Williams C F, Poddubnaya L G, Scholz T, Turnbull J F, Ferguson H W
Environment Agency, Bromholme Lane, Brampton, Cambridgeshire PE28 4NE, UK.
Dis Aquat Organ. 2011 Dec 6;97(2):143-54. doi: 10.3354/dao02406.
Monobothrium wageneri is a monozoic caryophyllidean tapeworm of tench Tinca tinca. The pathological changes caused by this parasite within the intestinal tract of wild tench are described for the first time. Parasites were found attached to the anterior third of the intestine in tight clusters comprising up to 109 tapeworms. Infection was associated with the formation of raised inflammatory swellings surrounding the parasites. This host response, combined with the deep penetration of the scolex into the gut wall, formed a very firm seat of parasite attachment. Histopathological changes were characterised by a pronounced fibrogranulomatous lesion that extended through all layers of the intestine. This was accompanied by haemorrhage, oedema, necrosis and degeneration of the muscularis. A marked eosinophilic interface layer between the scolex of the tapeworm and gut wall indicated intimate host-parasite contact. Ultrastructural examinations revealed coniform spinitriches covering the neck and lateral sides of the scolex and capilliform filitriches present on the apical end of the scolex. Numerous glandular cytons (tegumental glands) were recorded throughout the scolex tegument. Large numbers of secretory granules discharged from the glands through a network of processes onto the scolex surface were consistent with distancing the cellular responses of the host. Observations of severe inflammatory lesions, partial intestinal occlusion and the potential for intestinal perforation represent important pathological changes that are consistent with loss of normal gut function. The lesions associated with the attachment of M. wageneri are more severe than those recorded for any other tapeworm of British freshwater fish.
瓦氏单槽绦虫是丁鱥的一种单殖类叶形绦虫。首次描述了这种寄生虫在野生丁鱥肠道内引起的病理变化。发现寄生虫附着在肠道前三分之一处，紧密聚集，多达109条绦虫。感染与寄生虫周围炎性肿胀的形成有关。这种宿主反应，加上头节深深侵入肠壁，形成了寄生虫非常牢固的附着部位。组织病理学变化的特征是明显的纤维肉芽肿病变，贯穿肠道各层。同时伴有出血、水肿、坏死和肌层变性。绦虫头节与肠壁之间明显的嗜酸性界面层表明宿主与寄生虫密切接触。超微结构检查显示，头节的颈部和侧面覆盖着锥形棘状微毛，头节顶端有丝状微毛。在整个头节皮层记录到大量腺细胞（皮层腺）。大量分泌颗粒通过一系列突起网络从腺体排出到头节表面，这与宿主细胞反应的距离化一致。严重炎性病变、部分肠道阻塞和肠道穿孔的可能性等观察结果代表了与正常肠道功能丧失一致的重要病理变化。与瓦氏单槽绦虫附着相关的病变比英国淡水鱼的任何其他绦虫所记录的病变都更严重。
