1994 Vol.09(3)
Aedes albopictus and Ae.aegypti mosquitoes were tested by oral infection with four strains of Chikuirgunya(CHIK) virus isolated from Yunnan,China and Africa for their susceptibility and transmissibility.Studies showed that these two species of mosquitoes were susceptible to CHIK virus. Either Ae.al,bopietus or Ae aegypti for 5th to 6th day after infection were capable of transmitting CHIK virus by biteto suckling mice.Their transmission rates were 55.55%-100% on the 8th to 13th day post-infec.tion.In another experiment,infected mosquitoes were capoble of transmitting CHIK virtis by bite tochickens.Infection and transmission rates were hisher in Ae.aegypti tested than in Ae.albopictus tested.The susceptibility and transniission potentials of the defferent strains of CHIK virus had some differences from each other,such as the M81 strain isolated from Ae.albopietue in Yunnan was apparentlymore virulent than the other strains.These results indicate that Ae.albopictus and Ae.aegypti from China have the potential tu
The ultrastructure of CM_2 cell line,derived from peripheral blood of a patient with nervous syatem disease and the morphology and morphogenesis of its harbored type C virions were reported.Thecell size by electron micrcacopy in thin section was about 7-15 micron in diameter.The pleomorphiccells have markedly deforined nuclei and the feature of malignant lymphoblast.There were numeroustype C virions in the enlarged cistern of rough endoplasmic reticulum(RER)of the cell and out of thecell.The size of the virion was about 68.1-94.3 nanometer in diameter,in average about 81.2nanometer,The majority of virions out the cell had dense core,but the core of the virions in the RERcistern were with much less density,Virions were formed by budding at cell membrane.
Infectious mature human immunodeficiency virus type 1 (HIV-1) carruig pre-virus DNA was evidenced by pelpoerase chani reaction(PCR).When the samples were treated with lytic buffer,the result of PCR should be positive;however when PBS was added uistead of lytic buffer,the DNA wasnot detected. The DNA was sensitive to DNase treamient after lysisof viral particles.However,theDNA was not seasitive to DNase treatinent for the intact viral paricles.The DNA was not detected after the CD_4 receptor of the C8_(166) cells were covered by anti-CD_4 receptor monoclonal antibody(Leu3a),and the virus could not absorb to the cells.Furthermore,the number of DNA was correlativewith virus titer.This evidence supported the HIV-I virus carrying pre-virus DNA.
Genome of presumed hepatitis E virus XJ90 and R25 was partially amplified by antigen capturepolymerase chain reaction(AC/PCR).cDNA band same as ET1·1 clune was ubserved.After purification,this cDNA band was sequenced using dideoxy mediated chain termination method.The nu-cleotide and amino acid homology between XJ90 R25 and ET1·1 clone were 99.6%,100%and99%,99%,respectively. This result showed that both XJ90 and R25 are hepatitis E virus.
Agrotis segetum granulosis virus (AsGV) is an important biolosical control agent for A.segelum.Several PstI fragments from AsGV were cloned into pUC19.Under the very low strinsency(20% formamide,37℃ ),we have leealized the granulin sene on BglII-S or T,EcoRI-A,PstI-A or B frag.ments of AsGV DNA,by using the 32P-labelled polyhedrin gene of Buzura suppressaria nuclear polyhedrosis virus (BsNPV)as a prcbe.
n isolate of Chinese squash leaf curl virus(SqLCV-C),which is transmitted by whitefly Bemisia tabaci and caused leaf curl and severe stunting symptoms on Cucurbita moschata and C,pepo,have beenisolated and further confirmed by molecular hybridization using its coat protein gene probe in Nanningcity,Guangxi Province.ELISA tests indicated that this isolate had strong positive reactions with ACMV MAb-SCR18 and ICMV MAb-SCR56,-SCR66:mild reactions with ACMV MAb-SCR11 andICMV MAb-SCR62,but negative with ACMV MAb-SCR23 and ICMV MAb-SCR52.
n identification of a mosaic virtis disease of eggplant which occurs in Shenyang was carried outduring 1991 and 1992.The isolate can be transmitted to some plants by mechanical inoculation,butcannot be transniitted by peach aphid(Myzus pericicae Sulzer,Phopalosiphum pseudobrassicae).Host ranse tbets were made on 16 species,but cannot infect Cucumis sativus,Cucurbita pepo and Vicai faba.In eggplant sap,their proporties were thermal inactivation point (TIP)between 90～95℃,dilution and point(DEP)between 10-6～10-7,longevity of leaf extract at room temperature (>25℃ )between one-several montlis.As electron microscopic observation by dip method reveals the particle of the virus as rod-shapedmeasuring±300×18nm,cystalline inclusions were found in cytoplasma of leaf tissue of infectedpeanut by microscope.The isolate could react with the antiserum of TMV by agar gel double diffusion test.Especially,spesific nucleic acid frasment(±200bp)was amplified by the polymerase chain reaction(PCR).According to these characteristic
Comparative studies were made among five CMV isolates cullected from pea(Pisum sativum),hyacinth bean(Dolichus lablab),bean(Phaseolus vulgaris)and red bean(P.angularis),which were namedCMVP_2 CMVP_3,CMVHB,CMVB and CMVRB,respectively.No difference was found in stability insap,aphid transmission,molecular weight of coat protein and electrophoretic mobilities of virions,ex-cept for symptoms in some plant species and RNA components of the virus,In agar gel immunodiffusion tests,the five isolates could produce clear precipitant bands with CMV antiserum and the bandswere confluent.According to the symptoms in Pisum sativum,Vicia faba,Vigna anguiculata and Phaseolusvulgaris,the five isolates could be divided into two groups:group Ⅰwas represented by CMVHB,CMVB and CMVRB,which caused local lesions on inoculated leaves;groupⅡwas reprecented by CMVP_2 and CMVP_3,which produced systemic symptoms.CMUP_2 has five RNA components,whereasother isolates possess four components,so satellite RNAs are presented in CMVP_2.
