Nylund Are, Ottem Karl F, Watanabe Kuninori, Karlsbakk Egil, Krossøy Bjørn
Department of Biology, University of Bergen, Thormohlensgt 55, 5020 Bergen, Norway.
Arch Microbiol. 2006 Jun;185(5):383-92. doi: 10.1007/s00203-006-0109-5. Epub 2006 Apr 14.
In 2004, a new disease was detected in cod (Gadus morhua) in western Norway. Affected cod had white granulomas in the visceral organs and skin. A species of Francisella was isolated on blood agar plates from moribund cod. The bacterium could be grown at temperatures ranging from 6 to 22 degrees C, but did not grow at 37 degrees C. Challenge experiments showed that Francisella sp. was the cause for the new disease. The 16S rDNA gene sequence from Francisella sp. showed 99.17% similarity to F. philomiragia, and the 16S-23S ribosomal RNA intergenic spacer (249 nt), shows a similarity with that from Francisella isolated from tilapia and F. tularensis of 96.8 and 35.9%, respectively. The 23S sequence is more similar to F. tularensis, 97.7% (2,862 nt), compared to the tilapia isolate 96.8% (2,131 nt). The partial putative outer membrane protein (FopA) sequence (781 nt) from Francisella sp. shows a similarity with that from F. tularensis and F. philomiragia of 77.3 and 98.2%, respectively. Based on sequence data, culturing temperatures and pathogenicity for cod, it is suggested that this Francisella sp. from cod could be a new species of Francisella, Family Francisellaceae.
2004年，在挪威西部的鳕鱼（大西洋鳕）中检测到一种新疾病。患病鳕鱼的内脏器官和皮肤出现白色肉芽肿。从濒死鳕鱼的血琼脂平板上分离出一种弗朗西斯菌属细菌。该细菌能在6至22摄氏度的温度范围内生长，但在37摄氏度时不生长。攻毒实验表明弗朗西斯菌属是这种新疾病的病因。来自弗朗西斯菌属的16S rDNA基因序列与嗜肺弗朗西斯菌的相似度为99.17%，16S - 23S核糖体RNA基因间隔区（249 nt）与从罗非鱼分离的弗朗西斯菌以及土拉弗朗西斯菌的相似度分别为96.8%和35.9%。23S序列与土拉弗朗西斯菌更为相似，相似度为97.7%（2862 nt），而与罗非鱼分离株的相似度为96.8%（2131 nt）。来自弗朗西斯菌属的部分假定外膜蛋白（FopA）序列（781 nt）与土拉弗朗西斯菌和嗜肺弗朗西斯菌的相似度分别为77.3%和98.2%。基于序列数据、培养温度以及对鳕鱼的致病性，推测来自鳕鱼的这种弗朗西斯菌属可能是弗朗西斯菌科的一个新物种。
