Protecting Astronauts from Infectious Disease During Long-duration Space Missions

These investigators have studied the enteric bacterial pathogen, S. typhimurium, when grown in the true microgravity environment of spaceflight, as well as in a ground-based spaceflight-analog bioreactor culture system that mimics aspects of microgravity. Both the spaceflight-grown and bioreactor-grown bacteria had widespread alterations in expression of genes distributed globally throughout the chromosome as compared to control cultures. The spaceflight-grown and bioreactor-grown S. typhimurium were also found to be more virulent than control cultures in animal infection studies. The investigators identified a global regulatory mechanism for this spaceflight-induced genetic effect that also may explain the increased virulence. This research has revealed a potential threat to crewmembers on long-duration spaceflight as a consequence of adaptations of microbes to the spaceflight environment. It has also identified a mechanism by which these changes may be brought about, which could lead to development of effective countermeasures for spaceflight and toward better insight into mechanisms of pathogens that cause infections on Earth and novel strategies to combat infectious disease.