Objectives
Microorganisms are ubiquitous in spacecraft environments, as they are on Earth. Microbes pose several risks to humans in space including infectious diseases, allergies, degradation of air quality (e.g. release of volatiles), release of toxins, degradation of critical materials, and systems failure (e.g. water reclamation system). Maintaining the health and performance of humans in closed environments in microgravity while reusing reclaimed water is a duanting task. Determining medical and technological risks which are dependent on microbiological factors during long-term space flight is a vital problem in theory, as well as in practice. In such a closed environment, the humans will be a major source of microbes released into the spacecraft. Some microbial species will thrive and some will disappear, resulting in a unique microbiota in the spacecraft. Since the Mir was launched in 1986, the space station has been occupied continuously. Therefore, it is logical to assume that Mir has developed an environmental microbiota of its own which cannot be compared with the indoor microbial load of any terrestrial habitat. These conditions make the Mir Space Station an ideal place for studying the interactions of microbes with the spacecraft environment and crewmembers.
The objectives of this experiment were to characterize the microbiota of crewmembers, air, surface, and water microbes before, during, and after a long-duration mission aboard the Mir Space Station, and to determine the exchange and distribution of microbes throughout the Mir Space Station.
Shuttle-Mir Missions Approach
Air Microbiology: Air samples were collected from each Shuttle before and after launch using a Russian supplied impaction air sampler, in which a small fan unit draws a known volume of air through a sampler and airborne particles are impacted onto nutrient growth media. The number of colonies found on the surface of the culture media was used to determine the total bacteria and fungi present in the volume of air sampled. Samples were collected from four locations in the Mir, including the control panel #1, dining table, in the Commander's cabin and the Kristall Module hatch.
Water Microbiology: Water samples were collected from the Mir and processed using the Water Microbiology Kit. The kit contained a microbial capture device through which a water sample volume was processed. An ampuole containing nutrient growth medium was introduced into the microbial capture device to cultivate any microorganisms trapped on the filter. Unprocessed water samples were collected using the Water Sampler/Archiver. These archived samples and the processed water sample filters were returned for ground-based examination.
Surface Microbiology: Surface samples were collected using the Surface Sampler Kit from five locations in the Mir, including the Commander's seat, the dining table, Commander's cabin, the treadmill handle, and the wall above the Kristall Module hatch. The Surface Sampler Kit is a flexible plastic tray containing a microbial growth medium. After the medium was pressed into contact with a sample area, microorganisms from that are were captured on the growth medium. The kit was returned to Earth for analysis of the microbiota collected.
Results
Microbial water analysis was successfully performed for the first time aboard a spacecraft during the Mir-18 mission. The surface and water-borne bacterial and fungal loads were mostly within the limits set for the International Space Station. However, fungal counts in the air tended to be higher. In general, the microbiological profile of the Mir was comparable to that of the Shuttle and Spacelab.
Earth Benefits Publications
Koenig, D. W., Novikova, N. D., Mishra, S. K., Viktorov, A. N., Skuratov, V., Lizko, N. N., and Pierson, D. L. 1996. Microbiology investigations of the Mir Space Station and flight crew. American Society for Microbiology, New Orleans, LA.
Pierson, D. L. and Konstantinova, I. V. 1996. Reactivation of latent virus infections in the Mir crew. American Society for Microbiology, New Orleans, LA.
Sauer, R. L., Pierson, D. L., Limardo, J. G., Sinyak, Y. E., Schultz, J. R., Straub, J. E., Pierre, L. M., and Koenig, D. W. 1996. Assessment of the potable water supply on the Russian Mir Space Station. American Institute of Aeronautics and Astronautics. Life Sciences and Space Medicine Conference, Houston, TX.
Koenig, D. W., Bruce, J. L., Bell-Robinson, D. M., Ecret, L. D., Zakaria, Z., and Pierson, D. L. 1997. Analysis of bacteria isolated from water transferred from the Space Shuttle to the Mir Space Station. American Society for Microbiology, Miami, FL.
Pierson, D. L. and Viktorov, A. N. 1997. Microbiology of the Russian Space Station Mir. Society for Industrial Microbiology, Reno, NV.
Pierson, D. L., Viktorov, A. N., Lizko, N. N., Novikova, N. D., Skuratov, V., Groves, T. O., Bruce, R. J., Mishra, S. K., and Koenig, D. W. 1997. Microbiology of the Mir Space Station and flight crew during the Mir 19 mission. American Society for Microbiology, Miami, FL.
Mehta, S. K., Lugg, D. J., Payne, D. A., Tyring, S. K., and Pierson, D. L. 1998. Epstein-Barr Virus reactivation in spacecraft and ground-based analogs. American Society of Gravitational Biology, Houston, TX.
Principal Investigators
Aleksandr N. Viktorov, Ph.D. Co-Investigators
Mir-18, Mir 19
Crew Microbiology: Before and after flight, microbial samples were collected by swabbing the throat, nose, ear, hand, scapula, axilla, and groin. Urine and fecal samples were collected in sterile specimen containers. After the mission the samples from the crewmembers were examined for bacteria, fungi, ova and parasites.
The microbial flora of the crewmembers were characteristic of healthy individuals. No remarkable change in microbial load was apparent upon return to Earth, with the exception of the presence of A. niger on the skin and throat swabs of one crewmember. This fungus is commonly present in the terrestrial environment and was also isolated, in rather large numbers, from Mir surfaces and air samples. Therefore, it is obvious that the fungus was a "carry over" from Mir; no undesirable health effects were noticed. Two crewmembers were clearly a carriers of S. aureus, and completion of DNA fingerprinting will document dissemination of this species in the environment and will verify the suspected colonization of other crewmembers.
Microbes' colonization of inanimate surfaces and hardware of the spacecraft can also lead to biodeteriortion of critical life support instrumentation and equipment, as well as the release of toxic volatiles. All of these are conditions associated with an Earth problem commonly called "sick building syndrome" (SBS) or "building-related illness" (BRS). Reducing risk to SBS requires monitoring both the habitation environment and the occupants, such that the levels and types of microbes do not reach critical levels. A thorough understanding of the microbial population dynamics onboard spacecraft will allow for development of predictive measures that can be used on Earth. The information gained from this study will be helpful in the design of future spacecraft, as well as environmentally conscience buildings, and development of monitoring requirements to minimize microbial cross-contamination.
Isenberg, H.D., Pierson, D. L., Mishra, S. K., Viktorov, A. N., Novikova, N. D., and Lizko, N. N. 1996. Microbiological findings from the Mir-18 crew. Aerospace Medical Association, Atlanta, GA.
Duane L. Pierson, Ph.D.
NASA/Johnson Space Center
Institute of Biomedical Problems
Theron Groves
Rebekah Bruce
Natalia Novikova, Ph.D.
Vladimir Skuratov, Ph.D.
Nadezda Lizko, Ph.D.
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Curator:
Julie Oliveaux
Responsible NASA Official: John Uri |
Page last updated: 07/16/1999
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