Propionibacterium acnes

Propionibacterium acnes is a relatively slow growing, typically aerotolerant anaerobic gram positive bacterium (rod) that is linked to the skin condition acne; it can also cause chronic blepharitis and endophthalmitis, the latter particularly following intraocular surgery. The genome of the bacterium has been sequenced and a study has shown several genes that can generate enzymes for degrading skin and proteins that may be immunogenic (activate the immune system).

This bacteria is largely commensal and part of the skin flora present on most people's skin; and lives on fatty acids in the sebaceous glands on sebum secreted by follicles. It may also be found throughout the gastrointestinal tract in humans and many other animals. It is named after its ability to generate propionic acid.

When a pore is blocked, this anaerobic bacterium overgrows and secretes chemicals that break down the wall of the pore, spilling bacteria such as Staphylococcus aureus into the skin, and forming an acne lesion (folliculitis). It has also been found in corneal ulcers, and on very few occasions damaging heart valves leading to endocarditis, and infections of joints (septic arthritis) have been reported. Furthermore, Propionibacterium have been found in ventriculostomy insertion sites, and areas subcutaneous to suture sites in patients that have undergone craniotomy. Propionibacterium acnes can be found in bronchoalveolar lavage of approximately 70% patients with sarcoidosis and is associated with disease activity, however it can be also found in 23% of controls

Pic. P acnes

P. acnes can be killed by benzoyl peroxide, tetracycline group and other antibiotics, and many antibacterial preparations, including clove oil . Tetracycline-resistant P. acnes is now quite common. Clindamycin is also frequently used. New facts show that P. acnes is sensitive to some macrolides such as azithromycin, which has a wide spectrum of action. It is normally prescribed 500 mg by mouth, three times weekly for 4 to 6 weeks, but may have post-antibiotic effects by remaining concentrated in lung tissue for approximately 5 days after treatment stops. Fluoroquinolones may also be effective against P. acnes such as nadifloxacin, ciprofloxacin, ofloxacin and levofloxacin.[citation needed] They are active against P. acnes and some other microorganisms that are also part of the poly-infection