发展了一种微流控芯片纸基细菌分析技术,用于多重细菌鉴定与抗生素敏感性测试。制备了阵列培养池芯片,以滤纸作为衬底固定显色培养基和抗生素。利用PVDF疏水薄膜止流阀,将尿液样品引入芯片并分隔于不同培养池。借助于培养池阵列的空间分辨力,实现多重细菌分析。根据特异性显色结果实现细菌鉴定,通过实时显色强度分析实现细菌定量,依据抑制显色反应的最低抗生素浓度确定抗生素敏感性。以3种泌尿系统感染常见病原菌(大肠杆菌、金黄色葡萄球菌和粪肠球菌)为模拟测试对象进行分析,结果表明,芯片方法可以在18 h内实现对3种细菌的同时鉴定及6种抗生素敏感性测试。对照实验显示,芯片法与传统方法细菌鉴定和抗生素敏感性测试结果一致性分别为94.1%和93.9%。本研究建立的微流控芯片细菌分析方法简便快速,非常适合于医疗资源匮乏条件下的细菌分析。
A microfluidic chip assay was described for bacteria identification and antibiotic susceptibility test( AST). Filter paper pads were embedded in arrayed microchambers,with immobilized antibiotics and chromogenic medium. By taking advantage of the polyvinylidene fluoride( PVDF) membrane based valves,urine sample introduced was distributed in individual chambers without cross contamination. The simultaneous analysis of multiple bacteria was achieved by using the culture chamber array design. The identification of a bacterium was based on its specific colorimetric result. The density of a bacterium was determined by real-time monitoring color intensity in the chamber,and its susceptibility to an antibiotic was determined relying on the lowest antibiotic concentration that inhibited the colorimetric reaction. A set of three common uropathogenic bacteria were selected as models to test the microfluidic approach. Our results showed that the developed microfluidic assay was able to complete bacteria identification and the six-antibiotic AST in 18 h. In comparison with the conventional method,the microchip method showed a coincidence of 94. 1% and 93. 9%with regard to bacteria identification and AST,respectively. The developed microfluidic approach is simple and rapid,thus hold the potential to serve as a powerful tool for bacterial analysis under conditions of poor medical resource.