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Evaluation of an antimicrobial agent in reducing contamination of Staphylococcus epidermidis for spaceflight applications.   S.C. Figy1, and M.P. Hodges2  1 Siena College, Loudonville, NY 2The Bionetics Corporation, Kennedy Space Center FL.

   Microbial contamination of space hardware creates unique problems. Astronauts often experience suppression of their immune systems during spaceflight.  Consequently, microbial exposure within spacecraft may offer an increased health risk relative to the dangers bacteria pose on earth. Measures are taken to keep payloads and equipment aseptic prior to launch, including sterilization by cleansing with alcohol, addition of iodine, and heating to a germicidal temperature.  However, the benefits to these approaches are fleeting since humans host a natural flora of microbes which are brought onto spacecraft. Currently, there are no approved preventative antimicrobial agents being used on the Space Shuttle or the International Space Station during flight.  Therefore, an evaluation of a preventative antimicrobial agent (AMA) was performed using Staphylococcus epidermidis, a representative bacterium naturally found on human skin.  To determine the efficacy of AMA, the antimicrobial was applied to sterile fabric.  AMA treated swatches were inoculated with a sample of S. epidermidis of known concentration over several time periods. The swatches were gently sonicated in buffer, and pour plates were created using serial dilutions of the buffer.  After incubation, the colony forming units were recorded and the data analyzed.  It was discovered that there was a significant reduction in bacterial contamination when AMA was applied.  As the concentration of AMA was reduced, the efficacy remained constant.