Evaluation of pathogenesis and biofilm formation ability of <i>Yersinia pestis</i> after 40-day exposure to simulated microgravity

Abstract With the increase of crewed space missions and rise microbiology, research microbes grown under microgravity environment has been attracting more attention. The scope in microbiology extended beyond pathogens directly related to spaceflight. Y. pestis , causative agent plague, is also interest researchers. After being cultivated for 40 consecutive passages either simulated (SMG) or normal gravity (NG) conditions, strain 201 cultures were analysed regarding their phenotypic features. By using crystal violet staining assays, increased biofilm amount was detected SMG condition. Besides that, damage degrees Hela cell caused by SMG-grown found diminished comparison those NG Consistent with this observation, death course delayed mice infected suggesting that condition can contribute attenuated virulence. RNA-seq-based transcriptomics analysis showed a total 218 genes differentially regulated, which 91 upregulated 127 downregulated. We dozens virulence-associated downregulated, partially explained reduced virulence Our study demonstrated long-term exposure influences pathogenesis formation ability provides novel avenue mechanism physiology pathogen. Microgravity enhanced cytotoxicity pestis. Many regulated response stimulated microgravity. However, there no molecular evidence explain ability, requires further research. Taken together, phenotype changes conditions provide us new direction its potential pathogenesis.