Ucko M, Colorni A, Kvitt H, Diamant A, Zlotkin A, Knibb W R
Israel Oceanographic and Limnological Research Ltd., National Center for Mariculture, Eilat, Israel.
Appl Environ Microbiol. 2002 Nov;68(11):5281-7. doi: 10.1128/AEM.68.11.5281-5287.2002.
A molecular characterization of two Mycobacterium marinum genes, 16S rRNA and hsp65, was carried out with a total of 21 isolates from various species of fish from both marine and freshwater environments of Israel, Europe, and the Far East. The nucleotide sequences of both genes revealed that all M. marinum isolates from fish in Israel belonged to two different strains, one infecting marine (cultured and wild) fish and the other infecting freshwater (cultured) fish. A restriction enzyme map based on the nucleotide sequences of both genes confirmed the divergence of the Israeli marine isolates from the freshwater isolates and differentiated the Israeli isolates from the foreign isolates, with the exception of one of three Greek isolates from marine fish which was identical to the Israeli marine isolates. The second isolate from Greece exhibited a single base alteration in the 16S rRNA sequence, whereas the third isolate was most likely a new Mycobacterium species. Isolates from Denmark and Thailand shared high sequence homology to complete identity with reference strain ATCC 927. Combined analysis of the two gene sequences increased the detection of intraspecific variations and was thus of importance in studying the taxonomy and epidemiology of this aquatic pathogen. Whether the Israeli M. marinum strain infecting marine fish is endemic to the Red Sea and found extremely susceptible hosts in the exotic species imported for aquaculture or rather was accidentally introduced with occasional imports of fingerlings from the Mediterranean Sea could not be determined.
对来自以色列、欧洲和远东地区海洋及淡水环境中不同鱼类的21株海分枝杆菌（Mycobacterium marinum）的16S rRNA和hsp65这两个基因进行了分子特征分析。这两个基因的核苷酸序列显示，来自以色列鱼类的所有海分枝杆菌分离株属于两种不同的菌株，一种感染海洋（养殖和野生）鱼类，另一种感染淡水（养殖）鱼类。基于这两个基因核苷酸序列的限制性酶切图谱证实了以色列海洋分离株与淡水分离株的差异，并区分了以色列分离株与国外分离株，但来自希腊的三株海洋鱼类分离株中有一株与以色列海洋分离株相同。来自希腊的第二株分离株在16S rRNA序列中表现出单个碱基改变，而第三株分离株很可能是一种新的分枝杆菌物种。来自丹麦和泰国的分离株与参考菌株ATCC 927具有高度的序列同源性，直至完全相同。对这两个基因序列的联合分析增加了种内变异的检测，因此在研究这种水生病原体的分类学和流行病学方面具有重要意义。感染海洋鱼类的以色列海分枝杆菌菌株是红海特有的，在为水产养殖引进的外来物种中发现了极易感的宿主，还是通过偶尔从地中海引进的鱼种意外引入的，目前尚无法确定。
