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Acta virologica

Volume 45 / June 2001 / number 3

• TRANSMISSION OF ARBOVIRUSES WITHOUT INVOLVEMENT OF ARTHROPOD VECTORS
• OCCURRENCE OF GRAFT-TRANSMISSIBLE VIRUS DISEASES OF THE STRAWBERRY IN THE CZECH REPUBLIC
• SEQUENCE ANALYSIS OF RECENT INDIAN ISOLATES OF FOOT-AND-MOUTH DISEASE VIRUS SEROTYPES O, A AND ASIA 1 FROM CLINICAL MATERIALS
• COMPARISON OF VIRUS ISOLATION AND POLYMERASE CHAIN REACTION FOR DIAGNOSIS OF PESTE DES PETITS RUMINANTS
• ISOLATION AND EVALUATION OF COXIELLA BURNETII O-POLYSACCHARIDE ANTIGEN AS AN IMMUNODIAGNOSTIC REAGENT
• VIRUS-INHIBITORY EFFECT OF A YEAST RNA – TILORONE MOLECULAR COMPLEX IN CELL CULTURES
• HUMAN CYTOMEGALOVIRUS UL21.5 GENE IS EXPRESSED AS AN ”EARLY-LATE” GENE IN CULTURED HUMAN FIBROBLASTS
• THE CELLULAR NUCLEAR MATRIX REGULATORY PROTEIN YY1 DOES NOT DIRECTLY INTERACT WITH THE MOUSE POLYOMAVIRUS LARGE TUMOR ANTIGEN
• HOMOLOGY OF BOVINE HERPESVIRUS 2 AND HERPES SIMPLEX VIRUS 1 PROTEINS

TRANSMISSION OF ARBOVIRUSES WITHOUT INVOLVEMENT OF ARTHROPOD VECTORS

Summary. – Transmission of arboviruses (arthropod-borne viruses belonging to various virus families) without involvement of arthropod vectors has been documented for years, but the reports have not been reviewed systematically. The recent report of West Nile (WN) virus isolation from a hawk in mid-winter in New York (Garmendia et al., J. Clin. Microbiol. 38, 3110–3111, 2000) generated a considerable interest in this mode of arbovirus transmission. In this article, the data available worldwide are analyzed according to the factors involved in such a transmission under natural conditions, mode of infection, virus entry mechanism, administration and efficacy evaluation of vaccines, and significance in agricultural trade and public health. Analysis of numerous reports compiled for this review revealed that peroral and intranasal/aerosol transmissions are very common among arboviruses. The mechanism of virus infections in animals was most extensively studied for intranasal/aerosol infection, confirming two routes of virus spread to central nervous system (CNS), olfactory and hematogenous. To rule out the possibility of asymptomatic, cryptic infection the efficacy evaluation of candidates for vaccines against neurotropic arboviruses should include virus isolation from tissues of not only symptomatic but also of asymptomatic animals that survive intranasal virus challenge. Human activities, such as feeding livestock animals with food containing virus-contaminated meat and assembling a large number of livestock from many geographically-separated locations, have been identified as a cause of spread of some arboviral diseases. Despite numerous laboratory reports, the significance of this mode of transmission of arboviruses under natural conditions was rarely investigated, except for a few viruses important for veterinary medicine.

Key words: arbovirus; transmission mechanism; direct transmission; contact transmission
Acta virologica 45: 139 – 150, 2001

OCCURRENCE OF GRAFT-TRANSMISSIBLE VIRUS DISEASES OF THE STRAWBERRY IN THE CZECH REPUBLIC

Summary. – Strawberry virus diseases were monitored using a leaf graft bioassay in 17 cultivars of strawberry Fragaria ananassa Duchesne in the Czech Republic. Fragaria vesca indicator clones revealed after grafting several symptoms of strawberry mottle, crinkle, vein banding, and mild yellow edge as well as of mixed virus infections. Isometric virus-like particles (VLPs) ranging from 21 to 50 nm in diameter and flexuous filamentous VLPs (12 by 600–1400 nm) were observed by electron microscopy in negatively stained crude sap preparations. Our results confirmed the complexity of virus diseases of the strawberry and represent the first report on the detection of strawberry mild yellow edge disease (SMYED) and of filamentous particles in this crop in the Czech Republic.

