Vertical transmissibility of small ruminant lentivirus

Abstract

This study aimed to evaluate by means of Nested Polymerase Chain Reaction (nPCR), co-cultivation and sequencing, with genetic comparison between strains (mother/newborn), the occurrence of vertical transmission of Small Ruminant Lentiviruses (SRLV) from naturally occurring nannies infected for their offspring. For the detection of SRLV seropositive progenitors, blood was collected from 42 nannies in the final third of gestation in tubes with and without anticoagulant. The diagnostic tests used were Western Blot (WB) and nPCR. During the period of birth, the same blood collection procedure was performed on 73 newborns at zero hours of birth, with the same diagnostic tests. Seventeen blood samples from seven-day-old kids, proven positive for SRLV by nPCR, chosen at random, were subjected to coculture in goat synovial membrane (GSM) cells for 105 days. The pro-viral DNA extracted from the cell supernatant from the coculture was subjected to nPCR. For DNA sequencing from the nPCR products, nine positive samples were chosen at random, four nannies with their respective offspring, also positive. Each sample was performed in triplicate, thus generating 27 nPCR products of which only 19 were suitable for analysis. Among the 42 pregnant goats, in 50% (21/42) pro-viral DNA was detected by nPCR, while in the WB, only 7.14% (3/42) presented antibodies against SRLV. Regarding neonates, of the 73 kids, 34 (46.57%) were positive for the virus, using the nPCR technique, while in the serological test (WB), three positive animals (4.10%) were observed. The coculture of the 17 samples with a positive result in the nPCR was confirmed in viral isolation by amplification of the SRLV pro-viral DNA. When aligned, the pro-viral DNA sequences (nannies and their respective offspring) presented homology in relation to the standard strain CAEV Co. It was concluded that the transmission of SRLV through intrauterine route was potentially the source of infection in the newborn goats.

In vitro antiviral effect of ethanolic extracts from Azadirachta indica and Melia azedarach against goat lentivirus in colostrum and milk

“…Hence, the data obtained in this study performed with co-culture of SC of colostrum and SC of milk and OTE cells after use of ethanolic extracts of A. indica and M. azedarach may reveal a possible antiviral activity against CLV. This fact was observed mainly in the organic fraction of ethyl acetate, with an action time of 90 min, with marked inhibition of syncytium formation and cell destruction, which are considered the main characteristic cytopathic effects of CVL elucidated even in previous research studies, where the adoption of a qualitative evaluation through the visualization of their occurrence levels in cultured cells is standard 19,[42][43][44][45][46] .…”

Factores de riesgo asociados a la seroprevalencia de lentivirus en rebaños ovinos y caprinos del noreste de México

“…Pocos estudios se han enfocado a conocer las repercusiones del SRLV sobre la reproducción en rumiantes pequeños. Recientemente se reportó la habilidad de este virus para inducir infecciones intrauterinas en pequeños rumiantes y transmitirse vía semen ya sea con inseminación artificial o monta natural (44) . Sin embargo, no se encontró asociación entre la presencia de abortos o animales de bajo peso al nacimiento en el rebaño lo cual contrasta con estudios previos en los cuales se asoció el retraso del desarrollo de los cabritos recién nacidos con la seropositividad de la madre (37,39) .…”

Serological, Molecular and Culture-Based Diagnosis of Lentiviral Infections in Small Ruminants

“…The primary source of infection for newborn lambs is the consumption of colostrum and milk from infected ewes (lactogenic route) [ 8 , 9 ]. Horizontal transmission via respiratory secretions is also significant, especially in intensively reared small ruminants [ 10 , 11 ], whereas transplacental transmission [ 12 ] and transmission via semen during mating or artificial insemination are also possible, but their significance and extent has not been thoroughly studied [ 8 , 13 ].…”