Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary.
Department of Exotic Animal and Wildlife Medicine, University of Veterinary Medicine, Budapest, Hungary.
Parasitol Res. 2019 Oct;118(10):2811-2817. doi: 10.1007/s00436-019-06441-4. Epub 2019 Sep 7.
The main fish host reaction to an infection with third stage anisakid nematode larvae is a response in which host immune cells (macrophages, granulocytes, lymphocytes) in affected internal organs initially are attracted to the parasite whereafter fibroblasts may enclose the parasite forming granuloma. Generally, the reaction is non-lethal to the parasite which may survive for years in the fish host retaining infectivity to the final host. This may also apply for the anisakid nematode Contracaecum rudolphii (having the adult stage in cormorants, using copepods as first intermediate/paratenic host and zooplankton feeding fish as paratenic hosts). The present study has shown that most Contracaecum rudolphii larvae survive in bream (Abramis brama) (from Lake Balaton, Hungary) whereas the majority of the nematode larvae die in Cyprinus carpio (from Lake Hévíz, directly connected to Lake Balaton). Both cyprinid host species interacted with the nematode larvae through establishing a marked cellular encapsulation around them but with different effects. The differential survival in common carp and bream may theoretically be explained by ecological factors, such as the environmental temperature which either directly or indirectly affect the development of nematode larvae, and/or intrinsic host factors, such as differential immune responses and host genetics.
鱼类宿主对第三期异形科线虫幼虫感染的主要反应是一种宿主免疫细胞（巨噬细胞、粒细胞、淋巴细胞）在受影响的内脏器官中最初被寄生虫吸引的反应，随后成纤维细胞可能包围寄生虫形成肉芽肿。通常，这种反应对寄生虫是非致命的，寄生虫可能在鱼类宿主中存活多年，并保持对终宿主的感染力。这也可能适用于异形科线虫 Contracaecum rudolphii（在鸬鹚中有成虫阶段，以桡足类作为第一中间/副宿主，以浮游动物摄食鱼类作为副宿主）。本研究表明，大多数 Contracaecum rudolphii 幼虫在鲤鱼（来自匈牙利的巴拉顿湖）中存活，而大多数线虫幼虫在鲤鱼（直接连接到巴拉顿湖的黑维兹湖）中死亡。两种鲤鱼宿主都通过在寄生虫幼虫周围建立明显的细胞包裹来与寄生虫幼虫相互作用，但效果不同。鲤鱼和鲤鱼的存活率差异理论上可以用生态因素来解释，例如环境温度，它直接或间接影响线虫幼虫的发育，以及/或内在宿主因素，如不同的免疫反应和宿主遗传。
