Study On Screening And Preventive Effects Of Chinese Medicines For Inhibiting Haemophilus Parasuis

In recent years,systemic inflammatory diseases caused by Haemophilus parasuis?HPS?have caused huge economic losses to the global pig industry.How to prevent and control the occurrence of Haemophilus parasuis has become the focus of attention at home and abroad.Therefore,the research and development of vaccines has also received attention.The vaccines currently developed include inactivated vaccines,subunit vaccines,DNA vaccines and genetic engineering vaccines.For The past few years,the application of traditional Chinese medicine in antibacterial aspects has become more and more common,which inspired us to use traditional Chinese medicine to prevent and treat Haemophilus parasuis.This study mainly screens Chinese medicines that can effectively inhibit the growth of HPS and improve the immunity of animals,so as to provide effective data and scientific basis for the prevention and control of Haemophilus parasuis and the development of the pig industry,which has important practical significance and application value.Experiment 1:Select valuable antibacterial Chinese medicines through a large number of domestic and foreign literatures,and then through in vitro drug susceptibility tests,with the aid of agar diffusion method,growth inhibition test and other methods to screen out effective antibacterial drugs,and at the same time research and explore the three screened the inhibitory effect of traditional Chinese medicine on Haemophilus parasuis type 13;the relationship curve between bacterial concentration and OD₆₀₀ is calculated by the method of multiple dilution,which provides basic data for subsequent challenge.Experiment 2:Kunming female mice were randomly divided into 7 groups,namely blank group,negative control group,positive control group,Chinese medicine group 1,Chinese medicine group 2,Chinese medicine group 3 and mixed Chinese medicine group.Take the method of gavage every other day.After 14 days,HPS type 13 was used to challenge the virus.The peripheral blood of mice was used to detect the T lymphocyte subsets and T lymphocyte transformation rate.The ELISA method was used to detect the serum IL-2 content,and the QRT-PCR method was used to detect cytokine changes.The results showed:?1?Through the cultivation of TSA solid medium,the traditional Chinese medicines Chinese medicine 1 and Chinese medicine 2 have obvious inhibitory effects on HPS type 13.The diameter of the inhibitory ring is 28.5mm and 13.5mm,respectively.The growth inhibition test found that the three traditional Chinese medicines have an inhibitory effect on HPS;?2?The ratio of T lymphocyte subsets CD4+/CD8+showed that the positive group was extremely significantly lower than the blank and negative groups?P<0.01?,It shows that HPS suppresses the cellular immunity of mice.After pre-fed with traditional Chinese medicines 2 and 3,it is extremely or significantly higher than the positive group?P<0.01,P<0.05?,indicatingthat both Chinese medicines can effectively enhance the body's cellular immunity and reduce the harm caused by type 13 HPS;?3?The immune protection test found that the levels of IL-1?and IL-6 in the positive group were higher than those in the blank and negative groups?P<0.01?.The three traditional Chinese medicines had no effect on IL-2,but they were all significantly or extremely significant when used alone Decrease the content of IL-1?and IL-6 in the liver?P<0.05 or P<0.01?;Compared with the positive control group,the IL-6 content in the lungs of the four traditional Chinese medicine groups were significantly lower?P<0.01?,and the lung IL-1?content in the Chinese medicines 2group was extremely significantly lower?P<0.01?.Therefore,all three traditional Chinese medicines can stimulate the body to produce Anti-inflammatory immunity,thereby inhibiting the production of inflammatory factors IL-1?and IL-6.;?4?The protection rate of traditional Chinese medicine 1 against mice challenged with HPS type 13 is 50%,while the protection rate of Chinese medicine 3 is 33.3%,indicating that both Chinese medicine 1 and 3 have different degrees of protection against attacks of type13 HPS,Provide a new direction and basis for the prevention and control of Haemophilus parasuis disease.This study shows that traditional Chinese medicine can prevent HPS infection through cellular immunity,which provides a new direction and basis for the prevention and control of HPS disease.