Padrós Francesc, Constenla Maria
Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia and Servei de Diagnòstic Patològic en Peixos, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain.
Animals (Basel). 2021 Apr 1;11(4):991. doi: 10.3390/ani11040991.
Parasitic and amphizoic amoebae are ubiquitous and can affect a huge variety of hosts, from invertebrates to humans, and fish are not an exception. Most of the relationships between amoebae and fish are based on four different types: ectocommensals, ectoparasites, endocommensals and endoparasites, although the lines between them are not always clear. As ectocommensals, they are located specially on the gills and particularly the amphizoic is the most relevant species, being a real pathogenic parasite in farmed salmon. It causes amoebic gill disease, which causes a progressive hyperplasia of epithelial cells in the gill filaments and lamellae. Nodular gill disease is its analogue in freshwater fish but the causative agent is still not clear, although several amoebae have been identified associated to the lesions. Other species have been described in different fish species, affecting not only gills but also other organs, even internal ones. In some cases, species of the genera or , which also contain pathogenic species affecting humans, are usually described affecting freshwater fish species. As endocommensals, species have been described in the digestive tract of freshwater and marine fish species, but can reach other organs and cause systemic infections in farmed . Other systemic infections caused by amoebae are usually described in wild fish, although in most cases these are isolated cases without clinical signs or significance.
寄生性和兼性变形虫无处不在，可影响从无脊椎动物到人类等各种各样的宿主，鱼类也不例外。变形虫与鱼类之间的关系大多基于四种不同类型：体表共栖生物、体表寄生虫、体内共栖生物和体内寄生虫，尽管它们之间的界限并不总是很清晰。作为体表共栖生物，它们特别寄生于鳃上，尤其是兼性变形虫是最相关的物种，是养殖鲑鱼中一种真正的致病寄生虫。它会引发阿米巴鳃病，导致鳃丝和鳃小片上皮细胞进行性增生。结节性鳃病是其在淡水鱼中的类似病症，但病原体仍不明确，尽管已鉴定出几种与病变相关的变形虫。在不同鱼类中还描述了其他物种，它们不仅影响鳃，还影响其他器官，甚至是内部器官。在某些情况下，也包含影响人类的致病物种的属或属的物种，通常被描述为会影响淡水鱼物种。作为体内共栖生物，已在淡水和海水鱼类的消化道中描述了属的物种，但属的物种可到达其他器官并在养殖的中引起全身感染。变形虫引起的其他全身感染通常在野生鱼类中被描述，尽管在大多数情况下这些都是没有临床症状或意义的孤立病例。
