RESUMEN
Sulphate plays a vital role in the growth and development of the foetus. Sodium sulphate (Na2SO4) is utilised as a dietary protein nutrient factor and helps replenish sulphur elements in livestock and poultry. Therefore, this study aimed to investigate the effects of Na2SO4 supplementation in mid to late pregnancy on bile acid metabolism, amino acid metabolism, placental vascular development and antioxidant capacity of sows. At day 1 of gestation (G1), a total of twenty-six primiparous sows were carefully chosen and randomised into two groups: (1) control group, (2) Na2SO4 group (1.40 g/kg). Blood samples and placentas from sows were collected to measure biochemistry parameters, antioxidant indexes, placental vascular density, and indicators related to bile acid metabolism and amino acid concentrations, respectively. We found that dietary supplementation with Na2SO4 had a tendency for a reduction of incidence of stillborn at farrowing. Further observation showed that sows supplemented with Na2SO4 had decreased total bile acid level in cord blood, and increased placental gene expression of sulphotransferase and organic anion transport peptide. Na2SO4 supplementation increased catalase and total superoxide dismutase activity in cord blood, decreased placental malondialdehyde content, and enhanced placental protein expression of Sirtuin 1. Moreover, Na2SO4 consumption resulted in increased vascular density of placental stroma and elevated amino acid levels in sows and cord blood. Furthermore, maternal Na2SO4 consumption reduced serum urea concentrations of sows and umbilical cord blood at G114. In addition, dietary supplementation with Na2SO4 activated the protein expression of the placental mechanistic target of rapamycin complex 1. Collectively, these findings indicated that maternal supplementation with Na2SO4 during mid-to-late gestation elevated foetal survival via improving placental angiogenesis, bile acid metabolism and amino acid utilisation.
Asunto(s)
Aminoácidos , Angiogénesis , Alimentación Animal , Ácidos y Sales Biliares , Suplementos Dietéticos , Placenta , Sulfatos , Animales , Femenino , Embarazo , Aminoácidos/metabolismo , Angiogénesis/efectos de los fármacos , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Antioxidantes/metabolismo , Ácidos y Sales Biliares/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Placenta/metabolismo , Placenta/efectos de los fármacos , Sulfatos/administración & dosificación , PorcinosRESUMEN
Two envelope glycoprotein (Erns and E2) regions of the classical swine fever virus (CSFV) were amplified by RT-PCR and sequenced directly from 158 specimens collected between 1989 and 2003 in Taiwan. Phylogenetic analysis of the two regions revealed a similar tree topology and the Erns region provided better discrimination than the E2 region. One hundred and fifteen isolates out of the 158 isolates were clustered within subgroup 2.1 (further classified as 2.1a and 2.1b) and 2.2, which were considered to be likely of the introduced strains, whereas the remaining 43 isolates were clustered within subgroup 3.4 and were considered to be of the endemic strains. The subgroup 2.1a viruses were first detected in 1994 and predominated from 1995 onwards. However, subgroup 3.4 viruses were prevalent in the early years, not being isolated after 1996. We have observed a dramatic switch in genotype from subgroup 3.4 to 2.1a. The subgroup 2.1a isolates are closely related to the Paderborn and Lao isolates, whereas 2.1b isolates have a close relationship to the Chinese Guangxi isolates. The phylogenetic tree of 27 CSFV sequences based on the complete envelope glycoprotein gene (Erns-E2) displayed better resolution than that based on the complete open reading frame.
Asunto(s)
Virus de la Fiebre Porcina Clásica/clasificación , Virus de la Fiebre Porcina Clásica/genética , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/virología , Filogenia , Animales , ADN Viral/análisis , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Taiwán/epidemiología , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/genéticaRESUMEN
Subunit vaccination is effective in eliciting humoral responses to a variety of viral antigens, however, it has not generated persistent protective immunity to foot-and-mouth disease virus (FMDV). In this study, we observed that priming mice with a DNA plasmid encoding VP1 of the FMDV O/Taiwan/97 capsid protein followed by boosting with a VP1 peptide conjugate (P29-KLH) resulted in production of not only high titers of antibodies but also antibodies with FMDV neutralizing activities. Moreover, the mice immunized in this manner cleared the virus from their sera in FMDV challenge experiments. Mice subjected to DNA plasmid priming and P29-KLH protein boosting had relatively higher ratio of IgG2a/IgG1 than those primed and boosted with P29-KLH conjugate. Addition of an oligodeoxynucleotide (ODN) containing immunostimulatory cytosine-phosphate-guanosine (CpG) motifs to P29-KLH conjugate also induced a higher ratio of IgG2a/IgG1 and significantly higher titer of neutralizing antibodies. These results indicate that treating animals with DNA plasmids priming and FMDV antigen(s) boosting may elicit immunity to FMD and this immune response may be augmented by CpG ODN.
