RESUMO
The seroprevalence of the Influenza virus against H1N1 and H3N2 was determined by the hemagglutination-inhibition test (HI) and a commercial swine influenza ELISA kit, in 13 Argentinean swine herds. The results of within-herd and between-herd prevalence obtained by both tests were statistically correlated. The within-herd prevalence observed by the HI test varied from 38.46 to 100% against H1 and 7.69 to 100% for H3. When the within-herd prevalence was measured with the ELISA test, it varied from 2.33 to 6.9% for H1 and 9.65 to 48% for H3. No statistical differences were observed at herd level between HI and ELISA (H1: p = 0. 20; H3: p=0.11). No agreement between HI and ELISA detected prevalence was observed when the within-herd prevalence was compared (H1: 0.005; H3: 0.070), while the agreement at herd level was considered poor (H1: 0,350; H3: 0,235). The high within-herd prevalence values observed with the HI test and the high sensibility of this test might show that human strains or swine strains phylogenetically closely related to the humans strains used in the HI test in this study have been affecting the swine population since 2002.
Assuntos
Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/veterinária , Testes de Inibição da Hemaglutinação/veterinária , Vírus da Influenza A/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Sus scrofa/virologia , Doenças dos Suínos/epidemiologia , Animais , Argentina/epidemiologia , Reservatórios de Doenças/veterinária , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A/classificação , Vírus da Influenza A/imunologia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/diagnóstico , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Valor Preditivo dos Testes , Estações do Ano , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Suínos/virologia , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/virologiaRESUMO
The pig industry is growing very fast in Argentina with an increasing need for replacement animals, feedstuff and transportation of animals. One of the main competitive advantages of the Argentinian pig industry is its being free of most major pig diseases. Within this context, applying measures aimed to reduce the risk of introduction and spread of pathogens is critical. The aim of the present study was to assess the biosecurity of Argentinian pig farms. Two types of farms were assessed: firstly, all official suppliers of high-genetic-value (n = 110) and secondly, a sample from commercial farms (n = 192). Data on the external and internal biosecurity practices applied on the farms was collected with a questionnaire. Data was analysed using a correspondence analysis and a hierarchical clustering analysis, which allowed identification of types of farms with regard to the biosecurity measures applied. Key variables characterizing the clusters were identified through an indicator value analysis. In addition, the external biosecurity of the farms was evaluated by using risk assessment tools with respect to the potential introduction of porcine epidemic diarrhoea virus. Results made evident three clusters: the first one which, amongst other measures, applied several barriers to prevent the entry of people, trucks and other vehicles, and could be considered as a group of high biosecurity, and the two other groups which applied a lower number of external and internal biosecurity measures. The results of the risk assessment showed that the routes with the highest risk of disease introduction were: replacement animals, vehicles transporting feed or animals, and visitors. The assessment of the external biosecurity showed that most Argentinian farms were not prepared for the contingency of a pathogen such as porcine epidemic diarrhoea virus. Special efforts should be made in official suppliers of high-genetic-value farms with poor biosecurity scores since they are at the top of the pig production chain and can be key for the spread of diseases.
Assuntos
Criação de Animais Domésticos/métodos , Contenção de Riscos Biológicos/veterinária , Sus scrofa , Criação de Animais Domésticos/classificação , Animais , Argentina/epidemiologia , Contenção de Riscos Biológicos/métodos , Prevalência , Medição de Risco , Suínos , Doenças dos Suínos/epidemiologiaRESUMO
Antimicrobial resistance of Escherichia coil isolated from pigs in Argentina. Sixty-nine Escherichia coli isolates from healthy pigs or with clinical signs non-compatible with diarrhea caused by this microorganism, were studied. The purpose was to determine the resistance profile against antimicrobials frequently used in veterinary and human medicine. The agar diffusion method was used. High resistance percentages against antimicrobials used in swine farms such as ampicillin, streptomycin and tetracycline were observed, as well as against trimetoprim-sulfametoxazole and chloramphenicol, compounds that were stopped being used several years ago. Sixty two percent of isolates showed multidrug-resistance. The results obtained in this work corroborate the hypothesis that the phenotypic distribution of resistance and possibly that of its genetic determinants, are directly influenced by the antimicrobial treatments used.
