State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
J Appl Microbiol. 2011 Dec;111(6):1337-48. doi: 10.1111/j.1365-2672.2011.05166.x. Epub 2011 Oct 31.
The aim of this study was to classify Edwardsiella strains isolated from China aquaculture based on biochemical and molecular methods.
In this study, biochemical characterization of 19 Edwardsiella tarda isolates and two Edwardsiella ictaluri isolates was performed with API 20E system. Other pathogenicity-related phenotypes such as haemagglutination, haemolytic activities and lethality to fish were also examined in these strains. As it was difficult to categorize the subgroups of Edw. tarda according to their origins or phenotypic properties, three PCR-based methods, i.e. PCR amplification of virulence genes, Enterobacterial repetitive intergenic consensus-PCR and BOX-PCR, were carried out to further resolve the relatedness of the Edw. tarda isolates. As a result, all Edw. tarda isolates could be generally grouped into pathogenic and nonpathogenic branches before being classified into strain-specific or origin-specific clades.
Biochemical characterization was sensitive for interspecific typing, while PCR-based approaches permitted a more accurate discrimination for intraspecific typing resulting in pathogenic and nonpathogenic clusters and further more delicate clades for Edwardsiella.
PCR-based genomic fingerprinting to study the relatedness and trace the pathogenicity of the Edwardsiella strains will be helpful in investigating the virulence factors of Edwardsiella and in the development of vaccines and diagnostics for edwardsiellosis.
本研究旨在基于生化和分子方法对中国水产养殖中分离的爱德华氏菌菌株进行分类。
本研究采用 API 20E 系统对 19 株迟缓爱德华氏菌和 2 株鲑爱德华氏菌进行生化特征分析。还检测了这些菌株的其他致病性相关表型，如血凝、溶血活性和对鱼类的致死性。由于根据起源或表型特性难以对迟缓爱德华氏菌的亚群进行分类，因此进行了三种基于 PCR 的方法，即毒力基因的 PCR 扩增、肠杆菌重复基因间一致性-PCR 和 BOX-PCR，以进一步确定迟缓爱德华氏菌分离株的相关性。结果表明，所有迟缓爱德华氏菌分离株在被分类为菌株特异性或起源特异性分支之前，通常可以分为致病性和非致病性分支。
生化特征分析对于种间分型敏感，而基于 PCR 的方法对于种内分型具有更高的分辨率，导致致病性和非致病性聚类以及更精细的爱德华氏菌聚类。
基于 PCR 的基因组指纹图谱分析研究爱德华氏菌菌株的相关性和追踪其致病性，将有助于研究爱德华氏菌的毒力因子，并开发用于爱德华氏菌病的疫苗和诊断方法。
