Background and objectives

Peptic ulcer disease, chronic gastritis, and stomach cancer are all caused by H. pylori. The most notable drug for the treatment is the antibiotic clarithromycin, which is currently the drug of choice. H. pylori clarithromycin resistance has been associated with point mutations in 23srRNA, the most prominent of which are A2143 and A2144G. In H. pylori bacteria, methylase synthesis, macrolide-inactivating enzyme activity, and active efflux have all been found to be resistance mechanisms. The goal of the study is to determine how resistant H. pylori is to clarithromycin and what the minimum inhibitory concentration is for various antimicrobials. Furthermore, gastro-endoscopy will be performed on Iraqi patients to detect the presence of A2143G and A2144G point mutations in Helicobacter pylori infections, as diagnosed from the pyloric region and other anatomical regions.

Methods

One hundred fifteen samples were collected from patients strongly suspected of H. pylori infection presented for upper gastrointestinal endoscopy at Ramadi Teaching Hospitals and Private Clinics for the period from January 2020 until February 2021. Specimens were cultured on brain heart infusion agar containing various antibiotics and were incubated at 37 °C under microaerophilic conditions. For identification of H. pylori, isolates of the biochemical tests and RT-PCR assay were applied. The Epsilometer test was used in the antibiotic susceptibility testing as dependent on the CLSI standard. The Restriction Fragment Length Polymorphism technique was used to determine point mutations.

Results

In total, 55 (47.8%) Helicobacter pylori isolates were cultured from the 115 biopsy specimens, among which 16 (29.1%), 38 (69.1%), 20 (36.4%), and 40 (72.7%) revealed some degree of resistance to levofloxacin, clarithromycin, ciprofloxacin, and metronidazole, respectively. The frequency of A2144G and A2143 point mutations were 23 (60.5%) and 19 (50%), respectively.

Conclusions

According to our results, Helicobacter pylori showed high resistance to clarithromycin. Our results demonstrate the requirement for antibiotic susceptibility testing and molecular methods in selecting drug regimens.

中文翻译：

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幽门螺杆菌临床分离株克拉霉素耐药性和 23SrRNA 点突变的检测：表型和分子方法

背景和目标

消化性溃疡病、慢性胃炎和胃癌都是由幽门螺杆菌引起的。最值得注意的治疗药物是抗生素克拉霉素，目前是首选药物。幽门螺杆菌克拉霉素耐药与 23srRNA 的点突变有关，其中最突出的是 A2143 和 A2144G 。在幽门螺杆菌中，甲基化酶合成、大环内酯类灭活酶活性和主动外排都被发现是耐药机制。该研究的目的是确定H. pylori的抗药性如何是克拉霉素，各种抗菌药物的最低抑菌浓度是多少。此外，将对伊拉克患者进行胃内镜检查，以检测幽门螺杆菌感染中是否存在 A2143G 和 A2144G 点突变，这些突变是从幽门区域和其他解剖区域诊断出来的。

方法

从 2020 年 1 月至 2021 年 2 月期间，从拉马迪教学医院和私人诊所接受上消化道内镜检查的高度怀疑幽门螺杆菌感染的患者身上采集了115 个样本。样本在含有各种抗生素的脑心浸液琼脂上培养，并在在微需氧条件下在 37°C 下孵育。为了鉴定幽门螺杆菌，应用了生化测试和 RT-PCR 分析的分离物。根据 CLSI 标准，在抗生素敏感性测试中使用了 Epsiometer 测试。限制性片段长度多态性技术用于确定点突变。

结果

115份活检标本共培养出55份（47.8%）幽门螺杆菌分离株，其中16份（29.1%）、38份（69.1%）、20份（36.4%）和40份（72.7%）显示出一定程度的耐药性。分别为左氧氟沙星、克拉霉素、环丙沙星和甲硝唑。A2144G 和 A2143 点突变的频率分别为 23 (60.5%) 和 19 (50%)。

结论

根据我们的结果，幽门螺杆菌对克拉霉素表现出高耐药性。我们的研究结果表明，在选择药物方案时需要进行抗生素敏感性测试和分子方法。