RESUMO

Wild boar (Sus scrofa) is an exotic invasive species in Brazil and may be a reservoir for several pathogens, including those related to the porcine respiratory disease complex (PRDC), a critical infectious disease in pig production. The objective of this study was to investigate viral and bacterial pathogens related to PRDC in free-living wild boars from Brazil. Eighty animals were examined in search of genomes of porcine circovirus 2 (PCV2), Torque teno Sus virus 1a (TTSuV1a) and 1b (TTSuV1b), Influenza A virus (IAV), Actinobacillus pleuropneumoniae, Glaesserella parasuis, Pasteurella multocida, and Mycoplasma hyopneumoniae. The results demonstrated that 57.5% (46/80) of the animals had at least one detected pathogen, and 11.3% of them (9/80) were co-infected. TTSuV1a was the most prevalent genome, for which risk factors were associated with increased contact between wild boars and other animals. The other pathogens were detected at much lower frequencies or not detected (M. hyopneumoniae and IAV). An additional IAV serology search identified H1N1pdm09 antibodies in 35.5% (16/45) of the wild boars, bringing concern related to public health. In conclusion, wild boars are infected with pathogens that cause swine diseases, so their eventual contact with domestic pigs might risk animal production in Brazil.

Assuntos

RESUMO

We report here high rates of detection (50.8%, 31/61 pigs) of Torque teno sus virus (TTSuV) in kidneys of slaughter-age, apparently healthy pigs on St. Kitts island, Lesser Antilles. TTSuV1 and TTSuVk2a were detected in 23 (37.7%) and 13 (21.3%) pigs, respectively, including mixed infection in five animals. By nucleotide sequence identities and phylogenetic analysis, significant genetic diversity was observed among both TTSuV1 and TTSuVk2a on St. Kitts, with TTSuVk2a showing higher genetic diversity than TTSuV1. Fourteen (45.2%) and 10 (32.2%) of the TTSuV infected pigs tested positive for porcine circovirus type 2 (PCV2) and porcine parvovirus (PPV), respectively, revealing high rates of co-infection of TTSuV with PCV2 and PPV. This is the first report on detection and genetic diversity of TTSuV from the Lesser Antilles. Also, PCV2 and PPV were detected for the first time in the Lesser Antilles. Considering the impact of pig farming on the regional livestock economy, the increasing demand for local pork and lack of information on emerging and re-emerging porcine viruses in the Lesser Antilles, the present findings have important implications on swine health.

Assuntos

RESUMO

Worldwide Torque teno sus virus (TTSuV, genus Iotatorquevirus) species have been regarded as possible agents associated with porcine circovirus-associated disease. Iotatorquevirus species possess high genomic variability, suggesting that diverse genotypes are widely geographically distributed. In this study, we validated the genomic variability of Iotaroquevirus species in pigs with postweaned multisystemic wasting syndrome. Genomic DNA from nine TTSuV1a-positive tissues and 15 TTSuV1b-positive tissues was used to amplify the complete ORF2 of each species by nested PCR to perform a molecular characterization. It was found that Mexican TTSuV1a sequences belong to genotype B, sharing phylogenetic origin, high nucleic acid and amino acid sequence similarity and dominant epitope conformation with commercially linked countries, such as the United States, Canada and China, whereas the Mexican TTSuV1b sequences belong to genotype A, being more divergent among each other and displaying low nucleotide identity with worldwide genotype A sequences. In both Iotatorquevirus species, a PTPase-like signature motif was identified in the predicted amino acid sequence, being more conserved for Mexican TTSuV1b sequences than for Mexican TTSuV1a sequences, in which several substitutions were observed. These changes may influence the conformation of dominant epitopes as different arrays were determined among TTSuV1a genotypes. ORF2 variability may account for pathogenic differences by modifying viral replication and immune response, as depicted for human TTV.

