Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
J Virol Methods ; 329: 114986, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38914314

RESUMO

Porcine Epidemic Diarrhea Virus (PEDV) poses a significant threat to the swine industry, causing severe disease and resulting in substantial economic losses. Despite China's implementation of a large-scale vaccine immunization strategy in recent years, various strains of PEDV, including classical attenuated vaccine strains, continue to emerge in immunized pig herds. Here, we established a one-step real-time fluorescent reverse transcription PCR (one-step real-time RT-PCR) assay targeting a 24-nucleotide deletion in the ORF1 region of three PEDV classical attenuated vaccine strains, derived from classical strains. This assay effectively distinguishes between PEDV classical attenuated vaccine strains and wild-type strains, and we also explore the causes of this discriminatory target deficiency of this method through phylogenetic and recombination analysis. We found that these three classical attenuated vaccine strains exhibit closer phylogenetic relationships and higher sequence similarity with five cell-adapted strains. Recombination analysis revealed that although recombination is widespread in the PEDV genome, the 24-nucleotide deletion site remains stable without undergoing recombination and can be utilized as a target for identification. Further analysis revealed there are no enzyme cleavage sites near the 24-nucleotide site, suggesting that this deletion may have been lost during the process of culturing these viral strains in cells.The detection method we have established exhibits high specificity and sensitivity to PEDV, without cross-reactivity with other viruses causing diarrheal diseases. A total of 117 swine fecal samples were analyzed using this established one-step real-time reverse transcription PCR assay, indicating the presence of classical attenuated vaccine strains in pig herds in Gansu province, China. Additionally, the designed primer pairs and two probes can be placed in a single reaction tube to differentiate between these two types of strains, effectively reducing detection costs. These findings offer an efficient and cost-effective technological platform for clinical rapid identification testing of both wild-type and classical attenuated vaccine strains of PEDV, as well as for precise investigation of clinical data on natural infections and vaccine immunity in pig herds.


Assuntos
Infecções por Coronavirus , Vírus da Diarreia Epidêmica Suína , Reação em Cadeia da Polimerase em Tempo Real , Deleção de Sequência , Doenças dos Suínos , Vacinas Atenuadas , Vacinas Virais , Vírus da Diarreia Epidêmica Suína/genética , Vírus da Diarreia Epidêmica Suína/isolamento & purificação , Animais , Suínos , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Doenças dos Suínos/virologia , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/diagnóstico , Vacinas Virais/genética , Vacinas Virais/imunologia , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , China , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Filogenia , Sensibilidade e Especificidade , Análise Custo-Benefício
2.
Can J Vet Res ; 86(4): 241-253, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36211211

RESUMO

The goal of this study was to determine if seasonality of rotavirus A, B, and C infection is present in Ontario and Quebec swine herds by investigating submissions to a diagnostic laboratory. Samples (N = 1557) within 755 case submissions from Canadian swine herds between 2016 and 2020 were tested for rotaviruses A, B, and C using a real-time polymerase-chain reaction assay and described. Data from Ontario and Quebec were additionally analyzed using boxplots, 6-week rolling averages, time-series decomposition, and negative binomial regression models. Percentage positivity of submissions for rotaviruses A, B, and C were discovered to be highest in nursery/weaner (n = 100, 94.0%, 60.0%, 80.0%) and grower/finisher (n = 13, 84.6%, 46.2%, 61.5%) pigs and lowest in gilt/sow (n = 45, 68.9%, 20.0%, 40.0%) and suckling pigs (n = 102, 67.6%, 10.8%, 38.2%), respectively. The most common combination of rotavirus at the sample level was AC (n = 252, 17%) and ABC (n = 175, 23.2%) at the submission level. Percent positivity for rotavirus A, B, and C across all Canadian provinces included in the study were 69.9%, 32.6%, and 53.1%, respectively. Descriptive analysis suggested little to no evidence of seasonal patterns, although a spike in November was seen in the monthly total submissions and monthly total positive submissions. Statistically, the overall month effect could not be identified as statistically significant (P > 0.05) for any of the evaluated submission counts. Overall, there was no evidence supporting seasonality of rotavirus within Ontario and Quebec swine herds between 2016 and 2020.


