Asunto(s)
Enfermedades de los Gatos/prevención & control , Enfermedades de los Perros/prevención & control , Vacunación/veterinaria , Medicina Veterinaria/normas , Bienestar del Animal , Animales , Gatos , Perros , Esquemas de Inmunización , Sociedades , Estados Unidos , Vacunación/efectos adversos , Vacunación/normasRESUMEN
The ageing population of pet dogs and cats constitutes a group of animals that requires specific veterinary attention; particularly with respect to the prevention of infectious diseases. Although geriatric medicine for these species has received some recent attention; there has been little study of the vaccination requirements of such animals. A continuing challenge to the veterinary profession is the application of the principles of evidence-based medicine to the immune protection of companion animals. Recently, national and international vaccination guidelines have been developed to provide advice to the veterinary practitioner. There has been some reluctance to embrace these recommendations and an opinionated clientele has continued to delay acceptance of these recent insights. As has been the case in human medicine, antagonism and pessimism towards vaccination also occur in veterinary vaccinology, both for the young and the ageing animal.
Asunto(s)
Envejecimiento/inmunología , Gatos/inmunología , Perros/inmunología , Vacunación/veterinaria , Factores de Edad , Animales , Enfermedades de los Gatos/inmunología , Enfermedades de los Perros/inmunologíaRESUMEN
Vaccination guidelines are non-compulsory recommendations which assist the veterinary practitioner to use vaccines efficiently. They complement the official information contained in the shortened form of the summary of product characteristics that is included in the package insert of the product. The aim of this article is to clarify the role of guidelines and examine how they can improve the use of vaccines in practical conditions. The development of vaccination guidelines is explained. Several issues are discussed: primary vaccination schedule; interference with maternally derived antibodies; duration of immunity; vaccination and ageing. Three guidelines dealing with the vaccination of cats against upper respiratory tract disease are compared, as an example. In conclusion, vaccination guidelines are essential tools to assist veterinarians in good vaccination practices. They fill the gap that exists between the official recommendations included in the regulations and the licensing dossiers and the daily use of the vaccines.
Asunto(s)
Enfermedades de los Gatos/prevención & control , Inmunidad , Guías de Práctica Clínica como Asunto , Vacunación/veterinaria , Medicina Veterinaria/normas , Vacunas Virales/normas , Envejecimiento/inmunología , Animales , Gatos , Inmunidad/efectos de los fármacos , Inmunidad/fisiología , Inmunidad Materno-Adquirida , Vacunación/normas , Vacunas Virales/inmunologíaAsunto(s)
Enfermedades de los Gatos/prevención & control , Enfermedades de los Perros/prevención & control , Vacunación/veterinaria , Medicina Veterinaria/normas , Bienestar del Animal , Animales , Gatos , Perros , Esquemas de Inmunización , Sociedades , Estados Unidos , Vacunación/efectos adversos , Vacunación/métodos , Vacunación/normasRESUMEN
The Asian lineage highly pathogenic avian influenza (HPAI) H5N1 virus is a known pathogen of birds. Only recently, the virus has been reported to cause sporadic fatal disease in carnivores, and its zoonotic potential has been dominating the popular media. Attention to felids was drawn by two outbreaks with high mortality in tigers, leopards and other exotic felids in Thailand. Subsequently, domestic cats were found naturally infected and experimentally susceptible to H5N1 virus. A high susceptibility of the dog to H3N8 equine influenza A virus had been reported earlier, and recently also HPAI H5N1 virus has been identified as a canine pathogen. The ferret, hamster and mouse are suitable as experimental animals; importantly, these species are also kept as pets. Experimental intratracheal and oral infection of cats with an HPAI H5N1 virus isolate from a human case resulted in lethal disease; furthermore, cats have been infected by the feeding of infected chickens. Spread of the infection from experimentally infected to in-contact cats has been reported. The epidemiological role of the cat and other pet animal species in transmitting HPAI H5N1 virus to humans needs continuous consideration and attention.