Assuntos

RESUMO

Associations between Torque teno sus viruses (TTSuVs) and the occurrence of postweaning multisystemic wasting syndrome (PMWS) have been reported with controversial results. Currently, no studies have been performed comparing simultaneously viral loads of TTSuVs and PCV2. To examine the role for TTSuVs in PMWS-affected animals, a SYBR Green-based quantitative PCR (qPCR) was designed to detect and quantify TTSuV1, TTSuV2 and PCV2 genomes in swine sera. TTSuV1 genome loads were significantly higher in healthy adults than in young and SPF animals (p<0.05) suggesting that the prevalence of TTSuV1 infection increases with age and bears no association with PMWS. Regarding TTSuV2, no significant variation was detected in viral loads within any of the groups. As expected, PCV2 genome loads were higher in PMWS-affected swine than in healthy or SPF animals (p<0.001). These findings provide clear evidence to indicate that neither TTSuV1 nor TTSuV2 viral loads have any correlation with the occurrence of PMWS.

Assuntos

RESUMO

Torque teno sus virus (TTSuV) infection is present in pig herds worldwide. It has been demonstrated that TTSuV might increase the severity of other important viral diseases with economic and public health impacts. At present, there is no information on the age distribution of pigs infected with TTSuV in Brazilian herds. This study evaluated the frequency of TTSuV infection in pigs at different stages of production. Fecal samples (n=190) from pigs at 1 to 24 weeks of age and from breeders at 6 farrow-to-weaning (up to 8 weeks of age) and 9 grower-to-finish (9 weeks of age onwards) farms in the western region of Paraná state, Brazil, were evaluated by PCR. Fragments of the 5' UTRs of TTSuV1 and/or TTSuVk2 DNAs were identified in 126 (66.3%) of the fecal samples. Significant differences were found with the percentages of positive samples for TTSuV1, TTSuVk2, and mixed infections by both genera between and within the different pig production stages. Fecal samples from the grower-to-finish farms had TTSuV detection rates (90.1%; 64/71) that were significantly (p<0.05) higher than those from the farrow-to-weaning farms (52.1%; 62/119). TTSuV detection was significantly (p<0.05) more frequent in finisher pigs than in the animals from the other stages. The UTR nucleotide sequences in this study presented higher similarities to strains from Norway (96%, TTSuV1), and Argentina and China (97.1%, TTSuVk2). These results suggest that TTSuV infection has spread to pigs of all production stages and that the viral infection rate increases with the age of the animals. In the western region of Paraná state, Brazil, TTSuV1 and TTSuVk2-induced infections were more frequently observed in suckling piglets and finisher pigs, respectively. Phylogenetic analysis pointed out the possibility of different strains of TTSuV1 and TTSuVk2 circulating in pig herds of Brazil.(AU)

A infecção pelo Torque teno sus virus (TTSuV) está presente em rebanhos suinícolas em todo o mundo. Tem sido demonstrado que a infecção pelo TTSuV pode aumentar a gravidade de outras importantes doenças virais com impactos econômicos e na saúde pública. Atualmente não há informações sobre a distribuição da infecção pelo TTSuV, de acordo com a faixa etária, em rebanhos suinícolas brasileiros. Este estudo avaliou a frequência da infecção pelo TTSuV nas diferentes categorias de produção de suínos. Amostras fecais (n=190) de suínos com 1 a 24 semanas de idade e de reprodutores provenientes 6 unidades produtoras de leitão (até 8 semanas de idade) e 9 unidades de terminação (9 semanas de idade em diante) da região oeste do Paraná, Brasil, foram avaliadas pela técnica de PCR. Fragmentos da região 5' UTR do DNA do TTSuV1 e/ou TTSuVk2 foram identificados em 126 (66,3%) amostras fecais. Diferenças significativas foram encontradas em relação às porcentagens de amostras positivas para o TTSuV1, TTSuVk2 e infecção mista por ambos os gêneros inter e intra categorias. Amostras fecais provenientes de unidades de terminação apresentaram taxas de detecção de TTSuV (90.1%; 64/71) significativamente (p<0.05) mais altas do que aquelas provenientes de unidades produtoras de leitão (52.1%; 62/119). A detecção do TTSuV em animais de terminação foi significativamente (p<0.05) mais frequente do que nos suínos de outras categorias. As sequências de nucleotídeos da UTR deste estudo apresentaram maior similaridade com cepas da Noruega (96%, TTSuV1) e Argentina e China (97,1%, TTSuVk2). Estes resultados sugerem que a infecção pelo TTSuV encontra-se disseminada em suínos de todas as categorias de produção e que a taxa da infecção viral aumenta de acordo com a idade dos animais. Na região oeste do estado do Paraná, infecções induzidas pelo TTSuV1 e TTSuVk2 foram mais frequentemente observadas em leitões de maternidade e suínos de terminação, respectivamente. A análise filogenética indicou a possibilidade de diferentes cepas de TTSuV1 e TTSuVk2 circulando em rebanhos suinícolas brasileiros.(AU)

