A serological survey for Bhanja and tick-borne encephalitis viruses in sheep of eastern Slovakia

755 sheep from 41 farms in the districts of Trebisov, Michalovce, Humenné and Roznava in the East Slovakian region were investigated on the presence of antibodies to Bhanja (neutralization test) and tick-borne encephalitis (haemagglutination-inhibition test) viruses. In respective districts 2.2%, 0.4%, 1.7% and 26.7% of animals (total 5.3%) were found to be positive on Bhanja virus, 4.4%, 1.5%, 1.7% and 5.0% (total 2.6%) on tick-borne encephalitis (TBE) virus. The considerable infection rate in sheep with Bhanja virus in the district of Roznava (mean 26.7%-on one farm as high as 63.9% serologically positive animals) can be explained by the local occurrence of the tick Haemaphysalis punctata, the main vector of this virus in Europe. The serologic screening conducted indicates a low activity of natural foci of TBE in eastern Slovakia today, and confirms the existence of a natural focus of infection with Bhanja virus in the district of Roznava. Recent circulation of Bhanja virus is indicated by antibodies detected in several one-year-old sheep.     

Rapid serological diagnosis of tick-borne encephalitis by means of enzyme immunoassay

A system of IgM-capture EIA made up from Czechoslovak immunopreparations (SEVAC) was developed for a rapid serological diagnosis of tick-borne encephalitis (TBE). The method was tested on clinical material. The total IgM antibody titres were detected using pig antiserum and the selection of specific IgM antibodies was made with TBE antigen with following indirect way of detection. The antibody analysis made by means of this method is sensitive and fully conforms to the clinical picture of the disease.     

A contribution to the parasite fauna in winter nests of the common mole (Talpa europaea L.) and incidence of its infection with tick-borne encephalitis virus (TBE) and rickettsia Coxiella burnetii

A total of 45 winter nests of the common mole (Talpa europaea L.) from the Záhorska lowland (western Slovakia) were investigated in January through March during the years 1981-1985. Seven species of fleas with the eudominant species Ctenophthalmus assimilis were found in them, the other species were subrecedent. The acarinium of the mole winter nests was composed of 19 mite species. Predominant were euryphagous species Haemogamasus nidi, H. hirsutus, Eulaelaps stabularis and Androlaelaps fahrenholzi. TBE virus was detected in samples prepared from suspensions of the mites H. nidi, H. hirsutus, Hirstionyssus talpae and A. fahrenholzi and the fleas Ct. assimilis collected in three localities: Laksárska Nová Ves, Stupava, Pernek. C. burnetii was found neither in mites nor in fleas.     

Results of arbovirological examination of birds of the family Hirundinidae in Czechoslovakia

Migratory birds (swallow, Hirundo rustica; sand martin, Riparia riparia; house martin, Delichon urbica) caught in southern Moravia (Czechoslovakia) in 1984-87 were examined for arbovirus infections. Isolation experiments were carried out using blood samples of 183 birds (52 swallows, 107 sand martins, and 24 house martins). The results were negative. Serological examinations of 136 birds (36 swallows, 86 sand martins, and 14 house martins) were made by haemagglutination-inhibition test (HIT) using 6 arboviral antigens of the genera Alphavirus (Sindbis--SIN) and Flavivirus (tick-borne encephalitis--TBE, West Nile--WN) and of the family Bunyaviridae (Tahyna--TAH, Calovo, CVO, and Bhanja--BHA). Antibodies against all of the tested viruses were detected at different rates: SIN 2.9%, TBE 1.5%, WN 1.5%, TAH 4.4%, CVO 1.5%, and BHA 2.2%. The titres ranged from 1.20 to 1.80.     

芝麻坏死花叶病毒的鉴定

 自武昌芝麻坏死花叶病株得到1个病毒分离物,根据该分离物生物学特性、粒体形状、血清学性质、外壳蛋白分子量和核酸组分、大小,明确为自然侵染芝麻的一种新病毒,定名为芝麻坏死花叶病毒(Sesame necrotic mosaic virus,SNMV)。在人工接种7科38种植物中,SNMV侵染6科23种;体外稳定性状:稀释限点10^-4~10^-5,致死温度80~85℃,体外存活期限40d;病毒可通过土壤和接触传播。SNMV病毒粒体球状,表面有粒状突起,直径约32nm。制备病毒抗血清用琼脂双扩散方法测定效价为1:128。SNMV和红三叶草坏死花叶病毒(RCNMV)、甜三叶草坏死花叶病毒(SCNMV)、黄瓜花叶病毒(CMV)和花生矮化病毒(PSV)抗血清没有反应。病毒外壳蛋白亚基分子量为38 100道尔顿;核酸1个组分,大小约4700nt,另含RNA片段,大小约600nt,可能为卫星RNA。依据上述病毒特性,SNMV可能归属于番茄丛矮病毒科(Tombusviridae)。     