Assuntos
Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Sus scrofa/microbiologia , Criação de Animais Domésticos/métodos , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Antibioticoprofilaxia/veterinária , Argentina , Fezes/microbiologia , FenótipoRESUMO
The effects of aflatoxin B1 on the development of the immune response to oil-adjuvanted Bordetella bronchiseptica vaccine and on acquired resistance to bacterial challenge were studied in rabbits. The doses of aflatoxin used were insufficient to produce clinical intoxication. Rabbits were randomly assigned to three groups, each having six animals: control (T), vaccinated (V), and vaccinated plus aflatoxin (VA) at 0.05 mg/kg daily per os. Groups V and VA were vaccinated twice, and the three groups were subsequently challenged with virulent B. bronchiseptica. The average weight gain at weekly intervals was significantly reduced in group VA, and no statistically significant differences were found in the titers of agglutinating antibodies between groups V and VA. There were significant differences between groups V and VA in the extent and severity of the pneumonic process, group VA being most affected. Results indicated that agglutinating antibody titers were not related to the level of protection in the latter group. Other mechanisms, such as alveolar macrophage activity and cell-mediated immunity, were implicated in the impairment of the acquired resistance in rabbits subclinically intoxicated with aflatoxin.
Assuntos
Aflatoxinas/farmacologia , Vacinas Bacterianas/imunologia , Infecções por Bordetella/imunologia , Bordetella/imunologia , Aflatoxina B1 , Animais , Anticorpos Antibacterianos/biossíntese , Imunidade Ativa/efeitos dos fármacos , Pulmão/patologia , Coelhos , Distribuição Aleatória , Aumento de Peso/efeitos dos fármacosRESUMO
Fetal fluids of 738 stillborn piglets from three swine farms in Argentina were examined for antibodies to Toxoplasma gondii. Antibodies were detected in 15 samples at a 1:20 dilution in the indirect fluorescent antibody test and 10 samples were positive in the modified agglutination test (MAT) at a dilution of 1:25; four of these samples had a MAT titer of > or = 1:100. This survey indicates a low rate of congenital T. gondii infection in stillborn pigs in Argentina.
Assuntos
Anticorpos Antiprotozoários/análise , Morte Fetal/veterinária , Doenças dos Suínos/diagnóstico , Toxoplasma/imunologia , Toxoplasmose Animal/diagnóstico , Testes de Aglutinação , Animais , Argentina , Morte Fetal/parasitologia , Técnica Indireta de Fluorescência para Anticorpo , Suínos , Doenças dos Suínos/imunologia , Toxoplasmose Animal/imunologiaRESUMO
Pathological studies were carried out on the lungs of guinea pigs intratracheally inoculated with 4.6 x 10(6-8) colony forming units (CFU)/head of Actinobacillus pleuropneumoniae serovar 1. All animals in the highest dose group died within 24 hr post inoculation (hpi) and showed pulmonary lesions being hemorrhagic in nature while all animals in the lowest dose group were killed as scheduled at 11 days post inoculation (dpi) and showed only hyperplasia of peribronchial lymphoid tissues. In the middle dose group, two died within 24 hpi, two died at 9 dpi, and the remaining one was killed at 11 dpi. Two guinea pigs which died at 9 dpi showed fibrinonecrotic pleuropneumonia which is the most characteristic acute pulmonary lesion in swine, and has not yet been reproduced in laboratory animals up to the present time. This suggests that guinea pigs may be a useful laboratory animal for studying the pathogenesis of Actinobacillus pleuropneumoniae infection in swine.
Assuntos
Infecções por Actinobacillus/veterinária , Actinobacillus pleuropneumoniae/isolamento & purificação , Cobaias/microbiologia , Pulmão/patologia , Infecções por Actinobacillus/patologia , Actinobacillus pleuropneumoniae/patogenicidade , Animais , Modelos Animais de Doenças , Pulmão/microbiologia , Suínos , Doenças dos Suínos/microbiologiaRESUMO
Histochemical and lectinhistochemical examinations were carried out on nasal mucosa of pigs with or without respiratory diseases. As the results, both acid and neutral mucins coexisted in nasal mucosa of normal pigs while acid sialomucins were mainly observed in nasal mucosa of pigs infected with Bordetella bronchiseptica and/or Pasteurella multocida. Lectinhistochemistry revealed that the nasal epithelial cells of normal pigs were rich in N-acetylgalactosamine, fucose and N-acetyl-glucosamine residues which showed a tendency to disappear in porcine cytomegalovirus infection and to increase in atrophic rhinitis, respectively.