Le but de cette étude était de déterminer si la saisonnalité de l'infection à rotavirus A, B et C est présente dans les troupeaux de porcs de l'Ontario et du Québec en examinant les soumissions à un laboratoire de diagnostic. Des échantillons (N = 1557) de 755 cas soumis de troupeaux de porcs canadiens entre 2016 et 2020 ont été testés pour les rotavirus A, B et C à l'aide d'un test de réaction d'amplification en chaîne par polymérase en temps réel et décrits. Les données de l'Ontario et du Québec ont également été analysées à l'aide de diagrammes en boîte, de moyennes mobiles sur 6 semaines, d'une décomposition de séries chronologiques et de modèles de régression binomiale négative. On a découvert que le pourcentage de positivité des soumissions pour les rotavirus A, B et C étaient le plus élevé en pouponnière/sevrage (n = 100, 94,0 %, 60,0 %, 80,0 %) et en croissance/engraissement (n = 13, 84,6 %, 46,2 %, 61,5 %) des porcs et le plus bas chez les cochettes/truies (n = 45, 68,9 %, 20,0 %, 40,0 %) et les porcs à la mamelle (n = 102, 67,6 %, 10,8 %, 38,2 %), respectivement. La combinaison la plus courante de rotavirus au niveau de l'échantillon était AC (n = 252, 17 %) et ABC (n = 175, 23,2 %) au niveau de la soumission. Les pourcentages de positivité pour les rotavirus A, B et C dans toutes les provinces canadiennes incluses dans l'étude étaient de 69,9 %, 32,6 % et 53,1 %, respectivement. L'analyse descriptive a suggéré peu ou pas de preuves de tendances saisonnières, bien qu'un pic en novembre ait été observé dans les soumissions totales mensuelles et les soumissions positives totales mensuelles. Statistiquement, l'effet mensuel global n'a pu être identifié comme statistiquement significatif (P > 0,05) pour aucun des nombres de soumissions évalués. Dans l'ensemble, il n'y avait aucune preuve à l'appui de la saisonnalité du rotavirus dans les troupeaux de porcs de l'Ontario et du Québec entre 2016 et 2020.(Traduit par Docteur Serge Messier).


Assuntos
Infecções por Rotavirus , Rotavirus , Doenças dos Suínos , Animais , Feminino , Ontário/epidemiologia , Reação em Cadeia da Polimerase/veterinária , Quebeque/epidemiologia , Rotavirus/genética , Infecções por Rotavirus/diagnóstico , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/veterinária , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia
3.
Foodborne Pathog Dis ; 19(6): 394-399, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35443790

RESUMO

The aim of this study was to assess the agreement between anti-Toxoplasma gondii IgG antibody detection in serum and filter paper (FP) blood spots using the indirect immunofluorescence antibody assay (IFA) and to evaluate the potential impact of the packed cell volume (PCV) on antibody detection in FPs. A pair of a serum and an FP sample was collected from 96 sows at various farms in Greece, with previously identified high seropositivity and/or risk factors associated with high seropositivity against T. gondii. The PCV value was determined using the microhematocrit method. IFA was used for the detection of antibodies against T. gondii. T. gondii-specific antibodies were detected in 45.8% serum samples and 41.6% FP samples showing almost perfect agreement. Detection in FP samples presented high sensitivity (87.1-92.8%) and excellent specificity (100%) when compared with detection in serum, regardless of the PCV values. The findings of this study support the reliability of FPs for the evaluation of the serological status of swine against T. gondii. FPs could be a good alternative sample type compared with serum for large-scale epidemiological studies.


Assuntos
Doenças dos Suínos , Toxoplasma , Toxoplasmose Animal , Animais , Anticorpos Antiprotozoários , Tamanho Celular , Feminino , Reprodutibilidade dos Testes , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/diagnóstico , Toxoplasmose Animal/diagnóstico , Toxoplasmose Animal/epidemiologia
4.
Vet Parasitol ; 297: 109308, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33858726

RESUMO

Trichinella spp. is considered as one of the most widespread food-borne zoonotic parasites globally. The disease it causes impacts human public health, pig production, and food safety. Unfortunately in the Philippines, there is still insufficient research on the presence of Trichinella among livestock. This study aims to update its status and records in the country, by verifying the presence of Trichinella spp. IgG antibodies from the selected province, Bulacan, and link its potential presence to known animal husbandry and farm practices. This study was conducted in purposively selected slaughterhouses. Pigs were randomly selected for each slaughterhouse. Blood samples were collected and serum samples were harvested from each pig samples (n = 555). Sera were tested using ELISA for the detection of Trichinella spp. IgG antibodies. For serologically positive pigs, farm-based exposure assessment was conducted to evaluate potential routes of infection. For this study, a total of 555 blood sera, wherein three blood sera were detected to be serologically positive (low prevalence of 0.54 %, 95 % CI = 0.11-1.57). Potential infection routes point towards outdoor housing management, pigs with unknown origin, pig farms presence with rodents, and pigs fed with waste as important risks. In summary, the present paper confirms that Trichinella spp. antibodies were detected in very low prevalence in Bulacan, Philippines and demonstrated the potential utilization of antibody detection as an efficient and complementary early screening tool in Trichinella detection among pigs without immediately sacrificing livestock for the sake of testing. These results merit calls for a wider screening, testing, and isolation of Trichinella spp. in pigs from other Philippine provinces.