Haemagglutination-inhibiting antibodies against arboviruses of the families Togaviridae and Bunyaviridae in birds caught in southern Moravia, Czechoslovakia

A total of 295 birds belonging to 19 species of 7 families of wild Passeriformes were examined by haemagglutination-inhibition test. The birds were caught for an international research program "Balt" at the time of autumn migration (August-September 1984). Their blood sera were examined for antibodies against 6 arbovirus antigens of the genera Alphavirus (Sindbis-SIN) and Flavivirus (tick-borne encephalitis-TBE, West Nile-WN) and family Bunyaviridae (Tahyna-TAH, Calovo-CVO and Bhanja-BHA). Antibodies against all studied viruses were detected at different frequencies: SIN 6.4%, TBE 7.1%, WN 9.7%, TAH 16.3%, CVO 12.1%, and BHA 1.0%.     

Putative virus disease of sunflower in Zambia

Symptoms of a virus-like disease of unknown aetiology were observed in sunflower in five provinces of Zambia during the 1998 growing season. In the 20 surveyed farmers'fields, disease incidence was 80–100%. Yield loss in seed production as a result of the putative virus (or virus complex) was estimated at 60%. The virus was not seed-borne in sunflower. The weed Tridax procumbens was found to be an alternative host of the virus, and the virus was transmitted by Aphis gossypii from the weed to sunflower. Serological analysis suggests that the virus (or virus complex) is closely related to luteoviruses. It is tentatively named sunflower yellow blotch virus (SYBV).     

Serological relationships of geminivirus isolates from Gramineae in Australia

Three distinct viruses, named chloris striate mosaic virus (CSMV), paspalum striate mosaic virus (PaSMV) and digitaria didactyla striate mosaic virus (DDSMV), have been identified among the five Gramineae-infecting geminiviruses from Australia using polyclonal antisera. An isolate from Microlaena was confirmed as a strain of CSMV, and an isolate from Bromus catharticus was identified as PaSMV-BC. Enzyme-linked immunosorbent assay (ELISA) detected relationships between all but one of the viruses tested, the exception being miscanthus streak virus (MiSV) from Japan. The Australian viruses proved to be distantly related to similar viruses from Africa, digitaria streak virus (DSV) from Vanuatu, and wheat dwarf virus (WDV) from Europe. Three distinct groups of viruses from Africa, Australia and Europe were distinguished by phylogenetic analysis.     

Characterization of Distinct Tombusviruses that Cause Diseases of Lettuce and Tomato in the Western United States

A soilborne disease of lettuce, associated with necrosis and dieback, has been found with increasing frequency in California and Arizona over the last 10 years. An isometric virus, serologically related to Tomato bushy stunt virus (TBSV), was consistently isolated from lettuce plants with these disease symptoms. Back-inoculation to healthy lettuce plants and subsequent reisolation of the virus from symptomatic lettuce leaves suggested that this virus was the causal agent of this disease. A tombusvirus was also associated with a necrosis disease of greenhouse-grown tomatoes in Colorado and New Mexico. Complementary DNA representing the 3' end of viral genomic RNAs recovered from diseased lettuce and tomato plants had identical nucleotide sequences. However, these sequences were divergent (12.2 to 17.1%) from sequences of the previously described strains of TBSV, Petunia asteroid mosaic virus (PAMV), Artichoke mottled crinkle virus, and Carnation Italian ringspot virus. Additional tombusvirus isolates were recovered from diseased lettuce and tomato plants and these were most closely related to the TBSV-cherry strain (synonymous with PAMV) and to Cucumber necrosis virus based on comparison of 3'-end sequences (0.1 to 0.6% and 4.8 to 5.1% divergence, respectively). Western blot analysis revealed that the new tombusvirus isolated from diseased lettuce and tomato plants in the western United States is serologically distinct from previously described tombusvirus species and strains. Based on genomic and serological properties, we propose to classify this virus as a new tombusvirus species and name it Lettuce necrotic stunt virus.     

