寄生虫对水产养殖和渔业构成重大挑战。我们的研究重点是Polyonchobothriummagrum和非洲cat鱼,以解决水产养殖中潜在的健康问题,探索宿主-寄生虫的相互作用,可以帮助开发有效的管理实践,以确保鱼类健康和行业可持续性。从非洲cat鱼(Clariasgariepinus)的胃中分离出P.magnum作为感染的主要部位,患病率为10%。大多数受影响的鱼被严重感染(10个中有8个)。通过对烟酰胺腺嘌呤二核苷酸脱氢酶亚基1(ND1)基因的PCR靶向区域进行测序来确认感染,随着光和扫描电子显微镜。寄生虫有一个细长的scol和深bothria,比scolex本身宽的突出的顶端盘,和四瓣的外观。scolex包含一个被分成两个半圆的中央rostellum,轴承26-30个挂钩,平均28。顶端椎间盘有四个象限的大钩子,每个有6-8个钩子,平均每个象限7。没有观察到颈部。我们的序列的系统发育分析显示,与来自广州的分离株100%匹配,中国。在受感染的鱼中,前肾显示核因子κB和溶菌酶的表达水平增加,但主要组织相容性复合物抗原II的水平降低。血浆分析显示超氧化物歧化酶显著下降,白细胞介素-1β的升高,与未感染的对照相比,IgM水平较低。未感染的鱼类表现出更大的肠道微生物群多样性,主要家族包括莫拉科,肠杆菌科,梭杆菌科,和黄杆菌科,和普遍的属,如不动杆菌,细菌杆菌,还有Brevundimonas.相比之下,受感染的鱼类表现出非常低的多样性,与未感染的鱼类相比,肠杆菌科(45.99%)和气单胞菌科(41.79%)的比例明显更高,分别为13.76%和3.64%。在未感染的鱼类中,镰状芽孢杆菌很普遍,而受感染的鱼藏有流感气单胞菌,志贺洛类假单胞菌,和厦门五倍子菌。总的来说,马氏疟原虫破坏了宿主的免疫状态和肠道微生物群,从而影响其健康。
Parasites pose significant challenges to aquaculture and fisheries industries. Our study focuses on the Polyonchobothrium magnum and African catfish to address a potential health issue in aquaculture, explore host-parasite interactions that can help develop effective management practices to ensure fish health and industry sustainability. P. magnum was isolated from the stomach of African catfish (Clarias gariepinus) as the primary site of infection, with a prevalence of 10%. Most affected fish were heavily infected (8 out of 10). Infection was confirmed by sequencing the PCR-targeted region of the nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1) gene, along with light and scanning electron microscopes. The parasite had an elongated scolex with deep bothria, a prominent apical disc wider than the scolex itself, and a four-lobed appearance. The scolex contained a central rostellum divided into two semicircles, bearing 26-30 hooks, with an average of 28. The apical disc had large hooks arranged in four quadrants, with 6-8 hooks each, averaging 7 per quadrant. No neck was observed. Phylogenetic analysis of our sequence showed a 100% match with isolates from Guangzhou, China. In infected fish, the anterior kidney showed increased expression levels of nuclear factor kappa B and lysozyme, but decreased levels of in major histocompatibility complex antigen II. Plasma analysis revealed a significant drop in superoxide dismutase, a rise in interleukin-1 beta, and lower IgM levels compared to non-infected controls. Non-infected fish displayed greater gut microbiota diversity, with dominant families including Moraxellaceae, Enterobacteriaceae, Fusobacteriaceae, and Caulobacteraceae, and prevalent genera such as Acinetobacter, Cetobacterium, and Brevundimonas. In contrast, infected fish exhibited very low diversity, with significantly higher proportions of Enterobacteriaceae (45.99%) and Aeromonadaceae (41.79%) compared to non-infected fish, which had 13.76% and 3.64% respectively. Cetobacterium somerae was prevalent in non-infected fish, while infected fish harboured Aeromonas fluvialis, Plesiomonas shigelloides, and Gallaecimonas xiamenensis. Overall, P. magnum disrupted the immune status and gut microbiota of the host, thereby impacting its health.