幽门螺杆菌耐药基因的DNA序列分析
发布时间：2019-06-29 14:39
【摘要】：背景和目的:幽门螺杆菌(Hp)是一种能长期定植于胃黏膜的致病菌,全球约50%的人口感染Hp。Hp 感染与慢性胃炎、消化性溃疡、胃癌以及MLAT淋巴瘤的发生密切相关,1994 年国际癌症研究机构已将其列为人类Ⅰ类致癌因子。国内外学者已形成共识——对Hp 感染需要进行根除治疗。根除Hp 方案中常用的抗生素有甲硝唑、阿莫西林、克拉霉素和四环素等,但Hp 对这些抗生素相继产生高低不一的耐药率,已严重影响根除Hp 的治疗效果。Hp 的耐药性与耐药基因突变有密切关系,rdxA 与甲硝唑耐药有关,pbp1A 与阿莫西林耐药有关,23S rRNA 与克拉霉素耐药有关,16S rRNA 与四环素耐药有关。以往受技术限制,无法精确描述耐药基因中的DNA 序列变化情况,本研究采用DNA 测序技术研究耐药菌株与敏感菌株之间耐药基因的DNA 差异,探索基因突变在Hp 耐药产生过程中的作用。 方法:将胃镜活检标本,接种于含7%-10%羊血Skirrow 选择性培养基,37℃微需氧环境培养3-5 天,共分离262 株Hp,鉴定后,菌种-80℃保存。药敏试验采用纸片扩散法,对204 例Hp 临床分离菌株分别进行甲硝唑、阿莫西林、克拉霉素和四环素药敏试验,筛选出各药物的耐药菌株和敏感菌株。从MTZ~R 菌株、MTZS 菌株和Hp11637 扩增rdxA 基因;从AMXR 菌株、AMXS菌株和Hp11637 扩增pbp1A 基因;从CLR~R菌株、CLR~S菌株和Hp11637 扩增23S rRNA 基因;从TET~R 菌株、TETS 菌株和Hp11637 扩增16SrRNA 基因。PCR 产物进行DNA 测序,测序结果采用DNAStar 和NCBI Blast 分析,探讨临床菌株和标准菌株的DNA 序列和氨基酸序列差异。 结果:①Hp 对抗生素耐药率分别为:甲硝唑50.0%(102/204);阿莫西林4.4%(9/204);克拉霉素8.8%(18/204);四环素4.4%(9/204)。②临床分离菌株与26695 比较rdxA 基因同源性,MTZ~R菌株为93.25%±1.93%;MTZ~S菌株93.79%±1.14%,P0.05,无统计学意义,临床分离菌株与26695 比较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，
本文编号：2507896
[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，
本文编号：2507896
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