To Evaluate The Virulence And The Immune In Mice Protection Of Four Kinds Of Brucella Attenuated Strain

Brucellosis is caused by a Brucella, it widespread and chronically infected zoonotic disea ses, not only can cause significant economic losses to livestock, but also seriously harm huma n health; in addition, It is a serious threat that Brucella is also used as bioterrorist weapons to national security and world peace. In recent years, the morbidity of brucellosis is rising. Once the incidence of brucellosis of which characterized is transferred to chronic and can not be tho rough treatment. Currently, vaccination is the primary means of prevention and control measu res to the spread of brucellosis.It has three kinds of current veterinary vaccine strain of Brucella in China, namely sheep species of Brucella attenuated strains M5, attenuated strains Brucella strains S2 and cattle attenuated strain of Brucella S19. They played a crucial role that these three kinds of vaccines for the prevention and control of brucellosis epidemic in 1970 s to 1990 s. So far, these three kinds of vaccines are still widely used in the country. In some European countries, the rough-type Brucella abortus vaccine RB51(B. Abortus RB51) is mainly used in the prevention and treatment of bovine brucellosis and widely used in the world, but relatively few domestic reports, four kinds of vaccines brucellosis prevention and control of the world play an important role, however brucellosis vaccine applications and reports vary in different regions and different countries, the experiment on the current market evaluation of four vaccines intended for production practice providing some guidance; RB51 attenuated strains mutation mechanism is not clear, therefore, this experiment and LPS of 27 major virulence genes were sequenced at the molecular level and designed to provide some help for the study of new vaccines.1.To evaluate the virulence and the immune in mice protection of four kinds of brucella attenuated strain.For systematic comparison of existing brucellosis vaccine strain S19, M5 and S2 and is widely used abroad virulence and immune protection of the strength of the vaccine strain RB51. In this experiment, the above four kinds of vaccine strain were carried out by MOI 100: 1 infection of murine macrophage cell live experiments and found that the ability to live in the cell RB51>M5>S19>S2; only immunized Balb/c mice with 1×106CFU,spleen index measuring bacterial virulence, the ability of each group determined to settle the vaccine strain in the spleen of mice and result that M5≥S19>S2≥RB51; mice by intraperitoneal Brucella inoculated virulent strain 2308 with 1×105 CFU after vaccine strain was cleared to detect its protection, the results showed that the M5 best protection effect; sera were isolated by 1-10 weeks, ELSA serum IgG titres and expression levels of cytokine IFN-γafter the immunization, the antibody of each vaccine strain with the horizontal time fluctuation immunity found IgG in S2, M5 group levels general higher than other groups, and IFN-γ levels of each group in general were no significant differences(P>0.05); Bengal plateagglutinationtest(rbpt)andthestandardtubeagglutinationtest(sat)serumagglutinationsituationandfoundthem5group,s19groupleaderantibodydurationthantheothers;andsteriletakeimmunedifferentbrucellavaccinestrainspleen,liver,kidneysandothertissuesdopathologicalchangesobserveddifferencesinpathology,thegroupfoundthatm5 strongestdiseasethanothergroups.2.attenuatedstrainofbrucellarb51and2308 relatedtothevirulenceofthestraindifferencesinlps.rough-typebrucellastrainrb51vaccineweakfrombovinesmoothbrucella2308 byinvitroorinvivocontinuoussubcultureresultingmutantstrains,buttheexactnatureofthemutantstrainrb51mechanismisnotclear,inordertoclarifyvirulenceattenuatedstrainrb51 whetheritisduetotheosidechainofreasonsnotsyntheticorsyntheticlpsofcertaingenesisblockedorcausedbydeletionormutation.therefore,thisexperimentbyrb51andstrain2308 asthetemplate,pcrpolymerasechainreaction,andthemajor26 virulencegenesoflpswhichsequenceanalysisatthemolecularlevel.byhomologyanalysis,wecouldfoundrelativeto2308,thesizeof844bpsequenceinsertedinthesequenceofwboagenesofrb51,butinothervirulencegeneanalysisconsistenthomology.thisguideprovidesdirectionforfurtherresearchtounderstandthemolecularpathogenesisofbrucellastrainsandsubsequenttransformationofvaccineproduction.furthermore,itmayalsolaythefoundationforfurtherdevelopmentandselectionofbrucellavaccines.