双头tenacibaculumdicentrarchi是智利鲑鱼养殖中第二重要的病原体。这种微生物在养殖鱼的体表上引起严重的皮肤损伤。细菌还可以粘附到表面并形成生物膜,在鱼皮粘液中存活,并拥有不同的铁获取系统。然而,毒力机制仍未完全阐明。外膜囊泡(OMV)是致病性革兰氏阴性菌在生长过程中释放的纳米结构,但是还没有关于T.dicentrarchi的描述。在这项研究中,我们提供了首次报道的证据,表明鱼类病原体T.dicentrarchi在孵化后24小时产生和释放OMV,此后增加直到120小时。用T.dicentrarchiTdCh05,QCR29和CECT7612T型菌株进行分析。OMV大小,通过扫描电子显微镜确定,根据菌株和孵育时间点,范围为82.25nm至396.88nm(即,24到120小时)。SDS-PAGE显示,在双entrarchi菌株中,蛋白质条带的数量显示出急剧下降的趋势。反过来,OMV共享五种蛋白质(即,22.2、31.9、47.7、56.3和107.1kDa),但没有相同的蛋白质模式.异质量的蛋白质,RNA,并获得了DNA,取决于提取OMV的时间。纯化的OMV具有生物活性,并在虹鳟鱼(Oncorhynchusmykiss)头肾的富含巨噬细胞的细胞培养物中诱导了细胞毒性作用。这是了解OMV在T.dicentrarchi发病机理中可能发挥的作用的第一步。
Tenacibaculum dicentrarchi is the second most important pathogen in Chilean salmon farming. This microorganism causes severe skin lesions on the body surface of farmed fish. The bacterium can also adhere to surfaces and form biofilm, survive in fish skin mucus, and possess different systems for iron acquisition. However, the virulence mechanisms are still not fully elucidated. Outer membrane vesicles (
OMV) are nanostructures released by pathogenic Gram-negative bacteria during growth, but none has been described yet for T. dicentrarchi. In this study, we provide the first reported evidence of the fish pathogen T. dicentrarchi producing and releasing
OMV from 24 h after incubation, increasing thereafter until 120 h. Analyses were conducted with T. dicentrarchi TdCh05, QCR29, and the type strain CECT 7612T . The
OMV sizes, determined via scanning electron microscopy, ranged from 82.25 nm to 396.88 nm as per the strain and incubation time point (i.e., 24 to 120 h). SDS-PAGE revealed that the number of protein bands evidenced a drastically downward trend among the T. dicentrarchi strains. In turn, the OMV shared five proteins (i.e., 22.2, 31.9, 47.7, 56.3, and 107.1 kDa), but no protein pattern was identical. A heterogeneous amount of protein, RNA, and DNA were obtained, depending on the time at which
OMV were extracted. Purified
OMV were biologically active and induced a cytotoxic effect in macrophage-enriched cell cultures from rainbow trout (Oncorhynchus mykiss) head kidneys. This is the first step towards understanding the role that OMV could play in the pathogenesis of T. dicentrarchi.