PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Chronic pleuritis is the main reason for sending pig carcasses to the Department of Final Inspection (DIF), condemnation and led to economic losses to industries and producers. Most pleura lesions detected after slaughter are sequelae from bacterial infections by agents that do not pose risks to pork consumers. The objective of the present study was to generate science-based information for decision making in the evaluation and destination of chronic pleuritis by the Federal Inspection Service (SIF). Therefore, 200 carcasses, with and without pleurisy, from a swine slaughterhouse with SIF were assessed following the visual classification of the inspection agent. The study was carried out in two stages. In stage 1, 50 carcasses with pneumonic lesions adjacent to chronic pleuritis and 50 carcasses with only chronic pleuritis lesions were evaluated, through macroscopy, histopathology, and bacterial culture. In stage 2, 50 swine carcasses with chronic pleuritis and 50 without this lesion were sampled in the parietal pleura region to bacterial culture and PCR. The economic impact of not exporting these carcasses with chronic pleuritis was also assessed. Considering the stages of evolution of the lesions, the macroscopic examination showed high correlation with the histological examination. There was no bacterial isolation through pleural swabs, regardless of the presence or not of adjacent pulmonary lesions. Isolation was restricted to the adjacent pulmonary lesions of 70% samples, with Pasteurella multocida type A found in 48% of them, followed by P. multocida type D and Streptococcus suis in 12%, and Actinobacillus pleuropneumoniae in 3%. Only Streptococcus suis DNA was detected in 5/100 samples, with no correspondence to the isolation of viable bacteria. The reliability demonstrated in the macroscopic evaluation carried out during inspection, the absence of viable bacteria in the chronic pleural lesions, and the negative economic impact suggest that carcasses with chronic pleuritis can be submitted to pleura removal, with no need of sending to DIF.

• Slaughterhouse condemnations chronic pleurisy swine

Abstract in Portuguese:

Pleurite crônica é a principal causa do desvio de carcaças de suínos para o Departamento de Inspeção Final (DIF), podendo causar condenação e prejuízos econômicos às indústrias e produtores. A maioria das lesões de pleura detectadas após o abate são sequelas de infecções bacterianas por agentes que não oferecem riscos aos consumidores de carne suína. O objetivo do presente estudo foi gerar informações científicas para a tomada de decisão na avaliação e destino da pleurite crônica pelo Serviço de Inspeção Federal (SIF). Para tanto, 200 carcaças, com e sem pleurisia, provenientes de um frigorífico de suínos com SIF foram avaliadas seguindo a classificação visual do agente fiscalizador. O estudo foi realizado em duas etapas. No estágio 1, 50 carcaças com lesões pneumônicas adjacentes à pleurite crônica e 50 carcaças apresentando somente lesões de pleurite crônica foram avaliadas macroscopicamente, por histopatologia e cultura bacteriana. No estágio 2, 50 carcaças suínas com pleurite crônica e 50 sem esta lesão foram amostradas na região da pleura parietal para cultura bacteriana e PCR. O impacto econômico de não exportar essas carcaças com pleurite crônica também foi avaliado. Considerando os estágios de evolução das lesões, o exame macroscópico apresentou alta correlação com o exame histológico. Não houve isolamento bacteriano por meio de swabs pleurais, independentemente da presença ou não de lesões pulmonares adjacentes. O isolamento foi restrito às lesões pulmonares adjacentes de 70% das amostras, sendo Pasteurella multocida tipo A encontrado em 48% delas, seguido por P. multocida tipo D e Streptococcus suis em 12%, e Actinobacillus pleuropneumoniae em 3%. Apenas DNA de Streptococcus suis foi detectado em 5/100 amostras, sem correspondência com o isolamento de bactérias viáveis. A confiabilidade demonstrada na avaliação macroscópica realizada durante a inspeção, a ausência de bactérias viáveis nas lesões pleurais crônicas e o impacto econômico negativo sugerem que carcaças com pleurite crônica podem ser submetidas à remoção da pleura, sem necessidade de envio para DIF.

