GALVESTON, Texas When the space shuttle Endeavour touched down at the Kennedy Space Center August 22, University of Texas Medical Branch at Galveston microbiology and immunology department chairman David Niesel was waiting by the runway, looking forward to a reunion with some of its passengers.
The space travelers Niesel was meeting werent astronauts. They were Streptococcus pneumoniae bacteria, members of a species commonly found in the human upper respiratory tract but in this case riding in sealed experimental containers in the shuttles mid-deck.
Streptococcus pneumoniae is whats known as an opportunistic bacterium, one thats normally harmless but always ready to exploit the right circumstances and cause full-blown disease. For infants, the elderly and others with weaker-than-normal immune systems possibly including astronauts on long space flights it can be quite dangerous.
Strep pneumoniae is a very potent pathogen in people who are immunosuppressed its the number-one cause of community-acquired pneumonia, and a leading mediator of bacteremia [bacterial blood infections] and meningitis, Niesel said. Theres a decline in peoples immune function the longer theyre in the space environment, and its been shown that other bacteria also alter their properties in microgravity they grow faster, they tend to be more virulent and resistant to microbial treatment.
Niesel and other investigators want to know exactly how Streptococcus pneumoniae changes in microgravity and whether those changes could pose a threat to crew members on a mission with no chance of a quick return to Earth for example, a months- or years-long journey to Mars and back. In 1999, they began work on SPEGIS (Streptococcus pneumoniae Expression of Genes in Space), a project to grow the bacteria in orbit and bring them back home frozen in zero-g mode for study.
Eight years later, six tightly sealed vials of the bugs were launched into orbit in
|Contact: Jim Kelly|
University of Texas Medical Branch at Galveston