State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
Yunnan Institute of Endemic Diseases Control and Prevention, Dali, China.
Commun Biol. 2023 Aug 15;6(1):847. doi: 10.1038/s42003-023-05186-2.
Plague, caused by Yersinia pestis, is a zoonotic disease that can reemerge and cause outbreaks following decades of latency in natural plague foci. However, the genetic diversity and spread pattern of Y. pestis during these epidemic-silent cycles remain unclear. In this study, we analyze 356 Y. pestis genomes isolated between 1952 and 2016 in the Yunnan Rattus tanezumi plague focus, China, covering two epidemic-silent cycles. Through high-resolution genomic epidemiological analysis, we find that 96% of Y. pestis genomes belong to phylogroup 1.ORI2 and are subdivided into two sister clades (Sublineage1 and Sublineage2) characterized by different temporal-spatial distributions and genetic diversity. Most of the Sublineage1 strains are isolated from the first epidemic-silent cycle, while Sublineage2 strains are predominantly from the second cycle and revealing a west to east spread. The two sister clades evolved in parallel from a common ancestor and independently lead to two separate epidemics, confirming that the pathogen responsible for the second epidemic following the silent interval is not a descendant of the causative strain of the first epidemic. Our results provide a mechanism for defining epidemic-silent cycles in natural plague foci, which is valuable in the prevention and control of future plague outbreaks.
鼠疫是由鼠疫耶尔森菌引起的一种人畜共患疾病，在自然鼠疫疫源地潜伏几十年后可能会再次出现并引发暴发。然而，在这些无疫情周期中，鼠疫耶尔森菌的遗传多样性和传播模式仍不清楚。在这项研究中，我们分析了 1952 年至 2016 年间在中国云南褐家鼠鼠疫疫源地分离的 356 株鼠疫耶尔森菌基因组，涵盖了两个无疫情周期。通过高分辨率的基因组流行病学分析，我们发现 96%的鼠疫耶尔森菌基因组属于 1.ORI2 进化枝，可进一步细分为两个姐妹分支（Sublineage1 和 Sublineage2），它们具有不同的时空分布和遗传多样性。大多数 Sublineage1 菌株分离自第一个无疫情周期，而 Sublineage2 菌株主要来自第二个周期，呈由西向东传播的趋势。两个姐妹分支从一个共同的祖先平行进化，并独立导致了两次独立的流行，证实了导致第二次疫情的病原体并非第一次疫情的致病菌株的后代。我们的研究结果为自然鼠疫疫源地定义无疫情周期提供了机制，这对于未来鼠疫暴发的预防和控制具有重要价值。
