RESUMO
The development of a serological test for foot-and-mouth disease virus (FMDV) which is quick and easy to use, which can identify all seven serotypes, and which can differentiate vaccinated from convalescing or potential virus carriers would be a major advance in the epidemiological toolkit for FMDV. The nonstructural polyprotein 3ABC has recently been proposed as such an antigen, and a number of diagnostic tests are being developed. This paper evaluates the performance of two FMDV tests for antibodies to nonstructural proteins in an unvaccinated cattle population from a region of Cameroon with endemic multiple-serotype FMD. The CHEKIT-FMD-3ABC bo-ov (CHEKIT) enzyme-linked immunosorbent assay (ELISA) (Bommeli Diagnostics/Intervet) is a commercially available test that was compared with a competitive 3ABC ELISA (C-ELISA) developed in Denmark. The tests were compared with the virus neutralization test as the "gold standard." Diagnostic sensitivity and specificity were examined over a range of test cutoffs by using receiver operating characteristic curves, which allowed comparison of the overall performance of each test. The results indicated that the CHEKIT ELISA kit was 23% sensitive and 98% specific and the Danish C-ELISA was 71% sensitive and 90% specific at the recommended cutoff. These results have important implications if the tests are to be used to screen herds or individual cattle in surveillance programs, at border crossings for import-export clearance, or following emergency vaccination in an outbreak situation.
Assuntos
Doenças dos Bovinos/diagnóstico , Ensaio de Imunoadsorção Enzimática/métodos , Febre Aftosa/diagnóstico , Proteínas não Estruturais Virais/imunologia , Animais , Anticorpos Antivirais/análise , Antígenos Virais , Camarões , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/prevenção & controle , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Vírus da Febre Aftosa/imunologia , Testes Sorológicos/métodos , Testes Sorológicos/estatística & dados numéricos , Testes Sorológicos/veterinária , Vacinas Virais/farmacologia , Virologia/métodos , Virologia/estatística & dados numéricosRESUMO
After contact with foot and mouth disease virus (FMDV), cattle may become persistently infected, regardless of their pre-existing immune status or whether they develop clinical disease. The cellular sites of FMDV persistence have not previously been determined. The use of in-situ hybridization in combination with tyramide signal amplification (TSA) provided the first direct evidence that FMDV RNA is localized within the epithelial cells of the soft palate and pharynx during persistent infection, indicating that these cells remain persistently infected after contact with FMDV.
Assuntos
Aphthovirus/isolamento & purificação , Doenças dos Bovinos/virologia , Células Epiteliais/virologia , Febre Aftosa/virologia , Palato Mole/virologia , Faringe/virologia , Animais , Aphthovirus/genética , Líquidos Corporais/virologia , Bovinos , Doenças dos Bovinos/patologia , Células Epiteliais/patologia , Febre Aftosa/patologia , Hibridização In Situ/veterinária , Sondas de Oligonucleotídeos/química , Palato Mole/patologia , Faringe/patologia , RNA Viral/análiseRESUMO
Swine vesicular disease (SVD) is a notifiable viral disease of pigs included on the Office International des Epizooties List A. The first outbreak of the disease was recognized in Italy in 1966. Subsequently, the disease has been reported in many European and Asian countries. The causative agent of the disease is SVD virus which is currently classified as a porcine variant of human coxsackievirus B5 and a member of the genus enterovirus in the family picornaviridae. From a clinical point of view, SVD is relatively unimportant, rarely causing deaths and usually only a minor setback to finishing schedules. However, the clinical signs which it produces are indistinguishable from those caused by foot-and-mouth disease, and its presence prevents international trade in pigs and pig products. This article reviews recent findings on all aspects of the virus and the disease which it causes.
