Vancomycin-resistant Enterococcus faecium (VRE) presents significant challenges in healthcare, particularly for hospitalized and immunocompromised patients, including astronauts with dysregulated immune function. We investigated 42 clinical E. faecium isolates in simulated microgravity (sim. µg) using a 2-D Clinostat, with standard gravity conditions (1 g) as a control. Isolates were tested against 22 antibiotics and characterized for biofilm formation and desiccation tolerance. Results showed varied responses in minimum inhibitory concentration (MIC) values for seven antibiotics after sim. µg exposure. Additionally, 55% of isolates showed a trend of increased biofilm production, and 59% improved desiccation tolerance. This investigation provides initial insights into E. faecium’s changes in response to simulated spaceflight, revealing shifts in antibiotic resistance, biofilm formation, and desiccation tolerance. The observed adaptability emphasizes the need to further understand VRE’s resilience to microgravity, which is crucial for preventing infections and ensuring crew health on future long-duration space missions.

Fungal contaminations pose a persistent challenge in the fields of healthcare, agriculture, and industry, primarily due to their environmental adaptability and increasing resistance to antifungal agents. In this study Aspergillus niger is utilized as model organism. This work evaluates copper, brass, and steel surfaces functionalized with ultrashort pulsed laser‐induced periodic surface structures (USP‐DLIP) designed as 3 and 9 µm topographies. Fungal spore viability assays show that 9 µm periodicities on copper surfaces achieve a 99% reduction in spore viability, indicating that increased copper ion release is a key factor in enhanced antifungal effectivity. Scanning electron microscopy (SEM) analysis confirm substantial spore damage, linked to the viability testing and the measured copper ion release by inductively coupled plasma triple quadrupole mass spectrometry (ICP‐QQQ) spectrometry. Interestingly, 9 µm structured steel surfaces reveal a trend toward antifungal activity despite their inert nature. Whereas structured brass surfaces do not show significant improvement in antifungal activity. These findings suggest USP‐DLIP structuring on copper and stainless‐steel surfaces have considerable potential for antifungal applications, although interactions between surface structures, released ions, and fungal spores are highly complex. Yet, USP‐DLIP offers promising advantages for developing advanced antifungal materials.

Infections pose a major risk during long-term human spaceflight missions. By applying standard procedures in medical microbiology to a hypothetical urinary tract infection during a Mars-bound flight, important practical aspects become apparent. From infection diagnostics to antimicrobial treatment during spaceflight, issues include technological constraints, the lack of breakpoints, and epidemiological data. A potential solution is a combination of data acquisition, artificial intelligence, individualized medicine, novel diagnostic tools, and antimicrobial strategies. This work takes an exploratory approach to highlight challenges and potential directions in developing diagnostic strategies for long-term space missions.

The widespread use of antibiotics worldwide has led to an increase in multi‐resistant pathogens, including vancomycin‐resistant enterococci (VRE). To prevent the spread of multi‐resistant pathogens, antimicrobial surfaces have become more widely used. Various metals and surface topographies are researched to optimize their bactericidal effect. Copper surfaces have proven cost‐effective, easy to implement, and safe. However, concurrent metal resistance in Enterococcus faecium , leads to strains highly resistant to both vancomycin and copper. The efficacy of copper coatings are evaluated, and copper and brass surfaces are functionalized with Direct Laser Interference Patterning (DLIP) and determined the release of copper and zinc ions during cell‐surface. Additionally, the copper stress response of five E. faecium isolates is characterized by scanning and transmission electron microscopy, determination of the minimal inhibitory concentration (MIC) on copper‐infused media, and whole‐genome sequencing. The copper stress responses of the isolates differed due to their different copper resistance genes. In particular, it is shown that prior exposure to vancomycin enhanced copper tolerance in E. faecium . Furthermore, the copper‐tolerant isolate is the only one to survive direct contact with the functionalized copper surface. These results highlight the importance of investigating antimicrobial and functionalized surfaces against hospital pathogens and co‐resistance against metal and antibiotics.