Tamusred mosaic virus, a potexvirus from black bryony (Tamus communis)

A virus was isolated in Italy from Tamus communis in which it caused symptoms of red mosaic and leaf distortion. The virus, for which the name tamus red mosaic virus (TRMV) is suggested, was differentiated from other potexviruses or possible potexviruses on the basis of host range, particle properties and serology. In crude preparations, TRMV had elongated particles of modal length 550–560 nm and diameter of 13 nm. TRMV was easily purified from Chenopodium quinoa and had a buoyant density of 1·34 g/cm³ in CsCl and 1·27 g/cm-³ in Cs₂SO₄. An antiserum to TRMV was obtained with a titre of 1/1024 in slide precipitin tests. TRMV was related to, but distinct from, tamus latent virus, a potexvirus isolated from Tamus communis in the UK, and more distantly related to potato virus X, cactus virus X and commelina virus X. Polyacrylamide gel electrophoresis (PAGE) indicated that the virus particles contained a single protein species of estimated molecular weight 25·2 kDa. Enzymatic digestions, agarose gel electrophoresis and infectivity of the isolated nucleic acid indicated that the virus has a single major molecule of single-stranded positive-sense RNA of estimated molecular weight 2120 kDa ( ca. 6·4 kb).     

Molecular characterization, ecology, and epidemiology of a novel Tymovirus in Asclepias viridis from Oklahoma

Native virus-plant interactions require more understanding and their study will provide a basis from which to identify potential sources of emerging destructive viruses in crops. A novel tymovirus sequence was detected in Asclepias viridis (green milkweed), a perennial growing in a natural setting in the Tallgrass Prairie Preserve (TGPP) of Oklahoma. It was abundant within and frequent among A. viridis plants and, to varying extents, within other dicotyledonous and one grass (Panicum virgatum) species obtained from the TGPP. Extracts from A. viridis containing the sequence were infectious to a limited number of species. The virus genome was cloned and determined to be closely related to Kennedya yellow mosaic virus. The persistence of the virus within the Oklahoma A. viridis population was monitored for five successive years. Virus was present in a high percentage of plants within representative areas of the TGPP in all years and was spreading to additional plants. Virus was present in regions adjacent to the TGPP but not in plants sampled from central and south-central Oklahoma. Virus was present in the underground caudex of the plant during the winter, suggesting overwintering in this tissue. The RNA sequence encoding the virus coat protein varied considerably between individual plants (≈3%), likely due to drift rather than selection. An infectious clone was constructed and the virus was named Asclepias asymptomatic virus (AsAV) due to the absence of obvious symptoms on A. viridis.     

Severe mosaic caused by zucchini yellow mosaic virus in cucurbits from Jordan

A virus disease causing severe mosaic in melon (the melon isolate) was identified as a strain of zucchini yellow mosaic virus (ZYMV). Identification was based on host range, aphid transmissibility, electron microscopy, and serological tests. The virus was recovered from all cultivated cucurbits in Jordan and from naturally infected Moluccella laevis. It was seed-transmitted in Ranunculus sardous. Host-range comparison showed that the melon isolate and a French isolate belong to a different biotype group from a Connecticut isolate (ZYMV-CT); this was confirmed by indirect ELISA. During 1987–1988. ZYMV appeared to be the predominant virus affecting cucurbits.     

Increase of tospoviral diversity in Brazil with the identification of two new tospovirus species, one from chrysanthemum and one from zucchini

ABSTRACT During a survey conducted in several different regions of Brazil, two unique tospoviruses were isolated and characterized, one from chrysanthemum and the other from zucchini. The chrysanthemum virus displayed a broad host range, whereas the virus from zucchini was restricted mainly to the family Cucurbitaceae. Double-antibody sandwich-enzyme-linked immunosorbent assay and western immunoblot analyses demonstrated that both viruses were serologically distinct from all reported tospovirus species including the recently proposed peanut yellow spot virus and iris yellow spot virus (IYSV) species. The nucleotide sequences of the nucleocapsid (N) genes of both viruses contain 780 nucleotides encoding for deduced proteins of 260 amino acids. The N proteins of these two viruses displayed amino acid sequence similarities with the previously described tospovirus species ranging from 20 to 75%, but they were more closely related to each other (80%). Based on the biological and molecular features, these viruses are proposed as two new tospovirus species, designated chrysanthemum stem necrosis virus (CSNV) and zucchini lethal chlorosis virus (ZLCV). With the identification of CSNV and ZLCV, in addition to tomato spotted wilt virus, groundnut ring spot virus, tomato chlorotic spot virus, and IYSV, Brazil harbors the broadest spectrum of tospovirus species reported.     