Assuntos
Variação Antigênica/genética , Enterovirus/química , Infecções por Picornaviridae/veterinária , Doença Vesicular Suína/epidemiologia , Animais , Ásia/epidemiologia , Controle de Doenças Transmissíveis , Enterovirus/classificação , Enterovirus/genética , Enterovirus/patogenicidade , Europa (Continente)/epidemiologia , Febre Aftosa/prevenção & controle , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/patologia , Estomatite/prevenção & controle , Estomatite/veterinária , Suínos , Doença Vesicular Suína/patologia , Exantema Vesicular de Suínos/prevenção & controleRESUMO
Nucleotide sequence of the structural protein-encoding region of foot-and-mouth disease virus (FMDV) A22-India 17/77 was determined using non-radioisotopic technique. Comparison of nucleotide and deduced amino acid sequence with A22-Iraq 24/64 revealed 175 synonymous (silent) and 42 non-synonymous nucleotide changes resulting in 34 amino acid substitutions along the capsid proteins (VP1-VP4). Out of the 4 structural proteins VP4 is highly conserved. The highly variable and immunodominant protein VP1 showed 47% of the total amino acid substitutions. VP2 and VP3 contain 38.2% and 14.7% of the amino acid substitutions, respectively. The VP1-based phylogenetic analysis of 18 different type A viruses including A22-India 17/77 divided them in to two broad genetic groups (Asian and European/South American), and each group is further subdivided in to two separate genotypes. A22-India 17/77, A22-Iraq 24/64 and A22-Azerbaijan/65 formed one genotype and the 4 Chinese strains formed a separate genotype in the Asian group of viruses. In the European/South American group, A-Argentina/87 represents one genotype and the remaining 10 strains formed the second genotype in this group.
Assuntos
Aphthovirus/genética , Proteínas Estruturais Virais/genética , Sequência de Aminoácidos , Animais , Aphthovirus/classificação , Aphthovirus/isolamento & purificação , Sequência de Bases , DNA Viral/análise , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Análise de Sequência de DNA , Proteínas Estruturais Virais/análiseRESUMO
The sequence of 165 nucleotides at the 3' end of the 1D gene, determined from RT PCR amplified cDNA fragments, of 25 type O strains isolated from different parts/regions of India during 1987 1995 and the vaccine strain (R2/75) currently in use in India were subjected to phylogenetic analysis. One isolate from the neighbouring country Nepal was also included in the study. The virus/ field strains showed high degree of genetic heterogeneity among themselves with % divergence in nucleotide sequence ranging from 1.2 to 19.4%. The Indian strains were much away (13.3 20.6%) from the exotic type O strains of O1BFS, O1K, and O1Campos. The type O strains analyzed were classified into three genotypes basing on level of divergence observed in nucleotide sequence. The type O vaccine virus (R2/75) was > 71% divergent (7.3-15.2%) from the field strains which revealed significant ( > 5%) genetic heterogeneity between the two. The phylogenetic analysis identified three distinct lineages, viz., (i) lineage 1 represented by the exotic strains, (ii) lineage 2 represented by 25 of the field strains which clustered into seven subgroups/sublines (2a-2g), and (iii) lineage 3 represented by a unique field isolate which shared the branching/origin with the vaccine strain. The lineage 2 which comprised of 25 of the 26 type O field strains analyzed, was placed almost at equidistance from the lineages 1 and 3 in the phylogenetic tree. The vaccine strain was closer to the viruses in lineage 2. Though there was no specific distribution pattern of sequences in different geographical regions of India, the viruses/ sequences in subgroup 2f appeared to be restricted to the southern states. Comparison of deduced amino acid sequence in the immunodominant regions 133-160 and 200-208 of the 1D gene product (VP1) showed that the two viruses in lineage 3 had unique amino acid residues at the positions 138 (D), 139 (G), 144 (I), and 158 (A) compared to rest of the strains including the exotic ones. Comparison of amino acid residues at critical positions 144, 148, 149, 151, 153, 154, and 208 revealed similarity between the type O strains analyzed. The virus strains showed variation (V/L/I) at position 144. One field strain showed replacement from Q149-->E and another from P208-->L. Thus, the study revealed that the type O FMD virus populations circulating in India and causing disease outbreaks are genetically much heterogeneous but related at the immunodominant region of VP1 polypeptide, and there are more than one genetically distinct virus populations in almost every region of the country which is possible due to unrestricted animal movement in the country. The involvement of vaccine virus in disease outbreaks was ruled out as the field strains (excluding the one in lineage 3) were phylogenetically distinct from it.
Assuntos
Aphthovirus/genética , Capsídeo/genética , Febre Aftosa/virologia , Heterogeneidade Genética , Sequência de Aminoácidos , Animais , Aphthovirus/classificação , Proteínas do Capsídeo , Bovinos , Doenças dos Bovinos/virologia , Linhagem Celular , Cricetinae , Variação Genética , Índia , Dados de Sequência Molecular , Filogenia , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Sorotipagem , Suínos , Doenças dos Suínos/virologiaRESUMO
Partial nucleotide sequence of the capsid polypeptide coding gene 1D (VP1) was determined for 68 serotype O foot-and-mouth disease viruses isolated between 1983 and 1995 from outbreaks occurring in Saudi Arabia. The sequences were compared with previously published sequences: 14 viruses of Middle Eastern origin (isolated between 1987 and 1991); and with four vaccine virus strain sequences, three originating from the Middle East (O1/Turkey/Manisa/69, O1/Sharquia/Egypt/72 and O1/Israel/2/85) and one from Europe (O1/BFS 1860/UK/67). The virus isolates from Saudi Arabia and the Middle East vaccine virus strains formed a related genetic group distinct from the European O1 virus. Within this large group 12 distinct genetic sublineages were observed.
