Characteristics of antibiotic resistance: data from four different populations.

Aims: To describe the characteristics of () antibiotic resistance in clinical isolates from four populations.

Methods: In total, 1463 strains were examined for antibiotic resistance. Among these strains, 804 were isolated from treatment-naïve adults, 133 from previously treated adults, 100 from treatment-naïve children and 426 from a population who participated in a health survey (age ≥ 40 years). The minimum inhibitory concentration was determined by the E-test method.

Results: In the treatment-naïve adult group, the resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, rifampicin and tetracycline were 78.4, 19.0, 23.3, 1.2, 1.7 and 2.3%, respectively. Compared with this group, the previously treated adult group had significantly higher resistance rates for metronidazole (99.2%), clarithromycin (58.3%) and levofloxacin (52.3%). In addition, the treatment-naïve children had a lower metronidazole resistance rate (46.0%) than the treatment-naïve adults. The resistance rate for clarithromycin was low in treatment-naïve patients with ages ranging from 10 to 24 years. For the strains isolated from the general population group, the resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, rifampicin and tetracycline were 78.6, 10.1, 25.1, 0.5, 2.1 and 0.9%, respectively. Compared with the treatment-naïve adult group, the general population group showed significant differences in clarithromycin resistance.

Conclusion: The resistance rates for metronidazole, clarithromycin and levofloxacin were high, especially in previously treated adults. Compared to those in treatment-naïve younger patients, the resistance rates for clarithromycin were significantly lower in treatment-naïve patients with ages ranging from 10 to 24 years and in the general population.