Assuntos
Infecções por Bordetella/veterinária , Bordetella bronchiseptica , Lectinas/metabolismo , Mucosa Nasal/metabolismo , Infecções por Pasteurella/veterinária , Pasteurella multocida , Rinite Atrófica/veterinária , Doenças dos Suínos/metabolismo , Animais , Infecções por Bordetella/metabolismo , Infecções por Bordetella/microbiologia , Infecções por Citomegalovirus/metabolismo , Infecções por Citomegalovirus/veterinária , Infecções por Citomegalovirus/virologia , Células Epiteliais/metabolismo , Glicoconjugados/metabolismo , Histocitoquímica , Infecções por Pasteurella/metabolismo , Infecções por Pasteurella/microbiologia , Rinite Atrófica/metabolismo , Rinite Atrófica/microbiologia , Suínos , Doenças dos Suínos/microbiologiaRESUMO
Campylobacter jejuni and Campylobacter coli were isolated from aborted pig fetuses which proceeded from different animals and farms between February 2000 and March 2001. Seven Campylobacter jejuni biotype II, three biotype I and one Campylobacter coli biotype I were identified by phenotypic tests and Lior's scheme. To corroborate and compare the phenotypic results, 7.5, 10 and 12.5% polyacrilamide gel electrophoresis (SDS-PAGE) were used under reducing conditions. Characteristic bands of hypervariable dense zone within C. jejuni and C. coli species were observed in all the whole cell protein extracts with differences in mobility. It was possible to establish differences between identical phenotypic Campylobacter isolates and different protein profile from fetuses of the same litter. SDS-PAGE is a stable and reproducible method to establish differences between Campylobacter strains and is considered applicable for the differentiation of the wide variability of Campylobacter species for epidemiologic purposes.
Assuntos
Aborto Animal/microbiologia , Proteínas de Bactérias/análise , Técnicas de Tipagem Bacteriana/métodos , Infecções por Campylobacter/veterinária , Campylobacter coli/isolamento & purificação , Campylobacter jejuni/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Doenças dos Suínos/microbiologia , Animais , Argentina , Infecções por Campylobacter/microbiologia , Campylobacter coli/química , Campylobacter jejuni/química , Idade Gestacional , Fenótipo , Reprodutibilidade dos Testes , Especificidade da EspécieRESUMO
Ganglioneuromatosis (GNM) is a rare condition characterized by the benign proliferation of ganglion cells, nerve fibres and supporting cells of the enteric nervous system. Necropsy examination of a female piglet weighing 4 kg revealed a well-demarcated 20 cm segment of terminal ileum with thickening of the wall. Microscopically, the lamina propria was infiltrated by enteric glial cells and large ganglion cells. Within the submucosal and muscular layers, aggregates of neurons were interlaced by Schwann cells and enteric glial cells arranged in concentric rings. Immunohistochemically, the neurons were weakly labelled for S-100 and neuron-specific enolase, Schwann cells expressed S-100 and vimentin and enteric glial cells expressed glial fibrillary acidic protein and S-100. Pathological and immunohistochemical findings supported the diagnosis of ileal GNM.
Assuntos
Ganglioneuroma/veterinária , Neoplasias do Íleo/veterinária , Doenças dos Suínos/patologia , Animais , Feminino , Ganglioneuroma/patologia , Neoplasias do Íleo/patologia , Imuno-Histoquímica , Sus scrofa , SuínosRESUMO
Se evaluó la prevalencia serológica del virus de influenza mediante las pruebas de inhibición de la hemaglutinación (IHA) y ELISA para los subtipos H1N1 y H3N2 en 13 granjas porcinas de Argentina. Se compararon los resultados obtenidos mediante ambas pruebas en términos individuales y de establecimientos. La prevalencia individual por la técnica de IHA fue de 38,46% a 100% para H1 y de 7,69% a 100% para H3. Por la técnica de ELISA, la prevalencia individual fue de 2,33% a 6,9% para H1 y de 9,65% a 48% para H3. No se observaron diferencias significativas entre ambas técnicas a escala de granja (H1: p=0,20; H3: p=0,11). La concordancia entre las pruebas fue nula al tomar como unidad de referencia el animal (H1: 0,005; H3: 0,070), mientras que en términos de establecimiento fue escasa (H1: 0,350; H3: 0,235). Considerando la alta prevalencia individual obtenida por la prueba de IHA y la alta sensibilidad de esta técnica, se podría sugerir que en las poblaciones porcinas de la Argentina circularon cepas virales humanas o cepas porcinas con gran proximidad filogenética a las utilizadas en este estudio desde el año 2002.
The seroprevalence of the Influenza virus against H1N1 and H3N2 was determined by the hemagglutination-inhibition test (HI) and a commercial swine influenza ELISA kit, in 13 Argentinean swine herds. The results of within-herd and between-herd prevalence obtained by both tests were statistically correlated. The within-herd prevalence observed by the HI test varied from 38.46 to 100% against H1 and 7.69 to 100% for H3. When the within-herd prevalence was measured with the ELISA test, it varied from 2.33 to 6.9% for H1 and 9.65 to 48% for H3. No statistical differences were observed at herd level between HI and ELISA (H1: p = 0. 20; H3: p=0.11). No agreement between HI and ELISA detected prevalence was observed when the within-herd prevalence was compared (H1: 0.005; H3: 0.070), while the agreement at herd level was considered poor (H1: 0,350; H3: 0,235). The high within-herd prevalence values observed with the HI test and the high sensibility of this test might show that human strains or swine strains phylogenetically closely related to the humans strains used in the HI test in this study have been affecting the swine population since 2002.
