腹腔感染大肠埃希菌PFGE谱型及耐药一致性分析

PFGE analysis and antimicrobial resistance of E. coli isolated from intra-abdominal infection

目的探究腹腔感染大肠埃希菌菌株间的相关性及菌株间同源性与药敏结果一致性的关系。方法使用限制性内切酶XbaⅠ对菌株基因组进行酶切,对酶切后的DNA片段进行脉冲场凝胶电泳(PFGE),使用Bionumerics软件分析菌株间相关性,将菌株同源性与药敏结果一致性进行对比分析。结果47株大肠埃希菌PFGE图谱间同源性为60.4%~97.4%,同源性高于85%有6株。一次自发性细菌性腹膜炎(SBP)可以由一种PFGE谱型的大肠埃希菌引起,也可能是多种PFGE谱型大肠埃希菌的混合感染。一次SBP可能是新发感染,也可能是上次感染的复发。同源性高于85%的菌株对本研究中19种抗菌药物中的15种以上抗菌药物的药敏试验结果相同。结论导致不同患者腹腔感染的大肠埃希菌来源不同。同源性高于85%的菌株药敏结果具有较高的一致性。

Objective To study the relationship of E.coli strains isolated from intra-abdominal infection, and the relationship of homology and the antimicrobial susceptibility results of different strains. Methods DNA of strains were digested with XbaⅠ restriction enzyme, then were typed by pulsed field gel electrophoresis(PFGE). PFGE patterns were analyzed with Bionumerrics software. The antimicrobial susceptibility results of E. coli strains and the clinical information of patients were collected. Results The homology of strains were from 60.4% to 97.4%, 6 among 47 strains were above 85%. One episode of SBP could be a result of reinfection caused by one PFGE type strain, or more than one PFGE type strains, also could be a recurrent infection of the last episode. Antimicrobial susceptibility results of more than 15 antibiotics were indentical among strains with genetic similarity ≥ 85%. Conclusions Most strains isolated from intra-abdominal infection were different. Strains with genetic similarity ≥ 85% have identical or similar antimicrobial susceptibility.