耐阿奇霉素淋球菌的基因分型研究及头孢曲松低敏淋球菌的penA、porB、mtrR基因多态性研究

发布时间：2018-05-03 07:47

本文选题：淋球菌 + 基因分型　；参考：《北京协和医学院》2011年博士论文

【摘要】：淋病奈瑟菌(简称淋球菌)是淋病的病原体,可引起尿道炎、宫颈炎等。阿奇霉素是我国尿道炎、宫颈炎常用治疗药物之一,临床症状不典型的淋病患者可能只接受到阿奇霉素治疗,故开展淋球菌对阿奇霉素的敏感性监测是非常有意义的。与阿奇霉素不同,头孢曲松作为目前淋病一线治疗药物,一直是我国淋球菌耐药监测药物之一,监测结果显示近年来淋球菌对头孢曲松的敏感性下降趋势比较明显,故开展淋球菌对头孢曲松的耐药机制研究显得越来越重要。淋球菌多抗原序列分型方法(NG-MAST)是一种操作简便、分型能力强的基因分型方法,本研究应用NG-MAST方法分析耐阿奇霉素淋球菌和头孢曲松低敏株的基因型别和菌株间的进化关系,为淋病防治工作提供参考依据。全文分为3个部分,各部分的主要内容简述如下：第一部分南京和重庆地区淋球菌对阿奇霉素的敏感性测定本部分旨在了解南京和重庆地区淋球菌对阿奇霉素的敏感性。选取2008年及2009年南京和重庆地区分离的318株淋球菌,采用琼脂稀释法测定阿奇霉素、头孢曲松、大观霉素、四环素、环丙沙星对这318株淋球菌的最低抑菌浓度(MIC),耐阿奇霉素淋球菌定义为每批实验中大于或等于阿奇霉素对质控菌株WHO P(阿奇霉素耐药株)的MIC值的菌株。318株淋球菌中有17株(5.3%)淋球菌对阿奇霉素耐药。第二部分耐阿奇霉素淋球菌的NG-MAST基因分型研究本部分旨在了解南京和重庆地区耐阿奇霉素淋球菌的基因型别和菌株间的进化关系。对第一部分检测出的17株耐阿奇霉素淋球菌进行NG-MAST基因分型,并利用Mega软件作进化树分析。17株耐阿奇霉素淋球菌共有11种NG-MAST基因型别,其中5种为新注册的基因型别。有6株菌的基因型别(ST)为ST3356,2株高度耐阿奇霉素的菌株(MIC64mg/L)具有相同的基因型别ST1866。基因型别ST3367及4种新注册的基因型别与菌株数最多的基因型别ST3356亲缘关系较近,可能均为短传播链上同一来源菌株。第三部分头孢曲松低敏淋球菌的penA、porB、mtrR基因多态性研究本部分旨在了解penA、porB、mtrR基因多态性在淋球菌对头孢曲松敏感性下降中的作用。选取第一部分检测出的17株头孢曲松低敏株和4株头孢曲松敏感株进行penA、porB、mtrR基因测序和NG-MAST基因分型。21株淋球菌的penA基因编码的青霉素结合蛋白2(PBP2)中共发现9种氨基酸结构模式,其中2种未报道过。有8株头孢曲松低敏株中存在ⅩⅧ型PBP2,有4株头孢曲松低敏株中存在ⅩⅢ型PBP2,未发现镶嵌状结构模式(X)PBP2。有18株淋球菌含有porB1b基因(编码PorB1b蛋白),PorB1b中I218M、M257T/M257R和G259V氨基酸置换都只在头孢曲松低敏株中出现。21株淋球菌的1mtrR基因编码的MtrR中存在A39T或G45D或H105Y氨基酸置换,A39T氨基酸置换只在3株头孢曲松低敏株中出现,G45D或H105Y氨基酸置换在头孢曲松低敏株和头孢曲松敏感株中均出现。17株头孢曲松低敏株共有13种NG-MAST基因型别,其中3种为新注册的基因型别。PENa、porB、mtrR基因多态性可能在淋球菌对头孢曲松敏感性下降中起一定作用。
[Abstract]:Neisseria gonorrhoeae (Neisseria gonorrhoeae) is the pathogen of gonorrhea, which can cause urethritis and cervicitis. Azithromycin is one of the commonly used medications in Chinese urethritis and cervicitis. The patients with atypical gonorrhea may only receive azithromycin treatment. Therefore, it is of great significance to monitor the sensitivity of azithromycin to the gonorrhoeae. Unlike azithromycin, ceftriaxone is one of the first line treatment drugs for gonorrhea. It has been one of the drug resistance monitoring drugs of gonococcus in China. The monitoring results show that the tendency of gonococcus to ceftriaxone is more obvious in recent years. Therefore, it is becoming more and more important to carry out the study of the drug resistance mechanism of gonococcus to ceftriaxone. The original sequence classification method (NG-MAST) is a simple and highly typed genotyping method. This study applies the NG-MAST method to analyze the evolutionary relationship between the genotypes and the strains of the azithromycin resistant Neisseria gonorrhoeae and ceftriaxone low sensitive strains, and provides the reference basis for the prevention and treatment of gonorrhea. The full text is divided into 3 parts, the main parts of each part The following is as follows:
Part 1 sensitivity of Neisseria gonorrhoeae to azithromycin in Nanjing and Chongqing