Asunto(s)
Aphthovirus/genética , Aphthovirus/inmunología , Vacunas de ADN/administración & dosificación , Vacunas Virales/administración & dosificación , Secuencia de Aminoácidos , Animales , Aphthovirus/aislamiento & purificación , Secuencia de Bases , Cápside/administración & dosificación , Cápside/genética , Cápside/inmunología , Proteínas de la Cápside , ADN Viral/genética , Femenino , Fiebre Aftosa/inmunología , Fiebre Aftosa/prevención & control , Fiebre Aftosa/virología , Inmunización Secundaria , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Plásmidos/genética , Vacunas de ADN/genética , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas Virales/genéticaRESUMEN
Copper-zinc superoxide dismutase (Cu/ZnSOD), a key enzyme in defense against toxic oxygen-free radicals, is widespread in eukaryotes and several species of gram-negative bacteria. The presence of this enzyme in Mycoplasma hyopneumoniae (M. hyopneumoniae), the primary pathogen of mycoplasmal pneumonia in pigs, was examined since the polyclonal antibody against bovine Cu/ZnSOD was dominantly cross-reactive with the M. hyopneumoniae Cu/ZnSOD from whole cellular proteins. In situ activity staining on SDS-PAGE showed that the molecular mass of M. hyopneumoniae Cu/ZnSOD in reducing form was approximately 17kDa. The presence of Cu and Zn ions at the active site of the enzyme was confirmed on the basis of inhibition by KCN and by H(2)O(2). The activity of M. hyopneumoniae Cu/ZnSOD on both SDS- and native-polyacrylamide gels was completely inhibited by 2mM KCN and the gels showed no iron-containing SOD (FeSOD) or manganese-containing SOD (MnSOD) in the crude extracts. The activity of M. hyopneumoniae Cu/ZnSOD in crude extract was 70units/mg protein and was 55% inhibited by 5mM KCN and 56% inactivated by 40mM H(2)O(2). This enzyme was growth-stage dependent and evidenced markedly higher production during the early log phase. Different expression levels of Cu/ZnSOD activity in field isolates were also detected. Taken together, the presence of Cu/ZnSOD in M. hyopneumoniae was identified for the first time.
Asunto(s)
Mycoplasma/enzimología , Neumonía Porcina por Mycoplasma/veterinaria , Superóxido Dismutasa/aislamiento & purificación , Enfermedades de los Porcinos/microbiología , Animales , Western Blotting/veterinaria , Cobre/química , Peróxido de Hidrógeno/química , Indicadores y Reactivos/química , Indoles/química , Peso Molecular , Nitroazul de Tetrazolio/química , Neumonía Porcina por Mycoplasma/enzimología , Neumonía Porcina por Mycoplasma/microbiología , Cianuro de Potasio/química , Azida Sódica/química , Superóxido Dismutasa/química , Porcinos , Enfermedades de los Porcinos/enzimología , Zinc/químicaRESUMEN
Glucose-6-Phosphate-Dehydrogenase (G6PD) deficiency is common in Hong Kong with an incidence of 4.5% in male and 0.36% in female (Lo et al. 1996).The Neonatal Screening Unit of Clinical Genetic Service started its territory-wide neonatal screening program for G6PD deficiency and congenital hypothyroidism in 1984 (Lam et al, 1986). Because of insufficient manpower and resource, we have been giving health counseling on the phone to parents of G6PD deficient babies and then refer them to nearby maternal and child health centres for monitoring of jaundice. The disease, mode of inheritance, recurrence risk and the precaution against certain medicines (Chan 1996) and chemicals are explained. The purpose (Lam, 1994) is to reassure the parents that their G6PD deficient babies can be as normal as everyone and that they can have normal life. Nevertheless, it has not been established whether telephone counseling has any effect on the affected family in the form of psychological trauma (Marteau, 1989; Fyro, 1987; Li et al, 1996) or significant influence on the decision on future reproduction. This study tried to evaluate the service from the parents' point of view by 1) gathering information on parents' awareness and perception of G6PD deficiency, 2) determination of parents' attitude towards the telephone counseling, and 3) finding out the effect of G6PD deficiency on parents' decision on future reproduction. Over 300 parents were contacted by telephone, and were asked to respond to questions on a questionnaire . The telephone interview focused on parents' understanding of G6PD deficiency, their attitude towards this disease and the possible effect on future reproduction decision. Results showed that over 90% of cases that we had counseled attended the maternal and child health centres. Most of them accepted the presence of G6PD deficiency in their family which did not affect their decision on future pregnancy. Telephone counseling failed to establish a helping relationship with the parent as face to face counseling was more personal. The findings revealed that though telephone counseling had its shortcoming it served the target group effectively. Telephone counseling is still the method of choice for the G6PD deficiency counseling in this locality.
