This study s goal was to examine if any salivary microbiome changes were observed in astronauts as a result of spaceflight. In addition this study looked for any microbiome signature that may be associated with viral reactivation in humans

The microbial tracking-1 (MT-1) investigation allowed the characterization of the microbial population aboard the International Space Station (ISS).

The microbial tracking-1 (MT-1) investigation allowed the characterization of the microbial population aboard the International Space Station (ISS).

The BRIC-21 mission was designed to identify the response of Bacillus subtilis to the human spaceflight environment. For this mission samples were grown in rich-medium using the Biological Research in Canister Petri Dish Fixation Units (BRIC-PDFU) spaceflight hardware. B. subtilis spores were inoculated during spaceflight grown at the ambient ISS temperature and frozen in the onboard -80 C freezer prior to returning to Earth. RNA was extracted from samples grown onboard the International Space Station (ISS) and matching Ground Controls for transcriptome analysis.

Microbes interact with humans in complex ways and understanding how they respond to the spaceflight environment is important to the success of future manned spaceflight missions. The BRIC-23 mission was designed to measure the response of Bacillus subtilis and Staphylococcus aureus to the spaceflight environment. This experiment aimed to produce high quality omics data from B. subtilis and S. aureus grown aboard the International Space Station (ISS) to allow comparison to matched ground controls. There were two primary objectives for this experiment: (1) Demonstrate all post-flight processes and operations required for successful completion of GeneLab Reference Missions conducted on ISS and (2) Generate high quality GeneLab Reference Mission omics data sets for two prokaryotic model organisms Bacillus subtilis and Staphylococcus aureus. Freezing Control Experiment: The BRIC hardware has significant thermal inertia thus the freezing rate of samples placed at -80 C is quite slow. This could affect RNA-sequencing proteomic and metabolic data sets. In an effort to understand how slow freezing could affect these data sets a control experiment was designed in which B. subtilis and S. aureus were grown in petri plates and either slow frozen to -80 C at a rate matching the BRIC-23 spaceflight samples or processed immediately to harvest RNA and protein.

In an on-going Microbial Observatory experimental investigation on the International Space Station (ISS) multiple bacterial isolates of Biosafety Level 2 (BSL-2) were isolated and identified. The antibiotic susceptibility pattern was tested in these BSL-2 isolates for the following antibiotics: cefazolin ciprofloxacin cefoxitin erythromycin gentamycin oxacillin penicillin rifampin tobramycin and many of the BSL-2 isolates showed multiple drug resistance. Among these isolates 21 strains were chosen for whole genome sequencing (WGS) for a possible lead to develop appropriate countermeasures. In addition the genomic data would enable to determine the influence of microgravity on the pathogenicity and virulence in the BSL-2 microorganisms.

The International Space Station (ISS) is a unique habitat for humans and microorganisms. Here, we report the results of the ISS experiment EXTREMOPHILES, including the analysis of microbial communities from several areas aboard at three time points. We assess microbial diversity, distribution, functional capacity and resistance profile using a combination of cultivation-independent analyses (amplicon and shot-gun sequencing) and cultivation-dependent analyses (physiological and genetic characterization of microbial isolates, antibiotic resistance tests, co-incubation experiments). We show that the ISS microbial communities are highly similar to those present in ground-based confined indoor environments and are subject to fluctuations, although a core microbiome persists over time and locations. The genomic and physiological features selected by ISS conditions do not appear to be directly relevant to human health, although adaptations towards biofilm formation and surface interactions were observed. Our results do not raise direct reason for concern with respect to crew health, but indicate a potential threat towards material integrity in moist areas.