Assuntos

RESUMO

Torque teno sus virus (TTSuV) infection is present in pig herds worldwide. It has been demonstrated that TTSuV might increase the severity of other important viral diseases with economic and public health impacts. At present, there is no information on the age distribution of pigs infected with TTSuV in Brazilian herds. This study evaluated the frequency of TTSuV infection in pigs at different stages of production. Fecal samples (n=190) from pigs at 1 to 24 weeks of age and from breeders at 6 farrow-to-weaning (up to 8 weeks of age) and 9 grower-to-finish (9 weeks of age onwards) farms in the western region of Paraná state, Brazil, were evaluated by PCR. Fragments of the 5' UTRs of TTSuV1 and/or TTSuVk2 DNAs were identified in 126 (66.3%) of the fecal samples. Significant differences were found with the percentages of positive samples for TTSuV1, TTSuVk2, and mixed infections by both genera between and within the different pig production stages. Fecal samples from the grower-to-finish farms had TTSuV detection rates (90.1%; 64/71) that were significantly (p<0.05) higher than those from the farrow-to-weaning farms (52.1%; 62/119). TTSuV detection was significantly (p<0.05) more frequent in finisher pigs than in the animals from the other stages. The UTR nucleotide sequences in this study presented higher similarities to strains from Norway (96%, TTSuV1), and Argentina and China (97.1%, TTSuVk2). These results suggest that TTSuV infection has spread to pigs of all production stages and that the viral infection rate increases with the age of the animals. In the western region of Paraná state, Brazil, TTSuV1 and TTSuVk2-induced infections were more frequently observed in suckling piglets and finisher pigs, respectively. Phylogenetic analysis pointed out the possibility of different strains of TTSuV1 and TTSuVk2 circulating in pig herds of Brazil.

A infecção pelo Torque teno sus virus (TTSuV) está presente em rebanhos suinícolas em todo o mundo. Tem sido demonstrado que a infecção pelo TTSuV pode aumentar a gravidade de outras importantes doenças virais com impactos econômicos e na saúde pública. Atualmente não há informações sobre a distribuição da infecção pelo TTSuV, de acordo com a faixa etária, em rebanhos suinícolas brasileiros. Este estudo avaliou a frequência da infecção pelo TTSuV nas diferentes categorias de produção de suínos. Amostras fecais (n=190) de suínos com 1 a 24 semanas de idade e de reprodutores provenientes 6 unidades produtoras de leitão (até 8 semanas de idade) e 9 unidades de terminação (9 semanas de idade em diante) da região oeste do Paraná, Brasil, foram avaliadas pela técnica de PCR. Fragmentos da região 5' UTR do DNA do TTSuV1 e/ou TTSuVk2 foram identificados em 126 (66,3%) amostras fecais. Diferenças significativas foram encontradas em relação às porcentagens de amostras positivas para o TTSuV1, TTSuVk2 e infecção mista por ambos os gêneros inter e intra categorias. Amostras fecais provenientes de unidades de terminação apresentaram taxas de detecção de TTSuV (90.1%; 64/71) significativamente (p<0.05) mais altas do que aquelas provenientes de unidades produtoras de leitão (52.1%; 62/119). A detecção do TTSuV em animais de terminação foi significativamente (p<0.05) mais frequente do que nos suínos de outras categorias. As sequências de nucleotídeos da UTR deste estudo apresentaram maior similaridade com cepas da Noruega (96%, TTSuV1) e Argentina e China (97,1%, TTSuVk2). Estes resultados sugerem que a infecção pelo TTSuV encontra-se disseminada em suínos de todas as categorias de produção e que a taxa da infecção viral aumenta de acordo com a idade dos animais. Na região oeste do estado do Paraná, infecções induzidas pelo TTSuV1 e TTSuVk2 foram mais frequentemente observadas em leitões de maternidade e suínos de terminação, respectivamente. A análise filogenética indicou a possibilidade de diferentes cepas de TTSuV1 e TTSuVk2 circulando em rebanhos suinícolas brasileiros.

Assuntos