两种方法测定替加环素对鲍曼不动杆菌药敏结果的比较

目的：比较采用两种方法测定替加环素对鲍曼不动杆菌药敏结果的差异。方法：分别采用琼脂平板稀释法和微量肉汤稀释法测定替加环素对70株鲍曼不动杆菌的MIC值,比较其结果差异性。结果：应用琼脂平板稀释法测定的MIC50和MIC90为1μg·mL-1和2μg·mL-1,敏感率、中介率、耐药率分别为47.1%、48.6%、4.3%;应用微量肉汤稀释法测定的替加环素对鲍曼不动杆菌的MIC50和MIC90分别为0.25μg·mL-1和0.5μg·mL-1,敏感率为100%。两种方法测定结果的一致性和相关性均较差;以微量肉汤稀释法为基准时,应用琼脂平板稀释法测定的总误差率为52.9%。结论：应用琼脂平板稀释法和微量肉汤稀释法进行替加环素对鲍曼不动杆菌药敏测定时,其敏感率有明显的差别。

Comparison of two methods on susceptibility testing of tigecycline against Acinetobacter baumannii

Objective： To study the difference of two testing methods on the susceptibility results of tigecycline against Acinetobacter baumannii.Methods： Minimal inhibitory concentrations（MICs） of 70 isolates of Acinetobacter baumannii were determined by the agar dilution method and broth microdilution method respectively as described by the Clinical and Laboratory Standards Institute（CLSI）,and the differences of two methods were compared.Results： The MIC50 and MIC90 values obtained by agar dilution method were 1 μg.mL-1,2 μg.mL-1 respectively,and the susceptible,intermediate and resistant rates were 47.1%,48.6%,4.3%,respectively;while the MIC50 and MIC90 values obtained by broth microdilution method were 0.25 μg.mL-1,0.5 μg.mL-1 respectively,and the susceptible rate was 100%.Weak coherence and correlation were found between the two methods.If broth microdilution method was taken as the reference method,the total error rate of agar dilution method was 52.9%.Conclusion： There was significant difference on susceptible rate between the two methods for the susceptibility testing of tigecycline against Acinetobacter baumannii.