Electronic Library of Scientific Literature - © Academic Electronic Press
Volume 45 / April 2001 / number 2
D.T. MOURYA, M.D. GOKHALE, A. BASU, P.V. BARDE, G.N. SAPKAL, V.S. PADBIDRI, M.M. GORE
National Institute of Virology, 20-A Dr. Ambedkar Road, Pune 411 001, India
Summary. – Isofemale lines of Aedes aegypti mosquitoes highly and lowly susceptible to dengue type 2 (DEN-2) virus (DEN(h) and DEN(l), respectively) were established by oral feeding and individual rearing. The susceptibility at F13 generation was found to be 61% and 25% for the DEN(h) and DEN(l) line, respectively. The virus-infected mosquito females were allowed to probe on bovine albumin phosphate saline pH 7.2 (BAPS) through membrane feeders. The presence of virus in the probed BAPS was determined either by ELISA or by intrathoracic (i.t.) inoculation of mosquitoes or by both methods. The rate of oral transmission of virus was found to be 2 times higher in the DEN(h) isofemale line than in the DEN(l) one. Similarly, vertical transmission rate of the virus was found to be 7 times higher in the DEN(h) line. When batches of eggs obtained from infected female mosquitoes were allowed to hatch after two months the vertical transmission rate of the virus was very high. It is possible that, at room temperature, the virus gets an opportunity to multiply and increase its copy number in the quiescent embryos. The progeny obtained from the infected mosquitoes was found to be capable of transmitting the virus horizontally when allowed to probe on BAPS through the membrane feeder. This is the first report demonstrating horizontal transmission of DEN-2 virus by mosquitoes infected through vertical transmission. The higher vertical transmission rate of the virus in the progeny obtained from the eggs dessicated for a longer time and the horizontal transmission of the virus from the progeny is of very high epidemiological significance.
Key words: Aedes
aegypti; dengue virus type 2; isofemale lines; horizontal transmission;
transovarial transmission; vertical transmission
Acta virologica 45: 67 – 71, 2001
A.T. OWOLABI, E. PROLL
Department of Biological Sciences, University of
Calabar, P.M.B. 1115, Calabar, Nigeria;
Institute for Resistant Research and Pathogen Diagnostics, Aschersleben, Germany
Summary. – A virus inducing mosaic and severe leaf malformation, isolated from Senna hirsuta in Nigeria, was studied. The virus had a rather narrow host range, infecting a few species in Caesalpinaceae, Chenopodiaceae and Fabaceae families. The virus was widespread in southern Nigeria with prevalence ranging from 74% to 86.4% in some locations. It was transmitted mechanically and in a non-persistent manner by Myzus persicae, Aphis craccivora and A. spiraecola. There was no evidence of transmission by seeds. Electron microscopy of leaf dip preparations revealed flexuous rod-shaped particles. The viral coat protein had Mr of 32.5 K. The virus reacted positively with a monoclonal antibody (MAb) to peanut stripe virus specific for potyviruses (members of the Potyvirus genus) and with antisera to turnip mosaic virus (TuMV), potato virus Y (PVY), TuMV, potato virus A (PVA), potato virus V (PVV) and bean yellow mosaic virus (BYMV), but it failed to react with antisera to celery mosaic virrus (CeMV), bean common mosaic virus (BCMV), soybean mosaic virus (SMV), and clover yellow mosaic virus (ClYMV) in plate-trapped ELISA (PTA-ELISA). No positive reaction was obtained when the virus was tested against any of the antisera in double-antibody sandwich ELISA (DAS-ELISA). This is the first report of natural infection of Senna species in Nigeria. The virus, tentatively designated as Senna mosaic virus (SeMV), seems to differ from other viruses previously described from Senna species in the literature and indeed other legume potyviruses in Nigeria.
Key words: Senna
hirsuta; mosaic; Senna mosaic virus; potyvirus; Nigeria
Acta virologica 45: 73 – 79, 2001
University of Veterinary Medicine, Komenského 73, 041 81 Košice, Slovak Republic
Summary. – Three pestiviruses in fetal calf serum (FCS), a pestivirus in porcine ST cell line, and two pestiviruses in two of five bovine cell lines were detected by RT-PCR method employing panpestivirus primers selected from the 5´-non-coding region (5´-NCR). The 288 bp products were sequenced in both directions. To identify these pestiviruses, their nucleotide sequences and those of reference pestiviruses were used for construction of a dendrogram. Three viruses present in FCS and a virus present in the bovine RP-15 cell line were identified as bovine viral diarrhea virus 1 (BVDV-1). Bovine viral diarrhea virus 2 (BVDV-2) was identified in a batch of the bovine MDBK cell line. A pestivirus contaminating the porcine ST cell line was identified as a Border disease virus (BDV).
