金黄色葡萄球菌鉴定方法研究

Study on the identification methods for Staphylococcus aureus

中文关键词:  酱卤肉  国标法  VITEK 2 Compact  16S rDNA  PCR鉴定

英文关键词:soy sauce and pot-roast meat products  national standard method  VITEK 2 Compact  16S rDNA  PCR identification

中文摘要:

      目的 筛选出能够快速准确鉴定金黄色葡萄球菌的方法。方法 利用国家标准法、VITEK 2 Compact生化鉴定、16S rDNA序列分析和PCR鉴定等4种方法对酱卤肉制品中分离出的典型菌落进行鉴定。结果 国家标准法检测结果显示菌株为革兰氏阳性菌, 血平板上有明显的透明溶血圈且血浆凝固酶试验结果为阳性, 符合金黄色葡萄球菌判定标准。VITEK 2 Compact生化鉴定结果中不吻合的典型生化谱仅有1项(dMAL), 判定菌株为金黄色葡萄球菌(98%概率), 为极好的鉴定。16S rDNA序列比对分析及以邻接法构建的进化树均显示典型菌落为金黄色葡萄球菌。以耐热核酸酶基因(nuc)设计的引物能扩增出单一的清晰条带, 能快速准确的识别出金黄色葡萄球菌。结论 4种方法均能准确鉴定出金黄色葡萄球菌, 但耗时都比较长, 通过改进实验方法, 缩短DNA提取时间, PCR鉴定将表现出较大优势。

英文摘要:

      Objective To select the method for rapid detection and identification of Staphylocoocus aureus. Methods The typical colonies isolated from soy sauce and pot-roast meat products were identified with national standard method, VITEK 2 Compact identification, 16S rDNA sequence analysis and PCR identification. Results The results from national standard method showed that the strain was a gram-positive bacteria, there was a clear hemolytic circle on blood plate and the assay result of coagulase test was positive, all the identification met the criteria of Staphylocoocus aureus. Only one term (dMAL) did not match the typical biochemical spectrum in the identification results of VITEK 2 Compact, which was proved to be Staphylocoocus aureus (98% probability) and indicated to be an excellent identification. The result of 16S rDNA sequences analysis and phylogenetic tree constructed by Neighbor-Joint method indicated that the typical colony was Staphylocoocus aureus. The primers designed with gene nuc could amplify the specific positive bands, PCR identification could identify Staphylococcus aureus rapidly and effectively. Conclusion The four methods can accurately identify Staphylococcus aureus, but it takes a long time. By improving the experimental method, shortening the extraction time of DNA, PCR identification will show greater advantages.