2013-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/645670摘要：結核病仍舊是世界上最嚴重的傳染病，治療抗藥性結核病尤其是嚴格的考驗，其中多重抗藥性結核病(multidrug-resistant tuberculosis)更是嚴峻的問題。氟喹諾酮(Fluoroquinolone, FQs)是治療多重抗藥結核病最重要的藥物，若多重抗藥性結核菌產生FQs抗藥，會進一步變成更難治療的廣泛抗藥性結核病及全抗藥性結核病。FQs藉由抑制結核菌DNA gyrase，進而抑制細菌DNA的複製及轉錄，過去的研究顯示，結核菌對FQs抗藥性的產生多來自於gyrA基因上的諾酮抗性決定區域(quinolone resistance determining region, QRDR)突變，致使DNA gyrase結構發生改變，減弱FQs藥品的作用。然而，也只有約64%的FQs抗藥結核菌在gyrA QRDR發現到突變。多重藥物輸出幫浦(Efflux pump)的活化推測也是結核菌產生FQs及多重藥物抗藥的重要機轉。過去我們也發現，台灣地區FQs抗藥結核菌僅有43%發現位於QRDR內的的gyrA或gyrB基因突變；同時，FQs抗藥結核菌，容易同時伴隨其他藥物抗藥。然而，其他發生FQs抗藥的機轉，尤其是合併多重抗藥的機轉，仍然未知。因此，我們設計了這個研究，將從三個方向進行探討：(1)收集臨床上的FQs抗藥菌株，包括合併多重抗藥結核菌株，詳細臨床資訊，進行菌株分子演化分型、同時檢測gyrA, gyrB QRDR及QRDR以外區域、rifampicin抗藥基因rpoB、isoniazid 抗藥基因(inhA及katG) 基因變異和最低抑菌濃度(minimal inhibitory concentration，MIC)間的關係，(2)檢測多重藥物輸出幫浦活性和最低抑菌濃度，多重抗藥間的關係並探討不適當藥物和誘發多重藥物輸出幫浦的相關性；(3)挑選獲得性FQs抗藥配對菌株及多重抗藥菌株進行次世代全基因體定序及比較性分析，期望能進一步發現，台灣地區結核菌產生FQs抗藥的可能新機轉。期望經由三個面向的研究，能找出早期偵測及預防結核菌產生FQs抗藥的方法。<br> Abstract: Tuberculosis (TB), especially drug-resistant TB, remains one of the most serious challenges to public health in spite of global control efforts. The emergence of multidrug-resistant (MDR)-TB, defined as resistance of MTB to at least two of the most effective anti-tuberculosis drugs, namely isoniazid and rifampicin has hampered TB control. Fluoroquinolone(FQs) antibiotics are among the most potent second-line drugs used for treatment of MDR-TB, and gathering resistance to this class of antibiotics is the most critical step to extensively drug resistant (XDR) TB which is associated with very high mortality rate. FQs inhibit bacterial DNA gyrase which is essential for DNA replication, transcription, and recombination. Mutations in the quinolone resistance determining region (QRDR) of gyrA and gyrB genes were suspected as the most common mechanisms leading to FQs resistance in M. tuberculosis isolates. However, only 43% of clinical FQs resistance isolates in Taiwan have gyrA mutations in the QRDR region. The FQs resistance also tended to be cross resistant with other anti-tuberculous drugs. Studies regarding to other mechanisms including mutations in areas of gyrA or gyrB outside of the QRDR and activate a drug efflux pump (EPs) are still lacking. Therefore, in this study, we will measure the association between minimal inhibitory concentrations, cross resistance, strain genotype, clinical information, drug exposures and mutations in and outside of the QRDR of gyrA and gyrB, as well as, rpoB, inhA and katG. Secondary, we will measure the activity of drug efflux pump and associated risk factors. We also will measure the inducible activity of drug efflux pump with drug exposure. Finally, we will perform whole genome sequencing in selected paired acquired FQs resistance and MDR isolates. We will perform comparative analysis of these genomes with existing TB genomes, find SNPs and find correlations of genome variations with resistance of corresponding bacteria to FQs. We follow up these computational analyses with laboratory experiments to validate the importance of candidate FQ resistance-conferring mutations. We hope we can close the gap on critical deficiencies in data of the mechanisms and risk factors for FQs resistance to support TB patient treatment.結核病氟喹諾酮抗藥多重抗藥性結核病tuberculosisfluoroquinolone resistancemultidrug-resistant tuberculosis