Evaluation of the GenoType MTBDRplus assay for rifampin and isoniazid susceptibility testing of Mycobacterium tuberculosis strains and clinical specimens
Evaluation of the GenoType MTBDRplus assay for rifampin and isoniazid susceptibility testing of Mycobacterium tuberculosis strains and clinical specimens
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DOI：
10.1128/jcm.00521-07
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发表时间：
2007-08-01
影响因子：
9.4
通讯作者：
Richter, Elvira
中科院分区：
文献类型：
--
作者：
Hillemann, Doris;Ruesch-Gerdes, Sabine;Richter, Elvira
对125株临床分离株和72份涂阳痰标本进行了新的MTBDRplus基因分型试验(Hain Lifescience GmbH，Nehren)，以检测结核分枝杆菌复合体(MTBC)对利福平(RMP)和异烟肼(INH)的耐药性。用新旧MTBDR方法对106株RMPR/INHr、10株RMPs/INHr和80株RMPs/INHS MTBC进行了比较分析。除了检测rpoB和katG密码子315的81bp热点区域内的突变外，还设计了MTBDRplus基因型检测inha调控区的突变。新的检测方法直接适用于标本，因为72个涂阳痰标本中有71个结果是可解释的，所有125个临床分离株的结果都是可解释的，与实时荧光聚合酶链式反应或DNA测序的结果没有差异。与常规药敏试验相比，两种方法对RMP的耐药率分别为98.7%(74/75)和96.8%(30/31)。对两株含有rpoB P533L突变的菌株进行了RMP耐药性的误判。与原MTBDR法相比，新基因MTBDRplus法将75株异烟肼耐药株的异烟肼耐药率从66株(88.0%)提高到69株(92.0%)，在41例异烟肼耐药株中将36株(87.8%)提高到37株(90.2%)。因此，新的MTBDRplus基因型法是检测菌株中或直接从涂阳标本中检测异烟肼和RMP耐药性的可靠和升级的工具。
The new GenoType MTBDRplus assay (Hain Lifescience GmbH, Nehren, Germany) was tested with 125 clinical isolates and directly with 72 smear-positive sputum specimens for its ability to detect rifampin (RMP) and isoniazid (INH) resistance in Mycobacterium tuberculosis complex (MTBC) strains. In total, 106 RMPr/ INHr, 10 RMPs/INHr, and 80 RMPs/INHs MTBC strains were comparatively analyzed with the new and the old MTBDR assays. Besides the detection of mutations within the 81-bp hot spot region of rpoB and katG codon 315, the GenoType MTBDRplus assay is designed to detect mutations in the regulatory region of inhA. The applicability of the new assay directly to specimens was shown, since 71 of 72 results for smear-positive sputa and all 125 results for clinical isolates were interpretable and no discrepancies compared with the results of real-time PCR or DNA sequencing were obtained. In comparison to conventional drug susceptibility testing, both assays were able to identify RMP resistance correctly in 74 of 75 strains (98.7%) and 30 of 31 specimens (96.8%). The misidentification of RMP resistance was obtained for two strains containing rpoB P533L mutations. Compared to the old MTBDR assay, the new GenoType MTBDRplus assay enhanced the rate of detection of INH resistance from 66 (88.0%) to 69 (92.0%) among the 75 INH-resistant strains and 36 (87.8%) to 37 (90.2%) among the 41 specimens containing INH-resistant strains. Thus, the new GenoType MTBDRplus assay represents a reliable and upgraded tool for the detection of INH and RMP resistance in strains or directly from smear-positive specimens.