Department of Parasitology, Phramongkutklao College of Medicine, Ratchathewi, Bangkok, Thailand.
Department of Clinical Pathology, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, Thailand.
PLoS Negl Trop Dis. 2024 Aug 23;18(8):e0012445. doi: 10.1371/journal.pntd.0012445. eCollection 2024 Aug.
Opisthorchis-like eggs are a public health problem in northern and northeastern Thailand. However, the genetic epidemiology and structure of these parasites in northern Thailand are unknown. Thus, this study investigated their population genetic structure using cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) nucleotide sequences.
METHODOLOGY/PRINCIPAL FINDINGS: A study was conducted in the hill tribe regions of Chiang Mai Province, northern Thailand. Internal transcribed spacer 2 polymerase chain reaction and restriction fragment length polymorphism were used to distinguish 205 positive feces samples for Opisthorchis-like eggs. The results showed that the prevalence of O. viverrini and Haplorchis taichui was 10.5% and 38.2%, respectively, and the co-infection rate was 37.2%. To determine the genetic structure of O. viverrini and H. taichui using cox1 and nad1 genes, genetic analysis was performed using 30 randomly chosen fecal samples for Opisthorchis-like eggs. Pairwise FST analysis indicated that O. viverrini and H. taichui displayed nonsignificant genetic differentiation within Chiang Mai Province and between interpopulations from different geographic areas. Moreover, within the intrapopulation in Chiang Mai Province, cox1 presented higher gene flow than nad1 in O. viverrini, while nad1 demonstrated higher gene flow than cox1 in H. taichui. The neutrality tests based on Fu's Fs indicated population expansion and selective sweep from bottleneck or hitchhiking in O. viverrini and H. taichui populations, supported by haplotype network patterns. Phylogenetic tree analysis based on cox1 and nad1 revealed the monophyly of O. viverrini and H. taichui and genetic relationships with other isolates collected from Thailand, Lao People's Democratic Republic (PDR), and Vietnam.
CONCLUSIONS/SIGNIFICANCE: This study investigated the molecular discrimination and genetic structure of Opisthorchis-like eggs in northern Thailand. The genetic information derived from this study could be associated with the background, molecular epidemiology, and disease severity of these parasites.
在泰国北部和东北部，华支睾吸虫样卵是一个公共卫生问题。然而，这些寄生虫在泰国北部的遗传流行病学和结构尚不清楚。因此，本研究使用细胞色素 c 氧化酶亚单位 1（cox1）和 NADH 脱氢酶亚单位 1（nad1）核苷酸序列来研究其种群遗传结构。
方法/主要发现：在泰国北部清迈省的山地部落地区进行了一项研究。使用内部转录间隔区 2 聚合酶链反应和限制性片段长度多态性来区分 205 份阳性粪便样本中的华支睾吸虫样卵。结果显示，华支睾吸虫和哈氏睾吸虫的流行率分别为 10.5%和 38.2%，混合感染率为 37.2%。为了确定 cox1 和 nad1 基因中华支睾吸虫和哈氏睾吸虫的遗传结构，对 30 份随机选择的华支睾吸虫样卵粪便样本进行了遗传分析。成对 FST 分析表明，华支睾吸虫和哈氏睾吸虫在清迈省内以及不同地理区域种群之间没有表现出显著的遗传分化。此外，在清迈省内的种群内，cox1 对华支睾吸虫的基因流高于 nad1，而 nad1 对哈氏睾吸虫的基因流高于 cox1。基于 Fu 的 Fs 的中性检验表明，华支睾吸虫和哈氏睾吸虫种群经历了种群扩张和选择清扫，这得到了单倍型网络模式的支持。基于 cox1 和 nad1 的系统发育树分析表明，华支睾吸虫和哈氏睾吸虫具有单系性，并与来自泰国、老挝人民民主共和国（老挝）和越南的其他分离株具有遗传关系。
结论/意义：本研究调查了泰国北部华支睾吸虫样卵的分子鉴别和遗传结构。本研究获得的遗传信息可能与这些寄生虫的背景、分子流行病学和疾病严重程度有关。
