Department of Aquatic Animal Health Management, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh.
Fish Disease Laboratory, Department of Aquatic Animal Health Management, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh.
Syst Parasitol. 2024 Sep 19;101(5):62. doi: 10.1007/s11230-024-10175-y.
Parasites belonging to the trematode family Clinostomidae have a global distribution. Freshwater fish in Bangladesh frequently serve as hosts for different clinostomid species. During the metacercaria stage, the digenetic trematode Euclinostomum heterostomum exhibits a specific preference for Channidae species, where it undergoes encystment within the liver, kidneys, and muscles of these hosts. The study aimed to identify E. heterostomum in Channa punctata through combined morphological and molecular analysis. Light and scanning electron microscopy were conducted to investigate the morphological characteristics of the species. The histological examination of the infected liver tissue revealed the presence of encysted flukes, inflammatory leukocyte infiltrates, and degeneration and loosening of hepatic tissue. In molecular analysis, the generated internal transcribed spacer 1 (ITS1), 5.8S ribosomal DNA and ITS2 regions sequence (GenBank accession no: OR591452) of 830 bp showed 100% identity with Euclinostomum heterostomum identified in India (MT785786). The phylogenetic reconstruction provided substantial evidence of genetic similarities (0-1% genetic distance) among different isolates of the genus Euclinostomum, suggesting that there is a shared heritage.
隶属于裂体科的寄生虫具有全球分布。孟加拉国的淡水鱼经常作为不同的裂体科物种的宿主。在尾蚴阶段，双腔吸虫 Euclinostomum heterostomum 对 Channidae 物种表现出特定的偏好，在这些宿主的肝脏、肾脏和肌肉中形成囊蚴。本研究旨在通过结合形态学和分子分析鉴定出 Channa punctata 中的 E. heterostomum。通过光学显微镜和扫描电子显微镜观察研究了该物种的形态特征。对感染肝组织的组织学检查显示存在囊蚴、炎症性白细胞浸润以及肝组织变性和松动。在分子分析中，生成的内部转录间隔区 1（ITS1）、5.8S 核糖体 DNA 和 ITS2 区序列（GenBank 登录号：OR591452）长 830bp，与在印度鉴定的 Euclinostomum heterostomum（MT785786）具有 100%的同一性。系统发育重建提供了大量证据表明，不同 Euclinostomum 属分离株之间存在遗传相似性（0-1%遗传距离），表明存在共同的遗传遗产。