Assuntos
Animais , Humanos , Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/veterinária , Testes de Inibição da Hemaglutinação/veterinária , Vírus da Influenza A/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Sus scrofa/virologia , Doenças dos Suínos/epidemiologia , Argentina/epidemiologia , Reservatórios de Doenças/veterinária , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A/classificação , Vírus da Influenza A/imunologia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/diagnóstico , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Valor Preditivo dos Testes , Estações do Ano , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/virologia , Suínos/virologiaRESUMO
Seventeen Serpulina hyodysenteriae strains isolated from faeces, rectal swabs and intestinal contents of pigs with Swine Dysentery, from farms located in Buenos Aires province were serotyped. Samples on selective media (trypticase soy agar added by 5% ovine blood, 400 mg/l spectinomicin, 30 mg/l colistin, 30 mg/l vancomycin) were streaked and incubated under anaerobic atmosphere for 72 h at 42 degrees C. Suspected S. hyodysenteriae growth were identified by strong beta-hemolytic zone, without colonies, and the spirillar morphology, using the Victoria Blue 4-R stain were criteria following by S. hyodysenteriae preliminar identification. The following antigens were made by phenolic extraction from a concentrated inocula washed twice in PBS pH 7: whole-cell (WC), boiled cell (BC) and lipopolysaccharide (LPS). Two serological test were: coagglutination and immunodiffusion, using polyclonal rabbit antisera against the 9 serotypes of S. hyodysenteriae and S. innocens, using WC and BC like antigens for the first test and BC and LPS for the second. The Dot-ELISA Test was performed using BC and LPS antigens and monoclonal antibodies (AbM) against serotypes 1, 2, 3, 8, 9 of S. hyodysenteriae, AbM species-specific and AbM against S. innocens. All isolated S. hyodysenteriae strains belonged to serotype 8. Like in other countries occurred, it would exit a high regional prevalence of S. hyodysenteriae serotype, being the serotype 8 in Argentine.
Assuntos
Brachyspira hyodysenteriae/classificação , Disenteria/veterinária , Infecções por Spirochaetales/veterinária , Doenças dos Suínos/microbiologia , Suínos/microbiologia , Testes de Aglutinação , Animais , Antígenos de Bactérias/imunologia , Argentina/epidemiologia , Técnicas de Tipagem Bacteriana , Brachyspira hyodysenteriae/isolamento & purificação , Disenteria/epidemiologia , Disenteria/microbiologia , Ensaio de Imunoadsorção Enzimática , Immunoblotting , Imunodifusão , Prevalência , Estudos Soroepidemiológicos , Sorotipagem , Infecções por Spirochaetales/epidemiologia , Infecções por Spirochaetales/microbiologia , Doenças dos Suínos/epidemiologiaRESUMO
Peripheral neuroblastoma (PNB) is a rare neoplasia derived from neuroepithelial cells. PNB typically presents as a greyish mass, composed of round cells with features of neuronal differentiation. Necropsy, performed on a 1-day-old piglet, revealed a mass craniodorsally located in the abdominal cavity. Histologically, the predominant population consisted of small round to ovoid cells with scanty cytoplasm and dark round nuclei, besides, there were larger neurone-like cells. Neurone-specific enolase and S-100 protein were immunohistochemically detected, while glial fibrillary acidic protein was negative. Histological and immunohistochemical findings substantiated the diagnosis of a grade II peripheral neuroblastoma. This seems to be the first description of a PNB in a newborn piglet.
Assuntos
Neoplasias Abdominais/veterinária , Neuroblastoma/veterinária , Doenças dos Suínos/diagnóstico , Neoplasias Abdominais/diagnóstico , Animais , Animais Recém-Nascidos , Autopsia , Diagnóstico Diferencial , Imuno-Histoquímica/veterinária , Masculino , Neuroblastoma/diagnóstico , Suínos , Doenças dos Suínos/patologiaRESUMO
Campylobacter jejuni and Campylobacter coli were isolated from aborted pig fetuses which proceeded from different animals and farms between February 2000 and March 2001. Seven Campylobacter jejuni biotype II, three biotype I and one Campylobacter coli biotype I were identified by phenotypic tests and Liors scheme. To corroborate and compare the phenotypic results, 7.5, 10 and 12.5
polyacrilamide gel electrophoresis (SDS-PAGE) were used under reducing conditions. Characteristic bands of hypervariable dense zone within C. jejuni and C. coli species were observed in all the whole cell protein extracts with differences in mobility. It was possible to establish differences between identical phenotypic Campylobacter isolates and different protein profile from fetuses of the same litter. SDS-PAGE is a stable and reproducible method to establish differences between Campylobacter strains and is considered applicable for the differentiation of the wide variability of Campylobacter species for epidemiologic purposes.