Sodium dodecyl sulfate as a viral inactivator and future perspectives in the control of small ruminant lentiviruses / Emprego do dodecil sulfato de sódio como inativador viral e suas perspectivas no controle de lentivírus de pequenos ruminantes

Infections by small ruminant lentiviruses (SRLVs) affect goats and sheep causing chronic multisystemic diseases that generate great economic losses. The caprine lentivirus (CLV) and the ovine lentivirus (OLV) present tropism for cells of the monocyte/macrophage lineage, which are directly associated with the main route of transmission through the ingestion of milk and colostrum from infected animals. In this manner, controlling this route is of paramount importance. Currently, researches have investigated the use of chemical additives in milk that can preserve colostrum or milk and inactivate microbiological agents. Among the compounds, sodium dodecyl sulfate (SDS) has been shown to be satisfactory in the chemical inactivation of HIV and CLV in milk, and also as a biocide in goat colostrum.(AU)

As lentiviroses de pequenos ruminantes (LVPRs) são infecções que afetam caprinos e ovinos, causando doenças multissistêmicas crônicas, ocasionando grandes perdas econômicas. Os agentes causadores, lentivírus caprino (LVC) e o lentivírus ovino (LVO), apresentam tropismo por células da linhagem monocítico--fagocitária, as quais estão diretamente associadas à principal via de transmissão, por meio da ingestão de leite e colostro provindos de animais infectados. Desse modo, o controle por esta via é de suma importância. Atualmente, pesquisas vêm sendo desenvolvidas para o uso de aditivos químicos no leite, que possam conservar o colostro ou leite, e inativar agentes microbiológicos presentes. Dentre estes, o dodecil sulfato de sódio (SDS) vem apresentando resultados satisfatórios na inativação química do HIV e LVC em leite, e ainda como biocida em colostro caprino.(AU)

Transmissibilidade de Lentivírus de Pequenos Ruminantes para cabritos e cabras adultas por meio de sêmen infectado experimentalmente / Transmissibility of Small Ruminants Lentivirus in kids by experimentally infected semen

A Artrite Encefalite Caprina se caracteriza por ser multissistêmica e infecciosa, causada por um lentivírus. O estudo teve como objetivo avaliar a transmissibilidade do Lentivírus Caprino, para fêmeas e sua prole, por meio de sêmen infectado experimentalmente. Para tanto, onze fêmeas livres de CAEV foram inseminadas artificialmente com sêmen de bode livre de CAEV ao qual foi adicionado CAEV-Cork para obter título infectante com carga viral em 105 TCID50/ml. (grupo experimental 1). Destas, seis obtiverem prenhez confirmada, e a sua prole (n=6) constituiu o grupo experimental 2. Duas cabras livres de CAEV foram inseminadas artificialmente com sêmen do mesmo bode, sem o inócuo viral, constituindo-se o grupo controle. O diagnóstico da infecção pelo Lentivírus Caprino, foi realizado por IDGA, cELISA e nested-PCR. As fêmeas foram monitoradas durante 210 dias pós inseminação artificial. Já as proles foram imediatamente separadas das mães após o nascimento, e monitoradas nos momentos hora zero, aos quinze dias de idade e mensalmente, até doze meses de idade. Em relação às cabras, 56,96%(9/158) apresentaram positividade para cELISA, 24,05% (38/158) foram positivas a IDGA e nenhuma para nested-PCR. Em relação aos cabritos, 11,28% (15/133) amostras positivas para nested-PCR, 5,26% (7/133) amostras positivas para IDGA e nenhum para cELISA. As proles do grupo controle apresentaram resultados negativos para as três técnicas. A positividade encontrada em nested-PCR pode indicar grande importância para identificação de animais infectados, porém soronegativos, em situações de soroconversão tardia. De acordo com os resultados, concluiu-se que há a transmissão do Lentivírus caprino para a prole e para as mães pelo sêmen infectado.(AU)

Caprine Arthritis Encephalitis is a multisystemic infectious disease, caused by a lentivirus. The objective of this study was to evaluate the transmissibility of caprine lentivirus to goats and their offspring, through experimentally infected semen. Therefore, eleven free-CAEV goats were artificially inseminated using semen from a free-CAEV buck experimentally infected with CAEV-Cork strain (experimental group one). Pregnancy was confirmed in only six goats and their offspring (n=6) constituted the experimental group two. Two free-CAEV females were artificially inseminated with semen from the same seronegative buck, without viral inoculum to constitute the control group. The diagnosis of caprine lentivirus infection was performed using AGID, cELISA and nested-PCR. All females were monitored for 210 days after artificial insemination. Kids were immediately separated from their mothers after birth, and monitored at zero time, 15 days old and monthly until 12 months old. Regarding goat samples, 56.96% (9/159) were positive in cELISA, 24.05% (38/158) were positive in IDGA and none was positive in nested-PCR. Regarding to the offspring samples, 11.28% (15/133) and 5.26% (7/133) were positive in nested-PCR and IDGA, respectively, while no sample was positive in cELISA. The control group showed no positives in the three techniques. The positivity observed to nested-PCR may show its importance to identify infected, but seronegative animals, in late seroconversion situations. According to results, the transmission of caprine lentivirus to offspring and their mothers through infected semen is possible.(AU)

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.

Prevalência da infecção por lentivírus de pequenos ruminantes em caprinos em Teresina, Piauí / Prevalence of small ruminants lentiviruses infection in goats from Teresina, Piauí, Brazil

The prevalence of anti-lentiviruses antibodies of small ruminants was investigated in goat herds in the city of Teresina, PI, Brazil. A seroepidemiological survey was conducted involving 480 animals, apparently healthy, belonging to six rural properties. The diagnostic test was the agar gel immunodiffusion (AGID), using antigens produced from cellular cultures infected with caprine arthritis encephalitis virus (CAEV Cork). Prevalences by gender and age were estimated considering sampling fractions for each farm. A general prevalence of 4.2 percent, was observerved, being 4.2 percent for females and 3.6 percent for males. Prevalences were higher among older goats. Regarding the breed standard, 23.5 percent were of the Anglo Nubian, 5.9 percent of the Boer, 35.3 percent Anglo Nubian x Boer crossbred, and 35.3 percent of undefined breed. It is concluded that small ruminant lentiviruses are endemic among goat herds of Teresina.