肠球菌对氟喹诺酮类药物外排机制及主动外排泵EmeA与耐药关系的研究

发布时间：2018-06-18 02:09

本文选题：肠球菌 + 氟喹诺酮类药物　；参考：《南华大学》2006年硕士论文

【摘要】：目的：检测肠球菌临床分离株对3种氟喹诺酮类药物(FQs)的敏感性，探讨肠球菌对FQs产生耐药性机制，研究主动外排泵EmeA在肠球菌的分布以及表达情况，为临床合理使用抗菌药物、控制肠球菌感染、研发新一代抗肠球菌药物提供理论依据。方法：随时收集临床送检标本，按全国临床检验操作规程肠球菌检测方法分离、培养、鉴定和药敏试验。用二倍琼脂稀释法测定临床分离株肠球菌对3种氟喹诺酮类药物的最低抑菌浓度(MIC)，以及利血平对MIC值的影响。用聚合酶链反应(PCR)检测编码主动外排泵EmeA的基因emeA在肠球菌临床株的分布，随机挑选一emeA基因阳性菌株，将其PCR产物纯化后测序，并对测序结果用Blast软件进行同源性分析，探讨肠球菌耐药与emeA基因的关系。用逆转录(RT)—PCR测定emeA基因阳性菌株中emeA mRNA的表达水平。结果：临床标本中分离得到肠球菌共112株，其中粪肠球菌82株，占73.2％；屎肠球菌28株，占25.0％；鸟肠球菌、坚韧肠球菌各1株，，各占0.9％。肠球菌主要分离于尿液66株(58.9％)、痰液31株(24.1％)、伤口分泌物10株(11.6％)，而其他标本仅有5株(5.4％)。 3种氟喹诺酮类药物的抗肠球菌活性(MIC_(50)，MIC_(90))从强到弱为：加替沙星分别为1mg／L，4mg／L、司帕沙星为2mg／L，8mg／L和左氧氟沙星为2mg／L，32mg／L。 112株临床株肠球菌中47株为耐药菌，占42.0％，其中10株对3种氟喹诺
[Abstract]:Objective: to detect the sensitivity of clinical isolates of Enterococcus to three fluoroquinolones (FQs), to explore the mechanism of resistance of Enterococcus to FQs, and to study the distribution and expression of EmeA in Enterococcus. It provides theoretical basis for rational use of antimicrobial agents, control of enterococcal infection and development of a new generation of anti-Enterococcal drugs. Methods: clinical specimens were collected at any time, and Enterococcus was isolated, cultured, identified and drug sensitive test according to the national procedure of clinical examination. The minimal inhibitory concentration of Enterococcus to three fluoroquinolones and the effect of reserpine on MIC were determined by double Agar dilution method. The distribution of emeA encoding active efflux pump EmeA gene in clinical strains of Enterococcus was detected by polymerase chain reaction (PCR). A emeA gene positive strain was randomly selected and sequenced after purification. The results were analyzed by blast software. To investigate the relationship between drug resistance of Enterococcus and emeA gene. The expression of emeA in emeA positive strains was detected by reverse transcriptase reverse transcription-polymerase chain reaction (RT-PCR). Results: a total of 112 strains of Enterococcus faecalis (82 strains, 73.2%), 28 strains of Enterococcus faecium (25.0%), 1 strain of Enterococcus faecium and 1 strain of Enterococcus tenacity (0.9%) were isolated from clinical specimens. Enterococcus was mainly isolated from 66 strains of urine (58.9%), sputum from 31 strains of sputum (24. 1%), wound secretions from 10 strains (11. 6%), and other specimens from 5 strains (5. 4%). 3 The anti-Enterococcal activity of fluoroquinolones was as follows: gatifloxacin was 1 mg / L / L 4 mg / L, sparfloxacin was 2 mg / L 8 mg / L and levofloxacin was 2 mg / L 32 mg / L respectively. Of 112 clinical strains of Enterococcus, 47 were drug-resistant bacteria. 42.0, of which 10 were against 3 fluoroquinolones
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R378

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