Asunto(s)
Aves/virología , Enfermedades de los Gatos/virología , Felidae/virología , Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Infecciones por Orthomyxoviridae/veterinaria , Animales , Animales Domésticos/virología , Gatos , Humanos , Infecciones por Orthomyxoviridae/diagnóstico , Infecciones por Orthomyxoviridae/transmisión , Infecciones por Orthomyxoviridae/virología , Salud PúblicaRESUMEN
Toroviruses (family Coronaviridae, order Nidovirales) are enveloped, positive-stranded RNA viruses that have been implicated in enteric disease in cattle and possibly in humans. Despite their potential veterinary and clinical relevance, little is known about torovirus epidemiology and molecular genetics. Here, we present the first study into the diversity among toroviruses currently present in European swine and cattle herds. Comparative sequence analysis was performed focusing on the genes for the structural proteins S, M, HE, and N, with fecal specimens serving as sources of viral RNA. Sequence data published for animal and human torovirus variants were included. Four genotypes, displaying 30 to 40% divergence, were readily distinguished, exemplified by bovine torovirus (BToV) Breda, porcine torovirus (PToV) Markelo, equine torovirus Berne, and the putative human torovirus. The ungulate toroviruses apparently display host species preference. In phylogenetic analyses, all PToV variants clustered, while the recent European BToVs mostly resembled the New World BToV variant Breda, identified 19 years ago. However, we found ample evidence for recurring intertypic recombination. All newly characterized BToV variants seem to have arisen from a genetic exchange, during which the 3' end of the HE gene, the N gene, and the 3' nontranslated region of a Breda virus-like parent had been swapped for those of PToV. Moreover, some PToV and BToV variants carried chimeric HE genes, which apparently resulted from recombination events involving hitherto unknown toroviruses. From these observations, the existence of two additional torovirus genotypes can be inferred. Toroviruses may be even more promiscuous than their closest relatives, the coronaviruses and arteriviruses.
Asunto(s)
Torovirus/clasificación , Torovirus/genética , Animales , Secuencia de Bases , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , ADN Viral/genética , Europa (Continente)/epidemiología , Evolución Molecular , Variación Genética , Humanos , Microscopía Electrónica , Modelos Genéticos , Epidemiología Molecular , Datos de Secuencia Molecular , Filogenia , Recombinación Genética , Homología de Secuencia de Ácido Nucleico , Sus scrofa , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/virología , Torovirus/aislamiento & purificación , Infecciones por Torovirus/epidemiología , Infecciones por Torovirus/veterinaria , Infecciones por Torovirus/virologíaRESUMEN
The causative agent of tobacco mosaic and of foot and mouth disease (FMD) were recognized in 1898 as "filterable" or "invisible"--and eventually termed "virus". Four years later the viral aetiology of yellow fever was established, and the new discipline took off. Thus animal virology started with a veterinary problem, and Germany's contribution during the following decades came mainly from the chairs of veterinary teaching and research establishments in Giessen, Munich and Hanover, the Riems Institute, and the Federal Research Institute for Animal Virus Diseases in Tübingen. From a superficial bibliometric analysis, a wide divergence in impact figures is noted, with excellent contributions in international virology journals and lesser papers in German veterinary journals. The publications in the observed time frame reveal a fascination by virion structure, physical characteristics and structure-function relationships with little work published in journals dedicated to immunology and pathogenesis.
Asunto(s)
Medicina Veterinaria , Virología , Academias e Institutos , Alemania , Historia del Siglo XIX , Historia del Siglo XX , Edición/estadística & datos numéricos , Investigación , Medicina Veterinaria/historia , Virología/historiaRESUMEN
The alphaherpesvirus glycoproteins gE and gI form a hetero-oligomeric complex involved in cell-to-cell transmission. The gI-deficient recombinant feline herpesvirus (FHV), FHVdeltagI-LZ, produces plaques that are only 15% the size of those of wild-type FHV. Here, we have complemented FHV(delta)gI-LZ allotopically by expressing intact gI and C-terminally truncated gI derivatives from the thymidine kinase locus. The effect on gE-gI-mediated cell-to-cell spread was assessed by plaque assay employing computer-assisted image analysis (software available at http://www.androclus.vet.uu.nl/spotter/spotter.htm+ ++). Allotopic complementation with intact gI fully restored plaque size. Deletion of the C-terminal 11 residues of gI did not affect cell-to-cell spread, whereas deletion of the complete cytoplasmic tail reduced plaque size by only 35%. Mutants expressing gI166, roughly corresponding to the N-terminal half of the ectodomain, displayed a small-plaque phenotype. Nevertheless, their plaques were reproducibly larger than those of matched gI-deficient controls, indicating that the gE-gI166 hetero-oligomer, though crippled, is still able to mediate cell-to-cell spread. Our data demonstrate that plaque analysis provides a reliable and convenient tool to measure and quantitate gE-gI function in vitro.