• Frigorífico condenações pleurisia crônica suínos

Abstract in English:

ABSTRACT.- Holz C.L., Cibulski S.P., Teixeira T.F., Batista H.B.C.R., Dezen D., Campos F.S., Varela A.P.M. & Roehe P.M. 2010. Serum neutralization with different types and subtypes of bovine herpesvirus 1 and 5. Pesquisa Veterinária Brasileira 30(7):515-522. Instituto de Pesquisas Veterinárias Desidério Finamor, Fepagro Saúde Animal, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@gmail.com The serum neutralization (SN) test is the gold standard method to measure neutralizing antibodies to bovine herpesviruses. However, in view of the further subdivisions of bovine herpesviruses in types/subtypes, defining which virus to use at challenge in SN tests may be difficult. In view of that, this study was carried out to re-evaluate (SN) sensitivity with different types/subtypes of bovine herpesviruses types 1 (BoHV-1) and 5 (BoHV-5) as challenge viruses. Bovine sera (n=810) were collected from two distinct geographic regions and tested by SN with three type 1 viruses (BoHV-1.1 strains “Los Angeles” and “EVI123/98”; BoHV-1.2a strain “SV265/96”) and three type 5 viruses (BoHV-5a strain “EVI88/95”; BoHV-5b strain “A663” and BoHV-5c “ISO97/95”). SN tests were performed with a 1 hour incubation of the serum-virus mixtures at 37ºC against 100 TCID50 of each of the viruses. SN sensitivity varied greatly depending on the challenge virus used in the test. The highest sensitivity (327 positive/810 total sera tested; 40.37%) was attained when the positive results to the six viruses were added together. No association could be found between any particular type or subtype of virus and the sensitivity of the test. When positive results to each single strain were considered, SN sensitivity varied from 41.7% to 81.7%, depending on the virus and the geographic region of origin of the sera. Variation was detected even when challenge viruses belonged to the same subtype, where disagreement between positive results reached 41%. These results indicate that one hour incubation SN tests against single viruses, as performed here, may display a significantly low sensitivity (p=0.05); performing SN tests against a number of different viruses may increase considerably SN sensitivity. Furthermore, the choice of virus used for challenge is critical in SN tests. In addition, sera from different geographic regions may give rise to disagreeing results with different strains of BoHV-1 and BoHV-5. This might be particularly relevant for control programs and in international trade, were maximum sensitivity should be targeted.

• BoHV-1 BoHV-5 bovine herpesvirus 1 and 5 herpesvírus bovinos 1e 5

Abstract in Portuguese:

RESUMO.- Holz C.L., Cibulski S.P., Teixeira T.F., Batista H.B.C.R., Dezen D., Campos F.S., Varela A.P.M. & Roehe P.M. 2010. Serum neutralization with different types and subtypes of bovine herpesvirus 1 and 5. [Soroneutralização com diferentes tipos e subtipos de herpesvírus bovinos 1e 5.] Pesquisa Veterinária Brasileira 30(7):515-522. Instituto de Pesquisas Veterinárias Desidério Finamor, Fepagro Saúde Animal, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@gmail.com O teste de soroneutralização (SN) é o método padrão para a mensuração de anticorpos neutralizantes para herpesvírus bovinos. Entretanto, com as subdivisões propostas destes agentes em tipos e subtipos, a definição de qual amostra utilizar como virus de desafio à SN pode ser difícil. Em vista disso, este estudo foi realizado para re-avaliar a sensibilidade de testes de SN utilizando diferentes tipos e subtipos de herpesvírus bovinos tipos 1 (BoHV-1) e 5 (BoHV-5) como amostras de desafio. Soros bovinos (n=810) foram coletados de duas regiões geográficas distintas e testados frente a amostras do tipo 1 (BoHV-1.1: amostras “Los Angeles” e “EVI123/98”, BoHV-1.2a: amostra “SV265/96”) e três amostras do tipo 5 (BoHV-5a: “EVI88/95”; BoHV-5b: “A663” e BoHV-5c “ISO97/95”). Os testes de SN foram realizados com incubação de 1 hora a 37ºC da mistura soro-vírus, frente a 100 doses infectantes para 50% dos cultivos celulares (DICC50) de cada um dos vírus. A sensibilidade da SN variou grandemente em função do vírus utilizado no teste. A maior sensibilidade (327 soros positivos/810 soros testados; 40.37%) foi alcançada quando os resultados positivos frente aos seis diferentes vírus foram somados. Nenhuma associação foi detectada entre determinado tipo/subtipo de vírus e a sensibilidade do teste. Quando resultados positivos frente a cada vírus foram considerados isoladamente, a sensibilidade da SN variou entre 41,7% a 81,7%, dependendo do vírus de desafio e da região geográfica de origem das amostras de soro. Variação foi detectada mesmo quando as amostras de desafio pertenciam a um mesmo subtipo; a discrepância entre os resultados positivos atingiu até 41%. Estes resultados indicam que testes de SN contra amostras isoladas de vírus podem apresentar uma sensibilidade notadamente baixa; o emprego de diferentes amostras de vírus de desafio pode aumentar consideravelmente a sensibilidade da prova. Além disso, a escolha da amostra de vírus para a realização do teste é crítica. Outro achado importante é que sorors de diferentes regiões geográficas podem dar resultados discordantes frente a diferentes amostras de BoHV-1 e BoHV-5. Estes achados são particularmente relevantes para programas de controle destas infecções e para o comércio internacional, onde a sensibilidade deve ser maximizada.

