Specialists of the Jet Propulsion Laboratory (JPL) conducted a cataloging of microorganisms and fungi that live on board the International Space Station. We are not talking about living organisms that were deliberately delivered to the ISS for experimentation and study. We are talking about germs and fungi that live freely at the station. Scientists want to find out how these organisms affect the health of the station crew and what impact they have on the various systems of the ISS. In the future, this will help to develop more effective methods of protection against microbes in the conditions of long-term space flights into deep space.
The study is publicly available published in the journal Microbiome. Press release published by EurekAlert!
Despite the fact that the ISS is a closed system, it is inhabited by various microorganisms. How do they appear there? From life support systems, arriving spacecraft with new supplies and crews. To maximize coverage and estimate their number at the station, scientists asked three different station crews to collect samples in eight areas of the ISS: next to the viewing window, in the toilet, near the exercise area, in the dining room, in the sleeping rooms, inside the multifunction module, and also in laboratories.
Places where samples were taken for analysis
“Microbes in rooms on Earth have a different impact on human health. This is more important for the station crew, since their immunity has been changed, they cannot turn to a specialized medical institution with sophisticated equipment. Taking into account the prospects for future long-term flights, it is important to determine the types of microorganisms that accumulate in a closed environment, the duration of their existence and their impact on the human body, ”Kasturi Venkateswaran, one of the research participants, comments.
In the course of the study, it was found that microbes associated with a person live mainly at the station. Of the bacteria, the most prominent were Staphylococcus (26% of the total number of isolates), Pantoea (23%) and Bacillus (11%). Among the mushrooms, Rhodotorula mucilaginosa and Penicillium chrysogenum were the most prominent.
The samples showed a high content of microorganisms, which on Earth are considered opportunistic pathogens, that is, they do not cause disease in a healthy person with a strong immune system. Among them: Staphylococcus aureus (10% of the total number of identified isolates), usually living on the skin and in the respiratory tract, and Enterobacter. It is associated with the human gastrointestinal tract. On Earth, they predominate in places subject to regular disinfection: gyms, offices and hospitals. This means that the ISS is similar to artificial environments where the microbiome is formed as a result of human activity.
One of the authors of the study, Dr. Chechinsk Silaf, notes that it is not yet clear whether these conditionally pathogenic bacteria can cause diseases in the station crew.
Researchers also report one interesting fact. In contrast to the fungal formations that have always remained stable, the variety of microbes has changed. So, in samples taken during the second flight, a greater variety was found, compared with samples taken during the first and third flights. Scientists assume that such a difference is connected with the presence of different astronauts at the station.
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