Microbial colonization of normal skin: Direct visualization of 194 skin biopsies.

Recent genetic studies have suggested the presence of numerous microbial species on and in the skin. We characterised microbial colonization of a large collection of skin biopsies from 194 healthy subjects by fluorescence assay. Forty per cent of all biopsies did not show any evidence for microbial colonization. Propionibacterium acnes was the sole predominant bacterial species in both sebaceous and non-sebaceous areas. Non- P. acnes species were present in approximately 30% of all colonized samples. . Only hair follicles and stratum corneum were colonized. Understanding of cutaneous microbiota requires validation from a variety of approaches and techniques.