Martín-Torrijos Laura, Hernández-Pérez Ariadne, Monroy-López Jorge Francisco, Diéguez-Uribeondo Javier
Department of Mycology, Real Jardín Botánico-CSIC, Plaza Murillo 2, 28014 Madrid, Spain.
Departamento de Medicina Preventiva y Salud Pública. Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica s/n, 04510, Ciudad Universitaria, México.
J Invertebr Pathol. 2023 Nov;201:108000. doi: 10.1016/j.jip.2023.108000. Epub 2023 Oct 6.
The crayfish plague is an emerging infectious disease caused by the pathogen Aphanomyces astaci (Oomycota), which is responsible for the decimation of Eurasian freshwater crayfish. This pathogen can coexist with the North American crayfish. These are chronic carriers of the disease as consequence of an immune response that can contain the growth of the pathogen without killing it. The origin of A. astaci locates in the southeastern United States and coincides with the origin of the family Cambaridae. This diverse family of decapods is distributed in North America from southern Canada to Honduras. However, only the native crayfish species from Canada and the USA have been examined for the presence of A. astaci. In this study, we describe for the first time the presence of A. astaci in Mexico in a population of the native species Cambarellus montezumae. By analyzing the small (rrnS) and large (rrnL) mitochondrial ribosomal regions, we showed the presence of two haplotypes of A. astaci within the same population (d1-haplotype and, a novel haplotype that was named, mex1-haplotype). The finding of A. astaci in Mexico confirms the occurrence of this pathogen within the range of the family Cambaridae. The individuals of C. montezumae appear to be chronic carriers of A. astaci, indicated by the lack of documented crayfish plague outbreaks in this population, similar to the pattern observed in other North American species. Thus, the results are of special concern to susceptible species of southern regions of America, i.e., Parastacidae. Therefore, this work emphasizes the need to better understand the distribution and genetic diversity of A. astaci within the distribution range of the natural carriers, i.e., North American species, especially the unexplored area of the family Cambaridae.
小龙虾瘟疫是一种由病原体阿氏卵菌（卵菌纲）引起的新出现的传染病，该病原体导致了欧亚淡水小龙虾的大量死亡。这种病原体可以与北美小龙虾共存。由于免疫反应能够抑制病原体生长而不将其杀死，北美小龙虾成为了这种疾病的慢性携带者。阿氏卵菌的起源位于美国东南部，与螯虾科的起源地一致。这个多样的十足目动物科分布于从加拿大南部到洪都拉斯的北美地区。然而，仅对来自加拿大和美国的本地小龙虾物种进行了阿氏卵菌检测。在本研究中，我们首次描述了在墨西哥本地物种蒙特祖马小螯虾种群中存在阿氏卵菌。通过分析线粒体小（rrnS）和大（rrnL）核糖体区域，我们发现同一种群内存在阿氏卵菌的两种单倍型（d1单倍型和一种新命名的单倍型mex1单倍型）。在墨西哥发现阿氏卵菌证实了该病原体在螯虾科分布范围内的存在。蒙特祖马小螯虾个体似乎是阿氏卵菌的慢性携带者，这一点由该种群中未记录到小龙虾瘟疫爆发所表明，这与在其他北美物种中观察到的模式相似。因此，这些结果对美国南部地区的易感物种，即拟螯虾科来说尤为令人担忧。所以，这项工作强调需要更好地了解阿氏卵菌在自然携带者（即北美物种）分布范围内的分布和遗传多样性，尤其是螯虾科未被探索的区域。
