Neilan B A, Saker M L, Fastner J, Törökné A, Burns B P
School of Microbiology and Immunology, University of New South Wales, Sydney, New South Wales 2051, Australia.
Mol Ecol. 2003 Jan;12(1):133-40. doi: 10.1046/j.1365-294x.2003.01709.x.
Cylindrospermopsis raciborskii is a planktonic freshwater cyanobacterium that has become increasingly prevalent in tropical and temperate water bodies world-wide. This species is of concern from a water-quality perspective because of its known ability to produce toxins that can affect the health of humans and other animals. This study investigates genetic variation between strains of C. raciborskii isolated from freshwater rivers and reservoirs in Australia, Brazil, Germany, Hungary, Portugal and the USA. Strains were first characterized by analysis of their 16S rRNA gene nucleotide sequences and were found to have a sequence divergence of 99.1%. A phylogenetic tree, constructed using the 16S rRNA gene sequences showed that strains grouped into Australian, European and North/South American phylotypes. To investigate further the observed separation of strains into geographically distinct groups, we applied a cyanobacterium-specific short tandem repeat sequence technique, HIP1. An electrophoretic comparison of the HIP1 polymerase chain reaction products showed clear distinctions between the C. raciborskii strains. A phylogenetic tree, based on the repeat element banding patterns, also revealed three distinct groups of C. raciborskii strains. The first group consisted of strains from the USA and Brazil; the second comprised European strains from Germany, Hungary and Portugal; and the third were strains from Australia. In general, between-country variation was greater than within-country variation, indicating that this fingerprinting technique can successfully distinguish C. raciborskii strains taken from different global locations. The relationship between toxicity and the observed HIP1 polymerase chain reaction fingerprint profiles was less clear, although it is interesting to note that of the strains analysed in this study, only Australian strains are known to produce cylindrospermopsin and only Brazilian strains have been reported to produce paralytic shellfish poisoning toxins.
柱孢鱼腥藻是一种浮游淡水蓝细菌，在全球热带和温带水体中日益普遍。从水质角度来看，该物种令人担忧，因为它已知有产生毒素的能力，这些毒素会影响人类和其他动物的健康。本研究调查了从澳大利亚、巴西、德国、匈牙利、葡萄牙和美国的淡水河流及水库中分离出的柱孢鱼腥藻菌株之间的遗传变异。首先通过分析其16S rRNA基因核苷酸序列对菌株进行表征，发现序列差异为99.1%。使用16S rRNA基因序列构建的系统发育树表明，菌株分为澳大利亚、欧洲和北美/南美三种系统型。为了进一步研究观察到的菌株在地理上的明显分组情况，我们应用了一种蓝细菌特异性短串联重复序列技术，即HIP1。对HIP1聚合酶链反应产物的电泳比较显示，柱孢鱼腥藻菌株之间有明显差异。基于重复元件条带模式构建的系统发育树也揭示了柱孢鱼腥藻菌株的三个不同组。第一组由来自美国和巴西的菌株组成；第二组包括来自德国、匈牙利和葡萄牙的欧洲菌株；第三组是来自澳大利亚的菌株。总体而言，国家间的差异大于国家内的差异，这表明这种指纹识别技术能够成功区分来自全球不同地点的柱孢鱼腥藻菌株。毒性与观察到的HIP1聚合酶链反应指纹图谱之间的关系不太明确，不过值得注意的是，在本研究分析的菌株中，已知只有澳大利亚菌株能产生柱孢毒素，并且只有巴西菌株被报道能产生麻痹性贝类中毒毒素。
