In vitro and in vivo evaluation of sodium dodecyl sulfate (SDS) as an inactivator of caprine lentivirus (CLV) in colostrum and milk

Abstract

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.

Vertical transmissibility of small ruminant lentivirus

“…In the present study, results from nPCR and Western Blot demonstrated the occurrence of SRLV-positive neonates from mothers infected by these viral agents. These results were confirmed via cell culture, and observation of syncytia and cell destruction, which are some of the main cytopathic effects characteristic of SRLV evidenced in the literature [20,26,32,33].…”

“…After collection, the tubes without anticoagulant were centrifuged in a centrifuge at room temperature at 1500g for 10 minutes to separate the blood serum, subsequently subjected to the Western Blot test [23]. The anticoagulant tubes were destined for the extraction of deoxyribonucleic acid (DNA) according to standard methodology [26] and submitted to Nested PCR (nPCR) [27]. At birth, before ingesting colostrum, without any contact between the mother and the young, 73 kids were subjected to the same blood collection procedure, with subsequent performance of the same diagnostic tests.…”

“…Secondary cultures of goat synovial membrane (GSM) cells were obtained by explant from goat kidney proven to be negative for SRLV, followed by subcultures by trypsinization of the cells [26]. Seventeen samples of whole blood from seven-day-old kids, proven positive for SRLV by nPCR, were collected.…”

“…The extraction of pro-viral DNA from cell supernatant from co-culture was performed based on proteinase K and ethanol (Sigma-Aldrich1, USA), according to the methodology already described in the literature [26]. A first round of nPCR was performed, followed by a second round in order to amplify a final fragment of 185 base pairs (bp) of pro-viral DNA, which corresponds to the SRLV gag gene.…”

Western Blot in Immunodiagnosis of Small Ruminant Lentivirus

“…Outra forma de transferência proteica entre gel e MN é a passiva, em que ocorre a pressão física, por meio de pesos de aproximadamente 2 kg durante 72 horas [23]. Para o diagnóstico dos LVPRs são utilizadas ambas formas de transferências proteica: a forma passiva [23,71] e por meio de Eletroblotting [37,61,73].…”