Paillard Christine, Korsnes Kjetil, Le Chevalier Patrick, Le Boulay Christine, Harkestad Lisbeth, Eriksen Anne Grete, Willassen Endre, Bergh Øivind, Bovo Clément, Skår Cecilie, Mortensen Stein
Institut Universitaire Europeen de la Mer, LEMAR, UMR 6539, Université de Bretagne Occidentale, 29280 Plouzané, France.
Dis Aquat Organ. 2008 Aug 27;81(2):153-61. doi: 10.3354/dao01950.
The Manila clam Ruditapes philippinarum was introduced to Norway in 1987 and was produced in 2 hatcheries until 1991. Clam seed was planted at 6 sites. Two sites were on the Island of Tysnes, south of Bergen. Surviving adult Manila clams were recovered in 1995 and 1996. In the present study, Manila clams from the original seeding that displayed morphological signs of brown ring disease (BRD) were recovered in June 2003 (n=7) and in June 2004 (n=17). Samples from extrapallial fluid, tissues and haemolymph were inoculated on marine agar. Replicate subcultures on selective media were used to select potential Vibrio tapetis strains, and in total, 190 bacterial strains were isolated. One of these strains clustered within the V tapetis clade and was named NRP 45. DNA:DNA hybridisation with the type strain CECT4600 showed 52.7 and 57.3% DNA:DNA similarity. Hybridisation of NRP 45 and the V tapetis LP2 strain, isolated from corkwing wrasse Symphodus melops, produced 46.6 and 44.4% re-association. Partial gene segments encoding 16S rRNA, gyrase B protein (GyrB) and chaperonin 60 protein (Cpn60) were characterised and compared to CECT 4600. NRP 45 showed 5 differences in the 1416 nucleotides (nt) of the 16S rRNA encoding gene (99.6% similarity), while the GyrB encoding gene had 62 substitutions of 1181 nt compared (94.8% similarity) and the Cpn60 encoding gene had 22 substitutions out of 548 nt compared (96% similarity). This is the first finding of BRD and the first isolation of a V. tapetis-like bacterial strain from a bivalve in Norway.
菲律宾蛤仔于1987年被引入挪威，到1991年时在两家孵化场进行培育。蛤苗被投放至6个地点。其中两个地点位于卑尔根以南的蒂斯内斯岛。1995年和1996年发现了存活的成年菲律宾蛤仔。在本研究中，2003年6月（n = 7）和2004年6月（n = 17）采集到了来自最初投放且显示出褐环病（BRD）形态学迹象的菲律宾蛤仔。将外套膜外液、组织和血淋巴的样本接种于海洋琼脂上。在选择性培养基上进行重复传代培养以筛选潜在的塔氏弧菌菌株，总共分离出190株细菌菌株。其中一株菌株聚集在塔氏弧菌分支内，被命名为NRP 45。与模式菌株CECT4600的DNA:DNA杂交显示DNA:DNA相似性为52.7%和57.3%。NRP 45与从欧洲球吻鲈Symphodus melops分离出的塔氏弧菌LP2菌株的杂交产生了46.6%和44.4%的重结合率。对编码16S rRNA、解旋酶B蛋白（GyrB）和伴侣蛋白60（Cpn60）的部分基因片段进行了特征分析，并与CECT 4600进行比较。NRP 45在16S rRNA编码基因的1416个核苷酸（nt）中有5个差异（相似性为99.6%），而GyrB编码基因在1181 nt中有62个替换（相似性为94.8%），Cpn60编码基因在548 nt中有22个替换（相似性为96%）。这是挪威首次发现褐环病以及首次从双壳贝类中分离出类似塔氏弧菌的细菌菌株。
