Blue tongue virus in dairy cattle in the Southern region of Minas Gerais, Brazil - serological survey

Background: Blue tongue (BT) is a noncontagious viral disease transmitted by hematophagous arthropods, especially of the genus Culicoides. The economic impact of the disease is related not only to deaths in sheep herds but also to the possible correlation of virus infection with the development of other diseases, such as pneumonia, abortion and movement problems. The economic losses caused by Blue Tongue are linked to restrictions on the import and export of animals and their genetic material and to the reproductive disorders associated with this disease. In addition, the fact that cattle take the role of reservoir, combined with the care by other countries with outbreaks of infection and biological contamination of their products, hinders trade in Mercosul, United States and Europe. Cattle are affected by Blue Tongue Virus in endemic areas and in some epidemic areas, but the development of clinical disease is rare. The clinical signs, when evident, range from reproductive losses, such as embryonic death, abortion, fetal malformation, temporary sterility, infertility in bulls, stillbirths and the birth of weak animals. The objective of this study was to determine the epidemiological aspects of Blue Tongue Virus (BTV) infection in dairy cattle in the Lavras region, state of Minas Gerais, Brazil. Materials, Methods & Results: A cross-sectional study was conducted to evaluate the frequency of cattle and herds seropositive for Blue Tongue in the southern region of Minas Gerais. In this study, 54 dairy farms were visited. A total of 586 serum samples were collected from cows of reproductive age. Sampling was random, and serum samples were collected from lactating cows over 24 months of age by puncture of the jugular vein and/or coccidian vein. The samples were transported and stored at the Setor de Patologia Veterinária, at the Universidade Federal de Lavras (SPV-UFLA), where they were centrifuged, and the serum aliquots were obtained, transferred to microtubes and kept at -20°C until the serological tests were performed. The samples were tested with the agarose gel immunodiffusion test (AGID) for anti-blue tongue virus antibodies. The AGID test is more practical and is the main method used to identify Blue Tongue Virus seroprevalence in different ruminant species. They are considered important tools for epidemiological surveillance of the disease. A prevalence of 83.28% was observed among animals that were seropositive for Blue Tongue Virus (488/586; IC 95% = 80.0 - 86.21). In addition, 100% (54/54; IC 95% = 93.4 - 100.0) of the farms had at least 1 positive animal, with rates ranging from 45.45% to 100% within the herds and where 22.22% of the farms had rates of 100% of the animals being positive. Discussion: Blue Tongue is a disease known to affect domestic and wild ruminants in Brazil. However, there is a lack of more precise information about its epidemiology and occurrence in the country and of joint efforts of researchers, producers and the government to understand in detail both the biology of vectors and the viral biology of Blue Tongue Virus in Brazil. This is the first record of detection of anti-blue tongue virus antibodies in cattle in the southern region of Minas Gerais. The results suggest that Blue Tongue Virus is present in cattle in the study area.

Molecular analysis of NSP4 coding gene of porcine rotavirus in Brazil / Análise molecular do gene codificador da NSP4 de rotavírus suínos no Brasil

The non-structural protein 4 (NSP4) has different roles in rotaviral replication, morphogenesis, and enterotoxin-like activity causing secretory diarrhea. A total of 11 partial nucleotide sequences of NSP4 coding gene were defined from group A rotavirus circulating in Brazilian swine herds. On comparing the viral sequences of diarrheagenic peptide area (amino acid 114-135), there was a single point mutation at amino acid 135 presented by two strains with amino acid alanine, and valine in the others. The NSP4 gene phylogeny showed that all strains clustered into E1 genotype, and the nucleotide identity between Brazilian strains ranged from 92.4% and 100%, while the putative amino acid identity, between 95.8% and 100%. Only one site (138aa) was positively selected and at least 119 were negatively selected. As a conclusion, these data demonstrate the occurrence of a common NSP4 genotype described elsewhere in pigs and low diversity between the samples from the surveyed areas