Assuntos
Doenças dos Suínos , Trichinella , Triquinelose , Matadouros , Animais , Anticorpos Anti-Helmínticos , Fazendas , Filipinas/epidemiologia , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia , Triquinelose/diagnóstico , Triquinelose/epidemiologia , Triquinelose/veterinária
5.
Methods Mol Biol ; 2291: 19-86, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33704748

RESUMO

Cattle and other ruminants are primary reservoirs for Shiga toxin-producing Escherichia coli (STEC) strains which have a highly variable, but unpredictable, pathogenic potential for humans. Domestic swine can carry and shed STEC, but only STEC strains producing the Shiga toxin (Stx) 2e variant and causing edema disease in piglets are considered pathogens of veterinary medical interest. In this chapter, we present general diagnostic workflows for sampling livestock animals to assess STEC prevalence, magnitude, and duration of host colonization. This is followed by detailed method protocols for STEC detection and typing at genetic and phenotypic levels to assess the relative virulence exerted by the strains.


Assuntos
Doenças dos Bovinos , Infecções por Escherichia coli , Toxina Shiga II/metabolismo , Escherichia coli Shiga Toxigênica , Doenças dos Suínos , Animais , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/metabolismo , Doenças dos Bovinos/microbiologia , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Escherichia coli Shiga Toxigênica/classificação , Escherichia coli Shiga Toxigênica/isolamento & purificação , Escherichia coli Shiga Toxigênica/metabolismo , Escherichia coli Shiga Toxigênica/patogenicidade , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/metabolismo , Doenças dos Suínos/microbiologia
6.
Trop Anim Health Prod ; 53(1): 177, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33616787

RESUMO

Pig farming performs as an intricate part in the socio-economic situation in the north-eastern region of India. This region contributes 38% (3.95 million) of total pigs in India. In spite of this, the region unables to flourish as an enterprise as per the expectation due to a low productivity rate. Porcine infectious pathogens like porcine cirovirus2 (PCV2) and porcine parvovirus (PPV) have a direct economic impact on pig farming through slow growth rate, abortion, and mortality and ultimately maximize the production cost by increasing the usage of antibiotic or antiviral drugs. The veterinary diagnostic infrastructure is a fundamental aspect of the development of livestock status by rapid and effective detection of pathogens. Quantitative PCR (qPCR) is a precise and fast-track technique used for the routine diagnostic method. Hence, we developed a highly precise and comparatively cost-effective SYBR Green reporter dye-based qPCR assay for parallel identification of PCV2 and PPV. In the present assay, the correlation coefficient (R2) value was 0.99, and 10 copies of the gene/µl were the least limit of detection (LOD) concerning both viruses. Melt curve analysis of this study represented PCV2-specific melt curve (Tm) at 81.2 °C and PPV-specific melt curve (Tm) at 73.5 °C. Therefore, the assay easily differentiates the true positive amplicons of PCV2 and PPV through specific Tm values. Among the 50 field samples, 26 (52%) samples were PCV2 positive, 18 (36%) samples PPV positive, and 11 (22%) samples were co-infected of both the viruses. This method is cost-effective, precise, and sensitive to diagnose the concurrent or individual infection of the PCV2 and PPV in the pig. Hence, considering the impact of pig farming in the north-eastern part of the country, the present assay gives an unprecedented achievement in disease diagnosis.


Assuntos
Infecções por Parvoviridae , Parvovirus Suíno , Doenças dos Suínos , Animais , Análise Custo-Benefício , Índia/epidemiologia , Parvovirus Suíno/genética , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia
7.
J Nanobiotechnology ; 19(1): 34, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33526021

