bioRxiv Science⌕ Search

Biology subjects

Shuai, W.

Publications and source records attributed to Shuai, W..

6 recordsLinked to original sources

Development of a cell-based DIFF-rGFP assay system for generalized discovery of viral protease Inhibitors

1.Viral protease is an attractive target for antiviral therapeutics, but current viral protease inhibitor screening methods still need to be improved. Here, we systematically investigated the sites that may accommodate exogenous short peptides within Enhanced Green Fluorescent Protein (EGFP) and constructed a series of recombinant green fluorescent proteins (rGFPs). Meanwhile, a cell-based, simple and reliable assay system named DIFF-rGFP was developed relying on the co-expression of rGFP and the protease for protease inhibitor screening with the example of 3CLpro, in which the fluorescence intensity increases with the action of the inhibitor. The DIFF-rGFP assay avoided the requirement of a higher biosafety lab and can be performed in a high-throughput manner. For proof of concept, we demonstrated this method to discover novel inhibitors against SARS-CoV-2. We believe the proposed method, in combination with available drug libraries, may accelerate the identification of novel antivirals.

molecular biology↗

Maresin-2 Fine-tunes ULK1 O-GlcNAcylation to Improve Post Myocardial Infarction Remodeling

Maresin-2, a specialized pro-solving mediator of inflammation has been consolidated to be a novel cytokine fine-tuning inflammatory cascade. However, the underlying molecular basis is still largely unknown. Focused on cardiac dysfunction and remodeling, we employed in vivo- and in vitro- based genome editing methodology tools including adenosine associated virus, adenosine virus, lenti-virus, plasmid transfection, and CRISPR-Cas9 methodology for investigation. As suggested, exogenous maresin-2 supplement facilitated autophagosome formation by microtubule-associated proteins 1A/1B light chain 3B (LC3) conjugation system under the modulation of O-GlcNAcylation dependent ULK1 activation, whereas reversed by ULK1 S409A and S422A mutagenesis, showcasing the potential O-GlcNAc (O-linked {beta}- N-acetylglucosamine) modifiable sites on ULK1. Moreover, we found that hereafter maresin-2 treatment glutamine-fructose-6-phosphate aminotransferase 1 (GFAT1) which is accessary to sense hexosamine biosynthesis influx is more likely the prime checkpoint for conjugating O-terminal {beta}-N-acetylglucosamine motif onto ULK1, rather than O-linked N-acetylglucosaminyltransferase (OGT). Mechanistically, maresin-2 largely prohibits transforming growth factor-{beta} (TGF-{beta})-activated kinase 1 (TAK1), therefore increasing the availability of TAB1 for GFAT1, which encourages O-GlcNAcylation of ULK1.

molecular biology↗

Mitigation of Antimicrobial Resistance Genes in Greywater Treated at Household Level

Greywater often contains microorganisms carrying antimicrobial resistance genes (ARGs). Reuse of greywater thus potentially facilitates the enrichment and spread of multidrug resistance, posing a possible hazard for communities that use it. As water reuse becomes increasingly necessary, it is imperative to determine how greywater treatment impacts ARGs. In this study, we characterize ARG patterns in greywater microbial communities before and after treatment by a recirculating vertical flow constructed wetland (RVFCW). This greywater recycling method has been adopted by some small communities and households for greywater treatment; however, its ability to remove ARGs is unknown. We examined the taxonomic and ARG compositions of microbial communities in raw and treated greywater from five households using shotgun metagenomic sequencing. Total ARGs decreased in abundance and diversity in greywater treated by the RVFCW. In parallel, the microbial communities decreased in similarity in treated greywater. Potentially pathogenic bacteria associated with antimicrobial resistance and mobile genetic elements were detected in both raw and treated water, with a decreasing trend after treatment. This study indicates that RVFCW systems have the potential to mitigate antimicrobial resistance-related hazards when reusing treated greywater, but further measures need to be taken regarding persistent mobile ARGs and potential pathogens.

microbiology↗

Survival and Transcriptomic Response of Clinically relevant pathogens on Surfaces in Relation to Probiotic and Traditional Cleaning Strategies