Introduction: Conventional microbiological methods typically examine isolated bacterial species, which limits the insight into how microorganisms behave in more realistic, complex ecosystems. In contrast, synthetic bacterial consortia offer a practical and ecologically meaningful model for studying species interactions and responses to stress. These interspecies dynamics, both cooperative and competitive, can significantly influence the survival and physiology of individual species, revealing patterns that single-species tests often miss. Exploring microbial resilience under stress is vital for advancing space microbiology and ensuring the functionality of enclosed environments like the International Space Station (ISS) and in the future in spacecraft traveling to the Moon or Mars. Methods: To assess the stress tolerance of bacterial species within a consortium, a synthetic bacterial consortium was constructed using species representative of the spacecraft microbiome, including genera such as Bacillus, Pseudomonas , and Staphylococcus . The stress tolerance of Bacillus subtilis and Staphylococcus capitis was evaluated both individually and within the defined consortium under spaceflight-relevant conditions, including desiccation, X-ray irradiation, and hydrogen peroxide exposure. Survival rates were quantified by colony-forming unit (CFU) counts. Co-cultivation approaches were employed to assess biofilm formation and growth within the consortium. Consortium dynamics following stress exposure and cultivation were further investigated using 16S rRNA gene sequencing. Results: The stress tolerance of B. subtilis and S. capitis differed between individual exposure and consortium conditions. Hereby, the consortium context influenced stress responses in a stressor-specific manner. Co-cultivation experiments demonstrated observable growth in various combinations of consortium members, with differences in early-stage biofilm formation and CFU counts noted. Investigations of consortium dynamics revealed a statistically significant difference before and after incubation indicating that over time the consortium reaches a stabilized relative abundance profile. Discussion: Our findings underscore the importance of considering community-level interactions when evaluating bacterial stress tolerance. Synthetic bacterial consortia represent a valuable approach to bridging the gap between reductionist and systems-level microbiology, offering critical insights for both terrestrial biotechnology and the advancement of space exploration.

Environmental factors play a crucial role in the emergence, persistence, and spread of bacterial resistance. The habitat of microorganisms can define their stress resistance profile. Through interaction with other microorganisms, the exchange of microbial resistance traits can be facilitated, thereby enhancing their overall resilience. Microorganisms exposed to space-related stressors, such as microgravity, increased levels of ionizing radiation, and desiccation, face distinctive survival challenges. These stressors can induce cellular adaptations that can affect microbial resistance. Moreover, confinement and cleaning routine can further drive the evolution of more resistant strains that could influence microbial communities in spacecraft habitats. Hence, assessing the resistance to multiple stressors is critical for understanding how different habitats shape resistance profiles and for developing microbial control strategies that may help ensure the safety of space missions. This is particularly important as humanity plans for prolonged space travel and habitation on extraterrestrial surfaces. This study explores the stress resistance of bacterial isolates collected from the International Space Station and German schools in the context of the spaceflight experiment “Touching Surfaces,” which tested antimicrobial surfaces on the ISS and on Earth. The isolates were tested for their antibiotic resistance revealing no detectable increase in antibiotic resistance under the conditions tested in isolates from space or schools. Additionally, isolates of the skin commensal Micrococcus luteus and the opportunistic pathogens Staphylococcus haemolyticus , Staphylococcus epidermidis and a methicillin-resistant Staphylococcus aureus (MRSA) were tested for their tolerance to key environmental stressors relevant to spaceflight. Stress resistance assays included desiccation, X-ray irradiation, and hydrogen peroxide treatment. Overall, space isolates did not show an increased resistance to desiccation or, X-ray irradiation. However, both space and school isolates of Staphylococcus spp. recovered from surfaces showed increased survival after treatment with hydrogen peroxide compared to their respective type strains. Additionally, early-stage biofilm formation was significantly higher for space and school isolates of Micrococcus sp. compared to the type strain M. luteus .