Novel Antimicrobial Cellulose Fleece Inhibits Growth of Human-Derived Biofilm-Forming Staphylococci During the SIRIUS19 Simulated Space Mission

Wound-healing and onboard care during long-duration human deep space exploration from a surgical perspective through the lens of a scoping review

OBJECTIVE

The aim of this study was to develop a bridge between the fields of aerospace medicine and vascular surgery, and to emphasize the need for leading experts in vascular medicine, interventional radiology, and surgery to address the critical human spaceflight research gaps highlighted by the National Aeronautics and Space Administration (NASA).

METHODS

A scoping review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted on literature published between 2000 and 2024. A well-defined search strategy was employed for keyword searches across multiple databases, including PubMed, Scopus, Cochrane, Embase, the NASA Life Science Data Archive, NASA technical reports, and Google Scholar.

RESULTS

Our review identified 125 relevant studies. These included 30 studies on general health conditions in space and wound healing, 38 addressing risk factors associated with the space environment, and 57 studies examining prevention and treatment options. These findings address NASA's identified gaps in wound care capabilities (ExMC 4.07), contribute to defining the potential list of medical conditions that could arise during deep-space missions (ExMC 4.24, Med07, Med12, Medical-101), and serve as a milestone for developing integrated exploration medical system models for missions to the Moon and Mars (Medical-501).

CONCLUSIONS

Many of the identified NASA knowledge gaps-some of which have even been marked as closed due to a lack of research in the field-cannot be effectively addressed without bridging aerospace medicine with related disciplines, such as vascular surgery and chronic wound care.

Microbiology of human spaceflight: microbial responses to mechanical forces that impact health and habitat sustainability

SUMMARYUnderstanding the dynamic adaptive plasticity of microorganisms has been advanced by studying their responses to extreme environments. Spaceflight research platforms provide a unique opportunity to study microbial characteristics in new extreme adaptational modes, including sustained exposure to reduced forces of gravity and associated low fluid shear force conditions. Under these conditions, unexpected microbial responses occur, including alterations in virulence, antibiotic and stress resistance, biofilm formation, metabolism, motility, and gene expression, which are not observed using conventional experimental approaches. Here, we review biological and physical mechanisms that regulate microbial responses to spaceflight and spaceflight analog environments from both the microbe and host-microbe perspective that are relevant to human health and habitat sustainability. We highlight instrumentation and technology used in spaceflight microbiology experiments, their limitations, and advances necessary to enable next-generation research. As spaceflight experiments are relatively rare, we discuss ground-based analogs that mimic aspects of microbial responses to reduced gravity in spaceflight, including those that reduce mechanical forces of fluid flow over cell surfaces which also simulate conditions encountered by microorganisms during their terrestrial lifecycles. As spaceflight mission durations increase with traditional astronauts and commercial space programs send civilian crews with underlying health conditions, microorganisms will continue to play increasingly critical roles in health and habitat sustainability, thus defining a new dimension of occupational health. The ability of microorganisms to adapt, survive, and evolve in the spaceflight environment is important for future human space endeavors and provides opportunities for innovative biological and technological advances to benefit life on Earth.

Antimicrobial and Antibiofilm Activity of the Probiotic Strain Streptococcus salivarius K12 against Oral Potential Pathogens

Oral probiotics are increasingly used in the harmonization of the oral microbiota in the prevention or therapy of various oral diseases. Investigation of the antimicrobial activity of the bacteriocinogenic strain Streptococcus salivarius K12 against oral pathogens shows promising results, not only in suppressing growth, but also in eliminating biofilm formation. Based on these findings, we decided to investigate the antimicrobial and antibiofilm activity of the neutralized cell-free supernatant (nCFS) of S. salivarius K12 at various concentrations against selected potential oral pathogens under in vitro conditions on polystyrene microtiter plates. The nCFS of S. salivarius K12 significantly reduced growth (p < 0.01) in Streptococcus mutans Clarke with increasing concentration from 15 to 60 mg/mL and also in Staphylococcus hominis 41/6 at a concentration of 60 mg/mL (p < 0.001). Biofilm formation significantly decreased (p < 0.001) in Schaalia odontolytica P10 at nCFS concentrations of 60 and 30 mg/mL. Biofilm inhibition (p < 0.001) was also observed in Enterobacter cloacae 4/2 at a concentration of 60 mg/mL. In Schaalia odontolytica P10 and Enterobacter cloacae 4/2, the nCFS had no effect on their growth.