Pichia pastoris composition expressed aerolysin mutant of Aeromonas veronii as an oral vaccine evaluated in zebrafish(Danio rerio)

Vaccines are one of the most practical means to stop the spreading of Aeromonas veronii in aquaculture.In this study,virulence factor aerolysin mutant NTaer which has lost its hemolytic activity was used as a target antigen.Pichia pastoris constitutive secretory expression NTaer(GS115-NTaer)was used as a potential safe oral vaccine to evaluate its effectiveness on zebrafish immunity.The result shows that vaccination of GS115-NTaer for four weeks did not affect the growth performance of the host,while eliciting an effective immune protective response.Compared with the control group,the GS115-NTaer could significantly up-regulate the relative expression level of the intestinal tight junction protein 1α(TJP1α)gene,and significantly increased the contents of lysozyme(LYZ),complement C3 and C4 in the gut,indicating that the innate immune response of the fish was activated.The relative gene expression levels of macrophage-expressed gene 1(MPEG1)and T cell receptor(TCR-α)in the gut,and MPEG1,CD4,CD8,TCR-α,GATA3,and T-bet in the spleen were all increased significantly,indicating that the cellular immune response of the fish was activated.Furthermore,the contents of serum IgM and intestinal mucosa IgZ antibodies were significantly increased,which showed that humoral immunity was also activated.Moreover,inoculation with GS115-NTaer significantly changed the structure of gut microbiota.In particular,the relative ratio of(Firmicutes+Fusobacteriota+Bacteroidota)/Proteobacteria was significantly higher than that of the control and GS115 groups.Lastly,the vaccinated fish were challenged with A.veronii,and the relative percent survival of GS115 and the GS115-NTear groups was 14.28%and 33.43%.This improvement of immunity was not only due to the specific immune response but also attributed to the improvement of innate immunity and the gut microbiota which was demonstrated by the germ-free zebrafish model.Collectively,this study provides information on the effectiveness of GS115-NTear as an oral vaccine for the green prevention and control of A.veronii infection in fish aquaculture.

Associations between the use of red yeast rice preparations and adverse health outcomes:An umbrella review of meta-analyses of randomized controlled trials

Background:Red yeast rice(RYR),a natural lipid-lowering agent,is widely used in clinical practice.However,the existing meta-analyses concerning the safety of RYR preparations have yielded inconsistent results,and the credibility of the evidence has not been quantified.Objective:This study was designed to evaluate the existing evidence and offer a comprehensive understanding of the associations between the use of RYR preparations and various adverse health outcomes.Search strategy:Seven literature databases were searched from inception to May 5,2023,using medical subject headings and free-text terms(e.g.,“red yeast rice,”“Xuezhikang,”and“Zhibitai”).Inclusion criteria:Meta-analyses that investigated and quantitatively estimated associations between the use of RYR preparations and adverse health outcomes were included in this study.Data extraction and analysis:Two researchers independently extracted data using a standardized data collection table;any disagreements were resolved by consulting a third researcher.Based on the participant,intervention,comparator and outcome(PICO)framework in each eligible meta-analysis,a series of unique associations between the use of RYR preparations and adverse health outcomes were determined.The associations’effect estimates were re-evaluated using random-effect models.Results:Fifteen meta-analyses,comprising 186(164 unique)randomized controlled trials,were identified.Based on A Mea Surement Tool to Assess Systematic Reviews version 2,3(20%)and 12(80%)of these meta-analyses had low and critically low confidence,respectively.A total of 61 unique associations between the use of RYR preparations and adverse health outcomes were extracted from eligible metaanalyses.Based on the random-effect models,10(16.4%)associations indicated a significant protective effect of RYR preparations against adverse health outcomes,while 5(8.2%)indicated an increased risk of adverse health outcomes related to uric acid,alanine transaminase and aspartate transaminase levels.The other 46(75.4%)associations showed no significant difference between the use of RYR preparations and control treatments.Regarding the credibility of the evidence,21(34.4%),34(55.7%)and 6(9.8%)associations showed moderate,low and very low credibility,respectively.Conclusion:The evidence examined in this study suggests that RYR preparations are safe;however,the credibility of the evidence was not high.Further high-quality evidence is required.