Abstract in English:

Abstract.- Silva A.D., Esteves P.A., Dezen D., Oliveira A.P., Spilki F.R., Campos F.S., Franco A.C. & Roehe P.M. 2009. Efficacy of a gE-deleted, bovine herpesvirus 1 (BoHV-1) inactivated vaccine. Pesquisa Veterinária Brasileira 29(7):545-551. Instituto de Pesquisas Veterinárias Desidério Finamor, Fepagro Saúde Animal, Estrada do Conde 6000, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@gmail.com Bovine herpesvirus type 1 (BoHV-1) is recognized as a major cause of economic losses in cattle. Vaccination has been widely applied to minimize losses induced by BoHV-1 infections. We have previously reported the development of a differential BoHV-1 vaccine, based on a recombinant glycoprotein E (gE)-deleted virus (265gE-). In present paper the efficacy of such recombinant was evaluated as an inactivated vaccine. Five BoHV-1 seronegative calves were vaccinated intramuscularly on day 0 and boostered 30 days later with an inactivated, oil adjuvanted vaccine containing an antigenic mass equivalent to 107.0 fifty per cent cell culture infectious doses (CCID50) of 265gE-. Three calves were kept as non vaccinated controls. On day 60 post vaccination both vaccinated and controls were challenged with the virulent parental strain. No clinical signs or adverse effects were seen after or during vaccination. After challenge, 2/5 vaccinated calves showed mild clinical signs of infection, whereas all non vaccinated controls displayed intense rhinotracheitis and shed virus for longer and to higher titres than vaccinated calves. Serological responses were detected in all vaccinated animals after the second dose of vaccine, but not on control calves. Following corticosteroid administration in attempting to induce reactivation of the latent infection, no clinical signs were observed in vaccinated calves, whereas non vaccinated controls showed clinical signs of respiratory disease. In view of its immunogenicity and protective effect upon challenge with a virulent BoHV-1, the oil adjuvanted preparation with the inactivated 265gE- recombinant was shown to be suitable for use as a vaccine.

• Bovine herpesvirus type 1 BoHV-1 recombinant vaccine inactivated vaccine

Abstract in Portuguese:

Abstract.- Silva A.D., Esteves P.A., Dezen D., Oliveira A.P., Spilki F.R., Campos F.S., Franco A.C. & Roehe P.M. 2009. Efficacy of a gE-deleted, bovine herpesvirus 1 (BoHV-1) inactivated vaccine. Pesquisa Veterinária Brasileira 29(7):545-551. Instituto de Pesquisas Veterinárias Desidério Finamor, Fepagro Saúde Animal, Estrada do Conde 6000, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@gmail.com Bovine herpesvirus type 1 (BoHV-1) is recognized as a major cause of economic losses in cattle. Vaccination has been widely applied to minimize losses induced by BoHV-1 infections. We have previously reported the development of a differential BoHV-1 vaccine, based on a recombinant glycoprotein E (gE)-deleted virus (265gE-). In present paper the efficacy of such recombinant was evaluated as an inactivated vaccine. Five BoHV-1 seronegative calves were vaccinated intramuscularly on day 0 and boostered 30 days later with an inactivated, oil adjuvanted vaccine containing an antigenic mass equivalent to 107.0 fifty per cent cell culture infectious doses (CCID50) of 265gE-. Three calves were kept as non vaccinated controls. On day 60 post vaccination both vaccinated and controls were challenged with the virulent parental strain. No clinical signs or adverse effects were seen after or during vaccination. After challenge, 2/5 vaccinated calves showed mild clinical signs of infection, whereas all non vaccinated controls displayed intense rhinotracheitis and shed virus for longer and to higher titres than vaccinated calves. Serological responses were detected in all vaccinated animals after the second dose of vaccine, but not on control calves. Following corticosteroid administration in attempting to induce reactivation of the latent infection, no clinical signs were observed in vaccinated calves, whereas non vaccinated controls showed clinical signs of respiratory disease. In view of its immunogenicity and protective effect upon challenge with a virulent BoHV-1, the oil adjuvanted preparation with the inactivated 265gE- recombinant was shown to be suitable for use as a vaccine.

