Signature patterns in region V4 of small ruminant lentivirus surface protein in sheep and goats.

The env gene in Small Ruminant Lentiviruses (SRLV) encodes the surface glycoprotein (SU) that divides into conserved (C1-C4) and variable regions (V1-V5). SRLV region V4 has been found to be homologous to the V3 region of human lentivirus (HIV). HIV V3 is responsible for tropism and the development of nervous clinical patterns when there is a tendency to conserve amino acids in specific "signature pattern" positions. The goal of this study was to identify signature patterns in the V4 region of the SU, which is encoded by the SRLV env gene. Secondarily, to understand how these signature patterns are associated with different clinical status in naturally infected sheep and goats. Starting with 244 samples from seropositive animals from nine Mexican states, we amplified the V4 region using nested PCR and obtained 49 SRLV sequences from peripheral blood leukocytes. Based on phylogenetic analysis results, we identified three groups: asymptomatic genotypes A (Ssx GA) and B (Ssx GB), as well as animals with arthritic presentation, genotype B (A GB). Similarity levels between group sequences ranged from 67.9%-86.7%, with a genetic diversity ranging from 12.7%-29.5% and a dN / dS ratio that indicated negative selection. Analyses using Vespa and Entropy programs identified four residues at positions 54, 78, 79 and 82 in SU region V4 as possible signature patterns, although with variable statistical significance. However, position 54 residues "N" (p = 0.017), "T" (p = 0.001) and "G" (p = 0.024) in groups A GB, Ssx GA and Ssx GB respectively, best characterized the signature patterns. The results obtained identified a signature pattern related to different genotypes and clinical status by SRLV in sheep and goats.

Detección de anticuerpos contra lentivirus de pequeños rumiantes en fetos ovinos y caprinos / Detection of antibodies against small ruminant lentiviruses in ovine and caprine fetuses

The presence of antibodies against Maedi-Visna (MV) and caprine arthritis encephalitis (CAE) was evaluated in ovine and caprine fetuses obtained from pregnant females slaughtered in abattoirs. Sera from 54 caprine fetuses and 65 ovine fetuses were collected and evaluated by the indirect ELISA technique. Antibodies were detected in five caprine fetuses of 80 days of gestation and in four ovine fetuses of 90 to 100 days of gestation; three caprine fetuses and two ovine fetuses of 60 to 65 days of gestation were suspicious. The possibility of uterine infection with these retroviruses is confirmed, and its consequences in current disease control and eradication strategies are discussed.

Se evaluó la presencia de anticuerpos contra los virus del Maedi-Visna (MV) y la artritis encefalitis caprina (AEC) en fetos ovinos y caprinos obtenidos de hembras gestantes sacrificadas para consumo en México. Se recolectaron sueros de 54 fetos caprinos y 65 fetos ovinos que se evaluaron mediante ELISA indirecto. Se detectaron anticuerpos en cinco fetos caprinos de 80 días de gestación y en cuatro fetos ovinos de 90 a 100 días; tres fetos caprinos y dos ovinos de 60 a 65 días de gestación resultaron sospechosos. Se confirma la posibilidad de la infección uterina por estos retrovirus y se discuten sus consecuencias en las actuales estrategias de control y erradicación de las enfermedades.