What is the multi-drug-resistant pathogen found in the International Space Station?

Scientists from the Indian Institute of Technology Madras (IIT-M) and NASA’s Jet Propulsion Laboratory (JPL) have carried out a collaborative study of the behaviour of multi-drug resistant pathogens aboard the International Space Station (ISS). 

The study focused on the genomic, functional and metabolic adaptations of Enterobacter bugandensis, a bacterium notorious for causing hospital-acquired infections. Enterobacter infections are extremely difficult to treat, according to a 2018 report in the journal Microbiology Resource Announcements. “Broad resistance to third-generation cephalosporins and quinolones is an increasing problem. Enterobacter species are members of the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species) group of pathogens and are on the WHO priority list for developing new antimicrobials.”

The latest findings have implications for both space exploration and terrestrial healthcare, according to the researchers. The investigation delved into the mechanisms enabling these pathogens to thrive in the unique environment of the ISS. With microgravity, heightened carbon dioxide levels and increased radiation as constant challenges, ISS provides a distinctive setting for studying microbial dynamics. Researchers isolated 13 strains of E bugandensis from various surfaces within the ISS, revealing accelerated mutations that rendered them genetically and functionally distinct from their Earth counterparts.

One of the pivotal findings from the study underscored the role of stress-induced genomic adaptations in bolstering the pathogen’s resistance to antimicrobial treatments. The ISS strains of E bugandensis displayed remarkable persistence over time, coexisting with other microorganisms and sometimes even assisting in their survival. 

This resilience of microbial life in the confined and extreme environment of the ISS offers valuable insights into the behaviour of pathogens in analogous settings on Earth, such as hospital intensive care units and surgical theatres.

Understanding these adaptations is important given the formidable challenges posed by multi-drug resistant pathogens in healthcare settings.

Dr Kasthuri Venkateswaran, principal investigator from NASA’s JPL, stressed the dual importance of this research. “Investigating the pathogenic potential of microorganisms in space environments is crucial not only for safeguarding astronaut health but also for mitigating the risks associated with opportunistic pathogens in closed human-built environments on Earth,” she remarked.

Meanwhile, the potent pathogen created a stir in the Indian subcontinent with Indian-origin Sunita Williams being among the nine crew members aboard the ISS. Williams arrived at the space station on June 6, 2024. 

The ISS orbits approximately 400 kilometres above Earth and serves as a microgravity and space environment research laboratory. It has been continuously occupied since November 2000, providing a unique platform for scientific research across multiple disciplines, including biology, physics, astronomy and other fields. The presence of multi-drug resistant pathogens aboard the ISS added a new layer of complexity to the health and safety protocols for astronauts.

The findings of the study underscored the need for robust preventive measures to ensure the health and safety of astronauts, who operate under altered immune conditions with limited access to medical facilities.

The research, funded by an Ames Space Biology grant, brought together a multi-disciplinary team of scientists from IIT-Madras and NASA’s JPL. They used advanced analytical techniques, including metabolic modelling to explore the coexisting microbial communities alongside E bugandensis.