Anaerobic gram positive rod, P. acnes. As of 2018 (PubMed), P. humerusii, P. namnetense, P. acnes , P. avidum, P. granulosum are all now Cutibacterium. For now (1/1/18) I am not going to change the text in the Compendium until the name change is more established.
Lives in hair follicles, sweat and sebaceous glands and environment that protects it from both topical and systemic antibiotics (PubMed).
Often a contaminant in the LP that grows on day 5 in the thio only.
Post op wound infections where there is hair, often associated with devitalized tissue or prosthetic material. There can be months between the surgery and the clinical manifestation of the disease. Given its association with hair, it is found as a problem with neurosurgical operations: VP shunts, laminectomy infections, craniotomy infections, discitis is a commoner manifestation.
De novo infected discs can have anaerobes, including P. acnes. If the MRI is the right type (disc herniation with Modic Type 1) the herniated disc may indeed be infected (PubMed) (Review)(PubMed), although not supported in all studies, as is so often the case (PubMed).
Propionibacterium acnes may be a cause of prosthetic joint infections (PubMed), especially after shoulder surgery (PubMed). My son, at this writing six years old, uses the word worser; I have taken the liberty of extending the neologism. Perhaps because it is normal flora, the ususal inflammatory markers may be normal. Make sure the lab knows and holds the cultures for longer than the usual 5 days; it often doesn't grow until after day 7.
The odd infection associated with other hardware like fractures.
Occasional endocarditis ususally prosthetic valve; I have seen two. Often prosthetic valve, in men (the furry gender), often require valve surgery (PubMed).
P. avidum associated with prosthetic joint infections (PubMed).
In a series of 522 patients with P. acnes bacteremia, 3.5% of isolates turned out to be significant (PubMed). I do not think I have seen one, much less 522. Makes one wonder about their blood culture technique, or perhaps it was an adolescent hospital.
It may cause/be associated with the SAPHO syndrome (seronegative arthritis associated with skin manifestations and to show synovitis, acne, pustulosis, hyperostosis, and osteitis with and without sterile multifocal osteomyelitis. Sounds unpleasant) and treatment decreases symptoms (Online ref).
Although I often say the three most dangerous words in medicine are "In my experience", in my experience clindamycin works better. So there. BTW. It is usually resistant to metronidazole.
My record has been 7 years between the craniotomy and a symptomatic subdural empyema, That duration is not unusual in the literature.
Propionibacterium freudenreichii subsp. shermanii is used in cheesemaking to create CO2 bubbles that become the round holes in Swiss cheese.
Relevant links to my Medscape blog
Last Update: 04/16/18.