RESUMO

BACKGROUND: The widespread popularity of porcine circovirus type 2(PCV2) has seriously affected the healthy development of the pig industry and caused huge economic losses worldwide. A rapid and reliable method is required for epidemiological investigation and evaluating the effect of immunization. However, the current methods for PCV2 antibody detection are time-consuming or very expensive and rarely meet the requirements for clinical application. we have constructed the platform for expressing the nanobody(Nb)­horseradish peroxidase(HRP) fusion protein as an ultrasensitive probe to detect antibodies against the Newcastle disease virus(NDV), previously. In the present work, an Nb-HRP fusion protein-based competitive ELISA(cELISA) for rapid and simple detection antibodies against PCV2 was developed using this platform to detect anti-PCV2 antibodies in clinical porcine serum. RESULTS: Using phage display technology, 19 anti-PCV2-Cap protein nanobodies were screened from a PCV2-Cap protein immunized Bactrian camel. With the platform, the PCV2-Nb15­HRP fusion protein was then produced and used as a sensitive reagent for developing a cELISA to detect anti­PCV2 antibodies. The cut­off value of the cELISA is 20.72 %. Three hundreds and sixty porcine serum samples were tested by both newly developed cELISA and commercial kits. The sensitivity and specificity were 99.68 % and 95.92 %, respectively. The coincidence rate of the two methods was 99.17 %. When detecting 620 clinical porcine serum samples, a good consistent (kappa value = 0.954) was found between the results of the cELISA and those of commercial kits. CONCLUSIONS: In brief, the newly developed cELISA based PCV2-Nb15­HRP fusion protein is a rapid, low-cost, reliable and useful nanobody-based tool for the serological evaluation of current PCV2 vaccine efficacy and the indirect diagnosis of PCV2 infection.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Circoviridae/veterinária , Circovirus/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Doenças dos Suínos/imunologia , Animais , Anticorpos Antivirais/sangue , Camelus/imunologia , Infecções por Circoviridae/sangue , Infecções por Circoviridae/diagnóstico , Infecções por Circoviridae/imunologia , Circovirus/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/economia , Peroxidase do Rábano Silvestre/imunologia , Imunização , Masculino , Proteínas Recombinantes de Fusão/imunologia , Sensibilidade e Especificidade , Anticorpos de Domínio Único/imunologia , Suínos/sangue , Suínos/imunologia , Suínos/virologia , Doenças dos Suínos/sangue , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/virologia , Fatores de Tempo
8.
Vet Immunol Immunopathol ; 234: 110206, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33601087

RESUMO

Three commercial ELISAs -two based on spike (E1 and E3) and one on nucleocapsid protein (E2)-were used to analyze the development and persistence of antibodies against Porcine epidemic diarrhea virus (PEDV). Seventy-five four-week-old PEDV-negative piglets were inoculated orally with a European G1b PEDV (INOC) and fourteen were kept as controls (CTRL). After the inoculation, E3 detected positive animals as soon as 7 days post inoculation (dpi), while the earliest detection with E1 and E2 was at 14 dpi. All samples were positive at 21 and 28 dpi using E1 and E3, respectively, while E2 failed to detect 23.3 % of the inoculated pigs at any time point. The percentages of positive samples were different through the study: E1 and E3 > E2 from 14 to 56 dpi; and E3 > E1 > E2 from 56 to 154 dpi (P < 0.05). Five months after the inoculation, E3 still detected 92.0 % (IC95 % = 85.1-98.8 %) of pigs as positive, while E1 and E2 detected only 27.0 % (IC95 % = 16.0-37.9 %) and 0%, respectively. The sensitivity for E2 never exceeded 0.62. Specificity was 1 for all ELISAs. These different outcomes could be related to the ELISA strategies (indirect versus competition), the antigens used, the cut-off, or to other intrinsic factors of each test. The observed differences could be of importance when assessing whether older animals, such as fatteners or gilts, had previously been in contact with PEDV.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/veterinária , Ensaio de Imunoadsorção Enzimática/normas , Imunidade , Vírus da Diarreia Epidêmica Suína/imunologia , Kit de Reagentes para Diagnóstico/normas , Fatores Etários , Animais , Anticorpos Antivirais/imunologia , Fezes/virologia , Feminino , Vírus da Diarreia Epidêmica Suína/genética , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia
9.
Res Vet Sci ; 128: 9-15, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31706218

RESUMO

Postpartum dysgalactia syndrome (PDS) in sows is a frequent and important clinical problem in the field. Currently, the diagnosis is based on physical examination performed during first days after the farrowing. The present study aimed at evaluation the dynamics of pro- and anti-inflammatory cytokine (IL-4, IL-6, IL-8, IL-10 and TNF-α) changes in serum of sows during peripartum period (day - 28 to + 28) and assessment of their diagnostic utility during lactation impairment in pigs. The study was done on 139 sows divided into 3 groups: clinically healthy sows, sows with lactation disorders, sows which had experienced difficult parturitions, lameness, etc. In order to measure the level of serum cytokines, the quantitative species-specific ELISA assays were used. The investigation demonstrated a different kinetics of changes of studied cytokines in sows from various groups. IL-6 and TNF-alfa shown high dynamic changes after farrowing in in sows. The levels of IL-8 and IL-10 were relatively stable in healthy sows, while in sows with peripartum disorders usually increased during lactation. However, the detailed examination revealed that investigated cytokines cannot be a useful early diagnostic markers of lactation impairments in sow. They do not allow to detect with high probability which sows are susceptible to lactation disorders before the parturition.


