Hacettepe University, Vocational School of Health Services, Ankara, Turkey.
Department of Medical Biology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
Turk J Gastroenterol. 2023 Apr;34(4):427-432. doi: 10.5152/tjg.2023.21954.
The purpose of this study was to determine the antimicrobial status of stocked clinical Helicobacter pylori isolates by using antibiotic gradient test and subsequently identify the mutations that cause clarithromycin resistance by DNA sequencing. Turkey is a transition zone between Europe and Asia; therefore, we also aimed to show both continents' mutations in Turkish isolates.
One hundred forty-seven H. pylori isolates that had been stocked at -80°C between 1998 and 2008 were randomly selected and included in the study. Antibiotic susceptibility tests were performed using antibiotic gradient test for clarithromycin, amoxicillin, tetracycline, metronidazole, and levofloxacin. A polymerase chain reaction targeting the region of 23S rRNA gene domain V of H. pylori was performed and the mutations responsible for resistance against clarithromycin were defined by sequencing.
All of the tested isolates were found susceptible to amoxicillin and tetracycline. However, clarithromycin, metronidazole, and levofloxacin resistance were detected in 28.5% (42/147), 44.8% (66/147), and 23.1% (34/147) of the isolates, respectively. Point mutations were detected in 46 isolates (46/147, 31.2%). The majority of mutations were defined as A2143G (19/46, 41.3%), A2142G (14/46, 30.4%), and A2142C (7/46, 15.2%), respectively. T2188C, T2182C, G1949A, G1940A, and C1944T mutations were also identified in the isolates.
In conclusion, the most common mutations associated with clarithromycin resistance in H. pylori have been identified as A2143G, A2142G, and A2142C which are the most frequently detected mutations in European countries. Same mutations and other mutations like T2182C have also been detected frequently in north-eastern countries and China. Since Turkey is a transition zone between Europe and Asia, Turkey might have strains that carry mutations found in both continents.
本研究旨在通过抗生素梯度试验确定库存临床幽门螺杆菌分离株的抗菌状态，然后通过 DNA 测序鉴定导致克拉霉素耐药的突变。土耳其是欧洲和亚洲的过渡地带；因此，我们还旨在展示土耳其分离株中两个大陆的突变。
随机选择 1998 年至 2008 年间储存在-80°C 的 147 株幽门螺杆菌分离株进行研究。使用抗生素梯度试验对克拉霉素、阿莫西林、四环素、甲硝唑和左氧氟沙星进行药敏试验。针对幽门螺杆菌 23S rRNA 基因结构域 V 区的聚合酶链反应，并通过测序确定对抗生素克拉霉素耐药的突变。
所有测试分离株均对阿莫西林和四环素敏感。然而，在 28.5%（42/147）、44.8%（66/147）和 23.1%（34/147）的分离株中检测到克拉霉素、甲硝唑和左氧氟沙星耐药。在 46 株分离株（46/147，31.2%）中检测到点突变。大多数突变被定义为 A2143G（19/46，41.3%）、A2142G（14/46，30.4%）和 A2142C（7/46，15.2%）。在分离株中还鉴定出 T2188C、T2182C、G1949A、G1940A 和 C1944T 突变。
总之，已经确定了与幽门螺杆菌克拉霉素耐药相关的最常见突变，这些突变与欧洲国家最常检测到的突变相同，如 A2143G、A2142G 和 A2142C。在东北国家和中国也经常检测到相同的突变和其他突变，如 T2182C。由于土耳其是欧洲和亚洲的过渡地带，土耳其可能携带在两个大陆都发现的突变株。
