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Abstract EANA2024-87


Simulated microgravity effects on Enterococcus faecium: modifications in antibiotic resistance, biofilm formation, and desiccation tolerance

Franca Arndt (1,2), Katharina Siems (1), Sarah V. Walker (2,3), Noelle C. Bryan (4), Stefan Leuko (1), Ralf Moeller (1), Alessa L. Boschert (2)
(1) Institute of Aerospace Medicine, Aerospace Microbiology, German Aerospace Center (DLR), Cologne, Germany (2)Institute for Medical Microbiology, Immunology and Hygiene, University Hospital of Cologne, Germany (3) Regional Clinics Holding GmbH RKH, Institute for Clinical Microbiology and Hospital Hygiene, Ludwigsburg, Germany (4) Department of Cardiac Surgery, Brigham and Women’s Hospital, Boston, MA, United States


Vancomycin-resistant Enterococcus faecium (VRE) is a significant concern in healthcare settings, particularly affecting hospitalized and immunocompromised patients, including astronauts. This study explored the effects of simulated microgravity (sim. µg) on 42 clinical isolates of E. faecium using a 2-D Clinostat, with standard gravity (1 g) serving as the control. We assessed the isolates antibiotic resistance profiles, biofilm formation capabilities, and desiccation tolerance.

The isolates were tested against a panel of 22 antibiotics to determine variations in their minimum inhibitory concentrations (MICs) following exposure to sim. µg. Our results indicated diverse responses, with significant alterations in MIC values for seven antibiotics, suggesting a potential shift in resistance patterns under microgravity conditions. Furthermore, 55% of the isolates exhibited an increased capacity for biofilm production, an important factor in chronic infections and antibiotic resistance. Additionally, 59% of the isolates demonstrated improved desiccation tolerance, indicating enhanced survivability in dry conditions.

These findings underscore the remarkable adaptability of E. faecium to simulated spaceflight conditions, manifesting through significant changes in antibiotic resistance profiles, biofilm-forming ability, and desiccation tolerance. Understanding these adaptive mechanisms is crucial for developing targeted strategies to mitigate the risk of VRE infections during long-duration space missions. Ensuring the health and safety of astronauts requires comprehensive measures to address the potential challenges posed by resilient pathogens like VRE in the unique environment of space.