Assuntos
Citocinas/sangue , Inflamação/veterinária , Lactação , Período Periparto/imunologia , Doenças dos Suínos/diagnóstico , Animais , Feminino , Inflamação/diagnóstico , Inflamação/imunologia , Inflamação/fisiopatologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/fisiopatologia
10.
Prev Vet Med ; 162: 76-82, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30621901

RESUMO

Current macroscopic meat inspection cannot detect the most common pork-borne pathogens (Salmonella spp., Yersinia enterocolitica and Toxoplasma gondii). Furthermore, food chain information (FCI) may not provide sufficient data for visual-only inspection, which is supposed to be the common way of inspection of pigs in the European Union. Our observational study aimed to evaluate the serological monitoring and the clinical evaluation of on-farm health status of pigs and assess the feasibility of these data as part of the FCI in meat inspection. We studied the serological status of Salmonella spp., Yersinia spp. and T. gondii in pigs during the fattening period. Additionally, we evaluated the association between on-farm health status and meat inspection findings. On 57 indoor fattening pig farms in Finland, we collected blood samples (mean of 20 pigs/farm) and assessed the on-farm health (coughing, tail biting, lameness) at the end of the fattening period. We visited 34 of these farms also at the beginning of the fattening for sampling and on-farm health evaluation of the same pigs. Meat inspection results were obtained after slaughter for all 57 farms. Salmonella seroprevalence was low at the end of the fattening period: it was 17.6%, 10.6% or 1.9%, with the cut-off values of OD15% (recommended by the test manufacturer), OD20% (used by Danish monitoring programme) and OD40% (used by German monitoring programme), respectively. The overall seroprevalence of Salmonella spp. and Yersinia spp. increased significantly (P < 0.001) during the fattening period (from 8.1% to 17.2% and from 30.3% to 72.3%, respectively), while the seroprevalence of T. gondii remained low (<1%). The within-farm seroprevalences of Salmonella spp. and Yersinia spp. differed significantly between the farms and this farm-level serological data could be used as FCI for risk-based decisions to improve food safety. Such potentially feasible decisions could include additional carcass testing, carcass decontamination, carcass processing, slaughtering arrangements and improved biosecurity measures at the farm. However, risk mitigation targets and procedures must be carefully adjusted for each pathogen regarding also economic aspects. Tail biting observed on farm was associated with partial carcass condemnations and arthritis at slaughter. This information could be included in the FCI and used when making decisions regarding meat inspection procedure: visual-only or additional inspections.


Assuntos
Carne/normas , Suínos , Criação de Animais Domésticos/métodos , Animais , Estudos de Viabilidade , Finlândia/epidemiologia , Nível de Saúde , Fatores de Risco , Salmonelose Animal/sangue , Salmonelose Animal/diagnóstico , Salmonelose Animal/epidemiologia , Estudos Soroepidemiológicos , Suínos/sangue , Doenças dos Suínos/sangue , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia , Toxoplasma , Toxoplasmose Animal/sangue , Toxoplasmose Animal/diagnóstico , Toxoplasmose Animal/epidemiologia , Yersiniose/sangue , Yersiniose/diagnóstico , Yersiniose/epidemiologia , Yersiniose/veterinária , Yersinia enterocolitica
11.
Infect Genet Evol ; 69: 153-165, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30677534

RESUMO

In recent years, the outbreaks of porcine epidemic diarrhea (PED) caused by the highly virulent porcine epidemic diarrhea virus (PEDV) variants occurred frequently in China, resulting in severe economic impacts to the pork industry. In this study, we selected and analyzed the genetic evolution of 15 PEDV representative strains that were identified in fecal samples of diarrheic piglets in 10 provinces and cities during 2011-2017. The phylogenetic analysis indicated that all the 15 PEDV isolates clustered into G2 genotype associated with the current circulating strains. Compared with the genome of the prototype strain CV777, these strains had 103-120 amino acid mutations in their S proteins, most of which were in the N terminal domain of S1 (S1-NTD). We also found 37 common mutations in all these 15 strains, although these strains shared 96.9-99.7% nucleotide homology and 96.3-99.8% amino acid homology in the S protein compared with the other original pandemic strains. Computational analysis showed that these mutations may lead to remarkable changes in the conformational structure and asparagine (N)-linked glycosylation sites of S1-NTD, which may be associated with the altered pathogenicity of these variant PEDV strains. We evaluated the pathogenicity of the PEDV strain FJzz1 in piglets through oral and intramuscular infection routes. Compared with oral infection, intramuscular infection could also cause typical clinical signs but with a slightly delayed onset, confirming that the variant PEDV isolate FJzz1 was highly pathogenic to suckling piglets. In conclusion, we analyzed the genetic variation and pathogenicity of the emerging PEDV isolates of China, indicating that G2 variant PEDV strains as the main prevalent strains that may mutate continually. This study shows the necessity of monitoring the molecular epidemiology and the etiological characteristics of the epidemic PEDV isolates, which may help better control the PED outbreaks.


