定量分析铜绿假单胞菌第一类整合酶基因的表达  

Quantification of class 1 integrase gene expression of Pseudomonas aeruginosa in different conditions

作　　者：杨维青[1] 石磊[2] 谢轶[1] 苏建裕[2] 李心晖[2] 寇亚丽[2] 程曦[1] 曾蔚[1] 贾文祥[1] 

机构地区：[1]四川大学华西基础医学与法医学院 [2]华南理工大学轻工与食品工程学院,广州510640

出　　处：《中国抗生素杂志》2006年第3期149-153,共5页Chinese Journal of Antibiotics

基　　金：国家自然科学基金(30370079);纽约中华医学基金会(CMB;No.82-421);广东省自然科学基金项目(04020050);河北省医学科学研究重点课题计划项目(05086)

摘　　要：目的整合子是具有整合和表达外来耐药性基因盒能力的基因元件,在细菌耐药性基因的积累和传递中起重要作用。本研究通过定量分析第一类整合子整合酶基因(intI1)在细菌不同生存状态的表达水平,探讨整合子的作用机制。方法培养和提取两株第一类整合子阳性铜绿假单胞菌的液相培养菌、生物被膜菌、被膜脱落菌等三种生长状态的总RNA,采用竞争RTP-CR方法定量检测菌体在以上三种状态下intI1m RNA的表达水平。结果铜绿假单胞菌的液相培养菌、生物被膜菌和被膜脱落菌都有intI1m RNA表达;两株菌在三种状态下intI1m RNA的表达量不同,其中生物被膜菌表达最高,被膜脱落菌次之,液相培养菌最低;生物被膜菌intI1m RNA的量较液相培养物高约15倍,较被膜脱落菌高约4倍。结论铜绿假单胞菌intI1在生物被膜中m RNA表达上调,随着菌体从被膜脱落以及菌体持续的液相培养intI1表达下调。提示整合子在生物被膜菌中可进行活跃的基因盒的捕获、移动和积累,有利于细菌耐药性的提高及扩散。Objective Integrons played important roles in the spread of antibiotic resistance and muhidrug resistance. In order to study the mechanism of integron action, P. aeruginosa strains carrying class 1 integron, were measured for the expression of class 1 integrase gene （intI1） mRNA in different conditions respectively. Methods A competitive reverse transcription-PCR （cRT-PCR） method was designed to quantify class 1 integrase mRNA production in planktonic cultured cells, biofilm cells and amotic cells from the biofilm of two clinical strains of P. aeruginosa respectively. Results Two clinical strains of P. aeruginosa produced intI1 mRNA in the three different conditions on different levels, in which the quantities of the mRNA expressed by their biofilms were about 4 times higher than their amotic cells from biofilm and about 15 times higher than their planktonic cells. Conclusion In P. aeruginosa biofilm, the integrase gene was up-regulated at mRNA level. And the higher level of integrase maybe conduce to capture and accumulate gene cassettes for bacteria in biofilm, which may be one of the reasons for the spread of antibiotic resistance and the formation of multidrug resistance.

关 键 词：铜绿假单胞菌 生物被膜 整合子 整合酶 竞争RT—PCR 

分 类 号：R387.991[医药卫生—医学寄生虫学]