致病性大肠杆菌引起的感染严重威胁人类健康,而传统的抗生素敏感性试验(AST)有很长的周转时间,临床上迫切需要快速的抗生素敏感性方法来挽救生命,减少抗生素滥用,防止抗生素耐药菌的出现。我们优化并验证了基于SYBRGreenI和碘化丙啶的新型快速AST(SGPI-AST)用于大肠杆菌药敏试验的可行性。共收集了112株临床分离的大肠杆菌和4种抗生素(头孢曲松,头孢西丁,亚胺培南,选择美罗培南)进行测试。在不同的OD600值下,大肠杆菌的细菌存活率与S值呈显著的线性相关。优化抗生素浓度后,SGPI-AST的敏感性和特异性达到100%/100%,97.8%/100%,100%/100%和98.4%/99%为头孢曲松,头孢西丁,亚胺培南和美罗培南,分别,SGPI-AST与常规AST的对应一致性分别为1.000、0.980、1.000和0.979。SGPI-AST能在60min内快速准确地测定临床分离的大肠杆菌对多种抗生素的敏感性,并有潜力应用于指导临床治疗致病性大肠杆菌引起的感染的抗生素的精确选择。
Infections caused by pathogenic Escherichia coli are a serious threat to human health, while conventional antibiotic susceptibility tests (AST) have a long turn-around time, and rapid antibiotic susceptibility methods are urgently needed to save lives in the clinic, reduce antibiotic misuse and prevent emergence of antibiotic-resistant bacteria. We optimized and validated the feasibility of a novel rapid AST based on SYBR Green I and Propidium Iodide (SGPI-AST) for E. coli drug susceptibility test. A total of 112 clinical isolates of E. coli were collected and four antibiotics (ceftriaxone, cefoxitin, imipenem, meropenem) were selected for testing. Bacterial survival rate of E. coli was remarkably linearly correlated with S value at different OD600 values. After optimizing the antibiotic concentrations, the sensitivity and specificity of SGPI-AST reached 100%/100%, 97.8%/100%, 100%/100% and 98.4%/99% for ceftriaxone, cefoxitin, imipenem and meropenem, respectively, and the corresponding concordances of the SGPI-AST with conventional AST were 1.000, 0.980, 1.000 and 0.979, respectively. The SGPI-AST can rapidly and accurately determine the susceptibility of E. coli clinical isolates to multiple antibiotics in 60 min, and has the potential to be applied to guide the precise selection of antibiotics for clinical management of infections caused by pathogenic E. coli.