Asunto(s)
Consejo , Deficiencia de Glucosafosfato Deshidrogenasa/psicología , Educación en Salud , Padres/psicología , Adolescente , Adulto , Actitud , Preescolar , Femenino , Deficiencia de Glucosafosfato Deshidrogenasa/diagnóstico , Deficiencia de Glucosafosfato Deshidrogenasa/epidemiología , Deficiencia de Glucosafosfato Deshidrogenasa/prevención & control , Hong Kong/epidemiología , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Tamizaje Neonatal , TeléfonoRESUMEN
This study identifies an adhesin-like glycoprotein, which was a 110 kDa protein (P110) under HPLC-GPC assay. This adhesin consisted of one P54 and two P28 subunits. In addition, N-glycosidase F could cleave all N-linked oligosaccharides on the P54 subunit. Experimental results indicated that P110 with native conformations significantly inhibited the adherence of biotin-labeled porcine tracheal epithelial cell extracts to the intact M. hyopneumoniae cells (p < 0.01). Furthermore, the biotin-labeled porcine tracheal epithelial cell extracts specifically bound to P54 and P28 subunits. This binding could be competitively inhibited by unlabeled porcine tracheal epithelial extracts and SPF porcine antisera against Mycoplasma hyopneumoniae. Both P54 and P28 subunits were constitutively expressed in different strains of M. hyopneumoniae. Their production was negligibly changed at various passages during in vitro cultivation. The significant role of this adhesin-like glycoprotein in the pathogenesis of swine pneumonia is under study.
Asunto(s)
Adhesinas Bacterianas/inmunología , Glicoproteínas/inmunología , Mycoplasma/inmunología , Neumonía Porcina por Mycoplasma/veterinaria , Enfermedades de los Porcinos/inmunología , Adhesinas Bacterianas/química , Amidohidrolasas/química , Animales , Anticuerpos Antibacterianos/inmunología , Anticuerpos Monoclonales , Unión Competitiva/inmunología , Western Blotting/veterinaria , Cromatografía de Afinidad/veterinaria , Cromatografía en Gel/veterinaria , Cromatografía Líquida de Alta Presión/veterinaria , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática/veterinaria , Glicoproteínas/química , Reacción de Inmunoadherencia/veterinaria , Ratones , Peso Molecular , Mycoplasma/química , Péptido-N4-(N-acetil-beta-glucosaminil) Asparagina Amidasa , Neumonía Porcina por Mycoplasma/inmunología , Conejos , Organismos Libres de Patógenos Específicos , Porcinos , Tráquea/inmunologíaRESUMEN
E2 is the major neutralizing antigen for classical swine fever virus (CSFV) infection. Previously, we have cloned and sequenced the E2 cDNA of Taiwan strain p97 by the reverse transcription-polymerase chain reaction (RT-PCR) method from CSFV-infected tissue. The presence of RNA splicing donor and acceptor sites were found in the cDNA sequence. In this study, transfection of E2 cDNA into mammalian cells resulted in the production of a spliced RNA. Site-directed mutagenesis of the donor and acceptor sites prevented the RNA splicing event and generated a full length transcript in COS7 cells. Although the spliced E2 transcript has not been reported in natural infection of CSFV, this study suggested that the potential splicing sites affected the E2 gene expression when the plasmid-based E2 gene was introduced into mammalian cells.
