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Abstract：
African swine fever virus (ASFV) causes a devastating disease affecting domestic and wild pigs. ASF was first introduced in Sardinia in 1978 and until 2019 only genotype I isolates were identified. A remarkable genetic stability of Sardinian ASFV isolates was described, nevertheless in 2019 two wild boar isolates with a sustained genomic deletion (4342 base pairs) were identified (7303WB/19, 7212WB/19). In this study, we therefore performed in vitro experiments with monocyte-derived macrophages (moMФ) to unravel the phenotypic characteristics of these deleted viruses. Both 7303WB/19 and 7212WB/19 presented a lower growth kinetic in moMФ compared to virulent Sardinian 26544/OG10, using either a high (1) or a low (0.01) multiplicity of infection (MOI). In addition, flow cytometric analysis showed that both 7303WB/19 and 7212WB/19 presented lower intracellular levels of both early and late ASFV proteins. We subsequently investigated whether deleted virus variants were previously circulating in wild boars in Sardinia. In the four years preceding the last genotype I isolation (February 2015-January 2019), other eight wild boar isolates were collected, all belonging to p72 genotype I, B602L subgroup X, but none of them presented a sustained genomic deletion. Overall, we observed the deleted virus isolates in Sardinia only in 2019, at the end of a strong eradication campaign, and our data suggest that it might possess an attenuated phenotype in vivo. A better understanding of ASFV evolution in endemic territories might contribute to development of effective control measures against ASF.
摘要：
非洲猪瘟病毒（ASFV）引起了影响家猪和野猪的毁灭性疾病。ASF于1978年首次在撒丁岛引入，直到2019年，仅鉴定出基因型I分离株。描述了撒丁岛ASFV分离株的显着遗传稳定性，然而,在2019年,我们发现了两个持续基因组缺失(4342个碱基对)的野猪分离株(7303WB/19,7212WB/19).在这项研究中,因此,我们用单核细胞来源的巨噬细胞(moMΦ)进行了体外实验,以揭示这些缺失病毒的表型特征.7303WB/19和7212WB/19与毒力撒丁岛26544/OG10相比，使用高（1）或低（0.01）感染复数（MOI）时，moMΦ的生长动力学均较低。此外,流式细胞术分析显示,7303WB/19和7212WB/19的早期和晚期ASFV蛋白的细胞内水平均较低.我们随后调查了是否删除的病毒变体以前在撒丁岛的野猪中传播。在上一次基因型I分离之前的四年中（2015年2月至2019年1月），收集了其他八种野猪分离株，全部属于p72基因型I，B602L子组X,但是他们都没有出现持续的基因组缺失。总的来说,我们仅在2019年在撒丁岛观察到删除的病毒分离株，在强大的根除运动结束时，我们的数据表明它可能在体内具有减弱的表型。更好地了解流行地区的ASFV演变可能有助于制定针对ASF的有效控制措施。