Key words: grafting; strawberry; mottle, crinkle, vein banding, mild yellow edge; viruses; virus-like particles; electron microscopy
Acta virologica 45: 151 – 157, 2001

SEQUENCE ANALYSIS OF RECENT INDIAN ISOLATES OF FOOT-AND-MOUTH DISEASE VIRUS SEROTYPES O, A AND ASIA 1 FROM CLINICAL MATERIALS

Summary. – Partial nucleotide sequences of 1D gene of 38 isolates of foot-and-mouth disease virus (FMDV) of serotypes O, A and Asia 1 originating from various parts of India were determined. Field materials were subjected straight to RNA extraction, reverse transcription – PCR (RT-PCR) and sequencing. Also 3 FMDV vaccine strains, IND R2/75 (serotype O), IND 63/72 (serotype Asia 1) and IND 17/77 (serotype A) were included in the analysis. The seqences were compared mutually as well as with available corresponding sequences of other FMDV isolates, and their phylogenetic relationships were calculated. The deduced amino acid sequences showed that the serotype O isolates were relatively conserved as compared to serotype Asia 1 or A isolates from India. In phylogenetic analysis, the serotype O viruses clustered in two genotypes, one including the European vaccine strain (O1/K) and the other represented by the isolates from Bangladesh, India, Nepal and Turkey. The serotype Asia 1 viruses clustered in two groups of single genotype where the prototype strain from Pakistan (PAK 1/54) formed one group and the other was formed by the isolates from Bangladesh, Bhutan, India, Israel and Nepal. In serotype A viruses three well-differentiated genotypes were observed. The isolates from Azerbaijan, Bangladesh, Malaysia and India formed the first genotype. The second genotype was formed by isolates from Iran, Saudi Arabia and Turkey, while two recent Iranian isolates represented the third genotype. In India, the prevalence of at least one genotype could be identified in each serotype. This evolutionary clustering of isolates from the neighbor countries is not surprising, since these countries share border with India. The genetic relatedness between sequences of isolates from India and those from distant places is indicative of spread of the virus between the countries. Of importance is the fact that clinical materials proved useful for rapid generation of sequences and subsequent studying of molecular epidemiology of the disease.

Key words: FMDV; Indian isolates; 1D gene; VP1; phylogeny
Acta virologica 45: 159 – 167, 2001

COMPARISON OF VIRUS ISOLATION AND POLYMERASE CHAIN REACTION FOR DIAGNOSIS OF PESTE DES PETITS RUMINANTS

Summary. – Oculonasal swabs and tissue samples collected from peste des petits ruminants (PPR) suspected sheep and goats were tested for presence of the virus of peste des petits ruminants (PPRV) or its RNA by reverse transcription–PCR (RT-PCR) and virus isolation (VI). Of 44 samples 31.8% and 40.9% were positive by VI and RT-PCR, respectively. The RT-PCR-positive samples were subjected to the nested PCR. Three of six samples positive by RT-PCR but negative by VI were negative by the nested PCR. The specificity and accuracy of the nested PCR were higher than those of the RT-PCR although the sensitivity of both tests were similar. Nucleotide sequencing of one nested PCR product revealed a 92% homology with the sequence available in the GenBank (Acc. No. Z37017).

Key words: peste des petits ruminants; reverse transcription–polymerase chain reaction; virus isolation; nested PCR
Acta virologica 45: 169 –172, 2001

ISOLATION AND EVALUATION OF COXIELLA BURNETII O-POLYSACCHARIDE ANTIGEN AS AN IMMUNODIAGNOSTIC REAGENT

Summary. – A lipid A – deprived lipopolysaccharide (LPS) from Coxiella burnetii (C.b.) Priscilla strain in virulent phase I was separated by steric-exclusion chromatography and high performance liquid chromatography (HPLC). The isolated O-specific polysaccharide (PS) fractions were analyzed by different physico-chemical methods and showed noticeable differences in their overall composition. The antigenic potential of the PS fractions was evaluated by ELISA with animal and human sera and in comparison with those of the native C.b. LPSs and phase I and II C.b. Nine Mile stain cells of which the latter are routinely used in diagnosis of Q fever. The results indicate that the high molecular mass PS antigen SG501 could be used in ELISA for a sensitive and specific detection of anti-C.b. antibodies in the examined sera.

