Carla Caroline Valença de Lima

Interspecific transmission of small ruminant lentiviruses from goats to sheep

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.

Inquérito soroepidemiológico do lentivírus caprino e perfil das criações de caprinos na região do Baixo Médio São Francisco (BA)

This work aimed to determine the serological prevalence of caprine artrithis encephalitis (CAE) in the microregion of Juazeiro, in the state of Bahia, using the technique of agar gel immunodiffusion (AGID) to characterize the farming systems of the region. We collected 693 blood serum samples of goats from 46 farms in 8 different locations belonging to the municipalities forming the microregion (Campo Alegre de Lourdes, Casa Nova, Curaca, Juazeiro, Pilao Arcado, Remanso, and Sobradinho). During the visits, a questionnaire was applied emphasizing information related to health management. All of the visited properties had extensive breeding systems, with predominance of mixed breed animals, low productivity and low technology rate, aiming mainly to use the meat. The main diseases reported were caseous lymphadenitis, diarrhea, ectoparasites and keratoconjunctivitis. Concerning seroprevalence, 0.29% (2/693) of samples tested positive for AGID. The positive animals belonged to the same property in the municipality of Curaca, which showed 12.5% (1/8) of positive properties, in contrast to 2.17% (1/46) of total seroprevalence in the other visited properties. These results therefore suggest the need for new epidemiological surveys in the region, especially at a time when the importation of animals for genetic improvement is taking place.

Inquérito soro-epidemiológico de Brucella ovis em rebanhos ovinos no semiárido baiano

In order to analyze the occurrence of antibodies to Brucella ovis in sheep in a semi-arid region, this survey was conducted in the micro-region of Juazeiro, Bahia State, Brazil. The agar gel immunodifusion test (AGID) was used to examine 694 serum samples of 58 flocks. Antibodies to B. ovis were found in 5 (0.72%) of the investigated animals. It is believed that this low number of positive cases is related to the characteristics of the production. The predominant system is the extensive one, with presence of locally adapted breeds and crossbred animals, aiming at the production of meat and skin, with low productivity rates and technical development.

Caprine lentivirus in sheep milk and semen

Abstract: 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. [Lentivirus caprino em leite e semen de ovinos]. Resumo: Com o objetivo de detectar a presenca do lentivirus caprino (LVC) no leite de ovelhas e no semen 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 lactacao, ocorrendo cinco coletas por animal, totalizando 50 amostras. Quanto aos carneiros, realizaram-se oito coletas de semen por animal, durante um ano de experimentacao, totalizando 32 amostras. As amostras de leite e de semen foram submetidas a extracao de DNA e a prova de reacao em cadeia da polimerase do tipo nested (nPCR) visando a deteccao de DNA proviral do LVC. Oito (16%) amostras de leite foram positivas na nPCR oriundas de duas ovelhas. Apenas uma (3,12%) amostra de semen apresentou positividade. Produtos da amplificacao foram sequenciados, confirmando-se tratar de sequencia genomica do LVC. Dessa forma, demonstrou-se a presenca do DNA proviral do LVC em leite e semen de ovinos, confirmando a viabilidade da infeccao entre especies e, assim, alertando sobre o risco de que a infeccao seja disseminada.

Duration of passive immunity to small ruminant lentiviruses in lambs

In order to evaluate the passive immunity against small ruminant lentiviruses (SRLV) in lambs, this study was conducted from two experimental groups. The first one (G1) was established by nine lambs subjected to artificial feeding of colostrum of goats positive for SRLV. The second one (G2) was the control group, consisting of ten lambs subjected to suckling of colostrum from their negative mothers. Blood samples were obtained before the first feeding, after 24 hours of birth and at 7, 15, 30, 50, 70, 90 and 120 days of age. The concentrations of total serum protein (TSP), albumin (ALB), globulin (GLOB) and immunoglobulin G (IgG) were determined and antibodies to SRLV were surveyed from the techniques of agar gel immunodiffusion (AGID), enzyme linked immunosorbent assay (Elisa) and immunoblotting (IB). In both groups, the lowest averages of TSP, GLOB and IgG were observed at birth and the highest averages were observed at 24 hours of life, due to absorption of colostral immunoglobulins. For G1, transfer of immunity could also be detected by immunodiagnostic tests. At birth, the animals were seronegative. After 24 hours, all animals were positive in three serological tests. Negative results began to be observed after 15 days of age by the AGID test. As for Elisa testing, all animals remained reagent until 50 days old. Only IB was able to detect anti-SRLV at 70 days. Regarding G2, all animals tested negative in AGID and IB, from birth until 120 days of age. However, false-positive results were observed until day 15 in Elisa, due to nonspecific reactions. These data are consistent with the sensitivity and specificity of serological tests and show that starting at 90 days of age, colostral antibodies to SRLV are no longer detected in the serum of lambs.