幽门螺杆菌对克拉霉素的耐药性和基因型的同一性  

Genotypic homogeneity and susceptibility to clarithromycin for clarithromycin-resistant Helicobacter pylori strains

作　　者：郑小丽[1] 胡伏莲[2] 王蔚虹[2] 许乐[1] 

机构地区：[1]卫生部北京医院消化科,100730 [2]北京大学第一医院消化科

出　　处：《中华医学杂志》2009年第22期1558-1562,共5页National Medical Journal of China

摘　　要：目的明确克拉霉素耐药的幽门螺杆菌（Hp）菌株耐药性和基因型的混合感染情况。方法从16株对克拉霉素耐药的Hp混合菌落菌株中各随机挑选10个单菌落，转代扩菌后，用琼脂稀释法测定单菌落对克拉霉素的最低抑菌浓度（MIC），CTAB／NaCl方法提取单菌落的DNA，用PCR-限制性片段长度多态性（RFLP）检测其点突变，随机扩增的多态性DNA（RAPD）方法比较各菌落的基因型。结果来自16个耐药Hp菌株的共160个单菌落均对克拉霉素耐药，且都存在23SrRNA基因的点突变。来自同一患者的克拉霉素耐药菌株的10个单菌落具有相同的RAPD指纹图谱，与亲代混合菌落菌株也有相同的RAPD指纹图谱。结论克拉霉素耐药的Hp菌株中未发现耐药性或基因型的混合感染存在。Objective To investigate the mixed infection of clarithromycin susceptibility and genotype of Helicobacter pylori resistant strains. Methods Ten single colonies were picked randomly from each of 16 resistant strains. Genomic DNA was prepared from single colony isolates and their parental clarithromycin-resistant strains by the hexadecyltrimethylammonium bromide （CTAB）-phenol extraction method. Susceptibilities of single colony isolates to clarithromycin were determined by agar dilution and mutations in clarithromycin-resistant isolates identified by polymerase chain reaction and restrictions analysis. Genotypes of 16 resistant strains and their single colony isolates were tested by the fingerprinting patterns of random amplified polymorphic DNA （RAPD）. Results All single colony isolates derived from 16 resistant strains were also resistant to clarithromycin and had the A2143G point mutation in 23 S rRNA gene. The RAPD fingerprints of single colony isolates derived from the same patient were identical to each other and to the RAPD fingerprint of the corresponding parental isolate. Conclusion Neither mixed susceptibility nor mixed genotype was found in clarithromycin resistant strains.

关 键 词：螺杆菌 幽门 克拉霉素 点突变 混合感染 

分 类 号：R57[医药卫生—消化系统] R378[医药卫生—内科学]