Project description:The emerging foodborne pathogen, Aeromonas hydrophila, co-infects humans and animals, especially fish, threatening aquacultural production and public health. Previously we found that Scatophagus argus, a widely cultivated fish species with high economic value, exhibited enhanced growth but increased susceptibility to A. hydrophila infection under freshwater conditions compared to seawater conditions. However, the exact mechanisms involved remain unclear.Our study demonstrated that enhanced virulence of A. hydrophila 201416 isolated from S. argus induced by increasing salinity was associated with altered quorum sensing-related gene expression and regulated behaviors. Results from virulence assays combining phenotypic characterization indicated that increased salinity (from 0 to 35 g/L NaCl) impeded Ah201416 infection of S. argus, a trend aligning with increased biofilm mass and swimming motility, but opposite to bacterial growth. RNA-sequencing and quantitative reverse transcriptional PCR analysis confirmed significant upregulation of genes related to flagellar assembly (flgB, flgH, flgC, flgI, flhA, and fliA), bacterial secretion (HlyD and Ahh1), and quorum sensing (AhyR, LuxO, and LuxE) of Ah201416 in response to elevated salinity. These findings suggested that increased salinity not merely enhanced the virulence of Ah201416 but bolstered the resistance of S. argus, thereby mitigating its susceptibility. This study provides further insights into the microbial risks associated with A. hydrophila in aquacultural production, which is critical to developing appropriate prevention and control strategies and ensuring safe seafood supply.
Project description:We assessed the whole genome response of C. elegans exposed for 48 hours from L1 to the pristine silver nanomterials, artifically aged silver nanomatierls, and AgNO3.
Project description:Silver-resistant Saccharomyces cerevisiae mutant was obtained by evolutionary engineering method. Briefly, genetic diversity in reference strain, CEN.PK.113-7D, was increased by ethyl methane sulfonate (EMS)-mutagenesis. The mutant population was passaged several times in gradually increasing silver stress. Several mutant individuals were selected from the final population. Among selected mutant individuals, one of them was much more resistant to silver stress than the reference strain, called as 2E. Whole-genome transcriptomic analysis was performed to identify the silver resistance mechanisms in the silver-resistant mutant strain.
