2例利奈唑胺中介粪肠球菌血流感染的毒力及耐药机制

发布时间：2018-02-27 00:16

本文关键词： 利奈唑胺粪肠球菌细菌耐药机制毒力基因　出处：《中国感染控制杂志》2017年11期 　论文类型：期刊论文

【摘要】：目的对血流感染患者临床分离的利奈唑胺中介粪肠球菌的毒力因子及耐药机制进行初步研究。方法从2例血流感染患者血标本中分离2株利奈唑胺中介粪肠球菌,分析患者治疗经过,2株分离菌编号为A、B,测定其对利奈唑胺和万古霉素的最低抑菌浓度(MIC),采用聚合酶链反应(PCR)扩增毒力基因(esp、asa1、gelE、ace、agg、efaA、cylA、hyl)和利奈唑胺耐药相关基因,包括23SrRNA V区基因、cfr、cfr(B)及optrA基因片段,其中23SrRNA V区基因扩增产物送测序并分析有无突变位点。结果 2例患者培养出利奈唑胺中介粪肠球菌后均使用利奈唑胺治疗控制了临床症状。菌株A、B对万古霉素、替考拉宁、氨苄西林、呋喃妥因敏感,对利奈唑胺中介(MIC均为4μg/mL),对万古霉素敏感(MIC分别为1μg/mL和4μg/mL)。2株菌均含有多种毒力因子,菌株A仅cylA、hyl为阴性,菌株B仅hyl、esp为阴性,其余毒力基因均为阳性。菌株A的23SrRNA V区存在G2621T突变,菌株B未发现突变位点。菌株A和B耐药基因cfr、cfr(B)、optrA均为阴性。结论此研究中血流感染患者分离的利奈唑胺中介粪肠球菌对万古霉素和氨苄西林敏感,虽治疗结果提示利奈唑胺仍有效,但临床中选用利奈唑胺治疗需谨慎。靶位突变是该类药物重要的耐药机制,临床中治疗该类药物不敏感粪肠球菌感染需足够重视,其治疗策略仍需进一步探讨。
[Abstract]:Objective to study the virulence factor and drug resistance mechanism of alanzolamine mediated Enterococcus faecalis in blood stream infection patients. Methods two strains of Enterococcus faecalis were isolated from blood samples of 2 patients with blood flow infection. After treatment, two strains of isolated bacteria were identified as Anezolidomide and vancomycin. The virulence gene (Espasa1) and the related genes of linazolamine resistance were amplified by polymerase chain reaction (PCR). Including 23s rRNA V gene, cfrfrfrb) and optrA gene fragment, The amplified products of 23s rRNA V region were sequenced and the mutation sites were analyzed. Results the clinical symptoms were controlled by the treatment of alanzolamine in two patients after the culture of alanzolamine mediated Enterococcus faecalis. Strain Anb was used to treat vancomycin and teicoplanin. The mics of ampicillin and furantoin were 4 渭 g / mL, and the MIC of vancomycin sensitive to vancomycin were 1 渭 g / mL and 4 渭 g / mL, respectively. The virulence factors of strain A were negative only cylAtohyl, but only hylesp of strain B was negative, and the sensitivity to vancomycin was 1 渭 g / mL and 4 渭 g / mL, respectively. All the other virulence genes were positive. G2621T mutation existed in the 23s rRNA V region of strain A. No mutation site was found in strain B. strains A and B were both negative for cfrfrcfrcfrcfrcfrcfrboptrA. Conclusion the isolates isolated from patients with blood flow infection in this study were sensitive to vancomycin and ampicillin, and the strains were resistant to vancomycin and ampicillin. Although the therapeutic results suggest that linazolamide is still effective, it is necessary to be careful in the treatment of the drug. Target mutation is an important drug resistance mechanism of the drug, and enough attention should be paid to the treatment of the insensitive Enterococcus faecalis infection in clinic. Its treatment strategy still needs to be further explored.
【作者单位】：广东医科大学附属深圳市南山区人民医院深圳市内源性感染诊治研究重点实验室;
【基金】：深圳市科技创新委课题资助(No.JCYJ20150402152130167、JCYJ20150402152130173) 深圳市卫人委课题(No.201601058) 深圳市南山区课题资助(No.2015019、2015022、2016001、2016002、2016010、2016012、2016013、2016018、2016017) 深圳市南山区人民医院(No.2016010) 深圳市重点学科和重点实验室建设经费资助
【分类号】：R446.5

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