The efficacy of fluoroquinolone-based eradication therapy largely depends on the fluoroquinolone resistance of H. pylori. The aim of this study was to investigate the changes in the primary resistance rate of H. pylori to fluoroquinolone and the mechanism of resistance in Korea. A total of 153 strains and 48 strains of H. pylori were isolated at a tertiary hospital in 2005/2006 and 2017/2018, respectively. The minimum inhibitory concentrations (MICs) of fluoroquinolone were determined by the serial 2-fold agar dilution method. DNA sequences in the quinolone resistance-determining regions of gyrA/gyrB were analyzed in resistant strains. Subsequent natural transformation study was performed to determine the association between gyrase mutation and resistance. The resistance rates increased from 19.0% (29/153) to 43.8% (21/48) both for levofloxacin and moxifloxacin. The MIC values for resistant strains increased from 2–8 µg/mL to 4–16 µg/mL over time. Mutation of gyrA was detected in 93.1% (27/29) and 100% (21/21) among the resistant strains in both periods, respectively. A novel Gly-85 mutation of gyrA was found and confirmed to be associated with fluoroquinolone resistance. Fluoroquinolone resistance rate of H. pylori has markedly increased over time in Korea. The resistance is mostly due to the point mutation of gyrA. Fluoroquinolone-containing regimens should be carefully selected in Korea, considering the increasing fluoroquinolone resistance.

中文翻译：

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在14年的时间里发现一种新型的DNA促旋酶突变和幽门螺杆菌对氟喹诺酮耐药性的变化：韩国的单中心研究。

基于氟喹诺酮的根除疗法的疗效在很大程度上取决于幽门螺杆菌的氟喹诺酮耐药性。这项研究的目的是调查幽门螺杆菌对氟喹诺酮的主要耐药率的变化及其在韩国的耐药机制。2005/2006年和2017/2018年，三级医院共分离出153株幽门螺杆菌和48株幽门螺杆菌。氟喹诺酮的最低抑菌浓度（MICs）通过连续2倍琼脂稀释法确定。gyrA / gyrB喹诺酮耐药性决定区域中的DNA序列在抗性菌株中进行了分析。随后进行了自然转化研究，以确定回旋酶突变与抗性之间的关联。左氧氟沙星和莫西沙星的耐药率均从19.0％（29/153）增加到43.8％（21/48）。随着时间的推移，抗性菌株的MIC值从2–8 µg / mL增加到4–16 µg / mL。在两个时期的耐药菌株中，分别检测到gyrA突变为93.1％（27/29）和100％（21/21）。发现了一种新的gyrA Gly-85突变，并证实与氟喹诺酮耐药有关。在韩国，幽门螺杆菌对氟喹诺酮类药物的耐药率已随时间显着增加。抵抗力主要是由于gyrA的点突变。考虑到氟喹诺酮耐药性的增加，在韩国应谨慎选择含氟喹诺酮的治疗方案。