Department of Infectious Diseases, Kyorin University School of Medicine, Mitaka, Tokyo, Japan.
Department of Gastroenterology, National Hospital Organization Hakodate Hospital, Hakodate, Japan.
Helicobacter. 2017 Oct;22(5). doi: 10.1111/hel.12396. Epub 2017 May 22.
To prevent Helicobacter pylori infection in the younger generation, it is necessary to investigate the prevalence of antibiotic-resistant H. pylori.
The aim of this study was to evaluate the method of PCR-based sequencing to detect clarithromycin (CAM) resistance-associated mutations using fecal samples as a noninvasive method.
DNA extracted from fecal specimens and isolates from gastric biopsy specimens were collected from patients with H. pylori infection. Antibiotic resistance to CAM was analyzed by molecular and culture methods. The detection rates of CAM resistance-associated mutations (A2142C or A2143G) were compared before and after eradication therapy.
With CAM resistance of H. pylori evaluated by antibiotic susceptibility test as a gold standard, the sensitivity and the specificity of gene mutation detection from fecal DNA were 80% and 84.8%, respectively. In contrast, using DNA of isolated strains, the sensitivity and the specificity were 80% and 100%. Of the seven cases in which eradication was unsuccessful by triple therapy including CAM, CAM-resistant H. pylori, and resistance-associated mutations were detected in three cases, CAM-resistant H. pylori without the mutation was detected in two patients, and resistance-associated mutation was only detected in one patient.
PCR-based sequencing to detect CAM resistance-associated mutations using isolates or fecal samples was useful for finding antibiotic-resistant H. pylori infection. Although the specificity of the detection from fecal samples compared with antibiotic susceptibility testing was lower than that from isolates, this fecal detection method is suitable especially for asymptomatic subjects including children. Further improvement is needed before clinical application.
为了预防年轻一代感染幽门螺杆菌，有必要调查幽门螺杆菌对抗生素的耐药情况。
本研究旨在评估基于聚合酶链反应（PCR）测序检测粪便样本中克拉霉素（CAM）耐药相关突变的方法，该方法为非侵入性方法。
从幽门螺杆菌感染患者的粪便标本和胃活检标本中提取 DNA。采用分子和培养方法分析 CAM 耐药情况。比较根除治疗前后 CAM 耐药相关突变（A2142C 或 A2143G）的检测率。
以抗生素药敏试验评估的幽门螺杆菌 CAM 耐药性为金标准，粪便 DNA 基因突变检测的敏感性和特异性分别为 80%和 84.8%。相比之下，使用分离株的 DNA，敏感性和特异性分别为 80%和 100%。在包括 CAM 的三联疗法根除失败的 7 例中，3 例检测到 CAM 耐药幽门螺杆菌和耐药相关突变，2 例患者检测到无突变的 CAM 耐药幽门螺杆菌，1 例患者仅检测到耐药相关突变。
使用分离株或粪便样本进行基于 PCR 的测序检测 CAM 耐药相关突变有助于发现抗生素耐药的幽门螺杆菌感染。尽管粪便样本检测的特异性低于分离株，但该粪便检测方法特别适用于包括儿童在内的无症状患者。在临床应用之前需要进一步改进。
