RT-PCR法检测不同部位胃镜活检样本中幽门螺杆菌感染及耐药性的意义

Significance of Hp infection and drug resistance detection in different parts of gastroscopic biopsy specimens by RT-PCR method

目的应用实时荧光定量-聚合酶链反应(RT-PCR)方法,分别对胃窦和胃体部进行幽门螺杆菌(Hp)鉴定及其对克拉霉素耐药基因突变检测,以了解同一患者不同部位Hp感染及耐药情况,更好地为临床用药提供指导。方法选取60例功能性消化不良,且经14C呼气试验确诊Hp阳性的患者,经胃镜分别在胃窦及胃体部采样活检,采用RT-PCR方法对此120例标本Hp感染情况进行鉴定,随后对Hp阳性的标本进行克拉霉素耐药基因A2142G和A2143G突变情况检测。结果 120例标本中有116例Hp阳性,其中胃窦部56例(93.3%),胃体部60例(100%),有4位患者(6.7%)不同部位Hp感染的鉴定结果不一致。在116例Hp阳性标本中,48例(41.4%)为野生型,67例(57.8%)为突变型,1例(0.9%)同时存在野生型及A2143G、A2142G突变型。在67例耐药Hp中,47例为A2143G纯合突变,18例为A2143G杂合突变,2例为A2142G纯合突变。在56位胃窦和胃体Hp感染均为阳性的患者中,有7位患者(12.5%)不同部位Hp对克拉霉素耐药基因突变存在差异,主要为A2143G纯合与杂合突变间的差异(5/7),敏感与耐药间的差异(1/7),以及混合感染与单纯耐药间的差异(1/7)。结论使用RT-PCR方法将胃窦及胃体两个典型部位分别进行Hp相关检测,可提高Hp的检出率,且有助于正确判断Hp的存在部位以及耐药Hp的突变位点和类型,进而优化临床治疗方案,指导抗菌素的选择,从而提高Hp的根除率。

Objective To detect Helicobacter pylori（ Hp） infection and clarithromycin-based genotypic drug resistance in the antrum and corpus of stomach with RT-PCR,respectively,and to understand the infection and resistance of Hp in different parts of a same patient in order to guide clinical medication. Methods Sixty functional dyspepsia patients diagnosed as Hp-positive infection by 14 C-urea breath tests were involved in the study. RT-PCR was used to detect Hp from120 gastric biopsy specimens sampled from the antrum and corpus of stomach,and the A2142 G and the A2143 G mutations of clarithromycin-resistant genes of Hp were detected from Hp-positive specimens. Results Of the 120 specimens,116 were Hp-positive,including 56 cases of gastric antrum（ 93. 3%） and 60 cases of stomach（ 100%）. For 4 patients（ 6. 7%）,the detection results were different according to different sampling parts. Of the 116 Hp-positive specimens,48（ 41. 4%） were wild type,67（ 57. 8%） were mutation type,and 1（ 0. 86%） was both wild type and A2143 G/A2142 G mutation type. Of the 67 drug-resisting Hp specimens,47 were A2143 G homozygous mutation,18 were A2143 G heterozygous mutation,and 2 were A2142 G homozygous mutation. Of the 56 patients with positive antrum and corpus Hp infections,7（ 12. 5%） had differences in clarithromycin resistance mutations in Hp sampled from different parts,including differences（ 5/7） between A2143 G homozygous and heterozygous mutations,difference（ 1/7） between drug sensitivity,and difference（ 1/7） between polyinfection and simple drug resistance. Conclusions Using RT-PCR to detect Hp in the antrum and corpus of the stomach respectively could improve the detection rates of Hp infection. It is helpful to determine the location of Hp and the mutant site/type of the Hp resisting to drug,which could improve the therapy,guide the selection of antibiotics,and thus improve the eradication rate of Hp infection.