Performance of the microscopic observation drug susceptibility assay in pyrazinamide susceptibility testing for Mycobacterium tuberculosis
Performance of the microscopic observation drug susceptibility assay in pyrazinamide susceptibility testing for Mycobacterium tuberculosis
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显微观察药敏试验在吡嗪酰胺结核分枝杆菌药敏试验中的表现
DOI：
10.3760/cma.j.issn.0366-6999.20130108
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发表时间：
2013-11-20
影响因子：
6.1
通讯作者：
Li Jun-ming
中科院分区：
文献类型：
--
作者：
Huang Zi-kun;Luo Qing;Li Jun-ming
背景药敏试验在结核病治疗中具有重要意义。吡嗪酰胺是一线抗结核药物，结核分枝杆菌对吡嗪酰胺的耐药性检测。结核病）是困难和耗时的常规方法。在这项研究中，我们的目的是评估性能的显微镜观察药物敏感性（MODS）试验检测吡嗪酰胺耐药的M。相对于常规韦恩测定和Lowenstein-詹森（LJ）比例法，方法M.用MODS和韦恩法对132株结核病临床分离株进行检测，并与LJ比例法进行比较。通过直接测序吡嗪酰胺耐药的所有分离株的pncA基因，鉴定基因突变。结果与LJ法比较，MODS法的敏感性和特异性分别为97.8%和96.5%，韦恩法的敏感性和特异性分别为87.0%和97.7%。在吡嗪酰胺耐药的46株菌株中的41株（3次试验）、4株菌株中的1株（仅LJ）、48株菌株中的42株（至少1次试验）中发现pncA基因突变，但仅根据MODS试验，在1株敏感菌株中未发现突变。MODS测定、韦恩测定和LJ比例法分别在6、7和26天的中位时间内提供结果。结论MODS检测法是一种快速、简便、可靠的检测M.结核病，是资源有限国家的最佳替代方法。
Background Drug susceptibility assay is very important in tuberculosis therapy. Pyrazinamide is a first line antituberculosis drug and diagnosis of its resistance in Mycobacterium tuberculosis (M. tuberculosis) is difficult and time consuming by conventional methods. In this study, we aimed to evaluate the performance of the microscopic observation drug susceptibility (MODS) assay in the detection of pyrazinamide resistance in M. tuberculosis relative to the conventional Wayne assay and Lowenstein‐Jensen (LJ) proportion method. Methods M. tuberculosis clinical isolates (n=132) were tested by the MODS and the Wayne assay: the results were compared with those obtained by the LJ proportion method. Mutations in the gene were identified by direct sequencing of the pncA genes of all isolates in which pyrazinamide resistance was detected by any of the three methods. Results Compared to the LJ results, the sensitivity and specificity of the MODS assay were 97.8% and 96.5% respectively; the sensitivity and specificity of the Wayne assay were 87.0% and 97.7% respectively. Mutations in the pncA gene were found in 41 of 46 strains that were pyrazinamide resistant (3 tests), in 1 of the 4 strains (LJ only), in 42 of 48 strains (at least 1 test), but no mutations in 1 strain sensitive according to the MODS assay only. The MODS assay, Wayne assay and LJ proportion method provided results in a median time of 6, 7 and 26 days respectively. Conclusions MODS assay offers a rapid, simple and reliable method for the detection of pyrazinamide resistance in M. tuberculosis and is an optimal alternative method in resource limited countries.