Assuntos
Infecções por Coronavirus/veterinária , Evolução Molecular , Vírus da Diarreia Epidêmica Suína/genética , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Substituição de Aminoácidos , Animais , Linhagem Celular , China/epidemiologia , Fezes/virologia , Genes Virais , Variação Genética , Genótipo , História do Século XXI , Epidemiologia Molecular , Mutação , Filogenia , Vírus da Diarreia Epidêmica Suína/classificação , Vírus da Diarreia Epidêmica Suína/patogenicidade , RNA Viral , Análise de Sequência de DNA , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/história
12.
J Virol Methods ; 261: 98-103, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30096349

RESUMO

Senecavirus A (SVA), formerly known as Seneca Valley Virus (SVV), is one of causative agents of vesicular diseases in swine. Recently, the outbreaks associated with vesicular disease caused by SVA infection in pig herds have been reported in Brazil, USA, China, Thailand and Canada. Several molecular detection methods have been established to determine the infection of SVA, including real time reverse transcription PCR assay, nested PCR, a TaqMan-based qRT-PCR assay and RNA-based in situ hybridization method. In our study, an assay for the identification of SVA in pig herds using real time reverse transcription loop-mediated isothermal amplification (real time RT-LAMP) was developed. The limit of detection for the assay was 1 TCID50/ml. One hundred and eighteen field samples from pigs were used to validate the assay for clinical application. Our result demonstrated that real time RT-LAMP assay is a cost-effective and highly specific and sensitive alternative for the rapid detection of SVA in clinical samples.


Assuntos
Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Infecções por Picornaviridae/veterinária , Picornaviridae/isolamento & purificação , Doenças dos Suínos/diagnóstico , Animais , Análise Custo-Benefício , Picornaviridae/genética , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/virologia , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/virologia , Fatores de Tempo
13.
J Vet Diagn Invest ; 30(4): 538-544, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29629644

RESUMO

Since the identification of species Porcine circovirus 2, the relevance of genus Circovirus has increased given its impact on the swine industry. A new species ( Porcine circovirus 3, PCV-3) has been detected in association with various clinical conditions. Consequently, there is an urgent need for reliable and widely accessible tests for both routine diagnostic and research purposes. We developed a direct PCR (requiring no DNA extraction) and a quantitative (q)PCR targeting the conserved rep gene to detect the PCV-3 genome. Test performance was assessed by testing 120 field samples within different matrices. Both methods were sensitive (detection of 10 viral genome/µL), specific, and repeatable. The substantially perfect agreement between the 2 assays strongly supports their high sensitivity and specificity. The low cost and short processing time of the direct PCR protocol, together with the reliable quantitative results provided by qPCR, support the establishment of common testing guidelines.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Doenças dos Suínos/diagnóstico , Animais , Bioensaio/veterinária , Infecções por Circoviridae/diagnóstico , Circovirus/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos
14.
Vaccine ; 36(13): 1789-1795, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29472133

RESUMO

Safety testing is one major part of the licensing procedure for veterinary vaccines and demands a large number of animals. Magnetic resonance imaging (MRI) was tested as an alternative, which may lead to a reduction in numbers of animals required for safety testing, and, correspondingly to a detailed description of the three-dimensional extent of the local tissue reaction repetitively in live pigs. In previous pig studies the following questions arose:To answer these questions the following study was performed by comparing two vaccine groups of suckling piglets (8 animals per group; A and B) with two control groups (4 animals per group; C and D). One control group was injected with a saline solution (C) and the other was only tattoo marked (D). The animals were examined using MRI at days 1, 8, 15, 22, 29, 36, and 43 post vaccination, ending with a final pathomorphologic examination. Pathomorphologic examination confirmed MRI findings. Saline solution does not result in a local tissue reaction as detected after injecting vaccines. Tattoo marking causes no local tissue reaction, neither in MRI nor in pathomorphologic examination. Therefore, MRI can be used as an alternative method for safety testing of vaccines in pigs of different age categories offering repetitive measurements of local tissue reactions. Involved cells might be examined only in a final pathomorphologic examination at the end of the trial on a reduced number of animals.


