Background/Objectives: Helicobacter pylori infection remains a significant health concern, as increasing antimicrobial resistance compromises the efficacy of eradication. Understanding regional antimicrobial resistance profiles is crucial for optimizing eradication strategies. In this study, we aimed to evaluate the antimicrobial susceptibility patterns and identify the factors influencing H. pylori culture success. Methods: In this prospective study, 697 gastric tissue samples were collected from consecutive patients who underwent upper endoscopy between November 2023 and May 2025. Tissue samples obtained by forceps biopsy or recovered from rapid urease test kits were cultured for H. pylori. Antimicrobial susceptibility testing was performed using the agar dilution method; factors associated with successful culture were analyzed using logistic regression. Results: Among 488 patients with H. pylori infection, culture and antimicrobial susceptibility testing were successful in 387 (79.3%). The overall antimicrobial resistance rates were 17.8%, 27.1%, 29.5%, 0.3%, and 32.8% for amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin, respectively. Notably, 27.6% (107/387) of the isolates were resistant to two or more antibiotics. Using multivariate analysis, the use of fresh biopsy tissue (odds ratio [OR]: 1.646, 95% confidence interval [CI]: 1.046–2.591, p = 0.031), transport interval (OR: 0.911, 95% CI: 0.853–0.973, p = 0.005), and presence of prior eradication therapy (OR: 0.318, 95% CI: 0.156–0.648, p = 0.002) were identified as significant predictors of culture success. Conclusions: The high rate of clarithromycin resistance underscores the need for susceptibility-guided eradication strategies in this region. Optimizing sample handling, particularly by minimizing transport time and using fresh biopsy tissue, may improve culture yields.

Mycobacterium intracellulare is a leading cause of nontuberculous mycobacterial pulmonary disease, with a rapidly increasing prevalence worldwide. This bacterium, commonly distributed in soil and water, is known to be transmitted through the environment rather than between people. Therefore, it is imperative to establish distinguishable genotyping methods to understand the clinical outcome, disease relapses, and epidemiology. Therefore, in this study, representative band-based genotyping methods were performed using M. intracellualre clinical isolates, and their Hunter–Gaston discriminatory index (HGDI) was 0.947, 0.994, and 1 for variable number tandem repetition (VNTR), VNTR-mycobacterial interspersed repetitive units, pulsed field gel electrophoresis, and repetitive sequence based-PCR, respectively. Although VNTR showed relatively low HGDI, co-infection with other M. intracellualre strains could be determined by loci showing allele diversity from 0 to 0.69. Additionally, genetic distance of clinical isolates from Gyeongnam/Korea, and other regions/countries were visualized by minimum spanning tree (MST) using the globally available VNTR profiles. The results of MST revealed that M. intracellulare isolated from patients in Gyeongnam/Korea had specific VNTR genotypes, which may be evidence of the geographic distribution of M. intracellulare specific genotypes. The comparative results of genotyping techniques and geographical characteristics in this study may provide fundamental information for the epidemiology of M. intracellulare.

Chang Seok Bang, A In Choi, Jeong-Gyu Choi, Jae Jun Lee, Eun Jeong Gong. Gut and Liver -0001;0:. https://doi.org/10.5009/gnl250332

Jeong-Gyu Choi, Eun Jeong Gong, Chang Seok Bang, Jae Jun Lee. Gut and Liver -0001;0:. https://doi.org/10.5009/gnl260189