Colitti Barbara, Daif Soukaina, Choukri Imane, Scalas Daniela, Jerre Anniken, El Berbri Ikhlass, Fassi Fihri Ouafaa, Rosati Sergio
Department of Veterinary Science, University of Turin, Largo Braccini 2, 10095 Grugliasco, TO, Italy.
Department of Pathology and Veterinary Public Health, Agronomic and Veterinary Institute Hassan II, BP: 6202, Rabat-Institutes, Rabat 10101, Morocco.
Animals (Basel). 2024 Feb 7;14(4):550. doi: 10.3390/ani14040550.
Recent studies that investigated the origins of SRLV strains offered new insights into their distribution among domestic ruminants. The aim of the study was to investigate SRLV circulation in Morocco. A total of 51 farms were selected in different geographical locations and tested by screening and genotyping ELISA. Whole blood was used for DNA extraction and nested gag PCR. The sample size allowed for an estimation of prevalence lower than 20% (CI 95%). Surprisingly, a large proportion of screening-positive samples were not correctly serotyped. Sanger and NGS amplicon sequencing approaches allowed us to obtain new sequences even from difficult-to-amplify samples. The serological data support the evidence of an intrinsic difficulty of SRLV to spread, likely due to management practices. The low rate of success by genotyping ELISA led us to suppose that divergent strains might have escaped from diagnostic tools, as partially confirmed by the evidence of an A subtype carrying a mismatch in serotyping epitope. The sequence analysis revealed the circulation of novel B and recombinant A/B subtypes. This study highlights the importance of monitoring viral sequences and their evolution to develop specific diagnostic tests, particularly in countries where control measures are in place.
最近对绵羊和山羊反转录病毒(SRLV)毒株起源的研究为其在国内反刍动物中的分布提供了新的见解。该研究的目的是调查摩洛哥的SRLV传播情况。在不同地理位置共选择了51个农场,并通过筛选和基因分型酶联免疫吸附测定(ELISA)进行检测。使用全血进行DNA提取和巢式gag聚合酶链反应(PCR)。样本量允许估计患病率低于20%(95%置信区间)。令人惊讶的是,很大一部分筛选呈阳性的样本没有被正确血清分型。桑格测序法和二代测序(NGS)扩增子测序方法使我们即使从难以扩增的样本中也能获得新序列。血清学数据支持了SRLV传播存在内在困难的证据,这可能是由于管理措施所致。基因分型ELISA的低成功率使我们推测,不同的毒株可能逃脱了诊断工具的检测,携带血清分型表位错配的A亚型证据部分证实了这一点。序列分析揭示了新型B亚型和重组A/B亚型的传播。这项研究强调了监测病毒序列及其进化以开发特定诊断测试的重要性,特别是在已经实施控制措施的国家。