Epidemiology of Staphylococcus aureus during space flight

Area of Science:

• Microbiology
• Space Science
• Genomics

Background:

• * Staphylococcus aureus (S. aureus) is a common bacterium that can cause infections.
• * Understanding microbial dissemination in closed environments like spacecraft is crucial for crew health.
• * Previous studies have not extensively characterized S. aureus strains carried by astronauts.

Purpose of the Study:

• * To investigate the dissemination and retention patterns of Staphylococcus aureus among Space Shuttle crewmembers.
• * To determine if S. aureus strains are unique to individuals or shared within the crew.
• * To assess the potential for microbial transfer between crewmembers and the spacecraft environment.

Main Methods:

• * Collection of samples (nasal, throat, urine, feces, air, surface) from crewmembers before and after space missions over two years.
• * DNA fingerprinting of S. aureus isolates using SmaI restriction endonuclease digestion.
• * Analysis of DNA fragments via pulsed-field gel electrophoresis (PFGE).

Main Results:

• * Each crewmember consistently carried a unique S. aureus strain, identified by DNA fingerprinting.
• * Limited instances of S. aureus transfer were observed between crewmembers.
• * Bacterial strains found on interior shuttle surfaces after flight matched those carried by crewmembers.

Conclusions:

• * Astronauts primarily harbor individual S. aureus strains during space missions.
• * Microbial fingerprinting of S. aureus can effectively track strain dissemination and retention in isolated environments.
• * The findings suggest potential forensic applications for microbial fingerprinting in spacecraft.