Asunto(s)
Virus de la Fiebre Porcina Clásica/genética , ADN Complementario/genética , Expresión Génica , Empalme del ARN , Proteínas del Envoltorio Viral/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Células COS , Células Cultivadas , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Plásmidos , Reacción en Cadena de la Polimerasa , Biosíntesis de Proteínas , Porcinos , Transcripción Genética , TransfecciónRESUMEN
We report two cases of reticular dysgenesis (RD) successfully treated by BMT utilizing T cell-depleted haploidentical marrow grafts. One child failed to engraft after conditioning with ATG, and the other failed two transplant attempts with cyclophosphamide + ATG, and busulfan + cyclophosphamide + ATG, respectively. Donor engraftment was achieved in both patients following treatment with 700 cGy TBI, with or without other agents. These results, taken together with previous reports in the literature, suggest that children with RD may require more intensive conditioning than patients with other types of severe combined immunodeficiency syndrome.
Asunto(s)
Agranulocitosis/terapia , Trasplante de Médula Ósea , Inmunodeficiencia Combinada Grave/terapia , Preescolar , Femenino , Prueba de Histocompatibilidad , Humanos , Lactante , Acondicionamiento PretrasplanteRESUMEN
A strain of classical swine fever virus (CSFV) has been isolated in Taiwan. The cDNA coding for three envelope glycoproteins E1, E2 and E3 were molecularly cloned from purified viral particles using the reverse transcription-polymerase chain reaction (RT-PCR) method and sequence-specific primers. The resulting PCR products (1113 bp for E1. 699 bp for E2 and 567 bp for E3) were cloned into the SmaI site of pUC19 and then subjected to DNA sequence analysis. Data showed that nucleotide sequence of the three envelope genes shared a 82-83% homology with the corresponding genes of three other strains (Alfort, Brescia and Weybridge). However, the homology of the deduced amino acid sequence was greater than 90% among the four strains. The potential asparagine-linked glycosylation sites for E1 (5 sites), E2 (7 sites) and E3 (2 sites) were conserved. This suggests that the Taiwan p97 strain is distinct from other three strains described. The variations may have implications for future vaccine development. The sequence has been submitted to GenBank. The accession numbers are U43924 and U03290.
Asunto(s)
Virus de la Fiebre Porcina Clásica/genética , Análisis de Secuencia de ADN , Proteínas del Envoltorio Viral/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Virus de la Fiebre Porcina Clásica/metabolismo , Clonación Molecular , ADN Viral , Datos de Secuencia Molecular , Porcinos , TaiwánRESUMEN
Use of a combination of an effective gE gene-deleted pseudorabies virus (PRV) vaccine with a companion diagnostic kit for PRV glycoprotein gE has proven successful in several pseudorabies-eradication programs. To produce a large quantity of functional gE protein for development of a PRV-gE diagnostic kit, an Escherichia coli expression system containing the distal region of the PRV-gE gene of a PRV strain CF was constructed. The expressed protein contained 134 amino acids of gE protein (amino acids 77-210) fused to a 19-amino acids tag containing 6 histidine residues. After induction, a truncated PRV-gE polypeptide of 18-kd was expressed to about 20% of the total E coli proteins. Results of immunoblot analysis indicated that this E coli-produced PRV-gE protein reacted specifically with serum from PRV-hyperimmunized pigs and from field PRV-infected pigs, but not with serum samples from specific-pathogen-free pigs or pigs inoculated with gE-deleted PRV vaccine. These data indicate that, although the recombinant gE protein is produced in E coli, it still retains the antigenicity of the viral gE glycoprotein. Comparison between the recombinant gE protein, using immunoblot analysis with a commercial gE ELISA containing natural PRV-gE protein, revealed comparable test performance. This finding indicated that recombinant gE protein produced by E coli can be used for development of a companion serologic assay for a PRV-gE gene-deleted vaccine.
Asunto(s)
Antígenos Virales/genética , Herpesvirus Suido 1/genética , Seudorrabia/diagnóstico , Proteínas del Envoltorio Viral/genética , Animales , Antígenos Virales/inmunología , Secuencia de Bases , Southern Blotting/veterinaria , Clonación Molecular/métodos , Sondas de ADN , Escherichia coli , Herpesvirus Suido 1/inmunología , Datos de Secuencia Molecular , Plásmidos , Seudorrabia/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Pruebas Serológicas , Porcinos , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/inmunología , Proteínas del Envoltorio Viral/inmunologíaRESUMEN
A rapid method for the detection of hog cholera virus (HCV) in infected tissues, using polymerase chain reaction (PCR) was developed. Total RNA isolated from HCV-infected tissues was reverse transcribed with AMV reverse transcriptase and the resulting complementary DNA was amplified by Taq DNA polymerase in the presence of two HCV-specific primers. The amplified DNA fragment was detected by agarose gel electrophoresis. The sensitivity of this method was at 10(4) TCID50 of HCV. The sensitivity increased approximately 1000-fold when the DNA was reamplified with a set of nested primers. DNA sequencing analysis of the PCR products revealed that the HCV sequence amplified from a local field isolate was highly homologous to the HCV Alfort strain. This method may be useful for pathological and epidemiological studies of HCV in pigs.
