SPACE — Researchers from the California Institute of Technology studied bacteria retrieved from the ISS space toilet and exercise platform.

According to their study published in the journal BMC Microbiology, all five strains that were analyzed proved to be resistant to several common antibiotics such as penicillin, rifampin, cefazolin, cefoxitin and oxacillin among others. They showed a level of intermediate resistance for ciprofloxacin and erythromycin.

Researchers reported that the microbes found on the ISS are a variety of the Enterobacter, a bacterium that causes diseases in newborns and people with weak immune systems.

According to experimentation through computer modelling, there is a 79 percent chance that the bacteria could be pathogenic — or likely to cause a disease in humans.

Researchers are concerned about the health risks the propagation of such bacterias could pose for astronauts in future missions.

The team stated that ''in vivo" experiments would help further understand the true levels of pathogenicity of the bacteria in humans.

For now the bacteria are not threatening the lives of astronauts living in the ISS, but researchers will keep a close watch in order to prevent health risks for future expeditions.