The purpose of this section is to understand the sensitivity of gonococci to azithromycin in Nanjing and Chongqing. Select 318 strains of gonococcus isolated from Nanjing and Chongqing in 2008 and 2009, and determine azithromycin, ceftriaxone, ditamicin, tetracycline, ciprofloxacin, the minimum inhibitory concentration (MIC), and azithromycin resistance of the 318 strains of gonococcus by agar dilution method in 2008 and 2009. Neisseria gonorrhoeae was defined as a strain larger than or equal to the MIC value of azithromycin WHO P (azithromycin resistant strain) in each batch. 17 strains (5.3%) of Neisseria gonorrhoeae were resistant to azithromycin in Neisseria gonorrhoeae.
The second part is NG-MAST genotyping of azithromycin resistant Neisseria gonorrhoeae.
This part aims to understand the evolutionary relationship between the genotypes and strains of azithromycin resistant gonococci in Nanjing and Chongqing. 17 strains of azithromycin resistant Neisseria gonorrhoeae detected in the first part of NG-MAST genotyping and 11 NG-MAST genotypes in.17 resistant gonorrhoeae resistant.17 strains were analyzed by Mega software, of which 5 species were found. The genotypes (ST) with 6 strains of bacteria (MIC64mg/L) with the same genotype ST1866. genotype ST3367 and 4 newly registered genotypes were closely related to the genotype ST3356 of the most bacteria number, which may be the same source strain on the short transmission chain.
The third part is penA, porB and mtrR gene polymorphisms of ceftriaxone hypersensitivity Neisseria gonorrhoeae.
The purpose of this part is to understand the effect of penA, porB, and mtrR gene polymorphism on the sensitivity decline of gonococcus to ceftriaxone. 17 strains of ceftriaxone and 4 ceftriaxone sensitive strains detected in the first part were selected for penA, porB, mtrR gene sequencing and penA gene encoding of gonococci of.21 strain of.21 strain of.21 strain of NG-MAST White 2 (PBP2) found 9 amino acid structure patterns, 2 of which were not reported. There were 8 ceftriaxone low sensitive strains, 4 strains of ceftriaxone PBP2, no mosaic structure model (X) PBP2., 18 strains of gonococcus containing porB1b gene (encoded PorB1b protein), I218M, M257T/M257R and G25 PorB1b in PorB1b 9V amino acid replacement in the ceftriaxone low sensitive strain showed the presence of A39T or G45D or H105Y amino acid replacement in the 1mtrR gene encoding.21 strain of gonococcus, and A39T amino acid replacement only appeared in 3 ceftriaxone low sensitive strains. G45D or H105Y amino acid replacement appeared in the ceftriaxone low sensitive strain and the ceftriaxone sensitive strain. There are 13 NG-MAST genotypes in the hypersensitivity strain of triaxone, 3 of which are newly registered genotypes.PENa, porB, and mtrR gene polymorphisms may play a role in the decrease of ceftriaxone sensitivity.

【学位授予单位】：北京协和医学院
【学位级别】：博士
【学位授予年份】：2011
【分类号】：R759.2

【参考文献】