Asunto(s)
Alphaherpesvirinae/genética , ADN Recombinante , Proteínas del Envoltorio Viral/genética , Alphaherpesvirinae/patogenicidad , Animales , Gatos , Eliminación de Gen , Regulación Viral de la Expresión Génica , Virulencia/genética , Replicación Viral/genéticaRESUMEN
Bicyclams are low-molecular-weight anti-human immunodeficiency virus (HIV) agents that have been shown to act as potent and selective CXC chemokine receptor 4 (CXCR4) antagonists. Here, we demonstrate that bicyclams are potent inhibitors of feline immunodeficiency virus (FIV) replication when evaluated in Crandell feline kidney (CRFK) cells. With a series of bicyclam derivatives, 50% inhibitory concentrations (IC50s) against FIV were obtained in this cell system that were comparable to those obtained for HIV-1 IIIB replication in the human CD4(+) MT-4 T-cell line. The bicyclams were also able to block FIV replication in feline thymocytes, albeit at higher concentrations than in the CRFK cells. The prototype bicyclam AMD3100, 1-1'-[1,4-phenylene-bis(methylene)]-bis(1,4,8, 11-tetraazacyclotetradecane), was only fourfold less active in feline thymocytes (IC50, 62 ng/ml) than in CRFK cells (IC50, 14 ng/ml). AMD2763, 1,1'-propylene-bis(1,4,8, 11-tetraazacyclotetradecane), which is a less potent CXCR4 antagonist, was virtually inactive against FIV in feline thymocytes (IC50, >66.5 microgram/ml), while it was clearly active in CRFK cells (IC50, 0.9 microgram/ml). The CXC chemokine stromal-cell-derived factor 1alpha had anti-FIV activity in CRFK cells (IC50, 200 ng/ml) but not in feline thymocytes (IC50, >2.5 microgram/ml). When primary FIV isolates were evaluated for their drug susceptibility in feline thymocytes, the bicyclams AMD3100 and its Zn2+ complex, AMD3479, inhibited all six primary isolates at equal potency. The marked susceptibility of FIV to the bicyclams suggests that FIV predominantly uses feline CXCR4 for entering its target cells.
Asunto(s)
Antivirales/farmacología , Compuestos Heterocíclicos/farmacología , Virus de la Inmunodeficiencia Felina/efectos de los fármacos , Receptores CXCR4/antagonistas & inhibidores , Replicación Viral/efectos de los fármacos , Animales , Antivirales/química , Antivirales/metabolismo , Bencilaminas , Gatos , Línea Celular , Ciclamas , Células HeLa , Compuestos Heterocíclicos/química , Compuestos Heterocíclicos/metabolismo , Humanos , Virus de la Inmunodeficiencia Felina/fisiología , Receptores CXCR4/metabolismo , Timo/citologíaRESUMEN
We analysed the ability of a plasmid carrying the gene encoding glycoprotein D (gD) of pseudorabies virus (PRV) to induce humoral and cell-mediated immune responses and assessed the protection provided by PRV-gD DNA vaccination against challenge infection with PRV. Immunization with plasmid PRV-gD induced neutralizing antibodies and lymphocyte proliferative responses both in mice and pigs. Moreover, when challenged with virulent PRV six weeks following the last immunization, PRV-gD DNA vaccinated pigs excreted virus for a significantly shorter period and showed less clinical symptoms than pigs vaccinated with a control plasmid. Thus, in the target animal, DNA vaccination with PRV-gD DNA induces protective immunity against challenge infection.
Asunto(s)
Herpesvirus Suido 1/inmunología , Seudorrabia/prevención & control , Vacunación/veterinaria , Vacunas de ADN , Proteínas del Envoltorio Viral/genética , Animales , Clonación Molecular , Femenino , Herpesvirus Suido 1/genética , Células L , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Plásmidos , Porcinos , Vacunas de ADN/inmunología , Proteínas del Envoltorio Viral/inmunologíaRESUMEN
Adenoviral nucleic acid was detected by polymerase chain reaction (PCR) in pharyngeal and rectal swab samples of a cat seropositive for adenovirus and suffering from transient hepatic failure. The samples were taken at a one-year interval, and both faecal samples as well as the second pharyngeal sample were positive in PCR performed with general adenovirus primers. The size of the amplified products corresponded to that of the positive control. The identity of the amplicons was also confirmed by DNA sequencing. The 301 bp long hexon gene fragment was very similar to but distinguishable from the corresponding hexon sequence of human adenovirus type 2. This result suggests the possibility of persistent carrier status and shedding of adenovirus in cats.