Assuntos
Imageamento por Ressonância Magnética , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/prevenção & controle , Vacinas/efeitos adversos , Animais , Biópsia , Feminino , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Masculino , Suínos , Doenças dos Suínos/etiologia , Vacinação , Vacinas/administração & dosagem
15.
Prev Vet Med ; 144: 20-28, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28716200

RESUMO

Abattoir post-mortem inspections offer a useful tool for the development and monitoring of animal health plans and a source of data for epidemiological investigation. The aim of the present work was to develop an abattoir benchmarking system which provides feedback on the prevalence and severity of lesions of the pluck (lung, pleura and liver) in batches of pigs to inform individual producers and their veterinarians of the occurrence of pathological conditions affecting their herds. The weekly collection of data throughout a year (from September 2014 to September 2015) supported the further aim of providing benchmark values for the prevalence of lesions and their seasonality in Italian heavy pig production. Finally, correlations and redundancies among different lesions were evaluated. In total, 727 batches of heavy pigs (around 165kg live weight and 9 months of age) derived from 272 intensive commercial farms located in Northern Italy were monitored. Within each batch, an average number of 100 plucks was individually scored, assigning a value for lesions of lungs (0-24), pleura (0-4) and liver (1-3). Presence of lung scars, abscesses, consolidations, lobular/chessboard pattern lesions and pleural sequestra was also recorded. Statistical analysis showed a strong farm effect (36-68% of variation depending of the lesion) and a seasonal effect on all lesions. Winter showed the lowest percentage of severe lung and pleural lesions (P<0.001 and P=0.005), whereas lung scars from older lesions (P=0.003), as well as severe hepatic lesions (P<0.001), were reduced in autumn. In order to allow effective benchmarking of each farm in a determined health class, scores for each quartile of the population are reported. Whilst such a benchmarking scheme provides useful data for herd health management, challenges of repeatability of scoring and cost of implementation need to be overcome.


Assuntos
Matadouros , Benchmarking , Doenças dos Suínos/diagnóstico , Animais , Itália , Suínos , Doenças dos Suínos/epidemiologia
16.
J Anim Sci ; 95(7): 3270-3274, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28727118

RESUMO

Core body temperature (CBT) is one of the main vital signs that is used to evaluate the health status of pigs. The most common and feasible method for assessing CBT in pigs is rectal temperature (RT). Obtaining RT is stressful for animals, may generate inaccurate results, and has the risk of spreading disease. Infrared imaging (IR) thermography of the body of pigs may be a safer and less stressful alternative to RT. The objective of the current study was to evaluate the efficacy of using IR as an alternative for monitoring CBT in pigs. Twenty-three gilts (30.5 ± 5.62 kg BW) were housed in metabolism crates in an environmentally controlled facility and fed an 860 g/d grower diet. After 4 d of adaptation, the febrile response was induced by intramuscular injection of lipopolysaccharide (LPS; 25 µg/kg BW). Each pig's body temperature was recorded at 0, 2, 4, 6, 8, 10, and 24 h after LPS challenge using the following 3 methods: 1) RT, 2) IR of the eye and ear, and 3) CBT using an orally administered digital temperature sensor. Statistical analysis was performed in a completely randomized design in SAS using Mixed, Correlation, and Regression procedures. Relative to time 0 h, LPS increased the eye temperature, CBT, and RT by 0.92, 1.32, and 1.48°C, respectively ( < 0.01), but had no significant effect on ear temperature. Eye temperature, RT, and CBT, but not ear temperature, were highly correlated ( ≥ 0.96) during the course of the study ( < 0.01). Estimated regression parameters (α and ß) for predicting CBT using eye temperature were -28.2 ± 8.70 and 1.76 ± 0.221, respectively, and for RT were -24.5 ± 7.69 and 1.65 ± 0.196, respectively ( ≥ 0.96; 95% confidence interval). Collectively, these results indicated a strong relationship between eye temperature, RT, and CBT in pigs. Therefore, IR of the eye can be used as a precise, noncontact alternative to RT measurements for monitoring CBT in swine.


Assuntos
Temperatura Corporal/fisiologia , Febre/veterinária , Lipopolissacarídeos/toxicidade , Doenças dos Suínos/induzido quimicamente , Animais , Feminino , Febre/induzido quimicamente , Febre/diagnóstico , Raios Infravermelhos , Suínos , Doenças dos Suínos/diagnóstico , Termografia/métodos
17.
Acta Trop ; 165: 240-245, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26536396

