A microbiologist visited the ISS to see what else lives there besides human beans, and to offer NASA some advice on how to keep the crews healthy.

npr.org

“Staphylococcus aureus we’ll find once in a while; Staphylococcus epidermidis all the time,” says Castro-Wallace, running down a list of resident space station microorganisms. There’s also Staphylococcus hominis (usually harmless), Micrococcus luteus (lives in the mouth and throat), Burkholderia (common in soil; some types can cause lung infection), Sphingomonas (common in water, and rarely harmful), Penicillium (the fungus we find in bread mold) and Aspergillus (more mold), just to name a few.

Recently, an entire wall panel of the station turned green with mold.

“Imagine your shower curtain at its worst,” says Castro-Wallace, pointing out that the wall of mold happened on the Russian side of the space station.

She’s particularly interested in Staph. aureus; a strain of the bacterium that’s resistant to multiple drugs is a particular problem in hospitals, and can turn something as simple as a paper cut dangerous.