STS-115, STS-116, STS-117. STS-118, STS-120, STS-121

NOTE: End date is 9/30/2011, per HRP information (Ed., 10/20/2011)

NOTE: End date is now 9/30/2009 per CoI (4/08)

This study of the International Space Station (ISS) will include (1) sampling and analysis of ISS modules immediately prior to launch to develop baseline levels of contamination, (2) direct on-orbit sampling of the ISS and subsequent ground analysis.

This study will reveal previously undetected microorganisms, allergens, and microbial toxins in the spacecraft environment, which we anticipate will result in a more comprehensive health assessment of spacecraft during extended missions.

See also https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1003

Hardware development. Prior to the SWAB experiment, sample collection focused on subsequent processing for culture based analysis. For sample collection, the paradigm shifted from preservation of culture viability to preservation of the DNA integrity. Potable water and surface samples relied on DNA fixatives to maintain the DNA. Air sample integrity was achieved by using filtration through a gel membrane (Sartorius MD8 Air Port air sampler). This development effort will be beneficial for future experimental and monitoring efforts, as exemplified when the Sartorius air sampler from the SWAB experiment remained on board ISS at the request of JAXA investigators, who intend to use it in completion of their microbial ecology experiment. Within the design process were multiple side experiments to enable this effort. These side experiments will prove useful in future endeavors. Indeed, the simple determination of average extractable DNA from ISS potable water has already been used to size multiple flight experiments and will be used in the development of next-generation flight hardware.

Molecular techniques and microbial ecology. The development of molecular techniques for the SWAB flight experiment provided advances in the NASA laboratory processes associated with microbial identification. The first accomplishment of the SWAB experiment was the translation of 16S ribosomal DNA sequencing for the identification of bacteria from flight experiment to operational use on spaceflight samples to determine crew health risk. The use of this molecular technique increased bacterial speciation of environmental isolates three fold compared to conventional biochemical-based methodology. This increased efficiency in bacterial speciation provides a better understanding of the microbial ecology and the potential risk to the crew. Negative aspects concerning the use of molecular techniques for spaceflight applications were also identified during the development phase of the SWAB experiment. Sample preparation, data analysis, and potential contamination by genetic material pose tremendous challenges for future use of molecular identification during future exploration missions.

Early analyses for the SWAB experiment focused on the use of molecular-based DNA fingerprinting using repetitive sequence-based polymerase chain reaction (rep-PCR). This technology has allowed contamination tracking of microorganisms between crewmembers and their environment. This study not only demonstrated that ISS has a greater diversity of organisms than originally expected, but also provided insight into possible routes of infection to the crew. Additional ground-based studies used rep-PCR and protein based assays to determine the potential of methicillin resistant Staphylococcus aureus (MRSA) aboard ISS. MRSA has become increasingly common on Earth and poses a treatment problem for infections during flight. The first technique used to evaluate all DNA from the flight samples was Denaturing Gradient Gel Electrophoresis (DGGE). Unlike other techniques, DGGE does not depend on microbial growth on culture media, allowing a more comprehensive assessment of the spacecraft interior. The results indicated the presence of microorganisms not commonly isolated from surface and air samples using culture based techniques. While no medically significant organisms were detected using DGGE, results indicated that DGGE was much less sensitive than culture-based methods.

The use of Real Time PCR (RT-PCR) assays was exceptionally beneficial, as this technique proved more sensitive than DGGE. Analyses focused on the sensitive, targeted analysis of DNA for specific viruses including Varicella Zoster Virus (VZV), Cytomegalovirus (CMV), and Epstein Barr Virus (EBV). This technique detected the presence of VZV and EBV DNA in a number of the surface and air samples. An RT-PCR detection assay specifically for the detection of Stachybotrys chartarum and Aspergillus fumigatus was performed on ISS air and surface samples. No ISS samples indicated the presence of either organism. An additional RT-PCR assay investigating the presence of methicillin resistant Staphylococcus aureus was developed using custom designed primers and probes and performed on all of the surface and air DNA samples.

