【摘要】：背景和目的:幽門螺桿菌(Hp)是一種能長期定植于胃黏膜的致病菌,全球約50%的人口感染Hp。Hp 感染與慢性胃炎、消化性潰瘍、胃癌以及MLAT淋巴瘤的發(fā)生密切相關(guān),1994 年國際癌癥研究機(jī)構(gòu)已將其列為人類Ⅰ類致癌因子。國內(nèi)外學(xué)者已形成共識——對Hp 感染需要進(jìn)行根除治療。根除Hp 方案中常用的抗生素有甲硝唑、阿莫西林、克拉霉素和四環(huán)素等,但Hp 對這些抗生素相繼產(chǎn)生高低不一的耐藥率,已嚴(yán)重影響根除Hp 的治療效果。Hp 的耐藥性與耐藥基因突變有密切關(guān)系,rdxA 與甲硝唑耐藥有關(guān),pbp1A 與阿莫西林耐藥有關(guān),23S rRNA 與克拉霉素耐藥有關(guān),16S rRNA 與四環(huán)素耐藥有關(guān)。以往受技術(shù)限制,無法精確描述耐藥基因中的DNA 序列變化情況,本研究采用DNA 測序技術(shù)研究耐藥菌株與敏感菌株之間耐藥基因的DNA 差異,探索基因突變在Hp 耐藥產(chǎn)生過程中的作用。 方法:將胃鏡活檢標(biāo)本,接種于含7%-10%羊血Skirrow 選擇性培養(yǎng)基,37℃微需氧環(huán)境培養(yǎng)3-5 天,共分離262 株Hp,鑒定后,菌種-80℃保存。藥敏試驗采用紙片擴(kuò)散法,對204 例Hp 臨床分離菌株分別進(jìn)行甲硝唑、阿莫西林、克拉霉素和四環(huán)素藥敏試驗,篩選出各藥物的耐藥菌株和敏感菌株。從MTZ~R 菌株、MTZS 菌株和Hp11637 擴(kuò)增rdxA 基因;從AMXR 菌株、AMXS菌株和Hp11637 擴(kuò)增pbp1A 基因;從CLR~R菌株、CLR~S菌株和Hp11637 擴(kuò)增23S rRNA 基因;從TET~R 菌株、TETS 菌株和Hp11637 擴(kuò)增16SrRNA 基因。PCR 產(chǎn)物進(jìn)行DNA 測序,測序結(jié)果采用DNAStar 和NCBI Blast 分析,探討臨床菌株和標(biāo)準(zhǔn)菌株的DNA 序列和氨基酸序列差異。 結(jié)果:①Hp 對抗生素耐藥率分別為:甲硝唑50.0%(102/204);阿莫西林4.4%(9/204);克拉霉素8.8%(18/204);四環(huán)素4.4%(9/204)。②臨床分離菌株與26695 比較rdxA 基因同源性,MTZ~R菌株為93.25%±1.93%;MTZ~S菌株93.79%±1.14%,P0.05,無統(tǒng)計學(xué)意義,臨床分離菌株與26695 比較RdxA
[Abstract]:Background and objective: HP (Hp) is a kind of pathogen which can be planted in gastric mucosa for a long time. About 50% of the global population infected with Hp.Hp is closely related to the occurrence of chronic gastritis, peptic ulcer, gastric cancer and MLAT's lymphoma. in 1994, the International Cancer Research Agency listed it as a class I carcinogenic factor in human beings. Scholars at home and abroad have reached a consensus that Hp infection needs eradication treatment. Metronidazole, amoxicillin, clarithromycin and tetracycline are commonly used to eradicate Hp, but Hp has different resistance rates to these antibiotics, which has seriously affected the therapeutic effect of Hp eradication. HP resistance is closely related to drug resistance gene mutation, rdxA is related to metronidazole resistance, pbp1A is related to amoxicillin resistance, 23s rRNA is related to clarithromycin resistance, and 16s rRNA is related to tetracycline resistance. In the past, it was impossible to accurately describe the changes of DNA sequence in drug-resistant genes due to technical limitations. In this study, DNA sequencing technique was used to study the DNA difference of drug-resistant genes between drug-resistant strains and sensitive strains, and to explore the role of gene mutation in the production of Hp resistance. Methods: gastroscopic biopsies were inoculated in selective medium containing 7% 鈮，

本文編號：2507896