Takako Osaki1, Katsuhiro Mabe2,3, Cynthia Zaman1, Hideo Yonezawa1, Masumi Okuda4, Kenji Amagai5, Shinji Fujieda5, Mitsuhide Goto5, Wataru Shibata6, Mototsugu Kato2,3, Shigeru Kamiya1. 1. Department of Infectious Diseases, Kyorin University School of Medicine, Mitaka, Tokyo, Japan. 2. Department of Gastroenterology, National Hospital Organization Hakodate Hospital, Hakodate, Japan. 3. Division of Endoscopy, Hokkaido University Hospital, Sapporo, Japan. 4. Department of General Medicine and Community Health Science, Hyogo College of Medicine, Sasayama, Hyogo, Japan. 5. Ibaraki Prefectural Central Hospital, Ibaraki, Japan. 6. Department of Gastroenterology, Yokohama City University, Yokohama, Japan.
Abstract
BACKGROUND: To prevent Helicobacter pylori infection in the younger generation, it is necessary to investigate the prevalence of antibiotic-resistant H. pylori. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.
RCT Entities:
BACKGROUND: To prevent Helicobacter pyloriinfection in the younger generation, it is necessary to investigate the prevalence of antibiotic-resistant H. pylori. OBJECTIVE: 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. METHODS: DNA extracted from fecal specimens and isolates from gastric biopsy specimens were collected from patients with H. pyloriinfection. 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. RESULTS: 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. CONCLUSION: PCR-based sequencing to detect CAM resistance-associated mutations using isolates or fecal samples was useful for finding antibiotic-resistant H. pyloriinfection. 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.