Staphylococcus aureus colonizes the nares of approximately 30% of humans, a risk factor for opportunistic infections. Because of the potential threat of S. aureus to astronaut health, the effect of spaceflight conditions on this pathogen is of great interest. To gain insight into the virulence potential of S. aureus in the spaceflight environment, we performed differential expression (DE) analysis of RNA-Seq and cellular proteomics data from the “Biological Research in Canisters-23” (BRIC-23) GeneLab spaceflight experiment, a mission designed to measure the response of S. aureus to growth in low earth orbit (LEO) on the international space station (ISS). This experiment used Biological Research in Canisters-Petri Dish Fixation Units (BRIC-PDFUs) to grow asynchronous ground controls (GCs) and spaceflight cultures of S. aureus for 48 hours. Analysis of the RNA-Seq data revealed that RNAIII, the effector of the Accessory Gene Regulator (Agr) quorum sensing system, was the most highly upregulated gene in spaceflight cultures (~88-fold) relative to GCs. Genes of the agr operon (~14 fold) were also highly upregulated during spaceflight, followed by genes encoding secreted phenol-soluble modulins (PSMs) and secreted proteases, all of which are positively regulated by Agr. Upregulated spaceflight genes/proteins also had functions related to urease activity, Ess secretion, and copper transport. We also performed a secretome analysis of culture supernatant samples from BRIC-23. In line with the other BRIC-23 omics data, spaceflight supernatants displayed significantly increased abundance of several known secreted virulence factors, including Agr-regulated proteases (SspA, SspB), staphylococcal nuclease (Nuc), and EsxA, a small protein secreted by the type VII-like Ess secretion system. These data also suggested that S. aureus metabolism is altered in space flight conditions relative to the ground controls (increased amino acid metabolism, TCA cycle and PTS systems, and decreased glycolysis/fermentation and translation machinery). Collectively, these data suggest that S. aureus experiences increased quorum sensing and altered expression of virulence factors in response to the spaceflight environment that may impact its pathogenic potential.

The microbial tracking-1 (MT-1) investigation allowed the characterization of the microbial population aboard the International Space Station (ISS).

Presented here is the environmental microbiome study of the International Space Station surfaces. The environmental samples were collected with the polyester wipes from eight different locations in the ISS during two consecutive sampling sessions (three months apart). The specific objective was to unveil the pool of genes for each location during two separate sessions to learn of functional and metabolic diversity of microorganisms in the ISS. The International Space Station (ISS) as a closed built environment has its own environmental microbiome which is shaped by microgravity, radiation, and limited human presence. The microbial diversity associated with ISS environmental surfaces was investigated during this study. Polyester wipes and contact slides were used for sampling of eight various surface locations on the ISS at different time periods. The samples were retrieved and analyzed immediately upon the return to the Earth (via Soyuz TMA-14M or Dragon capsule from SpaceX). After surface sample collection, contact slides containing nutrient media for the growth of bacteria and fungi were incubated at 25C. The polyester wipes were processed to measure microbial burden (R2A, Blood Agar, and Potato Dextrose Agar) and recover cultivable bacteria as well as fungi. Subsequently, viable microbial burden was assessed using Adenosine Triphosphate (ATP) assay, and quantitative polymerase chain reaction (PCR) methods after propidium monoazide (PMA) treatment. The 16S-tag and metagenome analyses were used to elucidate viable microbial diversity. The cultivable bacterial population yield from the polyester wipes was very high (5 to 7-logs) when compared with the contact slides (10^2 to 10^3 CFU/m2). The PMA-qPCR analysis showed considerable variation of viable bacterial population (10^5 to 10^9 16S rDNA gene copies/m2) among locations sampled. Unlike contact slides, polyester wipes cover much larger sample surface (~1 m2) and produce much more reliable results of the microbial diversity of the ISS covering both cultivable and non-cultivable species. The cultivable, total, and viable microbial diversity was determined utilizing state-of-the art molecular techniques. The implementation of the PMA assay before DNA extraction allowed distinguishing viable microorganisms, which is crucial for determining their role to the crew health, the ISS maintenance and the general knowledge of the closed environmentally controlled built systems.