A proteína não estrutural 4 (NSP4) desempenha diferentes funções na replicação e na morfogênese dos rotavírus, apresentando, ainda, uma atividade de enterotoxina, causando diarreia do tipo secretória. Um total de 11 sequências parciais de nucleotídeos do gene codificador da NSP4 de rotavírus suínos de criações brasileiras foram definidas como pertencentes ao grupo A. Comparando-se as sequências virais da área do peptídeo toxigênico, que compreende a porção entre os aminoácidos de 114 a 135, constatou-se uma única mutação pontual no aminoácido 135, sendo que duas amostras apresentaram alanina, e as demais, valina. A análise filogenética do gene demonstrou que todas as amostras pertencem ao genotipo E1, e que a identidade nucleotídica das amostras brasileiras variou de 92,4% a 100%, enquanto que a identidade de aminoácidos, de 95,8% a 100%. Apenas um resíduo (aa 138) sofreu seleção positiva enquanto que pelo menos outros 119 apresentam seleção negativa. Assim, esses dados mostram a ocorrência de um genotipo comum da NSP4 já descrito anteriormente em suínos, com uma baixa diversidade entre as amostras encontradas

Molecular analysis of NSP4 coding gene of porcine rotavirus in Brazil / Análise molecular do gene codificador da NSP4 de rotavírus suínos no Brasil

The non-structural protein 4 (NSP4) has different roles in rotaviral replication, morphogenesis, and enterotoxin-like activity causing secretory diarrhea. A total of 11 partial nucleotide sequences of NSP4 coding gene were defined from group A rotavirus circulating in Brazilian swine herds. On comparing the viral sequences of diarrheagenic peptide area (amino acid 114-135), there was a single point mutation at amino acid 135 presented by two strains with amino acid alanine, and valine in the others. The NSP4 gene phylogeny showed that all strains clustered into E1 genotype, and the nucleotide identity between Brazilian strains ranged from 92.4% and 100%, while the putative amino acid identity, between 95.8% and 100%. Only one site (138aa) was positively selected and at least 119 were negatively selected. As a conclusion, these data demonstrate the occurrence of a common NSP4 genotype described elsewhere in pigs and low diversity between the samples from the surveyed areas(AU)

A proteína não estrutural 4 (NSP4) desempenha diferentes funções na replicação e na morfogênese dos rotavírus, apresentando, ainda, uma atividade de enterotoxina, causando diarreia do tipo secretória. Um total de 11 sequências parciais de nucleotídeos do gene codificador da NSP4 de rotavírus suínos de criações brasileiras foram definidas como pertencentes ao grupo A. Comparando-se as sequências virais da área do peptídeo toxigênico, que compreende a porção entre os aminoácidos de 114 a 135, constatou-se uma única mutação pontual no aminoácido 135, sendo que duas amostras apresentaram alanina, e as demais, valina. A análise filogenética do gene demonstrou que todas as amostras pertencem ao genotipo E1, e que a identidade nucleotídica das amostras brasileiras variou de 92,4% a 100%, enquanto que a identidade de aminoácidos, de 95,8% a 100%. Apenas um resíduo (aa 138) sofreu seleção positiva enquanto que pelo menos outros 119 apresentam seleção negativa. Assim, esses dados mostram a ocorrência de um genotipo comum da NSP4 já descrito anteriormente em suínos, com uma baixa diversidade entre as amostras encontradas(AU)

Visceral lesion induced experimentally by an artrotropic strain of reovirus in broiler (Gallus gallus) / Lesões viscerais induzidas experimentalmente pela inoculação de uma amostra artrotrópica de reovírus em frangos de corte (Gallus gallus)

