BGI-Shenzhen, Shenzhen, 518083, China.
Shenzhen Key Laboratory of Unknown Pathogen Identification, BGI-Shenzhen, Shenzhen, 518083, China.
Parasit Vectors. 2022 Mar 5;15(1):75. doi: 10.1186/s13071-022-05199-6.
Molecular markers are essential to identify Echinococcus species and genotypes in areas with multiple Echinococcus species to understand their epidemiology and pathology. Tibet Autonomous Region (TAR) is one of the areas worst hit by echinococcosis. However, molecular epidemiology is still missing among echinococcosis patients in TAR. This research explored the Echinococcus species and genotypes infecting humans in TAR and the population diversity and the possible origin of G1 in TAR.
Cyst samples were collected in one echinococcosis-designated hospital in TAR. Echinococcus species and genotypes were identified through a maximum-likelihood approach with near-complete/complete mtDNA using IQ-TREE. Phylogenetic networks were built with PopART, and the phylogeographical diffusion pattern was identified using a Bayesian discrete phylogeographic method.
Using phylogenetic trees made with near-complete/complete mtDNA obtained from 92 cysts from TAR patients, the Echinococcus species and genotypes infecting humans in TAR were identified as Echinococcus granulosus (s.s.) G1 (81, 88.04%), accounting for the majority, followed by G6 of the E. canadensis cluster (6, 6.52%), E. granulosus (s.s.) G3 (3, 3.26%), and E. multilocularis (2, 2.17%). An expansion trend and a possible recent bottleneck event were confirmed among the G1 samples in TAR. Adding the other near-complete mtDNA of G1 samples globally from the literature, we identified the possible phylogeographic origin of the G1 samples in TAR as Turkey.
Using near-complete/complete mtDNA sequences of Echinococcus spp. obtained from echinococcosis patients, a variety of Echinococcus species and genotypes infecting humans throughout TAR were identified. As far as we know, this is the first comprehensive molecular investigation of Echinococcus species and genotypes infecting humans throughout TAR. We identified, for the first time to our knowledge, the possible origin of the G1 in TAR. We also enriched the long mtDNA database of Echinococcus spp. and added two complete E. multilocularis mtDNA sequences from human patients. These findings will improve our knowledge of echinococcosis, help to refine the targeted echinococcosis control measures, and serve as a valuable baseline for monitoring the Echinococcus species and genotypes mutations and trends of the Echinococcus spp. population in TAR.
分子标志物对于在存在多种细粒棘球绦虫物种的地区识别棘球蚴物种和基因型至关重要，以便了解其流行病学和病理学。西藏自治区（TAR）是包虫病流行最严重的地区之一。然而，TAR 的包虫病患者的分子流行病学仍然缺失。本研究探讨了 TAR 地区感染人类的细粒棘球绦虫物种和基因型，以及 G1 群体的多样性和可能的起源。
在 TAR 的一家指定的包虫病医院采集囊样本。通过使用 IQ-TREE 对近乎完整/完整 mtDNA 进行最大似然法，鉴定细粒棘球绦虫物种和基因型。使用 PopART 构建系统发生网络，并使用贝叶斯离散系统发生方法确定系统发生扩散模式。
使用来自 TAR 患者 92 个囊的近乎完整/完整 mtDNA 构建的系统发生树，鉴定了 TAR 地区感染人类的细粒棘球绦虫物种和基因型为细粒棘球绦虫（s.s.）G1（81，88.04%），占大多数，其次是 E. canadensis 簇的 G6（6，6.52%）、G3（3，3.26%）和 E. multilocularis（2，2.17%）。在 TAR 的 G1 样本中证实了扩张趋势和可能的近期瓶颈事件。在添加来自文献的全球其他 G1 样本的近乎完整 mtDNA 后，我们确定了 TAR 的 G1 样本可能的起源地是土耳其。
使用从包虫病患者获得的细粒棘球绦虫属种的近乎完整/完整 mtDNA 序列，鉴定了 TAR 地区感染人类的各种细粒棘球绦虫物种和基因型。据我们所知，这是首次对 TAR 地区感染人类的细粒棘球绦虫属种进行全面的分子研究。我们首次确定了 TAR 的 G1 可能的起源地。我们还丰富了细粒棘球绦虫属的长 mtDNA 数据库，并添加了来自人类患者的两个完整的 E. multilocularis mtDNA 序列。这些发现将提高我们对包虫病的认识，有助于完善针对包虫病的控制措施，并为监测 TAR 地区细粒棘球绦虫属种的突变和种群趋势提供有价值的基线。
