Multi-resistant biofilm-forming pathogens on the International Space Station

ABSTRACT

The International Space Station (ISS) is a confined and closed habitat with unique conditions such as cosmic radiation, andmicrogravity. These conditions have a strong effect on the human and spacecraft microflora. They can affect the immuneresponse of the crew-members, thus posing a threat to their health. Microbial diversity and abundance of microorganismsfrom surfaces, air filters and air samples on the ISS have been studied. Enterobacteriaceae, Bacillus spp., Propionibacterium spp., Corynebacterium spp., and Staphylococcus spp. were among the most frequently isolated bacteria. Microbialgrowth, biofilm formation, stress response, and pathogenicity are affected by microgravity. Increased resistance toantibiotics in bacteria isolated from the ISS has often been reported. Enterococcus faecalis and Staphylococcus spp. isolatesfrom the ISS have been shown to harbor plasmid-encoded transfer genes. These genes facilitate the dissemination ofantibiotic resistances. These features of ISS-pathogens call for novel approaches including highly effective antimicrobialswhich can be easily used on the ISS. A promising material is the antimicrobial surface coating AGXX, a self-recyclingmaterial consisting of two noble metals. It drastically reduced microbial growth of multi-resistant human pathogens, such asstaphylococci and enterococci. Further novel approaches include the application of cold atmospheric plasma for thesterilization of spacecrafts.