Abstract：
Beiji nairovirus (BJNV), in the family Nairoviridae, the order Bunyavirales, was recently reported as a causative agent of an emerging tick-borne zoonotic infection in China. This study investigated the prevalence of BJNV in ticks in Japan. Screening of over 2,000 ticks from multiple regions revealed a widespread distribution of BJNV and BJNV-related viruses in Japan, particularly in the northern island, and in other high altitude areas with exclusive occurrence of Ixodes ticks. Phylogenetic analysis identified three distinct groups of nairoviruses in ticks in Japan: BJNV, Yichun nairovirus (YCNV) and a newly identified Mikuni nairovirus (MKNV). BJNV and YCNV variants identified in ticks in Japan exhibited high nucleotide sequence identities to those in China and Russia with evidence of non-monophyletic evolution among BJNVs, suggesting multiple cross-border transmission events of BJNV between the Eurasian continent and Japan. Whole genome sequencing of BJNV and MKNV revealed a unique GA-rich region in the S segment, the significance of which remains to be determined. In conclusion, the present study has shown a wide distribution and diversity of BJNV-related nairoviruses in Ixodes ticks in Japan and has identified unique genomic structures. The findings demonstrate the significance of BJNV as well as related viruses in Japan and highlight the necessity of monitoring emerging nairovirus infections and their potential risks to public health.
摘要：
Beijinirovirus(BJNV),在Nairoviridae家族中，Bunyavirales命令,最近被报道为中国新兴的tick传播的人畜共患感染的病原体。这项研究调查了日本蜱中BJNV的患病率。对来自多个地区的2,000多个蜱进行筛查，发现BJNV和BJNV相关病毒在日本分布广泛，特别是在北部岛屿，在其他高海拔地区，仅发生Ixodes蜱。系统发育分析在日本的壁虱中确定了三个不同的nairovirus组：BJNV，伊春nirovirus(YCNV)和一种新鉴定的mikuninirovirus(MKNV)。在日本的壁虱中鉴定出的BJNV和YCNV变体与中国和俄罗斯的变体具有高核苷酸序列同一性，并有证据表明BJNV之间存在非单系进化，提示BJNV在欧亚大陆和日本之间的多个跨境传播事件。BJNV和MKNV的全基因组测序揭示了S片段中独特的富含GA的区域，其意义还有待确定。总之,本研究显示了BJNV相关的nairovirus在日本Ixodes蜱中的广泛分布和多样性，并确定了独特的基因组结构。研究结果证明了BJNV以及相关病毒在日本的重要性，并强调了监测新出现的nairovirus感染及其对公共卫生的潜在风险的必要性。
