Microbiology of folliculitis: a histological study of 39 cases

Abstract

Folliculitis is a common inflammatory skin syndrome. Several microbial organisms have been put forward as causative agents, but few studies visualized microbes directly in inflamed hair follicles. This retrospective study investigated bacterial and fungal colonization of inflamed hair follicles in patients with clinically diagnosed non-infectious folliculitis. Skin biopsies from 39 folliculitis patients and 27 controls were screened by fluorescence in situ hybridization (FISH) using broad-range bacterial and fungal probes and by immunofluorescence microscopy using a monoclonal antibody towards Gram-positive bacteria. Specific monoclonal and polyclonal antibodies towards Staphylococcus spp. and Propionibacterium acnes were applied for further species identification. Inflamed follicles were associated with bacterial colonization in 10 samples (26%) and fungal colonization in three samples (8%). Staphylococcus spp. were observed in inflamed follicles in seven samples (18%). Two samples were positive for P. acnes, which were identified as either type II or type IB/type III. Both Staphylococcus spp. and P. acnes were seen in macrocolonies/biofilm structures. In conclusion, one-third of patients with clinically diagnosed, non-infectious folliculitis exhibited microbial colonization with predominance of Staphylococcus spp.

Three dimensional distribution of Propionibacterium acnes biofilms in human skin

“…So far, transversal sectioning has mainly been performed in alopecia studies where few sections are evaluated with a diagnostic purpose . Observations of bacterial biofilms in hair follicles have only been momentary snapshots of the reality . Transversal sectioning and following of an individual hair follicle from top to bottom in a defined area of biopsy tissue has provided further insight into biofilm size and span throughout the hair follicle.…”

“…Propionibacterium acnes ( P. acnes ) is a common member of the skin bacterial landscape inhabiting pilosebaceous units and occurring often as biofilms . Biofilms are large matrix‐encased cell aggregations of >1000 bacterial cells recognized as the default evolutionary mode of microbial growth and are associated with an increased antibiotic tolerance and the ability to persist over time.…”

Propionibacteriumspecies and follicular keratinocyte activation in acneic and normal skin

“…Fungal bodies were identified during the microscopic observation based on membrane autofluorescence. This method displays high sensitivity when compared with PAS staining …”

Eradication of <i>Staphylococcus aureus</i> and MRSA in the Nares: A Historical Perspective of the Ecological Niche, with Suggestions for Future Therapy Considerations

“…In 2014, Jans et al presented further evidence in infected folliculitis patients of "large biofilm-like macro colonies in the deep part of the hair follicle [104]. Also in 2014, Ulmer et al stated that the hair follicles could be used as a reservoir for topically applied substances, and that "non-particular" topicals could be detected for up to four days in a follicle after delivery [105].…”

“…[103] Large biofilm-like macro colonies have been observed in the deep part of the hair follicle. [104] Certain topicals could be detected for up to 4 days in a follicle after delivery.…”