益生菌发酵乳无菌提取物对空肠弯曲杆菌flaA σ28启动子的抑制作用

摘要

To study the inhibition of germfree extracts derived from milk fermented by lactic acid bacteria (LAB) on virulence gene flaA expression of foodborne pathogen bacteria Campylobacter jejuni,a luminescent phenotype fusion between the flaA σ28 promoter and a promoterless luxCDABE cassette carried on the plasmid pRYluxCDABE in Campylobacter jejuni was used.Through evaluation of the bioluminescence,the effect of germfree extracts derived from milk fermented by lactic acid bacteria (LAB) (5 Bifidobacterium strains and 6 Lactobacillus strains) was assessed on flaA σ28 promoter activity.The results showed that gremfree extracts of milk fermented by LAB were found to have a significant (P<0.05) inhibitive effect on the expression of flaA σ28 promoter,and down-regulate virulence gene flaA expression.%为了研究益生菌发酵乳无菌提取物对食源性有害微生物(空肠弯曲杆菌)有毒基因表达的抑制作用,以利用空肠弯曲杆菌的有毒基因flaA σ28启动子和无启动子的质粒pRYluxCDABE联结构建的生物冷光转基因模型为试验材料,通过检测生物发光特性的方法,研究了空肠弯曲杆菌有毒基因flaA表达与益生菌(5种双岐杆菌,6 种乳酸杆菌)发酵乳无菌提取物之间的关系.结果表明,益生菌发酵乳无菌提取物对空肠弯曲杆菌flaA σ28启动子的活性有显著的抑制作用(P《0.05),并可显著抑制空肠弯曲杆菌有害基因flaA的表达.