Researchers at New York University’s  School of Medicine report that they have found 182 species of bacteria in skin samples—and that 8% of them are unknown species that had never before been identified. According to the study, some of the bacteria on the skin appear to be permanent residents, while others are transient.

For the study, the researchers took swabs from the inner right and left forearms of six individuals. Because they also wanted to study change over time, they took swabs from four of the individuals 8 to 10 months after the first test.

The six individuals differed in the overall composition of the bacterial populations on their skin. They only had four species of bacteria in common: Propionibacterium acnes, Corynebacterium tuberculostearicum, Streptococcus mitis, and Finegoldia AB109769.

Almost three fourths of the total number of bacterial species were unique to the individuals, suggesting that the skin surface is highly diversified in terms of the bacteria it harbors.

According to the researchers, the sample is too small to draw conclusions. They believe that women and men may harbor some different bacterial species on their skin. The next step for the research team is to look at diseased skin, such as psoriasis or eczema to determine if it contains microbes.

[www.newswise.com, January 31, 2007]