Comparative Metabolomics and Proteomics Reveal Vibrio parahaemolyticus Targets Hypoxia-Related Signaling Pathways of Takifugu obscurus.

Coronavirus disease 2019 (COVID-19) raises the issue of how hypoxia destroys normal physiological function and host immunity against pathogens. However, there are few or no comprehensive omics studies on this effect. From an evolutionary perspective, animals living in complex and changeable marine environments might develop signaling pathways to address bacterial threats under hypoxia. In this study, the ancient genomic model animal Takifugu obscurus and widespread Vibrio parahaemolyticus were utilized to study the effect. T. obscurus was challenged by V. parahaemolyticus or (and) exposed to hypoxia. The effects of hypoxia and infection were identified, and a theoretical model of the host critical signaling pathway in response to hypoxia and infection was defined by methods of comparative metabolomics and proteomics on the entire liver. The changing trends of some differential metabolites and proteins under hypoxia, infection or double stressors were consistent. The model includes transforming growth factor-ß1 (TGF-ß1), hypoxia-inducible factor-1α (HIF-1α), and epidermal growth factor (EGF) signaling pathways, and the consistent changing trends indicated that the host liver tended toward cell proliferation. Hypoxia and infection caused tissue damage and fibrosis in the portal area of the liver, which may be related to TGF-ß1 signal transduction. We propose that LRG (leucine-rich alpha-2-glycoprotein) is widely involved in the transition of the TGF-ß1/Smad signaling pathway in response to hypoxia and pathogenic infection in vertebrates as a conserved molecule.

A newly developed polydopamine-coated paper-based microchip for rapid and highly selectivity detection of foodborne pathogens (preprint)

Background In 2020, Covid-19 pneumonia has had a great impact on human health in although the countries around the world, it brings serious threaten to people’s lives and resulted in serious economic losses. At the same time, a lot news about the detection of Covid-19 in food emerges endlessly, a rapid and high selectivity detection method or technology is in urgent need for its ability to help relevant departments effectively control the epidemic situation and ensuring people’s lives and property safety. In recent years, loop-mediated isothermal amplification (LAMP) has been certified as a quick and highly selective technique to detect foodborne microorganisms.Results In this paper, a newly developed microchip with polydopamine-coated paper based on LAMP was fabricated. This microchip consists of nine chambers for sampling and reactions, the targeted nucleic acid of foodborne pathogens was labeled by calcein fluorescence rather than SYBR. The microchip is advantageous of lower cost of materials and simple pretreated methods, and is easy to operate without the need for complex controlled fluid flow. The LAMP procedure and fluorescence detection of pathogens can be carried on the chip without opening the lid, preventing aerosol contamination and reducing the probability of false positives. In experiments, the LAMP reaction conditions including the optimal reaction temperature and reaction time are thoroughly discussed and have been executed for various foodborne bacteria samples, including Escherichia coli O157:H7 (E. coli O157:H7), Salmonella spp., Staphylococcus aureus (S. aureus), and Vibrio parahaemolyticus (V. parahaemolyticus). Testing of E. coli O157:H7 proved to be highly selective and sensitive (as low as 0.0134 ng µL− 1). Additionally, experimental test of real milk sample was figured, the complete detection duration time was within 68 min, the limit of detection(LOD) for Salmonella spp. was determined to be lower than 12 CFU mL− 1.Conclusion In summary, a newly developed LAMP microchip with polydopamine-coated and calcein fluorescence labeling paper-based provides a lower cost, easy to use, highly selective, and multiplexable pathogen detection capability with great promise as a rapid, highly efficient, and economical solution for future foodborne pathogen testing.