贵州省黔南州幽门螺杆菌克拉霉素的耐药性及23S rRNA基因突变的特征

Clarithromycin resistance and 23S rRNA gene mutation characteristics of Helicobacter pylori isolates from patients in Qiannan Autonomous Prefecture

目的:了解贵州省黔南州幽门螺杆菌(Helicobacter pylori,H.pylori)克拉霉素耐药相关基因突变情况.方法:采用改良琼脂稀释法检测分离自黔南州人民医院的74株H.pylori对克拉霉素的敏感性,选取H.pylori克拉霉素耐药菌株22株、敏感株10株,以及NCTC11637进行23S rRNA基因功能区V区片段的PCR扩增和测序,与GenBank中收录的H.pylori敏感菌株U27270相关序列进行比对和分析.结果:74株H.pylori克拉霉素耐药率为29.7%(22/74).共发现10种突变类型,其中在耐药菌株及敏感菌株23S rRNA V区均存在的基因突变包括:T2183C、T2245C和T2321C;仅在耐药株(22株)中检测到的突变包括:A2144G(4/22)、A2224G(4/22)、C2196T(1/22)、C2289 T(1/22)、A2435G(1/22)、C2695A(1/22)、T2712C(1/22).结论:黔南州医院分离的H.pylori克拉霉素耐药率较高;与耐药性相关的23S rRNA基因突变主要为A2144G和A2224G;本院菌株存在A2435G、C2695A、T2712C 3种尚未见报道的突变.

AIM：To investigate the antibiotic sensitivity of Helicobacter pylori（H.pylori） isolates from patients in the People＇s Hospital of Qiannan Autonomous Prefecture and to analyze mutations in the domain V of 23 S rRNA gene that are related with clarithromycin resistance.METHODS：Clarithromycin susceptibility tests of 74 H.pylori isolates were performed by the modified agar dilution method（breakpoint susceptibility testing）.Domain V of 23 S rRNA gene of 22 clarithromycin resistant strains,10 clarithromycin susceptible strains and a control stain（NCTC11637） were amplified and sequenced.Nucleotide homology of these sequences were compared to H.pylori U27270（GenBank accession number：U27270） which is a susceptible strain.RESULTS：Clarithromycin resistance rate of74 H.pylori isolates was 29.7%（22/74）.Ten types of mutations in domain V of 23 S rRNA gene were found in this study.T2183 C,T2245 C and T2321 C mutations were found in both clarithromycin resistant strains and susceptible strains.Mutations only found in resistant strains included A2144G（4/22）,A2224G（4/22）,C2196T（1/22）,C2289T（1/22）,A2435G（1/22）,C2695A（1/22） and T2712C（1/22）.CONCLUSION：Clarithromycin resistance rateof H.pylori isolates from the People＇s Hospital of Qiannan Autonomous Prefecture was high.A2144 G and A2224 G mutations were the most prevalent mutation types related with clarithromycin resistance and there were three novel mutation types（A2435G,C2695 and T2712C）.