淋球菌对大观霉素耐药机制的研究

发布时间：2018-04-14 04:37

本文选题：淋球菌 + 淋病奈瑟氏菌　；参考：《安徽医科大学》2015年硕士论文

【摘要】：目的探讨淋球菌16Sr RNA和rps E基因突变与淋球菌对大观霉素耐药性之间的关系。方法1.琼脂稀释法检测6株淋球菌对大观霉素的最小抑菌浓度(MIC)2.对临床分离的4株大观霉素耐药的淋球菌株(MIC128mg/L、256mg/L)的16S r RNA和rps E基因进行PCR扩增测序分析,寻找可能的突变位点.3.通过DNA转化技术将含有突变的rps E基因的细菌基因组DNA转化入敏感的淋球菌株,检测转化成功的淋球菌的MIC并进行PCR扩增测序,分析发现的突变位点与淋球菌大观霉素耐药的相关性。结果1.对大观霉素敏感,耐药者为4株、2株,2.4株大观霉素耐药的菌株均发现rps E基因A70C(Thr24Pro)突变,而16S r RNA大观霉素耐药决定区(SRDR)未发现任何突变;大观霉素敏感菌株的16S r RNA和rps E基因均未发现突变。转化后获得的大观霉素耐药淋球菌中亦发现了同样的rps E基因突变。结论淋球菌对大观霉素耐药菌株的耐药性问题已经出现,但是,全球范围内大观霉素耐药的案例还是非常罕见的。对广谱头孢菌素等抗菌药物敏感性降低的多重耐药淋球菌的出现,使得大观霉素仍然是目前世界上治疗泌尿生殖系统淋球菌感染的有效药物。本研究描述了核糖体5S蛋白中Thr24Pro突变可能影响其与16S r RNA 34螺旋的相互作用,从而导致大观霉素耐药。rps E等位基因中A70C单步突变与淋球菌大观霉素耐药性的形成有关。但本组研究耐药菌数量较少,研究范围有限,仍需进一步对淋球菌耐药性机制的研究。
[Abstract]:Objective to investigate the relationship between the mutations of 16Sr RNA and rps E genes in Neisseria gonorrhoeae and the resistance of Neisseria gonorrhoeae to spectinomycin.Method 1.The minimal inhibitory concentration of 6 strains of Neisseria gonorrhoeae to spectinomycin was detected by Agar dilution method.The 16s r RNA and rps E genes of four strains of gonorrhoeae resistant to spectinomycin were amplified and sequenced by PCR amplification.The genomic DNA of bacteria containing mutated rps E gene was transformed into a sensitive gonococcus strain by DNA transformation technique. The MIC of the transformed gonococcus was detected and sequenced by PCR amplification.The mutation site was found to be related to the resistance of Neisseria gonorrhoeae to spectinomycin.Result 1.4 strains were resistant to spectinomycin, and 4 strains were resistant to spectinomycin. All of them had the mutation of rps E gene A70CnThr24Pro. but no mutation was found in 16s r RNA.No mutation was found in 16s r RNA and rps E genes of Micromycin sensitive strains.The same mutation of rps E gene was also found in the transformed Neisseria gonorrhoeae.Conclusion the drug resistance of Neisseria gonorrhoeae to spectinomycin resistant strains has appeared, but the cases of resistance to spectinomycin in the world are very rare.The emergence of multidrug resistant Neisseria gonorrhoeae with decreased susceptibility to broad-spectrum cephalosporins makes spectinomycin still an effective drug for the treatment of gonococcal infection in the genitourinary system.This study described that Thr24Pro mutation in ribosomal 5S protein may affect its interaction with 16s r RNA 34 helix, leading to the single step mutation of A70C in the allele of spectinomycin resistance. RPS E allele is related to the formation of drug resistance of Neisseria gonorrhoeae.However, the number of drug-resistant bacteria in this study is relatively small and the scope of research is limited, so the mechanism of drug resistance of Neisseria gonorrhoeae needs to be further studied.
【学位授予单位】：安徽医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R446.5

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