P acnes and P granulosum may be isolated from the gastrointestinal tract.

Propionibacterium avidum is found in the axilla rather than on exposed areas and increases in numbers at puberty.

Propionibacterium propionicus has been implicated as a less-common causative agent of a disease process similar to that of actinomycosis. The most common cause of actinomycosis is Actinomyces israeli infection. 




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Acne vulgaris is sufficiently common that it may be considered physiologic.

There are limited data in the literature quantifying the exact incidence of Propionibacterium endovascular, orthopedic, or neurosurgical shunt infections as frequently their pathogenic potential is overlooked given that it is considered to be of low virulence. The ability of P acnes to adhere to and form a biofilm, particularly on prosthetics, for example, is characteristic of the infections that it may cause.


As noted above, data are limited concerning the incidence of Propionibacterium species infections for numerous reasons.

A review performed in 2006 by Clayton et al looked at the world literature available for cases of endocarditis caused by Propionibacterium over the preceding 25 years. [2] In addition to 3 of their own cases, 36 additional cases were identified. Fourteen cases (42.4%) involved native valves, 16 (48.5%) involved prosthetic valves, and 3 (9.1%) were associated with intracardiac prosthetic material. Ten of the 14 (71.4%) patients with native valve infection had an underlying cardiac factor predisposing to infection. In this group, the valves most commonly affected were the mitral and aortic valves, while those with prosthetic valves were more likely to have aortic valve involvement rather than mitral valve involvement, partly because of the pattern of the valves replaced. Twenty-nine of the cases were due to P acnes, 3 were due to P granulosum, and 1 was an unspecified Propionibacterium species.


Propionibacterium species endovascular, orthopedic, and neurosurgical infections remain problematic, causing significant morbidity and mortality in affected patients.


Acne appears to be a familial condition and is less common in Japanese people than in the white American population.


Acne tends to develop at earlier ages in girls than boys. The peak of acne activity occurs during the mid-to-late teenaged period, and the incidence subsequently decreases. Acne is equally common in males and females, but tends to be more severe in males. [3]


Acne vulgaris is a chronic disease that involves the sebaceous follicles, primarily in adolescents. In some cases, it is present at birth, and mild cases of acne vulgaris may be observed in the neonatal period. During puberty, acne typically becomes a common problem. Acne develops in adolescents during adrenarche, when sex hormone levels and subsequent sebaceous gland stimulation occurs. In young individuals, the predominant lesions are comedones, and inflammatory lesions are less common.