Key words: Coxiella burnetii, Chlamydophila psittaci, O-specific polysaccharide, ELISA, immunodiagnostic reagent
Acta virologica 45: 173 – 180, 2001

VIRUS-INHIBITORY EFFECT OF A YEAST RNA – TILORONE MOLECULAR COMPLEX IN CELL CULTURES

Summary. – The virus-inhibitory activity of a molecular complex (MC) of tilorone and yeast RNA was studied in vitro on three virus-cell systems: vesicular stomatitis virus (VSV) – murine fibroblast L929 cells, Venezuelan equine encephalittis virus (VEEV) – swine embryo kidney (SEK) cells and encephalomyocarditis virus (EMCV) – established piglet testicular (EPT) cells. In all these systems the MC exerted an antiviral effect similar to that of polynucleotide interferon (IFN) inducers such as poly(I)-poly(C), larifan and ridostin. The antiviral effect of the MC was similar when the compound was applied before or after virus adsorption to cells. The MC may be regarded as a perspective antiviral agent of common use.

Key words: yeast RNA; tilorone; molecular complex; antiviral effect; interferon; VSV; VEEV; EMC virus; cell cultures
Acta virologica 45: 181 – 184, 2001

HUMAN CYTOMEGALOVIRUS UL21.5 GENE IS EXPRESSED AS AN ”EARLY-LATE” GENE IN CULTURED HUMAN FIBROBLASTS

Summary. – The human cytomegalovirus (CMV) UL21.5 gene encodes a secreted glycoprotein of unknown function. Both the UL21.5 protein and mRNA accumulate in abundance at late stages of infection making the RNA an attractive target for diagnosis of active CMV infection. The UL21.5 was originally described as a ‘spliced late’ gene (SLG) (Rawlinson and Barrell, J. Virol. 67, 5502 (1993)). However, we found that the the UL21.5 mRNA was detectable in CMV-infected patients before the onset of CMV DNA replication (Boriskin et al., J. Clin. Virol., in press). Here, we re-examined the UL21.5 mRNA kinetic class in CMV-infected human fibroblast culture using a RNAse protection assay and RT-PCR. The UL21.5 mRNA was detectable before the ”true late” UL75 RNA, was resistant to a CMV DNA replication inhibitor but moderately sensitive to inhibitors of protein synthesis. In the presence of protein synthesis inhibitors the UL21.5 mRNA was detectable only by a nested reverse transcription – PCR (RT-PCR) with the bulk of it in unspliced form. This suggests that splicing factors for UL21.5 mRNA are encoded by the virus rather than by the cell. Our results indicate that UL21.5 should be defined as an ”early-late” rather than a ”late” (L) CMV gene.

Key words: human cytomegalovirus; UL21.5 gene; early-late gene
Acta virologica 45: 185 – 189, 2001

THE CELLULAR NUCLEAR MATRIX REGULATORY PROTEIN YY1 DOES NOT DIRECTLY INTERACT WITH THE MOUSE POLYOMAVIRUS LARGE TUMOR ANTIGEN

Summary. – The transcription factor Yin-Yang 1 (YY1) is a multifunctional protein involved in repressing and activating many promoters of cellular and viral genes. YY1 functions via protein-DNA but also protein-protein interactions. The latter has been documented between YY1 and early gene products of adenoviruses (Lewis et al., J. Virol. 69, 1628–1636 (1995)) and papillomaviruses (Lee et al., J. Virol. 72, 4911–4917 (1998)). In this study, first of this kind on mouse polyomavirus (Py), we report that YY1 and the main viral regulatory protein, large tumor antigen (LT), do not interact directly in vivo. This evidence was obtained by use of two separate methods, immunoprecipitation (IP) and a yeast two-hybrid system.

Key words: YY1; polyomavirus; large T antigen
Acta virologica 45: 191 – 195, 2001

LETTER TO THE EDITOR
HOMOLOGY OF BOVINE HERPESVIRUS 2 AND HERPES SIMPLEX VIRUS 1 PROTEINS

Acta virologica 45: 197 – 199, 2001

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