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. 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

Vertical transmissibility of small ruminant lentivirus

“…But, although nPCR DNA detection occurred in all nine samples and their respective replicates subjected to sequencing, it is believed that the concentration of pro-viral DNA was not adequate for the viable sequencing of all replicates. Small changes in the genetic sequence of the strains studied were also observed, such as insertions and/or base changes, a fact that has already been evidenced in another study [49]. Although these changes may be related to the natural replication process, as point mutations can generally occur due to reverse transcriptase errors [50], in the present study it is believed that they were due to in vitro DNA polymerase errors, as the use of a high fidelity enzyme was not adopted.…”

“…Sequencing is a valuable tool for evidencing similarities in strains and has even been used to confirm interspecific transmission of the virus among small ruminants [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]. But, although nPCR DNA detection occurred in all nine samples and their respective replicates subjected to sequencing, it is believed that the concentration of pro-viral DNA was not adequate for the viable sequencing of all replicates.…”

Evaluation of caprine arthritis-encephalitis virus transmission in newborn goat kids

“…The horizontal form of transmission may be intensified in infected flocks if animal concentration is increased, considering that closer contact promotes higher probability of contact with secretions containing infected macrophages or monocytes. Considering that the infection of goat kids occurs through the ingestion of colostrum or milk produced by infected animals, the digestive via is considered the natural form of CAEV transmission (LAMARA et al, 2001) and may occur from goats to sheep (LIMA et al, 2017).…”

Western Blot in Immunodiagnosis of Small Ruminant Lentivirus

“…Frequentemente o material utilizado nos testes sorológicos das lentiviroses de pequenos ruminantes ou de qualquer outra enfermidade, é o soro sanguíneo, obtido a partir da centrifugação do sangue coletado do animal a ser avaliado. No entanto, em virtude da detecção do vírus em outros fluidos corporais, como, sêmen [7,29,36]; fluido uterino [19]; soro fetal [38]; saliva [75]; e leite [36], em ausência de sintomatologia, e a compartimentalização viral [59] são fatores que tem incentivado a adaptação e uso da técnica em outros tipos de amostras biológicas. Assim, amostras de plasma sanguíneo [12], e plasma seminal [49], já têm sido alvo de estudos visando a detecção de anticorpos em animais potencialmente infectados por LVPRs.…”