RESUMO

Health education has been recognised as a specific intervention tool for control of Taenia solium taeniosis/cysticercosis but evaluation of the efficacy of the tool remains. The aim of our study was to assess the effect of a computer-based T. solium health education tool 'The Vicious Worm' on knowledge uptake among professionals and investigate attitudes towards the program. The study was carried out between March and May 2014 in Mbeya Region, Tanzania, where T. solium is endemic. The study was a pre and post assessment of a health education tool based on questionnaire surveys and focus group discussions to investigate knowledge and attitudes. A total of 79 study subjects participated in the study including study subjects from both health- and agriculture sector. The health education consisted of 1½h individual practice with the computer program. The baseline questionnaire showed an overall knowledge on aspects of acquisition and transmission of T. solium infections (78%), porcine cysticercosis treatment (77%), human tapeworm in general (72%), neurocysticercosis in general (49%), and porcine cysticercosis diagnosis (48%). However, there was a lack of knowledge on acquisition of neurocysticercosis (15%), prevention of T. solium taeniosis/cysticercosis (28%), and relation between porcine cysticercosis, human cysticercosis, and taeniosis (32%). Overall, the study subject's knowledge was significantly improved both immediately after (p=0.001) and two weeks after (p<0.001) the health education and knowledge regarding specific aspects was significantly improved in most aspects immediately after and two weeks after the health education. The focus group discussions showed positive attitudes towards the program and the study subjects found 'The Vicious Worm' efficient, simple, and appealing. The study revealed a good effect of 'The Vicious Worm' suggesting that it could be a useful health education tool, which should be further assessed and thereafter integrated in T. solium taeniosis/cysticercosis control.


Assuntos
Cisticercose/diagnóstico , Cisticercose/tratamento farmacológico , Pessoal de Saúde/educação , Neurocisticercose/diagnóstico , Neurocisticercose/tratamento farmacológico , Teníase/diagnóstico , Teníase/tratamento farmacológico , Adulto , Idoso , Animais , Instrução por Computador , Cisticercose/epidemiologia , Feminino , Educação em Saúde/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Neurocisticercose/epidemiologia , Inquéritos e Questionários , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/tratamento farmacológico , Doenças dos Suínos/epidemiologia , Taenia solium/efeitos dos fármacos , Teníase/epidemiologia , Tanzânia
18.
J Virol Methods ; 228: 103-7, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26611229

RESUMO

Porcine torovirus (PToV) is associated with swine gastroenteritis, but its pathogenesis is uncertain because there is limited information regarding PToV due to its difficulty to adapt in vitro. This study has developed a rapid one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the detection of PToV. A set of four primers specific to six regions within the PToV's highly conserved fragment of the M gene was designed for use with the RT-LAMP assay. The RT-LAMP assay was sensitive with a detection limit of 1 × 10(1)copies/µL, which was 100-fold higher than reverse-transcription PCR. No cross-reaction was observed with other similar viruses. A total of 175 clinical specimens were collected from the Sichuan province, and PToV was detected by the established RT-LAMP assay with a positive rate of 39.2% (69/175). This study developed the first rapid, sensitive, simple, cost-effective and accurate method for the detection of PToV. The results show that the RT-LAMP assay is highly feasible in clinical settings.


Assuntos
Técnicas de Amplificação de Ácido Nucleico/métodos , Doenças dos Suínos/virologia , Infecções por Torovirus/veterinária , Torovirus/isolamento & purificação , Animais , Reações Cruzadas , Primers do DNA , Humanos , Limite de Detecção , Técnicas de Amplificação de Ácido Nucleico/economia , RNA Viral , Transcrição Reversa , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/diagnóstico , Torovirus/genética , Infecções por Torovirus/diagnóstico , Infecções por Torovirus/virologia
20.
Animal ; 9(5): 871-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25557652

RESUMO

Given that surgical castration is a painful practice performed on millions of pigs every year, a need to identify novel reliable pain assessment tools exists in order to test anaesthetic and analgesic protocols that may reduce related pain. Two treatments were considered: handling (H) and surgical castration (C). Physiological (cortisol, lactate, glycaemia, rectal and eye temperature) and behavioural variables (latency to move after treatment and alterations in posture and walking) were analysed. Cortisol showed the greatest level in C piglets within 20 min after the surgical procedure and a positive correlation with glucose concentration. Eye temperature was higher in C piglets, and the same difference was detected for rectal temperature 3 h after castration. Behavioural parameters revealed that C piglets had longer latency to move and a higher percentage of them showed alterations in posture and walking. Results of this study showed that, in castrated piglets behavioural and physiological alterations occur mainly in the first 3 h from treatment. Latency to move, alterations in posture and walking, and eye temperature appear to give additional and useful information in piglet pain assessment. However, differently from the behavioural parameters considered, eye temperature involves several manipulations of the animals and a long process to acquire the data.


Assuntos
Orquiectomia/veterinária , Medição da Dor/veterinária , Dor/veterinária , Doenças dos Suínos/diagnóstico , Animais , Temperatura Corporal , Hidrocortisona , Masculino , Atividade Motora , Orquiectomia/efeitos adversos , Dor/diagnóstico , Dor/etiologia , Medição da Dor/métodos , Suínos/fisiologia , Doenças dos Suínos/etiologia , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA