Acinetobacter pittii (A. pittii), a type of bacteria, is evolving to become more resistant to antibiotics and is finding ways to survive in the harsh environment of the International Space Station, according to new research from scientists at Weill Cornell Medicine.
“The study of bacteria found on the space station and their resistance to antimicrobial drugs is essential for the health of astronauts,” said the principal investigator. Dr. Christopher E. Mason, professor of physiology and biophysics and co-director of the WorldQuant Initiative for Quantitative Prediction at Weill Cornell Medicine. His discoveries on A.pictii were published on December 12 in Microbiome.
ISS crew members have limited diagnostic tools and treatment options in space, he said. Understanding how microbes evolve and how these changes may impact antibiotic resistance can inform the types of drugs astronauts need to perform short-term missions, as well as possible long-term missions to the Moon and Mars, said Dr. Mason.
Using genome sequencing – or evaluating the complete set of genetic instructions that allow an organism to function – and laboratory analysis, Dr. Mason and his colleagues studied A.pictii it was recently collected on surfaces inside the ISS for two NASA Microbial Monitoring Missions. This bacterium, most often studied in hospitals, tends to be multiresistant and can be fatal in immunocompromised people.
Researchers compared 20 ISS genomes A.pictii to 291 genomes of A.pictii collected on Earth. They discovered that the ISS A.pictii was more resistant to antimicrobial cephalosporins, although it did not have specific genetic changes typically associated with drug resistance. “The Earth and ISS genomes seemed genetically similar,” Dr Mason said. “But surprisingly, the ISS bacterium has a distinct set of physical characteristics, leading to resistance that needs to be investigated further.”
The researchers also evaluated 402 samples of microbial genetic material collected from the ISS environment, including surfaces and crew members, and observed that A.pictii grew and developed in such a way as to survive in the harsh environment of space. Researchers discovered the ISS A.pictii contained the LexA gene, a transcriptional regulator that suppresses or disables other genes. “We think the high amount of radiation in space could be driving this change,” said Dr. Mason, co-founder of Biotia and Onegevity Health..
Dr. Mason and his colleagues continue to analyze bacteria from the ISS and study biological samples from astronauts involved in commercial activities SpaceX Flights. Dr. Mason contributes to a National Academies of Sciences report to Congress on space-related research and how space stations can be reservoirs of microbes.
“These ISS bacteria were probably not exposed to antibiotics, but they appear to be more resistant,” said first author Dr. Braden Tierney, postdoctoral associate in computational biomedicine at Weill Cornell Medicine. “This indicates how truly anthropomorphic our view of antimicrobial resistance really is; we define it in terms of exposure to antibiotics, but in fact there are many mechanisms by which it can occur. It makes you wonder: if there are so many ways the environment can make an insect resistant, are there ways we haven’t yet thought of it could be used to reduce said resistance ? »
“Ultimately, space is a different kind of environment, so we’re seeing a different evolution of microorganisms,” Dr Mason said.