Abstract in English:

ABSTRACT.- Teixeira T.F., Holz C.L., Caixeta S.P.M.B., Dezen D., Cibulski S.P., Silva J.R., Rosa J.C.A., Schmidt E., Ferreira J.C., Batista H.B.C.R., Caldas E., Franco A.C. & Roehe P.M. 2008. [Rabies diagnosis in the state of Rio Grande do Sul, Brazil, from 1985 to 2007.] Diagnóstico de raiva no Rio Grande do Sul, Brasil, de 1985 a 2007. Pesquisa Veterinária Brasileira 28(10):515-520. Instituto de Pesquisas Veterinárias Desidério Finamor, Fepagro-Saúde Animal, Cx. Postal 2076, Porto Alegre, RS 90001-970, Brazil. E-mail: proehe@ufrgs.br The results of 23 years of rabies diagnosis carried out at the Veterinary Research Institute Desidério Finamor, in the state of Rio Grande do Sul, RS, Brazil, are reported. From 1985 to 2007, a total of 23.460 specimens were examined, corresponding to 95% of the total number of samples submitted to rabies laboratory diagnosis notified within the state. Diagnostic methods included standard techniques such as the fluorescent antibody test (FAT) and mouse inoculation test (MIT). No cases of human rabies occurred in the period. Rabies virus (RV) was detected in 739 specimens (3.1%), from which 656 (88.7%) were from cattle. The virus was also identified in specimens from 23 dogs (3.1%), 21 horses (2.9%), 29 bats (4.0%), 4 cats (0.5%), 3 sheep (0.4%), 2 pigs (0.27%) and a wild animal of undetermined species (0.13%). The last case of rabies associated with a canine variant was diagnosed in 1988. Two cases of rabies associated with bat variant viruses were reported, in a domestic cat (2001) and in a dog (2007). In cattle, a marked tendency to a decrease in the number of cases was detected in the examined period. In contrast, an increase in the number of cases in haematophagous as well as in non haematophagous bats is noticed. However, as the number of bat specimens submitted for diagnosis has increased, this finding most likely reflects a higher degree of awareness on the possible role for bats in the rabies transmission cycle, rather than any particular changes on the virus or its hosts.

• Rabies epidemiology diagnosis incidence

Abstract in Portuguese:

ABSTRACT.- Teixeira T.F., Holz C.L., Caixeta S.P.M.B., Dezen D., Cibulski S.P., Silva J.R., Rosa J.C.A., Schmidt E., Ferreira J.C., Batista H.B.C.R., Caldas E., Franco A.C. & Roehe P.M. 2008. [Rabies diagnosis in the state of Rio Grande do Sul, Brazil, from 1985 to 2007.] Diagnóstico de raiva no Rio Grande do Sul, Brasil, de 1985 a 2007. Pesquisa Veterinária Brasileira 28(10):515-520. Instituto de Pesquisas Veterinárias Desidério Finamor, Fepagro-Saúde Animal, Cx. Postal 2076, Porto Alegre, RS 90001-970, Brazil. E-mail: proehe@ufrgs.br The results of 23 years of rabies diagnosis carried out at the Veterinary Research Institute Desidério Finamor, in the state of Rio Grande do Sul, RS, Brazil, are reported. From 1985 to 2007, a total of 23.460 specimens were examined, corresponding to 95% of the total number of samples submitted to rabies laboratory diagnosis notified within the state. Diagnostic methods included standard techniques such as the fluorescent antibody test (FAT) and mouse inoculation test (MIT). No cases of human rabies occurred in the period. Rabies virus (RV) was detected in 739 specimens (3.1%), from which 656 (88.7%) were from cattle. The virus was also identified in specimens from 23 dogs (3.1%), 21 horses (2.9%), 29 bats (4.0%), 4 cats (0.5%), 3 sheep (0.4%), 2 pigs (0.27%) and a wild animal of undetermined species (0.13%). The last case of rabies associated with a canine variant was diagnosed in 1988. Two cases of rabies associated with bat variant viruses were reported, in a domestic cat (2001) and in a dog (2007). In cattle, a marked tendency to a decrease in the number of cases was detected in the examined period. In contrast, an increase in the number of cases in haematophagous as well as in non haematophagous bats is noticed. However, as the number of bat specimens submitted for diagnosis has increased, this finding most likely reflects a higher degree of awareness on the possible role for bats in the rabies transmission cycle, rather than any particular changes on the virus or its hosts.