Prevalence, molecular detection, and pathological characterization of small ruminant lentiviruses in goats from Mexico

Small ruminant lentiviruses (SRLVs) exist as populations of closely related genetic variants, known as quasispecies, within an individual host. The privileged way of SRLVs transmission in goats is through the ingestion of colostrum and milk of infected does. Thus, characterization of SRLV variants transmitted through the milk, including milk epithelial cells (MEC), may provide useful information about the transmission and evolution of SRLVs. Therefore, the aim of this study was to detect SRLVs in peripheral blood leukocytes (PBLs) and milk epithelial cells of goats naturally infected with SRLVs and perform single nucleotide variations analysis to characterize the extent of genetic heterogeneity of detected SRLVs through comparison of their gag gene sequences. Blood and milk samples from 24 seropositive goats were tested in this study. The double immunolabeling against p28 and cytokeratin demonstrated that milk epithelial cells originated from naturally infected goats were infected by SRLVs. Moreover, PCR confirmed the presence of the integrated SRLVs proviral genome indicating that MECs may have a role as a reservoir of SRLVs and can transmit the virus through milk. The blood and MEC derived sequences from 7 goats were successfully sequenced using NGS and revealed that these sequences were genetically similar. The MEC and blood-derived sequences contained from 3 to 30 (mean, 10.8) and from 1 to 10 (mean, 5.4) unique SNVs, respectively. In five out of seven goats, SNVs occurred more frequent in MEC derived sequences. Non-synonymous SNVs were found in both, PBLs and MEC-derived sequences of analyzed goats and their total number differed between animals. The results of this study add to our understanding of SRLVs genomic variability. Our data provides evidence for the existence of SRLVs quasispecies and to our knowledge, this is the first study that showed quasispecies composition and minority variants of SRLVs present milk epithelial cells.

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Genetic characterization of small ruminant lentiviruses circulating in naturally infected sheep and goats in Ontario, Canada

Virus Research ◽

10.1016/j.virusres.2013.03.019 ◽

2013 ◽

Vol 175 (1) ◽

pp. 30-44 ◽

Cited By ~ 18

Author(s):

Lisa A. Santry ◽

Jondavid de Jong ◽

Alexander C. Gold ◽

Scott R. Walsh ◽

Paula I. Menzies ◽

...

Keyword(s):

Small Ruminant ◽

Genetic Characterization ◽

Infected Sheep ◽

Sheep And Goats ◽

Small Ruminant Lentiviruses

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Phylogenetic Analysis of Belgian Small Ruminant Lentiviruses Supports Cross Species Virus Transmission and Identifies New Subtype B5 Strains

Pathogens ◽

10.3390/pathogens9030183 ◽

2020 ◽

Vol 9 (3) ◽

pp. 183 ◽

Cited By ~ 3

Author(s):

Rodolphe Michiels ◽

Nadjah Radia Adjadj ◽

Nick De Regge

Keyword(s):

Small Ruminant ◽

Genetic Characterization ◽

Control Program ◽

Sequence Information ◽

Sheep And Goats ◽

Goat Population ◽

Depth Analysis ◽

Small Ruminant Lentiviruses

Small ruminant lentiviruses (SRLV) are a group of highly divergent viruses responsible for global and fatal infections in sheep and goats. Since the current phylogenetic classification of these viruses was proposed in 2004, it nowadays consists out of 5 genotypes and 28 subtypes. In support of our national SRLV control program, we performed the genetic characterization of SRLV strains circulating in the Belgian sheep and goat population. Fourteen sheep and 9 goat strains were sequenced in the gag-pol and pol regions using the method described by Shah. Most SRLV strains from sheep and goats belonged to prototype A1 and B1 subtypes, respectively. We, however, also found indications for cross-species transmission of SRLV strains between sheep and goats and vice versa, and identified a new subtype designated as B5. An in-depth analysis of the current SRLV phylogeny revealed that many subtypes have been defined over the years based on limited sequence information. To keep phylogeny as a useful tool, we advocate to apply more rigorous sequencing standards to ensure the correct classification of current and new emerging strains. The genetic characterization of Belgian SRLV strains will help in the development of appropriate diagnostic tools to assist the national control program.

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