Indoor surfaces are paradoxically presumed to be both colonized by pathogens, necessitating disinfection, and "microbial wastelands." In these resource-poor, dry environments, competition and decay are thought to be important drivers of microbial community composition. However, the relative contributions of these two processes have not been specifically evaluated. To bridge this knowledge gap, we used microcosms to specifically evaluate whether interspecies interactions occur on surfaces. We combined transcriptomics and traditional microbiology techniques to investigate whether competition occurred between two clinically important pathogens, Acinetobacter baumannii and Klebsiella pneumoniae, and a probiotic cleaner containing a consortium of Bacillus species. Probiotic cleaning seeks to take advantage of ecological principles such as competitive exclusion, thus using benign microorganisms to inhibit viable pathogens, but there is limited evidence that competitive exclusion in fact occurs in environments of interest (i.e., indoor surfaces). Our results indicate that competition in this setting has a negligible impact on community composition but may influence the functions expressed by active organisms. Although Bacillus spp. remained viable on surfaces for an extended period of time after application, viable colony forming units (CFUs) of A. baumannii recovered following exposure to a chemical-based detergent with and without Bacillus spp. showed no statistical difference. Similarly, for K. pneumoniae, there were small statistical differences in CFUs between cleaning scenarios with or without Bacillus spp. in the chemical-based detergent. The transcriptome of A. baumannii with and without Bacillus spp. exposure shared a high degree of similarity in overall gene expression, but the transcriptome of K. pneumoniae differed in overall gene expression, including reduced response in genes related to antimicrobial resistance. Together, these results highlight the need to fully understand the underlying biological and ecological mechanisms for community assembly and function on indoor surfaces, as well as having practical implications for cleaning and disinfection strategies for infection prevention.

microbiology↗

Sterilizing Effects of Novel Regimens Containing TB47, Clofazimine and Linezolid in a Murine Model of Tuberculosis.

Toxicity and inconvenience associated with the use of injectable drug-containing regimens for tuberculosis (TB) have made all-oral regimens a preferred alternative. Widespread resistance to fluoroquinolones and pyrazinamide makes it essential to identify new drug candidates and study their effects on current regimens for TB. TB47 is a pyrazolo[1,5-a]pyridine-3-carboxamide with powerful synergistic in vitro and in vivo activities against mycobacteria, especially with clofazimine. Here, we investigated the bactericidal and sterilizing activities of novel oral regimens containing TB47 + clofazimine + linezolid, and the potential roles of levofloxacin and/or pyrazinamide in such drug combinations. Using a well-established mouse model, we assessed the effect of these regimens on bacterial burden in the lung during treatment and relapse (4 months after stopping treatment + immunosuppression). Our findings indicate that the TB47 + clofazimine + linezolid + pyrazinamide, with/without levofloxacin, regimens had fast-acting (4 months) sterilizing activity and no relapse was observed. When pyrazinamide was excluded from the regimen, treatment times were longer (5-6 months) to achieve sterilizing conditions. We propose that TB47 + clofazimine + linezolid can form a highly sterilizing block for use as an alternative pan-TB regimen.

microbiology↗

Feammox Acidimicrobiaceae bacterium A6, a lithoautotrophic electrode-colonizing bacterium

An Acidimicrobiaceae bacterium A6 (A6), from the Acitnobacteria phylum was recently identified as a microorganism that can carry out anaerobic ammonium oxidation coupled to iron reduction, a process also known as Feammox. Being an iron-reducing bacterium, A6 was studied as a potential electrode-reducing bacterium that may transfer electrons extracellularly onto electrodes while gaining energy from ammonium oxidation. Actinobacteria species have been overlooked as electrogenic bacteria, and the importance of lithoautotrophic iron-reducers as electrode-reducing bacteria at anodes has not been addressed. By installing electrodes in soil of a forested riparian wetland where A6 thrives, as well as in A6 bioaugmented constructed wetland (CW) mesocosms, characteristics and performances of this organism as an electrode-reducing bacterium candidate were investigated. In this study, we show that Acidimicrobiaceae bacterium A6 is a lithoautotrophic bacterium, capable of colonizing electrodes in the field as well as in CW mesocosoms, and that it appears to be an electrode-reducing bacterium since there was a boost in current production shortly after the CWs were seeded with Acidimicrobiaceae bacterium A6.\n\nIMPORTANCEMost studies on electrogenic microorganisms have focused on the most abundant heterotrophs, while other microorganisms also commonly present in electrode microbial communities such as Actinobacteria have been overlooked. The novel Acidimicrobiaceae bacterium A6 (Actinobacteria) is an iron-reducing bacterium that can colonize the surface of anodes and is linked to electrical current production, making it an electrode-reducing candidate. Furthermore, A6 can carry out anaerobic ammonium oxidation coupled to iron reduction, therefore, findings from this study open up the possibility of using electrodes instead of iron as electron acceptors as a mean to promote A6 to treat ammonium containing wastewater more efficiently. Altogether, this study expands our knowledge on electrogenic bacteria and opens up the possibility to develop Feammox based technologies coupled to bioelectric systems for the treatment NH4+ and other contaminants in anoxic systems.

microbiology↗