Abstract: The present study was conducted to assess the occurrence of anti-Brucella sp., anti-BVDV-1, and anti-Leptospira spp. antibodies from captive white-lipped peccary (Tayassu pecari). A cross-sectional survey was performed testing 100 serum samples collected in a commercial breeding herd. All samples were submitted to the acidified antigen test (AAT), virus neutralization test (VNT) and microscopic agglutination test (MAT) with live antigens. None of the samples tested agglutinated in the AAT screening test. In the VNT, 28 samples presented a cytotoxic effect and were excluded from the evaluation. For BVDV-1, only one sample (1/72; 1.38%) was positive, with antibody titers of 40. For leptospirosis, 9% (9/100) of the samples reacted to at least one of the 24 serovars tested, with 8% (8/100) positive for serovar Patoc and 1% (1/100) for serovar Grippotyphosa. The maximum titer observed was 100. The identification of antibodies against the serovars Patoc and Grippotyphosa suggests that the sampled individuals have been exposed to the pathogen at some point during their lifetime. Regarding BVDV-1, this may be the first serological survey to describe seropositive samples in tayassuids.

RESUMO: Os suínos podem ser infectados pelo vírus da diarreia viral bovina (BVDV). No entanto, as vias de transmissão entre os suínos são ainda desconhecidas. O objetivo do presente estudo foi induzir a infecção experimental de BVDV-1 em leitões desmamados e avaliar a potencial transmissão pela lâmina d’água, que ajuda na troca de calor dos suínos alojados em baias. Duas repetições do experimento (BP1 e BP2) foram realizadas com 12 animais comprovadamente livres de BVDV (n=6 por repetição) alocados em três grupos: controle, sentinelas e infectados, com dois animais cada. Os animais foram mantidos em isoladores de aço inoxidável. O grupo infectado recebeu um inóculo contendo BVDV-1, estirpe Singer. Os animais permaneceram nos isoladores durante 25 dias e, durante esse período, amostras de suabe nasal foram coletadas diariamente e sangue coletado semanalmente. No final, os animais foram eutanasiados, necropsiados e fragmentos de órgãos foram coletados para histopatologia, imuno-histoquímica e RT-PCR. No primeiro experimento (BP1), os animais infectados excretaram partículas virais entre os dias 6 e 21 pós-infecção. Quanto ao grupo sentinela, a excreção ocorreu apenas em um animal, no 20º dia pós-infecção, e a soroconversão foi observada no 25º dia pós-infecção. Na BP2, os animais infectados I3 e I4 excretaram partículas virais nos dias 4 e 21 pós-infecção, respectivamente. Apenas um animal sentinela (S3) apresentou excreção no dia 13 pós-infecção. Concluiu-se que os suínos podem se infectar com BVDV-1 e excretar partículas virais potencialmente infecciosas, sendo capazes de transmitir o vírus a outros suínos através da lâmina d’água.

ABSTRACT: Swine can be infected by bovine viral diarrhea virus (BVDV). However, transmission routes among pigs are still unknown. The objective of the present study was to induce experimental infection of BVDV-1 in weaned piglets and to assess the potential transmission through pen back pond water, used to facilitate heat exchange of the pigs housed in barns. Two repetitions (BP1 and BP 2) were performed using 12 piglets proven to be free BVDV (n=6 per repetition) allocated into three groups: control, sentinels and infected with two piglets each. The piglets were placed in stainless steel isolators. The infected group received an inoculum containing BVDV-1, Singer strain. The piglets remained in the cabinets for 25 days, during which samples of nasal swab were collected daily and blood sampled weekly. At the end, the piglets were euthanized, necropsied and organ fragments were collected for histopathology, immunohistochemistry and RT-PCR. In the first experiment (BP1) the infected animals shed the virus between days 6 and 21 post-infection. Regarding the sentinel group, shedding occurred in only one piglet, on the 20th day after infection, and seroconversion was observed on the 25th day post-infection. In BP2, infected piglets I3 and I4 shed the virus on days 4 and 21 post-infection, respectively. Only one sentinel piglet (S3) she the virus on day 13 post-infection. Therefore, it was concluded that pigs can become infected with BVDV-1 and shed potentially infectious viral particles consequently, being able to transmit the virus to other pigs through back pond water.

RESUMO: O presente estudo foi realizado com o objetivo de se determinar a ocorrência de anticorpos anti-Brucella spp. em 1.940 amostras de sangue de suínos, das quais 1.594 amostras eram de 30 granjas comerciais, de sete diferentes Estados, coletadas durante o abate dos animais, e 346 amostras de 56 criações de subsistência da região de Jaboticabal, Estado de São Paulo, Brasil. Todas as amostras foram submetidas ao teste do Antígeno Acidificado Tamponado (AAT) e consideradas positivas caso ocorresse aglutinação. Quando positivas, as amostras eram submetidas ao teste de Reação de Fixação de Complemento (RFC) como teste confirmatório. Dentre as 1.594 amostras de suínos de granjas comerciais, duas se mostraram sensíveis ao AAT, porém, quando foram submetidas à RFC, ambas apresentaram reação negativa, levando a uma porcentagem de ocorrência de 0%. Já entre as 346 amostras de criações de subsistência, duas foram positivas ao AAT, sendo que apenas uma apresentou reação positiva no teste confirmatório, cujo título foi de 1:8. Desta forma, a ocorrência foi de 0,29%, resultado importante para demonstrar a melhoria do status sanitário dos rebanhos de subsistência brasileiros, apesar das condições precárias em que vivem.

ABSTRACT: The aim of this study was to determine the occurrence of antibodies anti-Brucella in 1,940 swine blood samples. Out of the 1,940 sera samples, 1,594 were from 30 intensive pig farming from seven different states, collected during the slaughtering of animals, and 346 samples from 56 non-technified (subsistence) pig herds from Jaboticabal region, São Paulo State, Brazil. All samples were tested by Buffered Plate Acidified Antigen (BPAA) and considered positive in case of agglutination. If positive, the samples were tested by Complement Fixation Reaction (CFR) as a confirmatory test. Out of the 1,594, two were positive for BPAA but negative for CFR, so the occurrence was 0%. Among the 346 samples, two were positive for BPAA but only one was positive in the confirmatory test, whith a titer of 1:8. Thus, the occurrence was 0.29%, an important result to demonstrate the improvement of the sanitary status of Brazilian non-technified pig herds, despite the low conditions of production.