The search for medically significant organisms using non-culture based technology did not reveal a large number of previously unseen medically significant organisms, thus providing a better understanding of the true microbial ecology that is experienced by the crew during flight. This information is leading toward an accurate microbial risk assessment to help set flight requirements to protect the safety, health, and performance of the crew.

STS-115, STS-116, STS-117. STS-118, STS-120, STS-121

NOTE: End date is 9/30/2011, per HRP information (Ed., 10/20/2011)

NOTE: End date is now 9/30/2009 per CoI (4/08)

This study of the International Space Station (ISS) will include (1) sampling and analysis of ISS modules immediately prior to launch to develop baseline levels of contamination, (2) direct on-orbit sampling of the ISS and subsequent ground analysis.

This study will reveal previously undetected microorganisms, allergens, and microbial toxins in the spacecraft environment, which we anticipate will result in a more comprehensive health assessment of spacecraft during extended missions.

See also http://www.nasa.gov/mission_pages/station/science/experiments/SWAB.html

Early accomplishments from this grant also included the development of flight hardware that could acquire samples and preserve them for later molecular analysis months later with no substantial loss of sample quality. Using this hardware, sample collection for SWAB was initiated in August 2006. Air and surface samples, including 9 in-flight sessions and multiple preflight samples, were completed in March 2008. ISS water sample collection from the U. S. water regeneration system called the Water Process Assembly (WPA) began in August 2009 and was completed in March of 2010.

Analyses of air and surface samples have already begun to provide new information. Early analyses focused on the use of molecular-based DNA fingerprinting using repetitive sequence-based polymerase chain reaction (rep-PCR). This technology has allowed contamination tracking of microorganisms between crewmembers and their environment. This study not only demonstrated that ISS has a greater diversity of organisms than originally expected, but also provided insight into possible routes of infection to the crew. Additional ground-based studies used rep-PCR and protein based assays to determine the potential of methicillin resistant Staphylococcus aureus (MRSA) aboard ISS. MRSA has become increasingly common on Earth and pose a treatment problem for infections during flight. The first technique used to evaluate DNA from the flight samples was Denaturing Gradient Gel Electrophoresis (DGGE). Unlike other techniques, DGGE does not depend on any microbial growth on culture media allowing a more comprehensive assessment of the spacecraft interior. The results indicate the presence of microorganisms not commonly isolated from surface and air samples using culture based techniques. Fortunately, none of the organisms isolated would be considered medically significant. More recent analyses focused on more sensitive, targeted analysis of the DNA for specific viruses including Varicella Zoster Virus (VZV), Cytomegalovirus (CMV), and Epstein Barr Virus (EBV). Real Time PCR assays detected the presence of the VZV and EBV DNA in a number of the surface and air samples, and investigators are continuing to analyze the data. An assay for PCR detection of MRSA developed using custom designed primers and probes is also currently being performed on all of the surface and air DNA samples. This study continues to provide insight into the true microbial ecology that is experienced by the crew during flight. This information will lead toward an accurate microbial risk assessment to help set flight requirements to protect the safety, health, and performance of the crew.

STS-115, STS-116, STS-117. STS-118, STS-120, STS-121

NOTE: End date is now 9/30/2009 per CoI (4/08)

This study of the International Space Station (ISS) will include (1) sampling and analysis of ISS modules immediately prior to launch to develop baseline levels of contamination, (2) direct on-orbit sampling of the ISS and subsequent ground analysis.

This study will reveal previously undetected microorganisms, allergens, and microbial toxins in the spacecraft environment, which we anticipate will result in a more comprehensive health assessment of spacecraft during extended missions.

