Ma Xiao-wei, Hu Zhong-yi, Wang Jie, Zhang Ying-rong, Cui Zhen-ling, Cao Xiang-yuan, Weng Xin-hua
The Laboratory of Tuberculosis, the Pneumonologic Hospital of Shanghai, Shanghai 200433, China.
Zhonghua Nei Ke Za Zhi. 2005 Mar;44(3):202-5.
To set up phage amplified biologically assay (PhaB) for rapid detection ethambutol (EMB) resistance and to evaluate the use of PhaB in the detection of EMB resistance.
To detect the EMB resistance of 138 clinical isolates of Mycobacterium tuberculosis (MTB) by PhaB and compare it with the results of BACTEC-960 system. The minimal inhibitory concentration (MIC) was detected for all the discrepant isolates.
Of all the 138 strains of MTB clinical isolates, 114 strains were EMB-susceptible and 24 strains were EMB-resistant with BACTEC-960 system while 118 strains were EMB-susceptible and 20 strains were EMB-resistant with PhaB. 112 of the 138 strains were EMB-susceptible and 18 strains were EMB-resistant with the two methods. The concordant isolates in determination of EMB resistance were 130 strains in the two methods and the concordance rate was 94.2%. The disconcordant isolates were 8 strains and the discrepancy rate was 5.8%. The sensitivity, specificity, positive and negative predictive value as well as overall accuracy for the PhaB assay was 75.0% (18/24), 98.2% (112/114), 90.0% (18/20), 94.9% (112/118) and 94.2% (130/138) respectively if the judgment standard was adopted by BACTEC-960 method.
The PhaB assay can be used for detection of EMB resistance in isolates of MTB easily and quickly in three days. This method do not need special instrument and may be used in rapid screening method for EMB resistance of MTB.
建立噬菌体扩增生物测定法（PhaB）用于快速检测乙胺丁醇（EMB）耐药性，并评估PhaB在EMB耐药性检测中的应用。
采用PhaB检测138株结核分枝杆菌（MTB）临床分离株的EMB耐药性，并与BACTEC-960系统的检测结果进行比较。对所有结果不一致的分离株检测其最低抑菌浓度（MIC）。
138株MTB临床分离株中，BACTEC-960系统检测出114株对EMB敏感，24株对EMB耐药；PhaB检测出118株对EMB敏感，20株对EMB耐药。两种方法检测结果均显示138株中有112株对EMB敏感，18株对EMB耐药。两种方法检测EMB耐药性的一致分离株为130株，一致率为94.2%。不一致分离株为8株，差异率为5.8%。以BACTEC-960法为判断标准，PhaB检测的灵敏度、特异度、阳性预测值、阴性预测值及总准确率分别为75.0%（18/24）、98.2%（112/114）、90.0%（18/20）、94.9%（112/118）和94.2%（130/138）。
PhaB检测法可在三天内简便快速地用于检测MTB分离株的EMB耐药性。该方法无需特殊仪器，可用于MTB EMB耐药性的快速筛查。
