Department of Parasitology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
Department of Livestock Services, Dhaka, Bangladesh.
Parasitology. 2022 Sep;149(10):1339-1348. doi: 10.1017/S0031182022000580. Epub 2022 May 10.
, the causative agent of tropical fasciolosis, is a food-borne zoonotic trematode that affects around 80% livestock of Bangladesh. Triclabendazole (TCBZ), nitroxynil (NTON) and oxyclozanide (OCZN) are frequently used against fascioliasis; however, the current status of potency of these flukicides was unknown. In this study, efficacy of TCBZ, NTON and OCZN at various concentrations on has been evaluated by relative motility (RM), morphological distortions of apical cone through an inverted microscope, architectural and ultra-structural changes through histopathological and scanning electron microscopy (SEM). It is observed that TCBZ, NTON and OCZN at higher concentrations significantly ( < 0.05) reduced RM of the flukes compared to untreated control. NTON at 150 g mL was the most potent to reduce the motility within 4 h whereas TCBZ and OCZN were much delayed. Histopathological changes showed swollen, extensive cracking, numerous vacuoles and splitting of the tegument surrounding the spines; spine dislodged from its socket in treated flukes compared to untreated worms. Histopathological changes were more conspicuous at higher doses of TCBZ, NTON and OCZN. SEM has shown the disruption of the apical cone, apart from swelling of the tegument on the ventral surface corrugation and disruption of the ventral apical cone. All these changes indicate that NTON is the most potent in killing flukes among the tested flukicides and suggest the presence of TCBZ-resistant fluke populations in Bangladesh. It is imperative to explore the effects of these flukicides and subsequently their molecular mechanisms.
，引起热带片形吸虫病的病原体，是一种食源性人畜共患的吸虫，影响孟加拉国约 80%的牲畜。三氯苯达唑（TCBZ）、硝氯酚（NTON）和氧氯苯达唑（OCZN）常用于治疗片形吸虫病；然而，这些驱虫药的当前效力状况尚不清楚。在这项研究中，通过相对运动性（RM）、倒置显微镜下顶锥的形态扭曲、组织病理学和扫描电子显微镜（SEM）下的结构和超微结构变化，评估了 TCBZ、NTON 和 OCZN 在不同浓度下对的效果。结果表明，与未处理的对照组相比，较高浓度的 TCBZ、NTON 和 OCZN 显著（<0.05）降低了吸虫的 RM。150 g/mL 的 NTON 是最有效的，可在 4 小时内降低运动性，而 TCBZ 和 OCZN 则延迟很多。组织病理学变化显示肿胀、广泛破裂、大量空泡和围绕棘突的表皮分裂；与未处理的蠕虫相比，处理过的蠕虫中棘突从其插座中脱落。在较高剂量的 TCBZ、NTON 和 OCZN 下，组织病理学变化更为明显。SEM 显示了顶锥的破坏，除了腹面表皮的肿胀、波纹和腹面顶锥的破坏。所有这些变化表明，NTON 是测试的驱虫药中最有效的杀死吸虫的药物，并表明孟加拉国存在对 TCBZ 有抗性的吸虫种群。探索这些驱虫药的效果及其随后的分子机制是至关重要的。
