肠球菌耐药性及esp基因与粪肠球菌耐药的相关性

发布时间：2018-05-13 06:10

本文选题：肠球菌 + esp基因　；参考：《南华大学》2005年硕士论文

【摘要】：目的:检测肠球菌临床分离株对6种抗菌药物的敏感性,分析粪肠球菌临床株的esp基因扩增序列,以揭示肠球菌临床株的耐药现状及esp基因与粪肠球菌耐药的关系,为临床合理选用药物治疗肠球菌感染提供实验及理论依据。方法:从临床实验室收集肠球菌感染标本,进行分纯、培养、鉴定;用琼脂平板稀释法检测去甲万古霉素、氨苄西林、环丙沙星、阿奇霉素和红霉素对肠球菌的最低抑菌浓度(MIC)及鉴定庆大霉素高浓度(MIC≥500μg/mL)耐药株,筛选出对6种抗菌药物呈不同程度耐药或多重耐药的肠球菌。然后用PCR法扩增粪肠球菌临床株的esp基因;随机挑选一阳性菌株,将其PCR产物克隆到pUC18载体,转化大肠杆菌JM109,蓝白斑筛选挑取阳性重组子进行限制性内切酶酶切、PCR及测序鉴定,并对测序结果用Blast软件进行同源性分析,探讨粪肠球菌耐药与esp基因的关系。结果:从临床分离的肠球菌共78株,其中粪肠球菌61株,占78.2%;屎肠球菌15株,占19.2%;鸟肠球菌、坚韧肠球菌各1株,共占2.6%。去甲万古霉素对肠球菌的MIC_(50)、MIC_(90)分别为0.μg/mL和4μg/mL;氨苄西林和环丙沙星的MIC_(50)、MIC_(90)分别为1μg/mL和4μg/mL、16μg/mL和64μg/mL:阿奇霉素和红霉素的MIC_(50)、MIC_(90)较高,分别为16μg/mL和32μg/mL、64μg/mL和128μg/mL。未检测出去对甲万古霉素耐药的肠球菌,肠球菌对氨苄西林、环丙沙星、高浓度庆大霉素、阿奇霉素和红霉素的耐药率分别为16.7%、53.8%、56.4%、74.4%、85.9%。粪肠球菌和屎肠球菌对氨苄西林的耐药率分别为9.8%和46.7%(P0.01);对环丙沙星的耐药率分别为50.8%和73.3%(P0.05),这两种主要肠球菌对氨苄
[Abstract]:Objective: to detect the susceptibility of clinical isolates of Enterococcus faecalis to 6 kinds of antimicrobial agents, and analyze the amplified sequence of esp gene of Enterococcus faecalis clinical strains, so as to reveal the current situation of drug resistance of Enterococcus faecalis and the relationship between esp gene and drug resistance of Enterococcus faecalis. To provide experimental and theoretical basis for clinical rational selection of drugs for enterococcal infection. Methods: enterococcal infection specimens were collected from clinical laboratory, isolated, cultured and identified, and norvancomycin, ampicillin and ciprofloxacin were detected by Agar plate dilution method. The minimal inhibitory concentration (MIC) of azithromycin and erythromycin against Enterococcus spp. Then the esp gene of Enterococcus faecalis clinical strain was amplified by PCR, and a positive strain was selected randomly, and its PCR product was cloned into pUC18 vector, and transformed into E. coli JM109. The positive recombinant was screened and identified by restriction endonuclease digestion and sequencing. The results of sequencing were analyzed by Blast software to investigate the relationship between drug resistance of Enterococcus faecalis and esp gene. Results: a total of 78 strains of Enterococcus faecalis, 15 strains of Enterococcus faecium, 1 strain of Enterococcus tenacity and 1 strain of Enterococcus tenacity, accounted for 78.2%, 19.2% and 2.6%, respectively, were isolated from clinic. The mice of ciprofloxacin and ampicillin are 1 渭 g/mL and 4 渭 g / mL, respectively, which are 1 渭 g/mL and 4 渭 g / mL, 16 渭 g/mL and 64 渭 g / mL, respectively, and 16 渭 g / mL and 64 渭 g / mL of azithromycin and erythromycin, respectively, which are 16 渭 g/mL and 32 渭 g / mL, 64 渭 g/mL and 128 渭 g / mL respectively. The resistance rates of Enterococcus to ampicillin, ciprofloxacin, high concentration of gentamicin, azithromycin and erythromycin were 16.73.8and 56.4%, respectively. The resistance rates of Enterococcus to ampicillin, ciprofloxacin and erythromycin were 56.4% and 85.9%, respectively. The resistance rates of Enterococcus faecalis and Enterococcus faecium to ampicillin were 9.8% and 46.7%, respectively, and those to ciprofloxacin were 50.8% and 73.3%, respectively.
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2005
【分类号】：R378

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