Secció de Parasitologia, Departament de Biologia, Sanitat i Medi Ambient, Facultat de Farmàcia i Ciènces de l'Alimentació, Universitat de Barcelona, Barcelona, Spain; Institut de Recerca Biomèdica Sant Pau, Barcelona, Spain; Servei de Microbiologia, Hospital de la Santa Creu i Sant Pau Barcelona, Spain & Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Department of Botany, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
Int J Parasitol. 2020 Nov;50(13):1079-1088. doi: 10.1016/j.ijpara.2020.06.013. Epub 2020 Sep 1.
Among the 20 or so Leishmania spp. described as pathogenic for humans, those of the Leishmania donovani complex are the exclusive causative agents of systemic and fatal visceral leishmaniasis. Although well studied, the complex is taxonomically controversial, which hampers clinical and epidemiological research. In this work, we analysed 56 Leishmania strains previously identified as L. donovani, Leishmania archibaldi or Leishmania infantum, isolated from humans, dogs and sandfly vectors throughout their distribution area. The strains were submitted to biochemical and genetic analyses and the resulting data were compared for congruence. Our results show: i) a partial concordance between biochemical and genetic-based data, ii) very limited genetic variability within the L. donovani complex, iii) footprints of frequent genetic exchange along an east-west gradient, marked by a widespread diffusion of alleles across the geographical range, and iv) a large-scale geographical spreading of a few genotypes. From a taxonomic point of view, considering the absence of relevant terminology in existing classes, the L. donovani complex could be treated as a single entity.
在大约 20 种被描述为对人类具有致病性的利什曼原虫属中，利什曼原虫复合体是唯一引起系统性和致命内脏利什曼病的病原体。尽管该复合体得到了很好的研究，但在分类学上仍存在争议，这阻碍了临床和流行病学研究。在这项工作中，我们分析了从人类、狗和沙蝇媒介中分离出的 56 株先前被鉴定为利什曼原虫、利什曼原虫或利什曼原虫的利什曼原虫株。这些菌株经过生化和遗传分析，并对所得数据进行了一致性比较。我们的结果表明：i）生化和遗传数据之间存在部分一致性，ii）利什曼原虫复合体内部的遗传变异性非常有限，iii）在东西梯度上频繁的遗传交换的痕迹，由地理范围内等位基因的广泛扩散标记，iv）少数基因型的大规模地理扩散。从分类学的角度来看，考虑到现有类别中缺乏相关术语，利什曼原虫复合体可以被视为一个单一的实体。