Asunto(s)
Virus de la Fiebre Porcina Clásica/aislamiento & purificación , Peste Porcina Clásica/diagnóstico , Reacción en Cadena de la Polimerasa/veterinaria , Animales , Secuencia de Bases , Células Cultivadas , Peste Porcina Clásica/genética , Virus de la Fiebre Porcina Clásica/genética , Clonación Molecular , ADN de Cadena Simple , ADN Viral , Escherichia coli/genética , Vectores Genéticos , Datos de Secuencia Molecular , Plásmidos , Reacción en Cadena de la Polimerasa/métodos , ARN Viral/aislamiento & purificación , Sensibilidad y Especificidad , PorcinosRESUMEN
A population consisting of 70 breeder cats, 43 clinical cases, and 16 feral cats was examined for the presence of Toxoplasma gondii, feline immunodeficiency virus (FIV), and feline leukaemia virus (FeLV). No oocysts of T. gondii were observed in 96 faecal samples; faecal samples were not available from the feral cats. Other intestinal parasites identified included Isospora felis (three cats), Isospora rivolta (five), Dipylidium canium (two), Toxocara cati (four), Toxascaris leonina (one), and Ancylostoma sp. (two). Using a kinetics-based enzyme-linked immunosorbent assay on 117 sera including all the feral cats, nine had antibody to T. gondii antigen, three for antigens to FIV, and seven to the p27 antigen of FeLV. Of the nine cats with antibody to T. gondii, only one was also infected with FIV.
Asunto(s)
Enfermedades de los Gatos/epidemiología , Síndrome de Inmunodeficiencia Adquirida del Felino/epidemiología , Parasitosis Intestinales/veterinaria , Leucemia/veterinaria , Toxoplasmosis Animal/epidemiología , Animales , Gatos , Virus de la Inmunodeficiencia Felina/aislamiento & purificación , Parasitosis Intestinales/epidemiología , Leucemia/epidemiología , Virus de la Leucemia Felina/aislamiento & purificación , Taiwán/epidemiologíaRESUMEN
We have isolated and sequenced several overlapping cDNA clones from a bovine lambda gt10 library which encode all but the first five amino acids of the entire mature 24 kDa subunit of NADH:ubiquinone oxidoreductase (EC 1.6.99.3), the first enzyme of the respiratory chain. The derived amino acid sequence agrees with that determined by direct sequencing of the purified protein, filling in a gap in the published sequence. A comparison of the nucleotide and amino acid sequences of the bovine 24 kDa subunit with those recently determined for the rat homologue has shown that this nuclear-encoded subunit of an OX-PHOS complex has diverged in these two species much less than the mitochondrial DNA-encoded subunits of the same enzyme complex, and also less than a set of available non-mitochondrial nuclear DNA-coded proteins. The sequence analysis of the clones has revealed the expression in the brain of two mRNAs differing in the length of the 3'-untranslated region. Furthermore, two polyadenylated RNA species, 930 and 1080 nucleotides in length, probably corresponding to the above mRNAs, have been detected in bovine brain and other tissues by RNA gel blot hybridization. The level of expression of the 24kDa subunit gene varies by more than an order of magnitude among different tissues. A cross-hybridizing mRNA species of 930 nucleotides has also been observed in HeLa cells and found to be strongly growth regulated.
Asunto(s)
Reductasas del Citocromo/genética , NADH Deshidrogenasa/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Southern Blotting , Bovinos , Clonación Molecular , Datos de Secuencia Molecular , ARN Mensajero/análisis , Ratas , Mapeo Restrictivo , Homología de Secuencia de Ácido NucleicoRESUMEN
These experiments were designed to study the effects of a synthetic drug--dexamethasone (DEX) on the immune response of weaned pigs against viral antigen (hog cholera vaccine) and bacterial antigen (formalin inactivated Salmonella enteritis vaccine). Twenty-three five-week-old pigs were divided into eight groups, six of which were injected twice daily with DEX at 1.0 mg or 0.1 mg per Kg of body weight for either four or five days. The other two groups served as controls. During this period, the two 0.1 mg/Kg DEX-treated groups were injected with live hog cholera vaccine at 1.0 or 0.1 dosage respectively. This same treatment was applied to the two 1.0 mg/Kg DEX-treated groups. One control group was injected with a dose of hog cholera vaccine, while the other was given 1.0 ml of Sal. enteritis vaccine. The hog cholera antibody response in DEX-treated pigs was significantly suppressed (p less than 0.01). However, consistent levels of antibody titers were maintained, indicating a slight antibody production. But in pigs injected with one tenth of the normal dose of hog cholera vaccine, there was little or no immune response (p less than 0.01). A comparison of the response of pigs given different levels of DEX concentrations to those with different doses of hog cholera vaccine showed that dexamethasone significantly suppressed antibody production when antigen concentrations were lower. Significant suppression of agglutinating antibody in response to bacterial antigen was also observed at 14 days post-vaccination (p less than 0.05).
