We have established a hybridoma producing monoclonal antibody (MAb) against a linear epitope of glycoprotein (G protein) of the RC-HL strain of rabies virus. This MAbl5-13 showed almost the same neutralizing activity to all of five rabies fixed strains, including RC-HL, and reacted to the denatured G protein in western blot analysis. To characterize and map this linear epitope, an antigenic variant NR15-13 was selected from RC-HL strain in the presence of neutralizing MAbl5-13. The variant reacted with MAbl5-13 in an immunofluorescent antibody test but was not neutralized by the antibody and the antibody did not bind to the variant G protein in a Western blot analysis. The variant NR15-13 had an amino acid substitution at position 251 of the G protein, where tryptophan of the parental RC-HL strain was replaced by arginine. Site-directed mutagenesis analysis using the expression system in simian COS7 cells revealed that a single amino acid substitution at 251-tryptophan by arginine on the G protein of the parental RC-HL strain abolished the antigenicity of the epitope for MAbl5-13 in western blot analysis, and the replacement of 251-arginine by tryptophan recovered the activity. These results strongly suggest that tryptophan at position 251 on the G protein is essential for construction of the linear epitope against MAbl5-13.

A gene encoding the major inner capsid protein, VP6, of avian rotavirus was inserted into the eukaryotic expression vector PAX-91 under the control of the SRa promoter and was expressed at a high level in simian COS7 cells. The expressed VP6 was indistinguishable in terms of electrophoretic mobility from the corresponding protein synthesized in simian MA104 cells infected with avian rotavirus. Bindin,g assays with a series of monoclonal antibodies (mAbs) that corresponded to four antigenic sites on VP6 of avian rotavirus showed that the antigenic characteristics of the expressed product were identical to those of the native VP6 of avian rotavirus virions. Fiber-like structures that reacted strongly with antiserum against rotavirus were observed in VP6-expressing COS7 cells. Furthermore, an analysis of the tertiary structure of the expressed VP6 protein indicated that it adopts a trimeric configuration, similar to that of the major inner capsid protein of PO-13 virus. From these tisults, it appears that recombinant VP6 will facilitate studies of the structure and function of authentic VP6, an important protein in avian rotavirus.

The cDNA encoding the VP6 gene of avian rotavirus PO-13 strain was inserted into the bacterial expression vector pET-3a. Upon isopropyl-1-thio-13-D-galactoside induction, the E. coti BL21 (DE3) harboring the vector containing cDNA of the VP6 gene produced an approximately 45-kDa polypeptide, which reacted with rabbit serum against PO-13 strain in Western blotting. To study the antigenic sites on VP6, various deletion mutants were constructed, expressed in E. coli and the reactivity with antigenic site I- and Iispecific MAbs analyzed by Western blotting. Site I, which is shared with all group A mammalian and avian rotaviruses except for chicken rotavirus, was found to be located at amino acid positions 45 to 65, and site II, which probably contributes to an authentic group A antigen common to both mammalian and avian rotaviruses, at amino acid positions 134 to 142.

本试验利用杆状病毒载体成功地表达狂犬病病毒糖（G）蛋白。从转染重组了日本动物用狂犬病病毒疫苗株RCHL株G蛋白基因的转移载体和野生型杆状病毒DNA的Sf-9细胞中，分离出2个重组杆状病毒克隆。应用印渍法和荧光抗体法（IFA）从重组杆状病毒感染的Sf-9细胞检出了狂犬病毒G蛋白。Sf-9细胞表达的G蛋白与狂犬病毒RCHL株感染NA细胞的G蛋白的分子量一致。35个抗RCHL株G蛋白的单克隆抗体均与重组杆状病毒感染的Sf-9细胞反应，表明表达的G蛋白的抗原性没有发生变异。表达的G蛋白主要分布在Sf-9细胞的膜表面，形成类似环状的荧光，这种荧光与RCHL株感染的NA细胞的荧光相同。

本试验对从广西分离的4株疑似副鸡嗜血杆菌（H.pg）（GX-95，GX-97，GX-98-1，GX-98-2）进行生物学特性研究。根据生物学特性，GX-97和GX-98-1被定为H.pg，GX-95和GX-98-2的生化反应特性有明显差异，用标准H.pg血清未能定型。交叉血凝抑制（HI）试验显示，各菌株之间的交叉HI效价达160，但各菌株与其本身的抗血清HI效价达1280，显示出很强的菌株特异性。抗菌素敏感试验也显示GX-97、GX-98-1和参考菌株的药敏谱更加相似。

