General InformationPropionibacterium species are nonsporulating, gram-positive anaerobic bacilli that are considered commensal bacteria on the skin. These species are slow-growing and require at least 6 days for growth in culture.
HistoryP. acnes was originally Corynebacterium acnes until two researchers named Douglas and Gunter proved that it was more closely related with the Propionibacterium. They proposed that Propionibacterium be modified to include bacteria that do not ferment lactose into propionic acid; and that C. acnes should then be changed to P. acnes. It was later discovered that P. acnes does actually ferment lactose into propionic acid under
FoodThe holes come from a byproduct of some of the microbes added to milk to make Swiss cheese. Specifically, there are three primary types of bacteria that are typically used to make Swiss cheese (these can vary slightly depending on the manufacturer): Streptococcus thermophilus; Lactobacillus helveticus; and Propionibacterium shermanii.The first two types of microbes produce significant amounts of lactic acid, which is, in turn, consumed by the latter type of microbes, Propionibacterium shermanii. It is this Propionibacterium shermanii that is responsible for the holes in Swiss cheese. Through the process of consuming the lactic acid, the shermanii produces acetate, propionic acid, and carbon dioxide as a byproduct.The acetate and propionic acid give the Swiss cheese much of its distinct flavor, while the carbon dioxide forms bubbles within the cheese block or wheel. These carbon dioxide bubbles are left in as the cheese continues to ferment, rather than pressing them out, which gives Swiss cheese its distinctive holes. Historically, however, these holes were seen as an
SymptomsPropionibacterium 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
TreatmentAcne vulgaris: Topical and oral agents act at various stages in the evolution of an acne lesion and may be used alone or in combination to enhance efficacy.