Assuntos
Aphthovirus/genética , Surtos de Doenças/veterinária , Febre Aftosa/virologia , Animais , Aphthovirus/classificação , Aphthovirus/isolamento & purificação , Bovinos , Febre Aftosa/epidemiologia , Oriente Médio/epidemiologia , Arábia Saudita/epidemiologia , Análise de Sequência de DNA , OvinosRESUMO
The gene coding for the capripoxvirus structural protein P32 was cloned, expressed in Escherichia coli as a fusion protein with glutathione-S-transferase, and purified on glutathione Sepharose. An indirect enzyme linked immunosorbent assay (ELISA) using this antigen was developed to screen bovine sera for antibodies to capripoxvirus. Sequential serum samples from experimentally infected animals tested by ELISA and by virus neutralisation test (VNT) showed that the ELISA was more sensitive and detected antibodies to capripoxvirus earlier post-infection than the VNT.
Assuntos
Anticorpos Antivirais/análise , Antígenos Virais , Capripoxvirus/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Animais , Antígenos Virais/genética , Antígenos Virais/isolamento & purificação , Sequência de Bases , Capripoxvirus/genética , Bovinos , Clonagem Molecular , Primers do DNA/genética , DNA Viral/genética , Genes Virais , Dados de Sequência Molecular , Testes de Neutralização , Infecções por Poxviridae/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Estruturais Virais/genética , Proteínas Estruturais Virais/imunologia , Proteínas Estruturais Virais/isolamento & purificaçãoRESUMO
A cDNA clone containing the complete coding sequence of the hemagglutinin (H) protein gene of the RBOK vaccine strain of rinderpest virus, under the control of the vaccinia late promoter p11, was inserted by homologous recombination into the thymidine kinase gene of the KS-1 strain of capripoxvirus. The recombinant virus produced authentic H protein as judged by its electrophoretic mobility, transport to the cell surface of infected lamb testis cells, and reactivity with monoclonal antibodies specific for the H protein of rinderpest virus. The recombinant virus induced significant levels of rinderpest virus neutralizing antibodies in vaccinated cattle and protected them from clinical rinderpest after challenge with a lethal dose of a highly virulent heterologous strain of the virus. Protection was achieved using vaccine doses lower than those used with a similar recombinant expressing the fusion protein gene of rinderpest. The parental KS-1 virus is widely used as a vaccine against capripox viruses and so the rinderpest recombinant acts as a dual vaccine to protect cattle against both rinderpest and lumpy skin disease.
Assuntos
Capripoxvirus/genética , Glicoproteínas/imunologia , Doença Nodular Cutânea/prevenção & controle , Vírus da Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vacinas Sintéticas/imunologia , Proteínas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Capripoxvirus/imunologia , Bovinos , Linhagem Celular , Expressão Gênica , Genes Virais/genética , Glicoproteínas/biossíntese , Glicoproteínas/genética , Hemaglutininas Virais , Imunidade Ativa , Doença Nodular Cutânea/imunologia , Proteínas de Membrana , Regiões Promotoras Genéticas/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/imunologia , Peste Bovina/imunologia , Vírus da Peste Bovina/genética , Timidina Quinase/genética , Vacinação , Vacinas Sintéticas/genética , Vaccinia virus/genética , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/imunologia , Proteínas Virais/biossíntese , Proteínas Virais/genética , Proteínas Estruturais Virais/genética , Vacinas Virais/genética , Vacinas Virais/imunologiaRESUMO
Cattle were protected against challenge with rinderpest and lumpy skin disease viruses by vaccination with a recombinant capripoxvirus containing the fusion protein (F) gene of rinderpest virus. The minimum protective immunising doses for rinderpest and lumpy skin disease were 5.5 x 10(4) plaque forming units (pfu) and 1.5 x 10(3) pfu, respectively.
