Department of Pathobiology, School of Veterinary Medicine, Basseterre, Ross University School of Veterinary Medicine, West Farm, Basseterre, St. Kitts, West Indies.
Microb Ecol. 2012 Feb;63(2):398-404. doi: 10.1007/s00248-011-9932-6. Epub 2011 Sep 1.
Francisella noatunensis subsp. orientalis (syn. Francisella asiatica), the causative agent of franciselliosis in warm-water fish, is a Gram-negative facultative intracellular bacterium. Although it has been characterized as one of the most pathogenic bacteria in fish, the water conditions that allow for its survival and infectious capacities outside the fish host are not known. Data obtained in this project indicate that both temperature and salinity are important factors in the culturability and persistence of F. noatunensis subsp. orientalis in both sea- and freshwater microcosms. These results indicate that culturable F. noatunensis subsp. orientalis persist for longer periods of time and at higher numbers in seawater, and its persistence is inversely related to water temperature. Moreover, the pathogenic properties of the bacteria suspended in water microcosms appear to decrease after only 24 h and become non-infective after 2 days in the absence of the fish host.
东方型努森菌亚种（原名：亚洲型弗朗西斯菌）是温水鱼类弗朗西斯菌病的病原体，是一种革兰氏阴性兼性细胞内细菌。尽管它被认为是鱼类中最具致病性的细菌之一，但目前尚不清楚其在鱼类宿主外生存和具有传染性的水条件。本项目获得的数据表明，温度和盐度都是东方型努森菌亚种在海水和淡水微生境中可培养性和持久性的重要因素。这些结果表明，可培养的东方型努森菌亚种在海水中能够更长时间和更高数量地存活，其持久性与水温成反比。此外，悬浮在水微生境中的细菌的致病性在 24 小时后似乎下降，并且在没有鱼类宿主的情况下 2 天后变得无传染性。