Asunto(s)
Infecciones por Adenoviridae/veterinaria , Adenoviridae/aislamiento & purificación , Enfermedades de los Gatos/virología , Adenoviridae/química , Adenoviridae/genética , Infecciones por Adenoviridae/virología , Animales , Secuencia de Bases , Cápside/química , Cápside/genética , Gatos , Cartilla de ADN/química , ADN Viral/química , ADN Viral/aislamiento & purificación , Electroforesis en Gel de Agar/veterinaria , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/veterinaria , Análisis de Secuencia de ADNRESUMEN
Alphaherpesvirus glycoproteins E and I (gE and gI, respectively) assemble into a hetero-oligomeric complex which promotes cell-to-cell transmission, a determining factor of virulence. Focusing on gI of feline herpesvirus (FHV), we examined the role of disulfide bonds during its biosynthesis, its interaction with gE, and gE-gI-mediated spread of the infection in vitro. The protein's disulfide linkage pattern was determined by single and pairwise substitutions for the four conserved cysteine residues in the ectodomain. The resulting mutants were coexpressed with gE in the vaccinia virus-based vTF7-3 system, and the formation and endoplasmic reticulum (ER)-to-Golgi transport of the hetero-oligomeric complex were monitored. The results were corroborated biochemically by performing an endoproteinase Lys-C digestion of a [35S]Cys-labeled secretory recombinant form of gI followed by tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the peptides under reducing and nonreducing conditions. We found that (i) gI derivatives lacking Cys79 (C1) and/or Cys223 (C4) still assemble with gE into transport-competent complexes, (ii) mutant proteins lacking Cys91 (C2) and/or Cys102 (C3) bind to gE but are retained in the ER, (iii) radiolabeled endoproteinase Lys-C-generated peptide species containing C1 and C4 are linked through disulfide bonds, and (iv) peptides containing both C2 and C3 are not disulfide linked to any other peptide. From these findings emerges a model in which C1 and C4 as well as C2 and C3 form intramolecular disulfide bridges. Since the cysteines in the ectodomain have been conserved during alphaherpesvirus divergence, we postulate that the model applies for all gI proteins. Analysis of an FHV recombinant with a C1-->S substitution confirmed that the C1-C4 disulfide bond is not essential for the formation of a transport-competent gE-gI complex. The mutation affected the posttranslational modification of gI and caused a slight cold-sensitivity defect in the assembly or the intracellular transport of the gE-gI complex but did not affect plaque size. Thus, C1 and the C1-C4 bond are not essential for gE-gI-mediated cell-to-cell spread, at least not in vitro.
Asunto(s)
Alphaherpesvirinae/química , Disulfuros , Glicoproteínas/química , Conformación Proteica , Proteínas Virales/química , Animales , Gatos , Línea Celular , Electroforesis en Gel de Poliacrilamida , Glicoproteínas/metabolismo , Cinética , Oxidación-Reducción , Pliegue de Proteína , Conejos , Dodecil Sulfato de Sodio , Proteínas Virales/metabolismoRESUMEN
A putative bovine respiratory torovirus (BRTV) was propagated in bovine fetal diploid lung and human colonic tumour cells, and fringed pleomorphic particles were detected in the culture supernatants by electron microscopy. Antisera directed against a bovine (Breda strain) and equine (Berne strain) torovirus failed to react with BRTV-infected cells in immunofluorescence assays and did not neutralise BRTV. No toroviral RNA was found in the supernatants of infected cells by means of a reverse transcriptase-polymerase chain reaction with torovirus-specific primers. On the other hand, bovine coronavirus-specific antisera and monoclonal antibodies did neutralise the cytopathic effects, and coronaviral antigen was detected in the cultures by immunofluorescence. Furthermore, bovine coronavirus RNA was detected in the supernatants of BRTV-infected cells after nucleic acid amplification. It is concluded that the cytopathic BRTV isolate is a coronavirus.