本研究采用醇沉淀法从350g玉米花粉提取得粗提复合物38.3g。经用蒽酮反应、A萘酚反应、间苯二酚反应、碘化反应及高效液相色谱法鉴定，证实为多糖。用上述多糖作为免疫增强剂按剂量50、100、200mg分别与猪瘟弱毒细胞冻干苗共同免疫猪，测定其免疫效果。结果表明，各剂量组的IHA抗体效价均高于对照组；T细胞活性E花环试验测得各剂量的活性E花环百分率分别为21.84%、25.46%、21.92%，均高于对照组15.91%；T淋巴细胞转化试验显示，各试验组的T淋巴细胞转化率分别为55.32%、56.39%、54.27%，均高于对照组47%，上述三种方法测定的结果均显示显著差异。对T淋巴细胞亚群的测定结果为，各试验组的CD3、CD4、CD8T淋巴细胞的测定平均值均明显高于对照组，但NK细胞的变化不显著。根据试验结果选取100mg剂量组在两个猪场进行田间扩大试验，测得的IHA抗体效价亦高于对照组。研究结果表明，玉米花粉多糖既可增强体液免疫，又能增强细胞免疫。

本研究建立了反转录聚合酶链反应（RT-PCR）技术检测猪瘟病毒（HogCholeraVirus，HCV）方法。合成的二对引物HCV-1/HCV-2和HCV-A1/HCV-A2成功地扩增兔化弱毒株、法国株和石门株的核酸，并对采自博白县3个、贵港市1个和武宣县1个猪场共13份病料进行检测。结果从博白县和贵港市的11份材料中检测到HCV的核酸。

广西一些养殖场频繁发生以母猪流产、死胎、木乃伊等为特征的流行性传染病，怀疑为猪繁殖与呼吸综合征病毒（PRRSV）所致。利用针对PRRSV的N基因的特异性引物P1和P2，通过RT_PCR技术对分别从广西贵港市（GXGG）和南宁市（GXNN）收集到的可疑病料进行检测，结果两份为阳性。合成针对M基因的引物M1和M2，分别扩增了GXGG和GXNN两株PRRSV的M基因，并进行克隆和测序，得到长582个核苷酸的目的基因片段。应用DNAStar序列分析软件对所测的两个广西毒株与国内外已发表的ATCCVR_2332、LV和CH_la毒株进行同源性比较。分析表明，GXGG与ATCCVR_2332、LV、CH_la的核苷酸同源性分别为9516%、6915%、9717%；GXNN与ATCCVR_2332、LV、CH_la的核酸同源性分别为9419%、6915%、9713%。对推定的氨基酸序列进行了比较，GXGG与ATCCVR_2332、LV、CH_la的氨基酸同源性分别为9717%、8015%、9717%；GXNN与ATCCVR_2332、LV、CH_la的氨基酸同源性分别为9813%、7919%、9711%。说明广西流行毒株与ATCCVR_2332和CH_la的同源性很高，而与LV毒株的同源性很低。从本研究构建的系统发育树分析，广西流行的PRRSV与ATCCVR_2332株的亲缘关系比较密切。

从广西南宁、隆安和巴马分离到三株狂犬病病毒野毒株，分别编号为GXN119、GXLA和GXBM。对三株的N基因和GXN119、GXBM株的G基因进行了RT-PCR扩增、克隆和测序。将测序所得结果和收集到的国内外已发表毒株相应基因进行了核苷酸和推定氨基酸的序列进行比较分析。三株野毒之间N基因的核苷酸同源性分别为：89.1%（GXN119/GXBM）、89.7%（GXN119/GXLA）和89.4%（GXLA/GXBM），G基因的核苷酸同源性为86.7%（GXN119/GXBM）。比较N基因推导氨基酸序列同源性，分别为：97.8%（GXN119/GXBM）、97.8%（GXN119/GXLA）和99.1%（GXLA/GXBM），表明N基因同义变异较多。将两株野毒株GXN119、GXBM与人用疫苗3aG株和兽用疫苗ERA株的G基因进行了核苷酸序列比较，同源性介于82.7%～84.0%之间，推定氨基酸同源性在88.0%～91.6%之间。N蛋白的第40位Ser和106位Asp显示了广西狂犬病流行病学的区域特异性。