Comparing the different morphotypes of a fish pathogen--implications for key virulence factors in Flavobacterium columnare.
Comparing the different morphotypes of a fish pathogen--implications for key virulence factors in Flavobacterium columnare.
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DOI：
10.1186/1471-2180-14-170
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发表时间：
2014-06-26
期刊：
影响因子：
4.2
通讯作者：
Sundberg LR
中科院分区：
文献类型：
--
作者：
Laanto E;Penttinen RK;Bamford JK;Sundberg LR
柱状黄杆菌（Bacteroidetes）是世界各地养殖淡水鱼柱状杆菌病的病原体。该细菌形成三种菌落形态类型（假根菌落、粗糙菌落和软菌落），但人们对形态类型的差异知之甚少。我们研究了虹鳟鱼 (Onconrhynchus mykiss) 中 F. columnare 菌株 B067 产生的形态型的毒力，并使用高分辨率扫描电子显微镜来识别在液体和琼脂上生长的细胞的精细结构。我们还分析了细胞外和膜囊泡中分泌的蛋白质，以确定可能的毒力因子。只有假根形态型对虹鳟鱼具有毒性。在电子显微镜下，观察到根状和软形态型的细胞在集落内显示有组织的结构，而在粗糙型中则不存在这种内部组织。假根和粗糙形态类型的浮游细胞产生大的膜囊泡，这在软形态类型的细胞上未见。纯化并分析囊泡。鉴定出两种具有预测功能的蛋白质：OmpA 和 SprF。此外，假根形态型分泌大量未鉴定的小型 13 kDa 蛋白质，而粗糙形态型和软形态型中不存在，这表明与细菌毒力有关。我们的结果表明与柱状镰刀菌毒力相关的三个因素：细胞的协调组织、分泌蛋白和外膜囊泡。菌落内细胞的内部组织可能与细菌的滑动运动有关，这被认为与柱状镰刀菌的毒力有关。毒性形态型细胞分泌的 13 kDa 蛋白的功能仍不清楚。膜囊泡可能与细胞对表面的粘附有关，并且还可能携带潜在的毒力因子。事实上，OmpA 是多种细菌病原体的毒力因子，通常与粘附和侵袭有关，而 SprF 是一种与黄细菌的滑行运动和蛋白质分泌有关的蛋白质。
Flavobacterium columnare (Bacteroidetes) is the causative agent of columnaris disease in farmed freshwater fish around the world. The bacterium forms three colony morphotypes (Rhizoid, Rough and Soft), but the differences of the morphotypes are poorly known. We studied the virulence of the morphotypes produced by F. columnare strain B067 in rainbow trout (Onconrhynchus mykiss) and used high-resolution scanning electron microscopy to identify the fine structures of the cells grown in liquid and on agar. We also analysed the proteins secreted extracellularly and in membrane vesicles to identify possible virulence factors. Only the Rhizoid morphotype was virulent in rainbow trout. Under electron microscopy, the cells of Rhizoid and Soft morphotypes were observed to display an organised structure within the colony, whereas in the Rough type this internal organisation was absent. Planktonic cells of the Rhizoid and Rough morphotypes produced large membrane vesicles that were not seen on the cells of the Soft morphotype. The vesicles were purified and analysed. Two proteins with predicted functions were identified, OmpA and SprF. Furthermore, the Rhizoid morphotype secreted a notable amount of a small, unidentified 13 kDa protein absent in the Rough and Soft morphotypes, indicating an association with bacterial virulence. Our results suggest three factors that are associated with the virulence of F. columnare: the coordinated organisation of cells, a secreted protein and outer membrane vesicles. The internal organisation of the cells within a colony may be associated with bacterial gliding motility, which has been suggested to be connected with virulence in F. columnare. The function of the secreted 13 kDa protein by the cells of the virulent morphotype cells remains unknown. The membrane vesicles might be connected with the adhesion of cells to the surfaces and could also carry potential virulence factors. Indeed, OmpA is a virulence factor in several bacterial pathogens, often linked with adhesion and invasion, and SprF is a protein connected with gliding motility and the protein secretion of flavobacteria.
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影响因子：
3.2
作者：
Li, ZS;Clarke, AJ;Beveridge, TJ
通讯作者：
Beveridge, TJ
影响因子：
4
作者：
Kunttu, H. M. T.;Jokinen, E. I.;Sundberg, L. -R.
通讯作者：
Sundberg, L. -R.
影响因子：
1.4
作者：
BERTOLINI, JM;ROHOVEC, JS
通讯作者：
ROHOVEC, JS
影响因子：
4.4
作者：
Declercq AM;Haesebrouck F;Van den Broeck W;Bossier P;Decostere A
通讯作者：
Decostere A
影响因子：
3.8
作者：
Dabo, SM;Confer, AW;Quijano-Blas, RA
通讯作者：
Quijano-Blas, RA