Urbacteria settle on human skin

Researchers discover archaea on human skin

12/10/2013

Archaea thrive under the most adverse conditions: extreme temperatures, hot springs and sludge, salt lakes and even the deep sea. Regensburg researchers have now discovered survivors on human skin. Accordingly, there is an interaction between the so-called archebacteria and humans.

Archaea in some people accounts for ten percent of all microorganisms on human skin
The microbiologist Christine Moissl-Eichinger from the University of Regensburg first discovered the primordial microorganisms in clean rooms in which space probes and spaceships are being built. The scientist suggested that the archebacteria could have entered the sterile environment only through contact with humans. On this basis, wipe samples of human skin were examined. In doing so, the researchers detected many archaea in all test subjects. „In some subjects Archaeen made even ten percent of all on the skin microorganisms, "it said in a statement of the University of Regensburg. „Previously, however, it was believed that archaea can not be found on human skin.“ Further findings of the bacteria in intensive care units of hospitals underpinned the results.

Using special staining methods, the archebacteria could be visualized under the microscope. The researchers discovered in addition to the other archaea and microorganisms of the group of so-called Thaumarchaeota. „This archaea group is found in many terrestrial and aquatic ecosystems. Thaumarchaeota are actively involved in the ammonium oxidation and thus play an essential role in the nitrogen cycle of the earth“, so the university. „Since these archaea are normally involved in the nitrogen cycle and the human skin is constantly excreting ammonium, the microorganisms may be in contact with the pH regulation of the skin, "Moissl-Eichinger suspects.

How an increased concentration of archaea on the human skin affects health is still unclear. Similarly, the scientists are researching an age-related relationship of microbial concentration on the skin. Their results were published by Moissl-Eichinger and her colleagues in the journal "PLOS ONE".

New microorganisms discovered
The scientist has previously made another spectacular find. Together with US colleagues, she first discovered the berry-shaped bacterium Tersicoccus phoenicis in clean rooms of NASA and ESA. What is special about this tiny microorganism is that it has already been detected in two locations, but 4,000 km apart, the Kennedy Space Center in Florida, USA, and the ESA Space Center in Kourou, French Guiana. Although the clean rooms should be thoroughly cleaned on a regular basis and should be sterile, bacteria will repeatedly enter these areas. „However, so far no organism could be detected at two different and widely separated locations“, informs the university. The results of the researchers were published in the journal „International Journal of Systematic and Evolutionary Microbiology“ released. (Ag)

Image: Sebastian Karkus