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Mycobacterium avium complex (MAC) infection is a growing public health concern worldwide, particularly affecting the elderly and immunocompromised population. The treatment of MAC lung disease relies on a combination of antibiotics in a three-drug regimen that includes macrolides, rifamycins, and ethambutol. Therefore, the investigation of antimicrobial susceptibility is crucial for successful treatment. This study aimed to assess the antibiotic susceptibility of the most prevalent MAC species causing MAC lung disease, Mycobacterium intracellulare, in the Southwestern Gyeongsang province of South Korea using a resazurin-based microtiter assay. A total of 97 strains of M. intracellulare were isolated and tested for antimicrobial susceptibility. The results demonstrated high susceptibility rates for two aminoglycosides (amikacin and streptomycin, 94.9% and 99%), rifampicin (90.9%), clarithromycin (98%), linezolid (100%), and moxifloxacin (94.9%) against M. intracellulare. However, notably high resistance rates were observed for ethambutol (97%) and clofazimine (98%) against M. intracellulare. In conclusion, our findings indicate relatively high susceptibility rates for these six antibiotics and significantly elevated resistance rates for clofazimine and ethambutol compared to other regions in South Korea and foreign countries. The investigated MIC data can offer valuable insights for developing an effective treatment regimen for MAC lung infection in this area.

Purpose: This study aimed to investigate the presence of autoantigens in the gastric juices of children. Methods: Gastric juice and serum samples were obtained from 53 children <15 years of age who underwent gastric endoscopy. Among these, 8, 22, and 23 participants were in the age groups 0-5, 6-10, and 11-15 years, respectively. These samples were analyzed using two-dimensional electrophoresis (2-DE), immunoblot analysis, and matrix-assisted laser desorption ionization-time of-flight mass spectrometry. Furthermore, we reviewed the histopathological findings and urease test results and compared them with the results of 2-DE and immunoblot analysis. Results: There were no statistically significant differences in urease test positivity, grades of chronic gastritis, active gastritis, or Helicobacter pylori infiltration of the antrum and body among the three age groups. Three distinct patterns of gastric juice were observed on 2-DE. Pattern I was the most common, and pattern III was not observed below the age of 5 years. Histopathological findings were significantly different among active gastritis (p=0.037) and H. pylori infiltration (p=0.060) in the gastric body. The immunoblots showed large spots at an approximate pH of 3-4 and molecular weights of 31-45 kDa. These distinct, large positive spots were identified as gastric lipase and pepsin A and C. Conclusion: Three enzymes, which are normally secreted under acidic conditions were identified as autoantigens. Further investigation of the pathophysiology and function of autoantigens in the stomach is required. [ABSTRACT FROM AUTHOR]