应用噬菌体裂解法测定吡嗪酰胺药物敏感性试验的方法学研究

目的　探索利用噬菌体裂解法测定吡嗪酰胺药物敏感性试验的更佳实验条件、时间及其临床应用价值。方法 应用已建立的PhaB法;但在Middlebrook 7H9酸性液体培养基中加入0.4%的丙酮酸钠作为探索实验对照组。然后观察原已建立的PhaB法与加入丙酮酸钠后实验对照组这两者间的空白管溶菌斑数量以及药物最佳作用时间,并以此对86例结核分枝杆菌临床分离株进行吡嗪酰胺药物敏感性试验,最后与比例法的药物敏感性试验结果进行比较。结果 在Middlebrook 7H9酸性液体培养基中加入丙酮酸钠后的实验对照组,其空白管溶菌斑平均有71个,而PhaB法空白管溶菌斑平均只有53个,两者间平均有18个溶菌斑的差异;药物与细菌的作用:实验对照组1d时间与比例法药物敏感性试验结果有90.7%的符合率,2d时间为87.2%,PhaB法的符合率是88.4%。结论 在已建立的PhaB法基础上,于Middlebrook 7H9酸性液体培养基中加入丙酮酸钠,可以提高实验的准确性以及缩短药物与细菌的作用时间。

Study on the methodology of pyrazinamide susceptibility testing by phage-based splitting assay

Objective To study the optimal experiment protocol,time of pyrazinamide susceptibility testing by phage-based splitting assay and its clinical applications.Result Middlebrook 7H9 acid liquid culture medium containing was added 0.4% sodium pyruvate as control.The numbers of plaques in the blank tubes and the optimal pyrazinamide action time of PhaB group and control group were observed.The drug susceptibility testing dilution method was used as control,pyrazinamide susceptibility testing by phage-based splitting assay and PhaB method were performed in 86 Mycobacterium tuberculosis isolates.Result The blank tubes in the control group and PhaB group formed 71 and 53 plaques,repectively.The agreement rates between the dilution method and new method were 90.7% and 87.2% after one day and two days of pyrazinamide action on the isolates,respectively.The agreement rate between the dilution method and PhaB method was 88.4%.Conclusions Based on PhaB,Middlebrook 7H9 acid culture medium containing sodium pyruvate could improve the accuracy of the test and shorten the action time between pyrazinamide and Mycobacterium tuberculosis.