Key words: pestivirus;
cell line; fetal calf serum; RT-PCR
Acta virologica 45: 81 – 86, 2001
T. VARADINOVA, D. KOVALA-DEMERTZI, M. RUPELIEVA, M. DEMERTZIS, P. GENOVA
Laboratory of Virology, Faculty of Biology, Sofia
University, Dragan Tzankov Blvd. 8, 1421 Sofia, Bulgaria;
Inorganic and Analytical Chemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
Summary. – A heterocyclic compound, pyridine-2-carbaldehyde thiosemicarbazone (HFoTsc), and its six metal coordinated bound complexes, three with platinum (II) and three with palladium (II), were studied for their activity against herpes simplex virus 1 (HSV-1) infection in cultured cells. According to their cytotoxicity the compounds were divided into two groups. Group 1 (cytotoxic compounds) included all three palladium complexes and [Pt(HFoTsc) 2] Cl2, with maximum non-toxic concentration (MNC) of 1–10 µmol/l and a 50% cytotoxic concentration (CC50) of 20–100 µmol/l. Group 2 (low cytotoxic compounds) with MNC of 100 µmol/l and CC50 of 548–5820 µmol/l included compounds in the following order: [Pt(HFoTsc)2 ] Cl2<HFoTsc<[PtCl FoTsc)]. The 50% inhibitory concentration (IC50) and a selectivity index (SI) values determined during 24 hrs and 48 hrs of action were indicative of antiviral activity. IC50 and SI values of HFoTsc increased in parallel with the duration of action in HSV-1-infected cells. All three platinum complexes as well as [Pd(HFoTsc)2]Cl2 and [Pd(FoTsc)2] inhibited HSV-1 infection following a structure-activity relationship but only [Pt(HFoTsc)2]Cl2 expressed a significant selectivity comparable to that of HFoTsc. However, [PdCl(FoTsc)] acting 48 hrs gave a higher infectious HSV-1 titer (170%) compared to control (100%, no compound).
Key words: herpes
simplex virus 1; thiosemicarbazone; platinum (II); palladium (II);
cytotoxicity; antiviral activity
Acta virologica 45: 87 –94, 2001
V. BALAMURUGAN, J.M. KATARIA, A.K. TIWARI, K.C. VERMA, R. TOROGHI, S.J. JADHAO
Division of Avian Diseases and 2National
Biotechnology Centre, Indian Veterinary Research Institute,
Izatnagar, Bareilly, U.P. 243 122, India
Summary. – A sandwich ELISA was standardized to detect fowl adenovirus (FAV) group I antigen in various tissues, namely liver, spleen, bursa, thymus and kidneys of chicks experimentally infected with fowl adenovirus 4 (FAV-4) isolated from cases of inclusion body hepatitis-hydropericardium syndrome (IBH-HPS). The assay was found to be more sensitive and more specific in comparison to an agar gel immunodiffusion (AGID) test, as it could detect FAV antigen below the titer of 20,000 TCID50/ml and below 1.14 µg in 5% (w/v) suspensions of liver tissue. In 2-week-old experimentally infected chicks, the antigens were detectable by ELISA in liver from 3 to 15 days, in thymus from 3 to 7 days, and in kidneys, bursa and spleen from 3 to 10 days post infection (p.i.). Maximum antigen concentration in terms of ELISA absorbance values was detected in liver and kidneys, which could be used as tissues of choice for virus isolation or detection of viral antigens from IBH-HPS cases.
Key words: fowl
adenovirus 4; hydropericardium syndrome; sandwich ELISA
Acta virologica 45: 95 – 100, 2001
V. MAJERČIAK, A. VAĽKOVÁ, D. SZABOVÁ, H. GEERLIGS, V. ZELNÍK
Institute of Virology, Slovak Academy of Sciences,
Dúbravská cesta 9, 842 46 Bratislava, Slovak Republic;
Fort Dodge Animal Health Holland, Weesp, The Netherlands
Summary. – CVI988/Rispens strain of Marek’s disease virus type 1 (MDV-1) is widely used as efficient vaccine to control Marek’s disease (MD) in chicken flocks. Similarly to other live MD vaccine viruses it is propagated in freshly prepared chicken embryo fibroblasts (CEF). In this study, MDV-1 CVI988/Rispens strain was adapted to QT35 cells. The adapted virus, designated QT-CVI, exhibited similar cytopathic effect (CPE) in vitro to that of parental virus propagated in CEF. In contrast, QT-CVI induced MD symptoms typical for mild MDV-1 strains after injection to birds. For identification of differentially expressed transcripts that might be involved in increased virulence of QT-CVI, we performed subtractive suppression hybridization (SSH). Subtracted PCR products mapped within MDV-1 BamHI-A and -H fragments and differential gene expression was also confirmed by Northern blot analysis with probes derived from these regions. To examine possible divergence at the virus genome level, PCR analysis was carried out. The BamHI-H fragment- specific 132 bp repeats were present at variable copy number, ranging from 2 to more than 30 copies in both CVI988/Rispens and QT-CVI DNAs. PCR assays with primers mapping at the US/IRS junction identified CVI988/Rispens-specific insertion of 116 bp in the region upstream of the ICP4 open reading frame (ORF). PCR analysis was positive also for DNA from non-infected QT35 cells and was consistent with the observation of Yamaguchi et al. (J. Virol. 74, 10176–10186, 2000) who have found that QT35 cells carry a latent MDV-1 genome. It is likely, that adaptation of CVI988/Rispens to QT35 cells resulted in reactivation of an endogenous MDV-1 or at least in induction of expression of virulence-related transcripts that have consequently led to QT-CVI pathogenicity for chickens.