See also http://www.nasa.gov/mission_pages/station/science/experiments/SWAB.html

Analyses of air and surface samples have already begun to provide new information. Early analyses focused on the use of molecular-based DNA fingerprinting using repetitive sequence-based polymerase chain reaction (rep-PCR). This technology has allowed contamination tracking of microorganisms between crewmembers and their environment. This study not only demonstrated that ISS has a greater diversity of organisms than originally expected, but also provided insight into possible routes of infection to the crew. Additional ground-based studies used rep-PCR and protein based assays to determine the potential of methicillin resistant Staphylococcus aureus (MRSA) aboard ISS. MRSA has become increasingly common on Earth and pose a treatment problem for infections during flight. While no MRSA have been isolated from ISS to date, the mecA gene product that is responsible for methicillin resistance was isolated in other Staphylococcus species aboard ISS suggesting a potential of MRSA through gene transfer. The first technique used to evaluate DNA from the flight samples was Denaturing Gradient Gel Electrophoresis (DGGE). Unlike other techniques, DGGE does not depend on any microbial growth on culture media allowing a more comprehensive assessment of the spacecraft interior. The results indicate the presence of microorganisms not commonly isolated from surface and air samples using culture based techniques. Fortunately, none of the organisms isolated would be considered medically significant. Future analyses will focus on more sensitive, targeted analysis of the DNA for specific pathogens. This study is providing insight into the true microbial ecology that is experienced by the crew during flight. This information will lead toward an accurate microbial risk assessment to help set flight requirements to protect the safety, health, and performance of the crew.

STS-115, STS-116, STS-117. STS-118, STS-120, STS-121

NOTE: End date is now 9/30/2009 per CoI (4/08)

This study of the International Space Station (ISS) will include (1) sampling and analysis of ISS modules immediately prior to launch to develop baseline levels of contamination, (2) direct on-orbit sampling of the ISS and subsequent ground analysis.

This study will reveal previously undetected microorganisms, allergens, and microbial toxins in the spacecraft environment, which we anticipate will result in a more comprehensive health assessment of spacecraft during extended missions.

Early accomplishments from this grant included the development of flight hardware that could acquire samples and preserve them for later molecular analysis months later with no substantial loss of sample quality. Using these improved sample collection technologies, flight sampling for SWAB was initiated in August 2006 and will continue at least through fall of 2007. Mission samples which have already been collected include those from STS-121 and its logistic module, STS-115, STS-116 and its SpaceHab cargo, and 3 separate ISS in-flight sampling sessions. Future sample collection opportunities include STS-117, STS-118 and its SpaceHab cargo, STS-118, the Node 2 module preflight analysis, the Columbus module preflight analysis, and 5 separate ISS in-flight sampling sessions.

The focus of these flight samples is the collection of DNA for evaluation by Denaturing Gradient Gel Electrophoresis (DGGE). Unlike other techniques, DGGE does not depend on any microbial growth on culture media allowing a more comprehensive assessment of the spacecraft interior. Preliminary results from the first few sample sessions confirmed the successful acquisition of microorganisms/DNA using the new air and surface sample collection techniques. Early processing results suggest the techniques will identify organisms that are not commonly identified using media based techniques. Water samples from ISS are yet to be collected as sampling agreements are still being negotiated.

This study should provide insight into the true microbial ecology that is experienced by the crew during flight. This information will lead toward an accurate microbial risk assessment to help set flight requirements to protect the safety, health, and performance of the crew.

STS-115, STS-116, STS-117. STS-118, STS-120, STS-121

This study of the International Space Station (ISS) will include (1) sampling and analysis of ISS modules immediately prior to launch to develop baseline levels of contamination, (2) direct on-orbit sampling of the ISS and subsequent ground analysis.

This study will reveal previously undetected microorganisms, allergens, and microbial toxins in the spacecraft environment, which we anticipate will result in a more comprehensive health assessment of spacecraft during extended missions.

The research also focused on optimizing the flight hardware for preflight and ISS sample collection. The hardware has passed Critical Design Review with only minimal backup testing required. The engineering expertise of the JSC support team has reconfigured the ASD air sampler for flight use with minimal changes. An association with Charm Sciences has led to the development of a custom subface sampling swab that contains the SDS - EDTA solution for DNA preservation. In addition, specialized water collection bags that are modification of the current ISS water collection bags, have been developed to release the SDS-EDTA solution into the bag without risking contact with the crew. Previous relationships with Russian colleagues at Energia and the Institue of Biomedcal Problems helped to incorporate the International Partners and their ISS components into this study.

The study is on schedule for sample collection starting in 2005.