Molecular and biological characterization of Macroptilium yellow mosaic virus from Jamaica

The molecular and biological characterization of a begomovirus infecting the common weed Macroptilium lathyroides from Jamaica are reported. The virus showed 92% sequence identity to an isolate of Macroptilium yellow mosaic virus (MaYMV) from Cuba, but was distinct from the two other begomoviruses isolated from M. lathyroides , namely Macroptilium yellow mosaic Florida virus (80% identity) and Macroptilium mosaic Puerto Rico virus (68% identity). Hence, the Jamaican begomovirus was considered an isolate of MaYMV and called Macroptilium yellow mosaic virus -[Jamaica] (MaYMV-[JM]). In infectivity studies using cloned DNA-A and DNA-B genomic components, MaYMV-[JM] infected red kidney bean ( Phaseolus vulgaris ) and produced mild symptoms in Scotch Bonnet pepper ( Capsicum chinense ), but did not infect cabbage ( Brassica oleracea ). This information has implications for the development of strategies to control begomovirus diseases in Jamaica and elsewhere.     

深度测序发现贵阳发生的辣椒病毒病由多种病毒复合侵染所致

2016年9月贵州省贵阳市发生严重的辣椒病毒病,症状复杂,主要表现为植株矮化,叶片黄化、花叶、皱缩、畸形以及枯死斑,果实有坏死斑等,根据症状难以判断病毒种类。本文采用小RNA深度测序技术对田间自然发病的2株辣椒标样进行了毒源鉴定,发现样品1由蚕豆萎蔫病毒2号(Broad bean wilt virus2,BBWV2)、辣椒脉斑驳病毒(Chilli veinal mottle virus,ChiVMV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)和辣椒内源RNA病毒(Bell pepper endornavirus,BPEV)4种病原复合侵染;样品2中除鉴定到上述4种病毒外,还检测到马铃薯Y病毒(Potato virusY,PVY)。进一步通过反转录PCR(RT-PCR)对深度测序结果进行了验证,证明其准确可靠。其中4个辣椒标样中均有的辣椒内源RNA病毒(BPEV)为贵州省首次报道。多种病毒复合侵染是辣椒产量和品质的重要限制因素之一,是辣椒生产的主要威胁。     

甜菜潜隐病毒的研究

 从市场出售的甜菜(Beta vulgaris)种子中首次得到了直径约30毫微米的等轴病毒粒子的分离物。接种试验证明,它不能由摩擦接种传病,也不能由桃蚜(Myzus persicae)传播,但可由种子传毒,种子带毒率高达87.5%。受侵染的甜菜植株不表现症状,体内含毒量很低,病株汁液须经部分提纯并浓缩后才能在电镜下观察到病毒粒子和用琼脂双扩散法检测到病毒。在病株叶片的超薄切片中,未发现病毒粒子和细胞学的变异。在氯化铯溶液中,病毒粒子的浮力密度为1.37克/毫升左右。该分离物能与甜菜潜隐病毒抗血清产生沉淀反应,但与黄瓜花叶病毒无血清学关系。根据上述基本性状,该分离物归属于甜菜潜隐病毒(Beet Cryptic Virus)。     

Biological and molecular characterization of a new cucurbit-infecting tobamovirus

ABSTRACT An uncharacterized virus was isolated from greenhouse-grown cucumber plants. Biological and serological data described in the present study indicated that the virus belonged in the genus Tobamovirus. The host range of the virus included several plant species within the family Cucurbitaceae. The virus designated Cucumber fruit mottle mosaic virus (CFMMV) causes severe mottling or mosaic on cucumber fruits, and its fast spread within greenhouses could lead to significant economic losses in cucumber crops. The genome of CFMMV has been completely sequenced and its genome organization was typical of a Tobamovirus. However, its sequence was distinct from other described viruses within the group of cucurbit-infecting Tobamoviruses. Comparisons of sequences and phylogenetic analysis suggested that the cucurbit-infecting Tobamoviruses be separated into two subgroups: subgroup I comprising the strains and isolates referred to in the literature as Cucumber green mottle mosaic virus (CGMMV) (CV3, CV4, CGMMV-W, CGMMV-SH, and CGMMV-Is) and subgroup II comprising CFMMV, Kyuri green mottle mosaic virus (KGMMV), and the Yodo strain of CGMMV, which is closely related to KGMMV and may be considered a strain of it.     

浙江甘蔗花叶病病原初步鉴定

 本文报道了一种在浙江省北部地区发生的甘蔗病毒病害。病毒粒子呈线状,长度为740 nm,在甘蔗病组织中形成风轮状内含体,病毒外壳蛋白分子量约36 kDa,表明其病原为马铃薯Y病毒科成员,血清学研究表明该病毒与高粱花叶病毒(Sr MV)反应强烈,与甘蔗花叶病毒(ScMV)及玉米矮花叶病毒(MDMV)反应次之,与约翰逊草花叶病毒(JGMV)的反应较弱,认为该病毒可能是甘蔗花叶病毒亚群的一个成员。