Asunto(s)
Formación de Anticuerpos/efectos de los fármacos , Dexametasona/farmacología , Animales , Vacunas contra el Cólera/inmunología , Relación Dosis-Respuesta a Droga , Salmonella enteritidis/inmunología , PorcinosRESUMEN
The infectivity of virulent strain, not attenuated strain, of transmissible gastroenteritis virus (TGEV) of swine could be enhanced as much as 50-fold by pancreatin incorporated medium. The mechanism(s) of enhancement was uncertained. Multiplication of TGEV, either virulent or attenuated strain, was inhibited by intestinal fluid of both TGEV infected and noninfected piglets. Pelleting virus particles from intestine fluid was likely to remove all inhibitors and resulted in facilitating the isolation of the virus by using swine testicle (ST) cell line. These findings contribute to the practical application in the isolation and identification of TGEV and in the preparation of high titred virus stocks.
Asunto(s)
Coronaviridae/patogenicidad , Pancreatina/farmacología , Virus de la Gastroenteritis Transmisible/patogenicidad , Animales , Antivirales/fisiología , Femenino , Interferón Tipo I/farmacología , Intestinos/microbiología , Intestinos/fisiología , Porcinos , Virus de la Gastroenteritis Transmisible/efectos de los fármacos , Virus de la Gastroenteritis Transmisible/aislamiento & purificación , Replicación Viral/efectos de los fármacosRESUMEN
Sequential appearance of both swine vesicular disease virus and Coxsackievirus B5 antigens in a pig kidney cell line was studied by immunofluorescence and electron microscopy. The replication cycle of each virus was approximately 3-4 h. Viral antigens were demonstrable in the cytoplasm 2 h after inoculation. A compact mass of fluorescence was seen when cells showed cytopathogenic effect at 5.5 h. After 3 h, a few viral particles, seen by electron microscopy, were in the cytoplasm. Morphological changes of cells occurred at the same time. Cytoplasmic crystalline arrays of virus were first detected at 7 h.
Asunto(s)
Enterovirus Humano B/patogenicidad , Infecciones por Enterovirus/veterinaria , Enterovirus/patogenicidad , Enterovirus Porcinos/patogenicidad , Enfermedad Vesicular Porcina/microbiología , Animales , Antígenos Virales/análisis , Línea Celular , Efecto Citopatogénico Viral , Enterovirus Humano B/crecimiento & desarrollo , Enterovirus Porcinos/crecimiento & desarrollo , Riñón , Porcinos , Replicación ViralRESUMEN
Pigs exposed to swine vesicular disease virus developed vesicular lesions by postinoculation day 2. Lesions first appeared on the coronary band and then on the dewclaw, tongue, snout, lips, and bulbs of the heels. The onset of viremia coincided with febrile response and the appearance of vesicles. Virus was isolated from the nasal discharge, esophageal-pharyngeal fluid, and feces as early as postinoculation day 1. Greater amounts of virus were isolated from samples collected during the first week of infection, and lesser amounts from samples collected during the second week. The appearance and the distribution of specific fluorescence in various tissues indicated that during the development of swine vesicular disease virus infection, the epithelial tissues were initially involved, followed by a generalized infection of lymph tissues, and subsequently, a primary viremia. Seroconversion was detectable as early as postinoculation day 4. A mild nonsuppurative meningoencephalomyelitis throughout the CNS was observed in both inoculated and contact-exposed pigs. The olfactory bulbs were most severely and were frequently affected, particularly in contact pigs. The most severe brain lesions were found in pigs 3 to 4 days after the onset of viremia; contact pigs showed more severe brain lesions than inoculated pigs. Microscopic changes were also found in the coronary band, snout, tongue, and heart.