第一类整合子整合酶基因intI1的定位分析

目的　整合子 ( integrons)介导的细菌耐药特性已成为研究细菌耐药机制的热点 ,在研究了来自正常人携带沙门氏菌中整合子的分布和特性的基础上 ,进一步探讨整合子的基因定位。方法　从已鉴定的整合子阳性菌株出发 ,分别提取其质粒和染色体 DNA,进行质粒的接合转移试验。对染色体 DNA进行限制性酶切 ,以第一类整合酶基因 int I1( DIG标记 )为探针 ,进行 Southern杂交。结果　 4株整合酶阳性菌株不存在含有第一类整合子的接合性质粒 ,确定 4株整合子阳性菌株的整合酶基因 int I1基因位于染色体上。结论　本文发现的整合子阳性菌株对耐药基因的捕获是通过染色体 DNA介导的。

Analysis of location of the integrase intI1 gene in class 1 integron positive Salmonella strains

Objective Integrons and gene cassettes have been recently the hotspot in the research of antibiotic resistance. Based on the distribution and characterization of Class 1 integron among Salmonella isolates from healthy human, localization was further investigated in this paper. Methods Plasmid and chromosome DNA of the integron positive strains were extracted. Then plasmids were conjugated. Digested with restriction endonuclease, of chromosomal DNA was performed by Southern hybridization with probe specific for intI 1 of PCR. Results No transconjugation plasmid was detected among four integron positive isolates, but all hybridization signals on chromosome. Integrons were all located on chromosomal DNA. Conclusion Acquisition of antibiotic resistance gene of the integrons containing strains was mediated by chromosomal DNA.