NASA closely follows the bacteria that inhabit the International Space Station with a program called Microbial Observatory (MO). The ICS is home to a variety of microbes, some of which pose a threat to the health of astronauts. As part of their monitoring, M.O. discovered antibiotic-resistant bacteria on the ISS toilet.
There are always microorganisms that act as spacecraft on a spacecraft. NASA's Microbiological Observatory returns samples from these passengers on Earth to study, for several reasons. They want to know about the diversity of the ISS microbiological flora and want to know how they change over time.
As it turns out, there are some differences between the Earth's microbes and the same kind in space. Microgravity of the space station may, in some cases, increase antibiotic resistance to microbes and make them more dangerous to humans.
M.O. found five strains of Enterobacter bugandensis bacteria and compared them with three clinical strains. They analyzed the genetic structure of all these strains and found that ISS strains contain genes associated with resistance to antibiotics and toxic compounds, although Enterobacter strains are not pathogenic to humans. This in itself may not be remarkable except in relation to the previous MO. study.
In May 2018, M.O. found that microgravity made bacterial strains more resistant to antibiotics. They captured 20 species of moderately dangerous bacteria and compared them with their terrestrial duplicates to see what effect microgravity had on their toxicity. They found that space bacteria show increased resistance to antibiotics. As the length of space missions increases, and we send astronauts to six-month missions on Mars, this can cause serious problems for the health of the astronauts.
Among the dangers of astronauts, microbes do not get many titles. Radiation and low gravity are the biggest points of conversation. But NASA is becoming more concerned about bacteria, both in the MSS itself and in the human biome in the astronauts' courage. M.O. is designed to examine five different aspects of the bacteria of ISS:
- The risk of infection and disease for astronauts in a closed setting.
- The risk of air pollution, liquids and food.
- Similarities and differences between ISS and Earth's microbial communities in nominal and extreme environments.
- Understanding which microbes are being developed in spacecraft and microgravity.
- Understanding how microorganisms adapt to microgravity and the spacecraft.
The microbial observatory is at the beginning of its mandate to understand these things, and no ringing alarms. They say that more studies are needed. But it's easy to see the potential dangers. All five types of ISS were either medium-resistant or completely resistant to potent antibiotics such as ciprofloxacin. They were all resistant to antibacterial oxacillin, most commonly used to treat staph outbreaks. Perhaps the most alarming discovery was that all five showed resistance to what is called fluoroquinolones, which are probably the most powerful antibiotics in use.
Sterilization of the spacecraft is not realistic. And the load is delivered to the ISS, and the arriving astronauts bring the microorganisms with them. Fungi also colonize the spacecraft, including ISS, Skilab and Mir. The risk can not be removed by eliminating the presence of microorganisms.
The best thing that can be done is to understand the risk, and NASA's efforts to catalog the microbial population in the spacecraft and understand how they develop over time in microgravity, paying dividends. Although it is a cause for concern that microgravity increases antibacterial resistance in some microorganisms, we still do not know the big picture. It is possible that the combined effect of weakened human immunity during long flights, along with increased antibacterial resistance in some bacteria, will create a dangerous situation for astronauts on long-haul aircraft. For now, NASA says more study is needed.