Preliminary Study On The Pathogenic Mechanism And Drug Resistance Mechanism Of Riemerella Anatipestifer

The purpose of this experiment is to conduct a preliminary study on the drug-resistant treatment of a multi-drug resistant and highly virulent Riemerella anatipestifer GD2019 and the heart transcriptomics of infected GD2019 Muscovy ducks.Preliminary research on the drug-resistant treatment of GD2019,GD2019 shows high resistance to aminoglycoside antibiotics such as gentamicin and neomycin.Importantly,the efflux inhibitor PAβN can reduce the resistance of GD2019 to neomycin in vitro.When neomycin acts on GD2019,neomycin can stimulate the transcriptional upregulation of most efflux pump genes(p<0.05),but more importantly,the transcription levels of efflux pump genes b739 and raeb in the PAβN+neomycin group Significantly higher than the neomycin group(p<0.05).Most importantly,at a relatively safe concentration of 40 μg/g body weight,the combined use of PAβN and neomycin significantly reduced the lethal concentration of Riemerella anatipestifer,which attacked duck’s organ bacterial load and pathological changes,and improved duck’s Survival rate(p<0.05).These results indicate that the efflux inhibitor PAβN can reduce neomycin resistance in vivo and in vitro,and may be a good anti-Riemerella anatipestifer antibiotic adjuvant drug.In the preliminary exploration of heart transcriptomics of infected GD2019 Muscovy ducks,GD2019 was used to infect 14-day-old Muscovy ducks at a sub-half lethal concentration,and the main targets were collected 24 hours,72 hours,and 168 hours after infection.Organs were tested for bacterial load,and target organs with severe disease and high bacterial load were selected for transcriptomics sequencing and analysis,and finally verified by RT-q PCR.Try to analyze the pathogenic mechanism of GD2019 by means of gene transcription sequencing.Analysis of the significantly enriched KEGG gene network in transcriptomics found that Riemerella anatipestifer infection up-regulated the expression of pattern recognition receptors F-actin,TUBB,FABP,Laminin,TLR2,and TLR4 in the heart.Riemerella anatipestifer activates NF-κB to promote the secretion and regulation of inflammatory factors,activates the JAK-STAT signal channel,stimulates the secretion of inflammatory factors,and enhances the body’s immune function.Verification of the transcriptome results by RT-q PCR confirms that the data is accurate and reliable.In summary,using transcriptomics sequencing methods,the shared and differentially expressed genes of R.anatipestifer in the heart were clarified,and these differentially expressed genes were verified and analyzed and verified simultaneously in terms of biological function and metabolic gene network..The molecular mechanism by which Riemerella anatipestifer activates the body’s innate immune function and induces inflammatory factors has been initially discovered.The body participates in the process of R.anatipestifer infection and cellulosic exudation by mobilizing multiple genes and pathways.