isbacterinandsubunitvaccine immunogenicitiesandprotectiveefficaciesagainstserotypes2and9.Clin VaccineImmunol. 2, 200-208.
[0086] 4.Berthelot-Herault，F.等人，2005.DilemmaofvirulenceofStreptococcus suis:Canadianisolate89 - 1591characterizedasavirulentstrainusinga standardizedexperimentalmodelinpigs.Can.J.Vet.Res. 69, 236-240.
[0087] 5.Chabot-Roy，G.等人，2006.PhagocytosisandkillingofStreptococcus suisbyporcineneutrophils.Microb.Pathog. 41, 21-32.
[0088] 6.DavidsonA.L等人，2008.Structure，function和evolutionofbacterial ATP-bindingcassettesystems^.Microbiol.Mol.Biol.Rev. 72, 317-364.
[0089] 7.DavidsonA.L. ,ChenJ. , 2004.ATP-bindingcassettetransportersin bacteria".Annu.Rev.Biochem73, 241-268.
[0090] 8.deGreeff，A.等人，2002.Contributionoffibronectin-bindingproteinto pathogenesisofStreptococcussuisserotype2.Infect.Immun. 70, 1319-1325.
[0091] 9.Fittipaldi，N.等人，2008a.SignificantcontributionofthepgdAgeneto thevirulenceofStreptococcussuis.Mol.Microbiol. 78, 1120-1135.
[0092] 10.Fittipaldi，N.等人，2008b.D-Alanylationoflipoteichoicacid contributestothevirulenceofStreptococcussuis.Infect.Immun. 76, 3587-3594.
[0093] ILFittipaldi，N.等人，201LLineageandvirulenceofStreptococcussuis serotype2isolatesfromNorthAmerica.EmergInfectDis.12,2239-2244.
[0094] 12.Gottschalk，M.等人，2007.Streptococcussuisinfectionsinhumans:the ChineseexperienceandthesituationinNorthAmerica.Anim.HealthRes. Rev. 8, 29-45.
[0095] 13.HendersonD.P. ,Payne,S.M. , 1994.Vibriocholeraeirontransport system:rolesofhemeandsiderophoreirontransportinvirulenceand identificationofageneassociatedwithmultipleirontransportsystems". Infect.Immun62, 5120-5125.
[0096] 14.Higgins，R.，Gottschalk，M.，2006.Streptococcocaldiseases?引 自：Straw，B.E.，D'Allaire，S.，Mengeling，W.L，Taylor，D.J.(编著），Diseasesof Swine.BlackwellPublishing，第 769-783 页.
[0097] 15.Jacobs,A.等人,1996.Protectionofexperimentallyinfectedpigs bysuilysin，thethiol-activatedhemolysinofStreptococcussuis.Vet. Rec. 139, 225-228.
[0098] 16.Li,Y.等人，2007.ImmunizationwithrecombinantSaoprotein confersprotectionagainststreptococcussuisinfection.Clin.Vaccine Immunol. 14, 937-943.
[0099] 17.McEvoy，G.K.编者，1989.AHFSDruginformation89.Bethesda，MD:American SocietyofHospitalPharmacists, 1925-1927.
[0100] 18.Perch，B.等人，1968.GroupRstreptococcipathogenicforman.Two casesofmeningitisandonefatalcaseofsepsis.ActaPatholMicrobiolScand 74, 69-76.
[0101] 19.Poole，R.K.等人，1994.ThecydDgeneproduct，componentofa heterodimericABCtransporter,isrequiredforassemblyofperiplasmic cytochrome-candofcytochrome-bdinEscherichiacoli".FEMSMicrobiol. Lett. 117, 217-224.
[0102] 20.Poolman,B.等人,2004.Bacterialosmosensing:rolesofmembrane structureandelectrostaticsinlipid-proteinandprotein-protein interactions^.Biochim.Biophys.Acta1666, 88 - 104.
[0103] 21.Quessy,S.等人,1995.Discriminationofvirulentandavirulent Streptococcussuiscapsulartype2isolatesfromdifferentgeographical origins.Infect.Immun. 63, 1975-1979.
[0104] 22.Smith,H.E.等人，1999.Identificationandcharacterizationofthe cpslocusofStreptococcussuisserotype2:thecapsuleprotectsagainst phagocytosisandisanimportantvirulencefactor.Infect.Immun. 67, 1750-1756.
[0105] 23.Sinha，R.P.，1977.Acriflavine-ResistantMutantofStreptococcus cremoris.AntimicroandChemo12,383-389.
[0106] 24.Vecht,U., 1991.Identificationoftwoproteinsassociatedwith virulenceofStreptococcussuistype2.Infect.Immun.59, 3156-3162.
[0107] 25.Vecht，U.等人，1992.VirulenceofStreptococcussuistype2strainsin newborngermfreepigsdependsonphenotype.Infect.Immun. 60, 550-556.
[0108] 26.Wisselink，H.J.等人，2002.Assessmentofprotectiveefficacyoflive andkilledvaccinesbasedonanon-encapsulatedmutantofStreptococcussuis serotype2.Vet.Microbiol. 84, 155-168.
[0109] 27.Zhou，Z.M.等人，1998.FunctionofEscherichiacoliMsbA，anessential ABCfamilytransporter,inlipidAandphospholipidbiosynthesis^.J.Biol. Chem. 273, 12466-12475.
[0110] 28.George，A.M?和S.B.Levy. 1983.Geneinthemajorcotransductiongapof theEscherichiacoliK_121inkagemaprequiredfortheexpressionofchromosomal resistancetotetracyclineandotherantibiotics.J.Bacteriol. 155:541 - 548.
[0111] 本发明将现在通过以下非限制性例子进一步描述。
【具体实施方式】
[0112] 实施例1 _减毒猪链球菌的产生和基因组分析
[0113] 为了开发针对猪链球菌感染的保护作用宽泛的疫苗，从猪脑棉拭子分离美国野外 株（亲本株，纽波特实验室编号8-1433-l，SEQ ID N0:9)。基于生物化学反应和凝集试验， 分离株经鉴定为猪链球菌血清型2。如Sinha等人所描述，通过使用盐酸吖啶黄化学诱变， 完成对这个亲本株的减毒。简而言之，将猪链球菌亲本细胞在含5%羊血的补充有IOyM/ ml盐酸吖啶黄的胰蛋白酶解酪蛋白大豆培养液中培育18小时。幸存的细胞在羊血琼脂平 板上再分离。选择20个单菌落并在相同的液体培养基