Gritti Tommaso, Chicharro Carmen, Carrillo Eugenia, Solana Jose Carlos, Moreno Javier, Carra Elena, Ortalli Margherita, Morselli Sara, Gaspari Valeria, Zanazzi Margherita, Lazzarotto Tiziana, Rugna Gianluca, Varani Stefania
Department of Medical and Surgical Sciences, University of Bologna, 40138, Bologna, Italy.
WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, 28220, Majadahonda, Spain.
Infect Dis Poverty. 2025 May 26;14(1):41. doi: 10.1186/s40249-025-01309-5.
Tegumentary leishmaniasis (TL) caused by Leishmania infantum is an overlooked yet re-emerging disease endemic in Mediterranean Europe. Currently, no standardized molecular surveillance of circulating Leishmania strains is performed in European endemic areas, despite the potential public health implications of parasite biodiversity. This study aims to characterize parasite population haplogroups causing TL in two active endemic areas in southern Europe, i.e. Bologna (northern Italy) and Fuenlabrada (central Spain).
In this retrospective study, we typed 87 L. infantum samples from TL cases in the areas of Bologna and Fuenlabrada; these areas hosted the main European foci of human TL occurring in the last 15 years. Two Leishmania genomic typing targets were used: the heat shock protein 70 (Hsp70) and the cysteine peptidase b (Cpb). Simpson's index was used to calculate the discriminatory power of the used typing methods.
Typing results depicted the presence of a heterogeneous parasite population circulating in Bologna with two main haplogroups, i.e. Hsp70(A)_Cpb(F) (n = 7, 30.4%) and Hsp70(G)_Cpb(E/F) (n = 7, 30.4%), differing from the reference L. infantum strain JPCM5 haplogroup and partially overlapping with L. donovani lineages. Among the samples from Fuenlabrada, n = 19 samples were typed by both targets, revealing a homogeneous population expressing Hsp70(A) and Cpb(E), matching the JPCM5 reference strain haplogroup. Overall, the Cpb typing method exhibited higher discrimination power as compared to the Hsp70 method (Simpson's index of diversity, P-value < 0.05).
Our findings show differences among L. infantum populations causing TL in two southern European epidemiological foci of human leishmaniasis and support the recent discovery of L. infantum/L.donovani hybrid strains circulating in northern Italy. These results underscore the critical need to identify the circulating Leishmania strains in endemic areas and assess their potential public health implications in active foci.
婴儿利什曼原虫引起的皮肤利什曼病（TL）是地中海欧洲地区一种被忽视但又重新出现的地方性疾病。目前，尽管寄生虫生物多样性对公共卫生有潜在影响，但欧洲流行地区尚未对循环中的利什曼原虫菌株进行标准化的分子监测。本研究旨在对欧洲南部两个活跃流行地区，即博洛尼亚（意大利北部）和丰拉夫拉达（西班牙中部）引起TL的寄生虫种群单倍群进行特征分析。
在这项回顾性研究中，我们对来自博洛尼亚和丰拉夫拉达地区TL病例的87株婴儿利什曼原虫样本进行了分型；这些地区是过去15年中欧洲主要的人类TL疫源地。使用了两个利什曼原虫基因组分型靶点：热休克蛋白70（Hsp70）和半胱氨酸蛋白酶b（Cpb）。辛普森指数用于计算所用分型方法的鉴别力。
分型结果显示，博洛尼亚存在一个异质的寄生虫种群，有两个主要单倍群，即Hsp70(A)_Cpb(F)（n = 7，30.4%）和Hsp70(G)_Cpb(E/F)（n = 7，30.4%），与参考婴儿利什曼原虫菌株JPCM5单倍群不同，且与杜氏利什曼原虫谱系部分重叠。在丰拉夫拉达的样本中，有19个样本通过两个靶点进行了分型，显示出一个表达Hsp70(A)和Cpb(E)的同质种群，与JPCM5参考菌株单倍群匹配。总体而言，与Hsp70方法相比（多样性辛普森指数，P值<0.05），Cpb分型方法表现出更高的鉴别力。
我们的研究结果显示了在欧洲南部两个人类利什曼病流行病灶中引起TL的婴儿利什曼原虫种群之间的差异，并支持了最近在意大利北部发现的婴儿利什曼原虫/杜氏利什曼原虫杂交菌株。这些结果强调了在流行地区识别循环中的利什曼原虫菌株并评估其在活跃疫源地对公共卫生的潜在影响的迫切需求。
