This study was conducted in order to evaluate the transmission of caprine lentivirus to sheep using different experimental groups. The first one (colostrum group) was formed by nine lambs receiving colostrum from goats positive for small ruminant lentiviruses (SRLV). The second group (milk group) was established by nine lambs that received milk of these goats. Third was a control group, consisting of lambs that suckled colostrum and milk of negative mothers. Another experimental group (contact group) was formed by eight adult sheep, confined with two naturally infected goats. The groups were monitored by immunoblotting (IB), enzyme-linked immunosorbent assay (ELISA), agar gel immunodiffusion (AGID) and nested polymerase chain reaction (nPCR). All lambs that suckled colostrum and milk of infected goats and six sheep of the contact group had positive results in the nPCR, although seroconversion was detected only in three of the exposed animals, with no clinical lentiviruses manifestation, in 720 days of observation. There was a close relationship between viral sequences obtained from infected animals and the prototype CAEV-Cork. Thus, it was concluded that SRLV can be transmitted from goats to sheep, however, the degree of adaptation of the virus strain to the host species probably interferes with the infection persistence and seroconversion rate.
Small ruminant lentiviruses, caprine arthritis encephalitis virus, and Maedi-Visna virus cause diseases that result in significant productive losses, mostly in dairy animals. These viruses belong to the Retroviridae family, Lentivirus genus, and constitute a heterogeneous group, which may generate implications for the diagnosis and control of small ruminant lentiviruses. Losses caused by them are associated with reproductive failure, short productive life, and decreased milk production by the infected animals. In addition, these viruses may reduce milk quality, affecting the production of dairy products such as cheese. Small ruminant lentiviruses lead to indirect losses, decreasing herd value and forcing the development of epidemiological trade barriers for animal germplasm. Control of small ruminant lentiviruses is important to promote optimal milk production and to reduce costs with medicine and technical assistance. This control may vary in caprine and ovine populations of each country, according to seroprevalence, variety of breeds, and peculiarities of the practiced management.
The aim of this study was to evaluate in vitro and in vivo the effect of sodium dodecyl sulfate (SDS) on the caprine lentivirus (CLV) in colostrum and milk. This was performed to develop a practical and efficient method of blocking the lactogenic transmission of the virus. In the in vitro experiment, colostrum and milk were treated with 0.25%; 0.50% and 1% SDS. Then, somatic cells of colostrum and milk were submitted to co-culture with caprine synovial membrane cells (CSM). In the in vivo test, goats were fed with colostrum and milk provided from CLV-positive goats treated with SDS in the same concentrations used in the in vitro experiment. Animals were tested by nested polymerase chain reaction (nPCR) and Western blot (WB) assays. In the in vitro experiment, inhibitory activity against CLV without inactivation occurred in colostrum with all SDS concentrations. However, concentrations of 0.25 and 0.5% SDS presented only inhibitory activity against CLV in milk cells, and 1% concentration provided inactivation of the virus. In the in vivo tests, none of the three concentrations of SDS was effective in inactivating LVC in colostrum or goat milk, which was confirmed by seroconversion and presence of proviral DNA in animals afterwards.
The objective of this experiment was to evaluate the efficacy of iodine tincture at 10% and sodium hypochlorite at 2.5% applied into the abscess of animals affected by Caseous Lymphadenitis (CL). Eighteen ewes were used, assorted into three groups: one treated with iodine tincture at 10% (IT), another one with sodium hypochlorite at 2.5% (SH) and the last group underwent the conventional treatment (CT). Conventional treatment was based on surgical drainage and chemical cauterization of the lesion with iodine tincture at 10%. Natural rupture of six abscesses from IT group was observed and in five of them the viability of Corynebacterium pseudotuberculosis was confirmed on the lesion place, after rupture of lymph node. As for the SH group, spontaneous rupture was observed in five out of six abscesses treated, and the microorganism was identified on the lesion of five animals, after rupture. In the sixth animal of this group, abscess involution was noticed. A severe swelling was identified in the region of lymph node treated, resulting in wide lesion in animals from groups IT and SH. No difference (p > 0,05) was found in blood parameters due to treatments. As for the serological monitoring of animals, comparative analysis between months within each group showed that months 1, 2, 3 and 4 were different (p < 0,05) from month 0, for groups IT and SH. For CT group, there was no difference (p > 0,05) between months 1 to 5 and 0. Then, the application of iodine tincture at 10% or sodium hypochlorite at 2.5% into the abscess of animals affected by CL, at stage in which lesions are detected through inspection, is not effective for its control.
Resumo: Vários estudos têm confirmado diferenças fisiológicas entre a glândula mamária caprina e a bovina, demonstrando que devem ser realizadas adaptações para caprinos, determinando escores que melhor reflitam o verdadeiro estado sanitário da glândula mamária nesta espécie. O objetivo deste estudo foi correlacionar os resultados do Califórnia Mastitis Test (CMT), da contagem de células somáticas (CCS) e do exame bacteriológico do leite de caprinos e comparar com os padrões existentes na literatura. Foram utilizadas 23 fêmeas da raça Saanen pertencentes a Embrapa Caprinos e realizados exame clínico dos animais e teste da caneca telada, sendo que nenhum animal apresentava sintomas de mastite clínica. Posteriormente realizou-se o CMT, a coleta de leite para a contagem de células somáticas e exame microbiológico. Para a análise estatística foi utilizado o programa Assistat 7.5. Não foi observada diferença estatística significativa entre os escores 3+ e 2+ ou entre os escores 1+, traços e 0 do CMT, quando correlacionado com o exame microbiológico. A reação 3+ foi estatisticamente diferente (p<0,01) das reações 1+, traços e 0. Considerando o valor de 1120 x 10 3 céls/mL como o limite máximo de células no leite caprino, foi demonstrada diferença altamente significativa (p<0,001) entre as amostras microbiologicamente positivas e negativas. Quanto à correlação entre a CCS e o CMT, foi constatada diferença significativa (p<0,05) somente entre os escores 0 e 3+ do CMT.
