Ferguson Hugh W, Delannoy Christian M J, Hay Stephen, Nicolson James, Sutherland David, Crumlish Margaret
Marine Medicine Program, School of Veterinary Medicine, St. George's University, Grenada, W. Indies.
J Vet Diagn Invest. 2010 May;22(3):376-82. doi: 10.1177/104063871002200305.
Swarms or blooms of jellyfish are increasingly problematic and can result in high mortality rates of farmed fish. Small species of jellyfish, such as Phialella quadrata (13 mm in diameter), are capable of passing through the mesh of sea cages and being sucked into the mouth of fish during respiration. Results of the current study show that the initial damage to gills of farmed Atlantic salmon, likely produced by nematocyst-derived toxins from the jellyfish, was compounded by secondary bacterial infection with Tenacibaculum maritimum. Results also demonstrate that these filamentous bacteria were present on the mouth of the jellyfish and that their DNA sequences were almost identical to those of bacteria present on the salmon gills. This suggests that the bacterial lesions were not the result of an opportunistic infection of damaged tissue, as previously thought. Instead, P. quadrata is probably acting as a vector for this particular bacterial pathogen, and it is the first time that evidence to support such a link has been presented. No prior literature describing the presence of bacteria associated with jellyfish, except studies about their decay, could be found. It is not known if all jellyfish of this and other species carry similar bacteria or the relationship to each other. Their source, the role they play under other circumstances, and indeed whether the jellyfish were themselves diseased are also not known. The high proteolytic capabilities of T. maritimum mean that partially digested gill tissues were readily available to the jellyfish, which rely heavily on intracellular digestion for their nutrition.
水母的大量聚集或繁殖造成的问题日益严重，可能导致养殖鱼类的高死亡率。小型水母物种，如四叶小舌水母（直径13毫米），能够穿过海上网箱的网眼，并在鱼类呼吸时被吸入鱼嘴。当前研究结果表明，养殖大西洋鲑鱼鳃部的初始损伤可能是由水母的刺丝囊毒素引起的，随后又因海生栖热袍菌的继发细菌感染而加剧。结果还表明，这些丝状细菌存在于水母的口部，其DNA序列与鲑鱼鳃上的细菌几乎相同。这表明，细菌损伤并非如先前认为的那样是受损组织的机会性感染所致。相反，四叶小舌水母可能是这种特定细菌病原体的传播媒介，这是首次有证据支持这种联系。除了关于水母腐烂的研究外，未发现之前有描述与水母相关细菌存在的文献。尚不清楚该物种和其他物种的所有水母是否都携带类似细菌或它们之间的关系。它们的来源、在其他情况下所起的作用，以及水母本身是否患病也均不明确。海生栖热袍菌的高蛋白水解能力意味着部分消化的鳃组织很容易被水母获取，而水母严重依赖细胞内消化获取营养。
