Yüksel Pelin, Tansel Ozlem
Medical Faculty of Trakya University, Department of Clinical Microbiology and Infectious Diseases, Edirne, Turkey.
New Microbiol. 2009 Apr;32(2):153-8.
Mutations in the pyrazinamidase (PZase) gene (pncA) are considered the major mechanism of pyrazinamide (PZA) resistance in Mycobacterium tuberculosis. The aim of this study was designed to determine pncA mutations among ten PZA resistant and two PZA susceptible M. tuberculosis strains from Turkey and also to compare the PZase activity of them with the genotype. All isolates were identified by BACTEC NAP (P-nitro-alpha-acetylamino-beta-hydroxy-propiophenone) test and PCR-RFLP (Polymerase Chain Reaction- Restriction Fragment Length Polymorphism) method. Drug sensitivity tests were performed by BACTEC system. PncA mutations were detected by DNA sequence analysis. No mutation was detected in two PZA susceptible and three out of ten PZA resistant strains. While, two of the PZA resistant strains had mutations in the same region (Gly24Asp), two of the PZA resistant strains had mutations in different regions (Thr160Lys), (His51Pro). Three of the PZA resistant strains had frameshift as a 167 bp deletion at nucleotide position 102. As a result, we detected two new mutations and a frameshift which may be responsible for PZA resistance in this study different from the other studies which previously 51st codon mutation was reported.
吡嗪酰胺酶（PZase）基因（pncA）突变被认为是结核分枝杆菌对吡嗪酰胺（PZA）耐药的主要机制。本研究旨在确定来自土耳其的10株对PZA耐药和2株对PZA敏感的结核分枝杆菌菌株中的pncA突变情况，并将它们的PZase活性与基因型进行比较。所有分离株均通过BACTEC NAP（对硝基-α-乙酰氨基-β-羟基苯丙酮）试验和PCR-RFLP（聚合酶链反应-限制性片段长度多态性）方法进行鉴定。药敏试验通过BACTEC系统进行。通过DNA序列分析检测PncA突变。在2株对PZA敏感和10株对PZA耐药菌株中的3株中未检测到突变。同时，2株对PZA耐药的菌株在同一区域发生突变（Gly24Asp），2株对PZA耐药的菌株在不同区域发生突变（Thr160Lys）、（His51Pro）。3株对PZA耐药的菌株在核苷酸位置102处发生167 bp缺失导致移码突变。结果，我们在本研究中检测到两个新的突变和一个移码突变，它们可能是PZA耐药的原因，这与之前报道第51位密码子突变的其他研究不同。
