【摘要】 蜡状芽胞杆菌是一种条件致病菌 ,它能引起食物中毒和其它形式的疾病。潜在的致病因子包括磷脂酶C、溶血素、肠毒素和呕吐毒素等。在很多致病菌中致病因子的表达都是协同调控的。从蜡状芽胞杆菌模式菌株ATCC1 4579经转座子诱变的文库 ,筛选到一株磷脂酶阴性的突变子 ,该突变子的蛋白酶活性明显减弱了。插入位点的序列分析表明 ,一个高度同源于苏云金芽胞杆菌转录激活子PlcR的基因被插入失活了。研究结果表明 ,除在苏云金芽胞杆菌中能激活磷脂酰肌醇磷脂酶C基因的转录外 ,转录激活子PlcR至少还能调控卵磷脂酶和一个或多个蛋白酶基因的表达 ,这是一个多效调节因子。更多还原

【Abstract】 Food\|poisoning and some diseases of human can be caused by potential pathogenic factors including phospholipases of c\|type,hemolysins,enterotoxins,emetic toxin and others from Bacillus cereus which is an opportunistic pathegon.Generally,the expression of pathogenic genes is completed by a co regulation in many bacteria.The isolation of a mutant,displaying significant reducing expression of lecithinase and general proteolytic activities,from a transposon\|induced bank of B.cereus type strain ATCC14579T were described.Sequencing data revealed that a gene with high homology to transcriptional activator (plcR) of B.thuringiensis was inactivated by insertion in this mutant.The results suggest that plcR regulates the expression of multiple genes in B.cereus .更多还原