Assuntos
Capripoxvirus/imunologia , Doença Nodular Cutânea/prevenção & controle , Vírus da Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vacinação/veterinária , Animais , Temperatura Corporal , Bovinos , Vírus da Peste Bovina/genética , Vacinas Sintéticas , Proteínas Virais de Fusão/genética , Vacinas ViraisRESUMO
A recombinant capripoxvirus has been constructed containing a full-length cDNA of the fusion protein gene of rinderpest virus. The gene was inserted in the thymidine kinase gene of the capripox genome under the control of the vaccinia virus major late promoter p11 together with the Escherichia coli gpt gene in the opposite orientation under the control of the vaccinia early/late promoter p7.5. A vaccine prepared from this recombinant virus protected cattle against clinical rinderpest after a lethal challenge with a virulent virus isolate. In addition, the vaccine protected the cattle against lumpy skin disease.
Assuntos
Glicoproteínas/imunologia , Doença Nodular Cutânea/prevenção & controle , Poxviridae/imunologia , Vírus da Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vacinas Sintéticas , Proteínas Virais de Fusão/imunologia , Vacinas Virais , Animais , Anticorpos Antivirais/biossíntese , Bovinos , DNA Viral/química , DNA Viral/genética , Escherichia coli/genética , Expressão Gênica , Glicoproteínas/genética , Masculino , Proteínas de Membrana , Poxviridae/genética , Vírus da Peste Bovina/genética , Vacinas Sintéticas/imunologia , Proteínas Virais de Fusão/genética , Vacinas Virais/imunologiaRESUMO
In 1986 and 1987 foot-and-mouth disease virus (FMDV) serotype A was isolated from outbreaks of disease in Saudi Arabia and Iran. Selected virus isolates were antigenically distinct from the prototype A22 virus strain (A22/Iraq/64), but were serologically related to each other. However, polyacrylamide gel electrophoresis showed that whilst the respective Saudi Arabian structural polypeptides were homogeneous, those from an Iran isolate were distinct. Direct sequencing of part of the P-1D (VP1) gene demonstrated considerable difference in nucleotide homology between the two groups of viruses; the Saudi Arabian viruses were closely related to each other but only distantly related to both the A22 prototype virus strain and the Iranian virus isolate. The latter viruses were only slightly more closely related to each other. Thus there appeared to be at least two distinct FMDV type A variants co-circulating in the Middle East, both of which differed considerably from the classical A22 subtype.
Assuntos
Aphthovirus/análise , Febre Aftosa/microbiologia , Animais , Antígenos Virais/análise , Aphthovirus/classificação , Aphthovirus/imunologia , Sequência de Bases , Oriente Médio , Dados de Sequência Molecular , Peso Molecular , Testes de Neutralização , RNA Viral/genética , Proteínas Virais/análiseRESUMO
The proteins of sheep pox, goat pox, sheep and goat pox and lumpy skin disease (Neethling) viruses were labelled with [35S]methionine. The major structural polypeptides of these viruses co-migrated on polyacrylamide gels, demonstrating the very close biochemical relationship between them. Using the agar gel immunodiffusion (AGID) test with radiolabelled antigen preparations, a major common precipitating antigen was identified. This co-migrated on polyacrylamide gels with one of the major structural polypeptides [mol. wt. 67000 (67K)]. The use of [35S]methionine-labelled antigen preparations considerably improved the sensitivity of the AGID test as a diagnostic test for capripoxvirus antibody detection.
Assuntos
Antígenos Virais/análise , Poxviridae/análise , Proteínas Virais/análise , Animais , Células Cultivadas , Cabras , Imunodifusão , Vírus da Doença Nodular Cutânea/análise , Masculino , Metionina/metabolismo , Poxviridae/imunologia , Poxviridae/isolamento & purificação , Ovinos , Especificidade da Espécie , Radioisótopos de Enxofre , TestículoRESUMO
Isolates of sheep pox and goat pox from Nigeria, Sudan, Kenya, Yemen Arab Republic, Turkey, Pakistan and India were inoculated into British breeds of sheep and goats. Although the isolates displayed a host preference the gross clinical pathology of the disease produced by the different isolates was indistinguishable. The Yemen, Nigeria and India isolates could not be distinguished using homologous and heterologous antisera in neutralisation tests. Animals that had recovered from infection with one isolate were resistant to challenge with any of the other isolates and a single vaccine for use against sheep pox and goat pox is described. The classification of the malignant pox diseases of sheep and goats is discussed.