Current clinical and microbiological information on acne fail to demonstrate a clear association between particular species, including Propionibacterium acnes, and disease, and the disease continues to be a considerable problem. To test if acne is associated with hitherto uncultured bacteria residing in diseased skin follicles, sequencing and phylogenetic analysis of approximately 5,700 amplified and cloned 16S rRNA genes were used to determine the microbial diversity in follicles from acne patients and healthy individuals and from superficial skin of acne patients. Follicles from healthy skin were exclusively colonized by P. acnes, whereas the follicular microbiota of acne patients, in addition, included S. epidermidis and minor proportions of other species. In comparison, samples from superficial skin showed a complex microbiota with 12 to 16 bacterial species represented. The study excludes that acne is associated with yet uncultured bacteria and shows that healthy skin follicles constitute a remarkably exclusive habitat allowing colonization only by P. acnes.
Journal of Clinical Microbiology, 2008, Vol 46, p. 3355-3360