From September 1991 to August 1992,leaves,stem barks and roots collected in each monthfrom four-year-old satsuma budling infected with satsuma dwarf virus(SDV) and from four-year-oldsweet orange seedling infected with citrus tristza virus(CTV)were used for detecting SDV and CTVby using DAS-ELISA.The results show that SDV could not be detected in old leaves and stem barksall over the year.It could be stably detected in young leaves in March,April,May,June,Septemberand October but not in July and August,and in young steni barks it could be detected in April,May,June,July and Octuber,the concentration of SDV in young stem bark decreased sharply in July,Lowconcentratiun of SDV in roots could be detected in July and August as the new roots grow,This indicates that SDV propagated in young tissues under the terms of cool temperature.CTV could be stablydetedted not only in stem barks but also in leaves and roots all over the year,but the ELISA values(A410nm)decreased in summer and winter season,especially in old lea
sphere-sliaped virus has been isolated from the diseased sugar beet in Nighxia,The virus parti cle was 28nm in diameter.The virus could infect seventeen plants,They belong Cenopodiaceae,Legu minosae,Cucurbitaceae,Solanaceae and Aizoaceae,respectively,There has serological relationship be tween this virus and TRSV.On the basis of the symptomes in different host plants morphological structure of the virus particle and serological test,we preliminarily conclude that the virus belongs to a strain of the Tobacco ringspot virus.
The present study established and further improved the direct antisen cuating form of indirectELISA(DAC-ELISA)and Dot-ELISA for the detection of papaya rinsspot virus(PRV)in infected tissuses of papaya(Carica papsys L.)or zucchini squash(Cucurbita pepo L.).The results showed if theELISA method to be employed or the host plant to be detected were different,then the proper phosphate buffer solution for preparing the crude plant sap to be detected should be different.With a pro-per phosphate buffer solutions for preparins the crude plaut sap to be detected,it was pirssible to increase the sensitivity of DAC-ELISA and Dot-ELISA up to a dilution of plant sap at a rate of 1/4096and 1/1024 respectively.The main factors of interfering the accuracy of quantitative measurement ofthe concentration of viral antigens in crude plant sap were the amount of carbonate coating buffer solution(0.05mol/L,pHg.6)and the dilution rate of the crude plant sap.With a hisher dilution rate ofthe plant sap and a consistent aniount of carb
The morphogenesis and antigen localization of infectious canine hepatitis virus(ICHV)in dog kidney cells were studied with electron microscopy and immunogold electron microscopy,Apart from theassembly of ICHV in nuclei,virions were also assembled in cytoplasm of the infected cells.The modeof viral morphogenesis in homogeneous dense inclusions and paracrystalline ones in cytoplasm was similar to that well known in nuclei.Result of immunogold labelling showedthathere there were a lot of anti-genic components of ICHV providing the viral structural protein for the assembly of nucleocapsids inthese two kinds of inclusions in cytoplasm,In addition,some virus core-like electron opaque structuresaround 50nm in diameter were presented in cytoplasm as those in nuclei.
specific,sensitive,fast and convenient HBV-DNA detection system has been developed by usin8 two-step PCR combining with a biotinylated oligonucleotide hybridization method.The specificityof the system was proved by hybridizing both ￣(32)P-labelled HBV-DNA and biotinylated oligonucleotideprobes with PCR preduets,We also explored the sensitivity of the system,which can detect as less asabout 1-2 HBV-DNA molecules.The convenience of the system was demonstrated by the simple twotemperature PCR stepe and fast preducts detection with biotinylated oliunucleotide probe,This systemcan be used for both labortltory and clinical detection of HBV-DNA.
In isolate of Chinese squash leaf curl virus(SqLCV-C),which is transmitted by whitefly Bemisia tabaci and caused leaf curl and severe stunting symptoms on Cucurbita moschata and C,pepo,have beenisolated and further confirmed by molecular hybridization using its coat protein gene probe in Nanningcity,Guangxi Province.ELISA tests indicated that this isolate had strong positive reactions with ACMV MAb-SCR18 and ICMV MAb-SCR56,-SCR66:mild reactions with ACMV MAb-SCR11 andICMV MAb-SCR62,but negative with ACMV MAb-SCR23 and ICMV MAb-SCR52.
PCR was adapted to detect HSV-DNA sequence in samples from 72 petients with clironic cervici-tis and 30 healthy cotrols,and compared with McAb-ELISE and virus isolation(VI).The plsitive rateof HSVby these three methods was 28.4% 22.5% 20.6% respotively,and coinciuent rates a-mong threelmired methforwere allover 90%,It isshown that PCR cpmbined withcell lysis isa fast,effective and relle ble methed to detect HSV in the cervix,It can detect not only very low quantityHSV-DNA,but also inactive and latent HSV.HSV postivity rate of chronic cervicitis is markedly high-er than healthy control(P<0.05).
Duck hepatitis B virus re plicativc complexe~ (DHBV RCs)wcl~e isol~ted from DI-~V—infected duck liver by chromato~aphy thxou Bio--Oel A 5m followed crose gradient centrifugation．The feIathe endogenous DNA polymcra．se activity of the purified RCs was 100 tim es higher than that of the unchromatosraphed one，confirmed by detecting their DHBcAg with Dot-EIA method．
