Pathological Anatomy Section, Animal Health Department, School of Veterinary Medicine, University of Leon, via Profesor Pedro Carmenes s/n Campus de Vegazana, 24071 León, Spain.
School of Biosciences and Veterinary Medicine, University of Camerino, Via Circonvallazione 93/95, 62024 Matelica (MC), Italy.
Viruses. 2018 Jun 9;10(6):315. doi: 10.3390/v10060315.
Small Ruminant Lentiviruses (SRLVs) are widespread in many countries and cause economically relevant, slow, and persistent diseases in sheep and goats. Monitoring the genetic diversity of SRLVs is useful to improve the diagnostic tools used in the eradication programs. In this study, SRLVs detected in Spanish Assaf sheep with different grades of lymphoproliferative mastitis were sequenced. Genetic characterization showed that most samples belonged to type A and were closer to Spanish SRLV isolates previously classified as A2/A3. Four samples belonged to subtype B2 and showed higher homology with Italian B2 strains than with Spanish B2 isolates. Amino acid sequences of immuno-dominant epitopes in the gag region were very conserved while more alterations were found in the LTR sequences. No significant correlations were found between grades of mastitis and alterations in the sequences although samples with similar histological features were phylogenetically closer to each other. Broader genetic characterization surveys in samples with different grades of SRLV-lesions are required for evaluating potential correlations between SRLV sequences and the severity of diseases.
小反刍兽瘟病毒（SRLV）广泛存在于许多国家，可引起绵羊和山羊具有经济相关性的缓慢且持续的疾病。监测 SRLV 的遗传多样性有助于改进用于根除计划的诊断工具。在这项研究中，对具有不同程度淋巴增生性乳腺炎的西班牙 Assaf 绵羊中检测到的 SRLV 进行了测序。遗传特征表明，大多数样本属于 A 型，与之前分类为 A2/A3 的西班牙 SRLV 分离株更为接近。有 4 个样本属于 B2 亚型，与意大利 B2 株的同源性高于与西班牙 B2 分离株的同源性。在 gag 区免疫显性表位的氨基酸序列非常保守，而在 LTR 序列中发现了更多的改变。尽管具有相似组织学特征的样本在系统发育上彼此更接近，但在乳腺炎程度和序列改变之间未发现显著相关性。需要对具有不同程度 SRLV 病变的样本进行更广泛的遗传特征调查，以评估 SRLV 序列与疾病严重程度之间的潜在相关性。