Animal agglomerations at commercial events such as trade fairs represent an important facilitator in infectious disease transmission. Thus, it is crucial to understand the epidemiology of infectious diseases in small ruminants. The objective of this study was to examine lentiviral presence in goats and sheep traded at the animal fair of Tabira city (Sertão region of Pernambuco) and identify possible risk factors associated with infection. We collected serum samples from 233 crossbred goats and 119 crossbred sheep, belonging to 12 breeders, at the Tabira livestock fair from November 2014 to June 2015. An epidemiological questionnaire was used to analyze the risk factors. Agar gel immunodiffusion (AGID) and western blotting (WB) were performed to diagnose small ruminant lentivirus (SRLV) infection. In the AGID test, we used maedi-visna virus (MVV) antigens for sheep and caprine arthritis/encephalitis virus (strain Cork) (CAEV-Co) antigen for goats. The WB analysis used CAEV-Co antigen for both species. Variables from the questionnaire were analyzed with univariate and multivariate statistics. One seropositive goat but no sheep was identified via AGID. According to the WB results, 15/233 goats (6.44%; CI95% = 3.94 -10.35%) and 8/119 sheep (6.72%; CI95% = 3.45 -12.71%) were seropositive, totaling 23/352 reactive animals (6.53%; CI95% = 4.39 -9.61%) from 12 herds. Annual vermifugation of the animals was a significant risk factor (odds ratio = 5.9; CI95% = 1.7-19.8; p = 0.04) for disease in goats, but no variables associated with infection risks were identified in sheep. We concluded that SRLV was present in goats and sheep at the animal fair. Western blots were more sensitive than AGID for SRLV diagnosis. Practices aiming to improve sanitary management may reduce the risk of infection in goats. All studied herds included animals identified as seropositive for SRLV. Therefore, we recommend adopting measures that increase disease diagnosis while intensifying traffic control and surveillance of animal agglomerations.
ABSTRACT:Caprine arthritis encephalitis causes considerable losses in goat production. The main form of the caprine arthritis encephalitis virus transmission is through the ingestion of colostrum or milk from infected females. However, some transmissions cannot be explained in this manner. Therefore, this study aimed to evaluate transplacental transmission of caprine arthritis encephalitis virus. Blood samples were collected from 283 newborn kids of Anglo-Nubian and Saanen breeds born from seropositive and seronegative goats. Samples were collected immediately after birth and analyzed with agarose gel immunodiffusion and western blot. All samples were negative in the agarose gel immunodiffusion. However, the western blot test demonstrated that four kids were born positive for caprine arthritis encephalitis virus. This result indicates that although in a low frequency (1.4%), there is a possibility of transplacental transmission of small ruminant lentivirus.KEYWORDS: small ruminant lentivirus; agarose gel immunodiffusion; western blot. RESUMO:A artrite encefalite caprina causa perdas considerá-veis para a produção caprina. A principal forma de transmissão do vírus da artrite encefalite caprina é a ingestão de colostro ou leite de fêmeas infectadas. No entanto, algumas transmissões não podem ser explicadas por esta via. Dessa forma, este estudo teve como objetivo avaliar a transmissão do vírus da artrite encefalite caprina por via transplacentária (vertical). Foram realizadas coletas de sangue em 283 crias recém-nascidas das raças Anglo-Nubiana e Saanen, provenientes de progenitores soropositivos e soronegativos. As amostras foram coletadas logo após o nascimento e analisadas pelas técnicas de imunodifusão em gel de agarose e western blot. No teste de imunodifusão em gel de agarose, nenhum cabrito foi detectado reagente. Porém, no teste de western blot, quatro cabritos nasceram soropositivos. Esse resultado indica que, apesar de baixa frequência (1,4%), existe a possibilidade de transmissão via transplacentária do lentivírus de pequenos ruminantes.PALAVRAS-CHAVE: lentivírus de pequenos ruminantes; imunodifusão em gel de agarose; western blot.
With the objective of detecting the presence of caprine lentivirus (CLV) in ewe milk and in ram semen, ten matrixes and four reproducers experimentally infected with CLV were used. Samples of ewe milk were collected during the four months of lactation, five collections per animal, totaling 50 samples. Regarding the rams, eight semen collections were made per animal, during one year of experimentation, totaling 32 samples. The milk and semen samples were submitted to DNA extraction and the nested polymerase chain reaction test (nPCR) to detect CLV proviral DNA. Eight (16%) of the milk samples were positive in nPCR originating from two ewes. Only one (3.12%) semen sample was positive. The amplification products were sequenced, and were confirmed to be a CLV genomic sequence. Thus, the presence of CLV proviral DNA in sheep milk and semen was demonstrated, confirming the feasibility of infection between species, and alerting to the risk of spreading infections. Keywords: lentiviruses, transmission, cross infection RESUMO Com o objetivo de detectar a presença do lentivírus caprino (LVC) no leite de ovelhas e no sêmen de carneiros, utilizaram-se 10 matrizes e quatro reprodutores infectados experimentalmente com o LVC. Foram coletadas amostras de leite das ovelhas durante os quatro meses de lactação
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