Because of a general lack of starting material, analysis of the skin microbiome mostly has been limited to analysis of those microbes on skin swabs or scrapings [20–22]. To analyze skin viral populations, Foulongne et al. recently used high-throughput sequencing techniques to sequence the skin metagenome, and to analyze those viruses present by targeted analysis of viral reads [23]. In most human sample types, the majority of the viruses X-396 solubility dmso present have been identified as bacteriophage [1–3, 19], which may reflect the 10 to 1 proportion

of bacterial to human cells in these environments. In analysis of the skin virome, however, bacteriophage constituted only a small proportion of the metagenome sequences [23]. By examining the CRISPR spacer profiles of the skin, we may improve our understanding of the sequence features of viruses to which skin bacteria have previously encountered. Study of the human microbiome has detailed unique populations of microbes inhabiting different body surfaces. While the oral cavity and the skin surfaces differ substantially in their bacterial constituents, they share some bacterial genera including some species from the genus Streptococcus[24]. Streptococci generally are present on the skin and in the saliva of most humans [25–28], and represent a substantial proportion

of the oral microbiota and a much smaller proportion of the skin microbiota [29–33]. The human oral cavity is known to harbor various types of viridans streptococci, including S. mutans, S. gordonii, S. oralis, S. mitis, INCB024360 order S. milleri (includes S. anginosus, S. constellatus, and S. intermedius), S. sanguinis, and S. parasanguinis, and also some non-viridans streptococci, including S. bovis (includes S. gallolyticus, S. equinus, and S. infantarius, among others). PJ34 HCl The skin generally harbors different species of streptococci, including S. pyogenes and S. agalactiae, which

belong to Lancefield groups A and B, respectively. The skin also is known to harbor streptococci that belong to Lancefield groups C and G [24]. In this study, we sought to characterize the CRISPR profiles present in a cohort of human subjects on both their skin and in their oral cavities. Our goals were to determine whether there were similar CRISPR profiles among streptococci on human skin and saliva, whether CRISPR content on the skin and saliva was relatively conserved over time, and whether there were CRISPR spacers present on human skin that matched viruses present in saliva. Results CRISPR spacer sequencing We sampled 4 human subjects with good overall cutaneous and periodontal health, collecting skin swabs and saliva samples 3 times per day on days #1, #2, #4, #14, #28, and week #8. Skin and saliva samples were collected at the same time in the AM prior to breakfast or oral hygiene (AM), approximately noon each day before lunch (Noon), and in the early evening prior to dinner [34].