摘要
目的了解我院肠球菌的耐药形势,探讨耐利奈唑胺肠球菌的耐药形成机制,使临床更合理使用抗生素。方法采用琼脂稀释法和E-test纸片法对222株肠球菌菌株进行最低抑菌浓度(Minimum inhibitory concentration,MIC)的药敏检测,采用基因组提取试剂盒及煮沸法分别提取细菌DNA,对3株耐利奈唑胺的肠球菌提纯的DNA基因进行多重PCR检测,通过琼脂糖凝胶电泳以及基因测序对扩增产物进行鉴定,通过PFGE指纹图谱鉴定其同源性,对3株耐利奈唑胺肠球菌进行了接合转移实验。结果近3年来从临床分离的标本中共得到菌株222株,粪肠球菌113株;屎肠球菌103株。肠球菌对头孢克罗的耐药率最高(70.7%),接着为高单位庆大霉素(65.8%)、左氧氟沙星(39.6%)和氨苄西林(20.3%),替考拉宁及万古霉素二者的耐药率为最低(均为1.8%)。临床检测结果显示对利奈唑胺出现耐药的肠球菌为3株,且均为粪肠球菌。将三株菌株的PCR扩增产物测序、对序列进行比对后发现:23s rRNA-V区域2576位未发现点突变。PFGE指纹图谱显示三株菌株在条带上存在3条条带以上的差异。结论我院分离的肠球菌对头孢克罗、高单位庆大霉素呈现出高度耐药。对利奈唑胺、万古霉素、替考拉宁有较好的敏感性。本院临床分离的3株耐利奈唑胺粪肠球菌,在流行病学上可能无相关性(非同源),未出现23S rRNA-V区域G2576U、G2576T突变,耐药性也可能不经过质粒接合而传递。是否存在其他耐药机制,需进一步检测。
Objective To figure out the drug-resistance condition of Enterococcus and analyse the gene sequence of the resistant strains of Enterococcus and define the resistance formation mechanism in order to better guide the use of antimicrobial agents rationally in clinical. Methods Agar dilution method and E-test paper diffusion method had been used to test the drug susceptibility of minimum inhibitory concentration（MIC） of 222 strains of Enterococcus isolated in clinical and to measure its minimum antibacterial depth. The bacterial DNA had been extracted by genome extraction kit and boiling method. Multiplex PCR had been used to detect the DNA extracted from the 3 strians linezolid-resistance enterococcus and PCR products were identified by agarose gel electrophoresis and gene sequencing. To identify homology and resistance transfer of the 3 strians linezolid-resistance enterococcus by the PFGE fingerprint and plasmid conjugation transfer experiments. Results During the past 3 years, a total of 222 strains of enterococci were isolated from a variety of clinical specimens, including 113 strains of Enterococcus faecalis and 103 strains of Enterococcusfaecium. Among the various antibiotics commonly used in clinical, high concentration gentamicin exhibited the highest resistance to the isolates （70.7%）, about 65.8%, 39.6%, and 20.3% of Enterococcus isolates were resistant to cefaclor, levofloxacin and ampicillin, respectively. Enterococci showed thelowest resistance rate to vancomycin and teicoplanin （1.8% and 1.8%）. There were three strain enterococci showed resistant to Linezolid and those tested were Enterococcus faecalis. DNA of the 3 strains detected by PCR, and PCR products sequence alignment found： The DNA sequence of the 23s rRNA area of three samples showed that locus 2576 have not found any point mutations. PFGE fingerprint show the difference of more than 3 strips. Conclusion Vancomycin, teicoplanin and linezolid still possess the most potent antibacterial activity against enterococcus were isolate
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2013年第8期624-628,共5页
Chinese Journal of Antibiotics
基金
重庆市科委自然科学基金项目"应用比较基因组学研究中国屎肠球菌致病性增强机制"(cstciiλl0093)
