Localization of the bacterial agent of juvenile oyster disease (Roseovarius crassostreae) within affected eastern oysters (Crassostrea virginica)
Localization of the bacterial agent of juvenile oyster disease (Roseovarius crassostreae) within affected eastern oysters (Crassostrea virginica)
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DOI：
10.1016/j.jip.2007.08.007
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发表时间：
2008-02-01
影响因子：
3.4
通讯作者：
Boettcher, Katherine J.
中科院分区：
文献类型：
--
作者：
Boardman, Cynthia L.;Maloy, Aaron P.;Boettcher, Katherine J.
细菌Roseovarius crassostrae导致美国东北部商业生产的东部牡蛎（Crassostrea virginica）的季节性死亡。系统发育上，该物种属于海洋细菌的一个主要谱系（Roseovarius crassostrae分支），其中Roseovarius crassostrae是唯一已知的在实验室培养中分离的病原体。本研究的目的是确定R. crassostrae相互作用的牡蛎受青少年牡蛎病（JOD）。扫描电子显微镜显示，患病个体的内壳表面有大量的细菌定植，这些细菌在形态上与R。crassostrae。同样类型的细胞也观察到内部阀上的主机衍生的贝壳蛋白层内。大多数细菌细胞是活的，如通过使用荧光活力染色所确定的。此外，大多数明显附着在细胞两极，这与R的能力一致。粗条纹表达极伞。当培养来自套膜液、软组织和瓣膜内表面的材料时，R。从内瓣中回收crassostrae。这些样品也含有最丰富的R。crassostrae占总菌落的百分比。16S rRNA基因的克隆和测序为R.与JOD感染动物的内壳表面相关的细菌聚生体中的crassostreae。R. crassostrae定殖壳和贝壳蛋白与所描述的JOD病理学一致，并且可以帮助细菌避免血细胞介导的杀伤。(C)2007年爱思唯尔公司All rights reserved.
The bacterium Roseovarius crassostreae causes seasonal mortalities among commercially produced eastern oysters (Crassostrea virginica) grown in the Northeastern United States. Phylogenetically, the species belongs to a major lineage of marine bacteria (the Roseobacter clade), within which Roseovarius crassostreae is the only known pathogen to be isolated in laboratory culture. The objective of the current study was to determine the location and nature of R. crassostreae interactions with oysters affected by juvenile oyster disease (JOD). Scanning electron microscopy of diseased individuals revealed abundant colonization of the inner shell surfaces by bacteria which were morphologically similar to R. crassostreae. The same types of cells were also observed on and within layers of host-derived conchiolin on the inner valves. Most bacterial cells were alive as determined by the use of a fluorescent viability stain. Further, most were clearly attached at the cell poles, which is consistent with the ability of R. crassostreae to express polar fimbriae. When material from the pallial fluid, soft tissue and inner valve surfaces was cultured, the highest numbers of R. crassostreae were recovered from the inner valves. These samples also contained the greatest abundance of R. crassostreae as a percentage of total colonies. Cloning and sequencing of 16S rRNA genes provided culture-independent evidence of the numerical dominance of R. crassostreae among the bacterial consortia associated with the inner shell surfaces of JOD-affected animals. The ability of R. crassostreae to colonize shell and conchiolin is consistent with the described JOD-pathology and may aid the bacteria in avoiding hemocyte-mediated killing. (C) 2007 Elsevier Inc. All rights reserved.