Key words: Marek’s
disease virus type 1; differential expression; herpesvirus reactivation
Acta virologica 45: 101 – 108, 2001
Institute of Molecular Genetics, Academy of
Sciences of the Czech Republic, Flemingovo nám. 2,
166 37 Prague 6, Czech Republic
Summary. – Activities of the primase (Pr)-alpha DNA polymerase (pol) enzyme complex belonging to the naturally occurring reaction systems represented by special NP complexes harboring an extrachromosomal DNA identical with avian myeloblastosis virus (AMV) core-bound DNA (J. Říman, A. Šulová and K. Horská, Acta virol. 39, 149–159 (1995); J. Říman and A. Šulová, Acta virol. 41, 181–192 (1997)) were studied in the absence and presence of carbonyldiphosphonate (COMDP), mimosine (MIMO), to it related ciclopirox olamine (CPX) and butylphenyl deoxyguanosine-5´-triphosphate (BuPdGTP). Reaction products radioactively labeled for RNA and DNA and synthesized with the common four ribonucleoside triphosphates (rNTPs) or rNTPs and deoxyribonucleoside triphosphates (dNTPs) in the reaction medium, were analyzed by polyacrylamide gel electrophoresis (PAGE) at denaturing conditions. It was shown that COMDP strongly activates the Pr and uncouples its activity from that of alpha DNA pol with accumulation of initiator (i) RNAs of the basic length. This phenomenon is not affected by BuPdGTP. MIMO, in contrast, stimulates both pol activities of this enzyme complex and preserves their mutual coupling. The effects of COMDP, MIMO and CPX seem to be modulated by concentration of the ambient dNTPs. Addition of dNTPs to rNTPs makes the effects of COMDP and MIMO mutually exclusive, suggesting that both these agents, though chemically quite different, are competing for one active site responsible for coupling these both pol activities into the one Pr-alpha DNA pol reaction.
Key words: primase;
alpha DNA polymerase; enzyme complex; carbonyldiphosphonate, mimosine;
ciclopirox olamine; butylphenyl deoxyguanosine-5´-triphosphate; Okazaki
fragments; initiator RNA; lagging DNA strand synthesis.
Acta virologica 45: 109 – 124, 2001
A.S. MUSTAFA, E.A. ELBISHBISHI, S. GROVER, A.S. PACSA, A.A. AL-ENEZI, U.C. CHATURVEDI
Department of Microbiology, Faculty of Medicine,
Kuwait University, P.O. Box 24923, Safat 13110, Kuwait;
Infectious Diseases Hospital, Ministry of Health, Safat, Kuwait
Summary. – This study was carried out on sera from 210 patients in Kuwait in 1997–1999. All of the patients were suffering from febrile illness and had recently visited dengue- (DEN) endemic areas. The sera were screened for DEN virus by inoculation into cultures of the Aedes albopictus cell clone C6/36 (virus isolation) and by IgM capture ELISA (detection of DEN virus-specific IgM antibodies). In the cell cultures, DEN virus could not be isolated from any of the patients’ sera. However, sera from 19 patients were positive for DEN virus-specific IgM antibodies. All these 19 sera were tested for the presence of DEN virus-specific RNA by reverse transcription–PCR (RT-PCR) using DEN virus types-common (consensus) primers. In addition, the type of DEN virus was identified by using type-specific primers in a semi-nested PCR. The results showed that two of the 19 patients were infected with DEN virus type 2. This report of 19 patients with serological evidence of DEN infection indicates that imported DEN is a real threat to Kuwait, a country non-endemic for DEN but with a large portion of the population vacationing in DEN-hyperendemic areas during the peak DEN season and then returning to Kuwait.
Key words: dengue;
Acta virologica 45: 125 – 128, 2001
R. CHANDRA, J.C. GOMEZ-VILLAMANDOS
Department of Microbiology, College of Veterinary
Sciences, G.B. Pant University of Agriculture and Technology, Pantnagar
263145, U.S. Nagar, Uttaranchal, India;
Departamento de Anatomia Patologica, Facultad de Veterinaria, Universidad de Cordoba, Cordoba, Spain
Key words: fowl
adenovirus 4; experimental infection; domestic fowl; hydropericardium
syndrome; ultra structural changes; liver
Acta virologica 45: 129 – 131, 2001
Acta virologica 45: 133 – 136, 2001
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