Toxin gene profiling of enterotoxic and emetic Bacillus cereus
Toxin gene profiling of enterotoxic and emetic Bacillus cereus
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DOI：
10.1111/j.1574-6968.2006.00320.x
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发表时间：
2006-07-01
影响因子：
2.1
通讯作者：
Svensson, Birgitta
中科院分区：
文献类型：
--
作者：
Ehling-Schulz, Monika;Guinebretiere, Marie-Helene;Svensson, Birgitta
由蜡状芽孢杆菌引起的两种类型的胃肠道疾病的原因是非常不同的毒素：肠综合征与非溶血性肠毒素NHE、溶血性肠毒素HBL和细胞毒素K有关，而呕吐是由缩肽毒素cereulide的作用引起的。最近鉴定的催泪素合成酶基因允许开发一种分子测定法，该测定法仅使用四组不同的引物，在单一反应中靶向已知与食物中毒有关的所有毒素。49株菌株的肠毒素基因，分属于B的不同系统发育分支。cereus组，进行了部分测序，以涵盖这些基因的分子多样性。序列比对结果表明B基因具有高度的多态性。蜡样芽胞杆菌肠毒素基因，这是建立PCR系统时必须考虑的。针对肠毒素复合物基因的引物位于相应操纵子的不同CDS中，以用一组引物靶向两个毒素基因。使用一组B评估试验的专属性。具有已知毒素谱的蜡样芽胞杆菌菌株，并成功地应用于表征来自食品和临床诊断实验室的菌株以及用于B的毒素基因谱。从筒仓罐群中分离的蜡状芽孢杆菌。
Very different toxins are responsible for the two types of gastrointestinal diseases caused by Bacillus cereus: the diarrhoeal syndrome is linked to nonhemolytic enterotoxin NHE, hemolytic enterotoxin HBL, and cytotoxin K, whereas emesis is caused by the action of the depsipeptide toxin cereulide. The recently identified cereulide synthetase genes permitted development of a molecular assay that targets all toxins known to be involved in food poisoning in a single reaction, using only four different sets of primers. The enterotoxin genes of 49 strains, belonging to different phylogenetic branches of the B. cereus group, were partially sequenced to encompass the molecular diversity of these genes. The sequence alignments illustrated the high molecular polymorphism of B. cereus enterotoxin genes, which is necessary to consider when establishing PCR systems. Primers directed towards the enterotoxin complex genes were located in different CDSs of the corresponding operons to target two toxin genes with one single set of primers. The specificity of the assay was assessed using a panel of B. cereus strains with known toxin profiles and was successfully applied to characterize strains from food and clinical diagnostic labs as well as for the toxin gene profiling of B. cereus isolated from silo tank populations.