【摘要】 目的发现炭疽芽胞杆菌与蜡样芽胞杆菌rpo B基因PCR交叉反应,对产生交叉反应的原因进行研究。方法对分离自食品及土壤的芽胞杆菌进行形态染色、生化反应、飞行时间质谱、蛋白毒素结晶试验、根状生长试验、炭疽噬菌体裂解试验、炭疽杆菌及蜡样杆菌荧光定量PCR等鉴定,并对rpo B基因实时荧光定量PCR扩增产物进行克隆测序,比对基因序列。对部分菌株进行MLST分型,探讨交叉反应的遗传关系。结果部分芽胞杆菌炭疽实时荧光定量PCR试验出现rpo B扩增阳性,经鉴定为蜡样芽胞杆菌。rpo B扩增产物测序显示,与炭疽杆菌高度相似。MLST分型显示分布在不同的群,发现4种新的ST型。结论蜡样芽胞杆菌与炭疽芽胞杆菌的rpo B基因存在PCR交叉反应,其分子生物学基础是基因组序列的高度相似性,与菌株遗传变异关系不大,对炭疽杆菌及蜡样杆菌的基因诊断应该参考毒素质粒及染色体基因的联合鉴定。更多还原

【Abstract】 The rpo B gene PCR cross-reactivity between Bacillus anthrax and Bacillus cereus in Shanxi of China was reported.The Bacillus isolated from food and soil was identifiedbased on morphological, biochemical reaction, MOLDI-TOF,protein toxin crystal test, root growth test, anthracis phage lysis test, Bacillus anthracis and Bacillus cereus real-time PCR.The rpo B gene real-time PCR amplification, cloning and sequencing, analyzing and alignment of the gene sequence were conducted. The results indicated that some of Bacillus real-time PCR showed Bacillus athracis rpo B gene was positive and identified as Bacillus cereus. PCR amplification product sequencing showed that the high similarity with Bacillus anthricais.So the main reason of rpo B gene PCR cross-reaction between Bacillus cereus and Bacillus anthracis was highly similar genome sequences. Multilocus sequence typing(MLST) of 9 Bacillus ceres strains showed in different groups, and four new ST profiles were found. PCR cross-reaction between strains had little genetic variation. Gene diagnosis of Bacillus anthracis and Bacillus cereus should be combined with identification of toxin plasmid gene and chromosome gene.更多还原