This paper describes visceral lesions induced by inoculation of one-day-old broiler chicks with an avian reovirus strain (S-1133) by oral and foodpad routes. The bursa of Fabricius, intestine, liver, spleen and heart of five birds from inoculated and control groups were collected in the periods of 24, 48, 72 hours and at weekly intervals from 1 to 8 weeks post inoculation for histopathological examination. Interstitial myocarditis was observed 48 hours post inoculation, pericarditis and necrotic myocarditis were seen in the first week post inoculation. The pericardium presented lymphoid follicles at 2 weeks post inoculation and in the subsequent periods there was progressive fibrosis seen until 8 weeks post inoculation. In the liver, infiltration of heterophils and mononuclear cells was observed 72 hours post inoculation, followed by degeneration and necrosis of hepatocytes at one week post inoculation. Lymphoid follicles and heterophilic infiltration were seen from 2 to 8 weeks post inoculation. The spleen presented a progressive necrosis from 48 hours to one week post inoculation and at 2 weeks post inoculation hyperplasia lymphoid was observed in the splenic tissue. No lesions were seen in the other examinated organs. Visceral lesions were similar occurring simultaneously in both inoculated groups, nevertheless the lesions were more severe in the group inoculated via footpad

Este trabalho descreve as lesões viscerais induzidas pela inoculação oral e podal de uma amostra artrotrópica de reovírus aviário (S-1133) em pintos de corte de um dia de idade. Realizou-se o exame histopatológico de fragmentos da Bursa de Fabricius, intestinos, fígado, baço e miocárdio utilizando-se cinco aves dos grupos inoculados e do grupo controle, nos períodos de 24, 48, 72 horas e semanalmente até a oitava semana após a inoculação. No miocárdio, observou-se miocardite intersticial 48 horas pós-inoculação, miocardite necrótica e pericardite na primeira semana após a inoculação. Houve no pericárdio, na segunda semana após a inoculação, a formação de folículos linfóides e seu espessamento fibroso em períodos subseqüentes até a oitava semana. No fígado, foi observado um infiltrado inflamatório misto 72 horas após a inoculação e degeneração vacuolar e necrose dos hepatócitos na primeira semana pós-inoculação. Observou-se, ainda, a presença de tecido linfóide ativo e de infiltrado heterofílico na segunda semana após a inoculação, persistindo até o final do experimento. Verificou-se necrose progressiva do tecido esplênico de 48 horas até a primeira semana após a inoculação e a partir da segunda semana observou-se hiperplasia dos folículos linfóides esplênicos. Os demais órgãos examinados não apresentaram alterações. As lesões viscerais foram similares ocorrendo simultaneamente

Articular lesion in experimental infeccion with avian reovirus in broiler (Gallus gallus) / Lesões articulares em frangos de corte (Gallus gallus) na infecção experimental pelo reovírus aviário

This paper describes articular lesions induced by inoculation of one-day-old broiler chicks with an avian reovirus strain (S-1133) by oral and foodpad routes. The hock joint of five birds from inoculated and control groups were collected in the periods of 24, 48, 72 hours and at weekly intervals from 1 to 8 weeks post inoculation for histopathological examination. The first inflammatory changes were seen in tendon sheaths one week post inoculation. On the second week postinoculation there were fibroplasia, formation of lymphoid follicles and sinovial membrane cells hyperplasia, progressive lesions seen until the end of experiment. The articular lesions were similar occurring simultaneously in both inoculated groups, nevertheless the lesions were more severe in the group inoculated via footpad.

Este trabalho descreve as lesões articulares induzidas pela inoculação oral e podal de uma amostra de reovírus aviário (S-1133) em pintos de corte de um dia de idade. Realizou-se o exame histopatológico de fragmentos da articulação tibiotársica utilizando-se cinco aves dos grupos inoculados e grupo controle nos períodos de 24, 48, 72 horas e semanalmente até a oitava semana após a inoculação. A primeira alteração observada foi um infiltrado inflamatório misto nas bainhas tendinosas uma semana após a inoculação. Na segunda semana após a inoculação, houve fibroplasia, formação de folículos linfóides e hiperplasia das células da membrana sinovial, alterações progressivas observadas até o final do período experimental. As lesões articulares foram similares, ocorrendo simultaneamente nos dois grupos inoculados, contudo as alterações foram mais severas no grupo inoculado no coxim plantar.