志贺菌主动外排泵调控基因marOR突变与耐药的关系  

The relationship between marOR mutations and the antibiotic resistance in Shigella spp

作　　者：任静朝[1] 段广才[1] 杨海燕[1] 吕锐利[1] 张卫东[1] 郗园林[1] 

机构地区：[1]郑州大学公共卫生学院流行病学教研室,450001

出　　处：《中华微生物学和免疫学杂志》2010年第11期1044-1047,共4页Chinese Journal of Microbiology and Immunology

基　　金：基金项目：卫生部科研基金资助课题（WKJ2007-2-024）

摘　　要：目的 探讨临床分离志贺菌调控基因marOR的突变对细菌耐药性的影响.方法 利用重叠延伸PCR扩增4个碱基缺失的marOR基因,与T载体连接后转入DH5α,得到4个碱基缺失的marOR基因克隆株 4个碱基缺失联合3个点突变的marOR基因克隆株是扩增具有该突变菌株的marOR基因,然后与T载体连接后转入DH5α所得 通过凝胶电泳图谱和核酸序列分析证实克隆成功与否 检测DH5α、转入T载体后的DH5α[DH5α（T）]、完整marOR基因克隆株[DH5α（marOR）]、4个碱基缺失的marOR基因克隆株[DH5α（marOR-ACTT）]及4个碱基缺失联合3个点突变的marOR基因克隆株[DH5α（marOR-CATT＋3m）]对多种抗生素的耐药性,并进行比较.结果 按抑菌环直径相差5 mm以上为抗生素耐药性有差别：与DH5α（T）比较,DH5α（marOR-ACTT）对链霉素、妥布霉素、先锋V、头孢氨苄的耐药性增加,DH5α（marOR-ACTT＋3m）对链霉素和四环素的耐药性增加 与DH5α（marOR）比较,DH5α（marOR-ACTT）和DH5α（marOR-ACTT＋3m）对链霉素、四环素、氯霉素、先锋V、左氟沙星、环丙沙星和氟哌酸的耐药性增加 DH5o（marOR-CATT）与DH5α（marOR-CATT＋3m）相比对除甲氧苄啶外的试验所用抗生素的抑菌环直径无明显差异.结论 marOR基因第1376～1379处的4个碱基缺失,使志贺菌对部分抗生素的耐药性增加 marOR基因第1411、1417、1435处的点突变对志贺菌的耐药性的影响较小.Objective To detect the influence of marOR mutations on antibiotic resistance in Shigella spp. Methods The marOR gene with four-base deletion was amplified by overlap PCR, then inserted in a T-vector and transformed into DH5α. The clone of marOR gene with four-base deletion and three point mutations was prepared from the strain having these mutations. Electrophoresis and sequencing were preformed to certify the correction of the cloned genes. Drug susceptibility tests were preformed for the strains harbouring the different clones [DH5α, DH5α （T）, DH5α （marOR）, DH5α （marOR-CATT）, DH5α（marOR-CATT ＋ 3m）]. Results Compared with the control strain （DH5α-T）, the antibiotic resistances of marOR with four-base deletion [DH5α （marOR-CATT）] were higher to streptomycin, tobramycin, cefazolin and cefalexin, and the antibiotic resistances of marOR with four-base deletion and three point mutations [DH5α （marOR-CATT ＋ 3m）] were higher to streptomycin and to tetracycline. The antibiotic resistances of DH5α （marOR-CATT） and DH5α （marOR-CATT ＋3m） to streptomycin, tetracycline, chloramphenicol, cefazolin, levofloxacin, ciprofloxacin and norfloxacin were higher than DH5α （marOR）. The diameters of the antibiotics except the trimethoprim between DH5α （marOR-CATT） and DH5α （marORCATT ＋3m） had not significant disparity. Conclusion The four-base deletion in 1376-1379 sites of the marOR gene increased the resistance of Shigella spp to some antibiotics. The point mutations in 1411, 1417,1435 sites of the marOR gene have little influence on the antibiotic resistance of Shigella spp.

关 键 词：志贺菌 marOR基因突变 marOR基因克隆 耐药性 

分 类 号：R440[医药卫生—诊断学]