| MadSci Network: Microbiology |
Your reference to 'bacteria living at the base of human eyelashes' could refer to many species of bacteria that are comonly found on the skin. Members of the genus Priopionibacterium, Streptococcus and Staphylococcus are all commonly found on human skin. The 'proper' generic term for these bacteria would be 'members of the normal skin flora.' Their distinct 'purpose' is more difficult to answer in terms of a functional aspect. As the skin is ever in contact with microbes in the air, water and soil, it is unavoidable that they should be present on our skin. Unlike other areas of the body such as the mouth or the digestive tract, the skin is a harsher environment for bacteria to colonize. It is generally very dry, has fewer avilable sources of food, and is readily exposed to oxygen in the atmosphere. Bacteria that can live on the skin tend to be aerotolerant (either require oxygen for growth, or can tolerate its presence) and somewhat resistant to drying out.