engleski

No Progression of Primary Azithromycin and Clarithromycin Resistance Progression of Primary Metronidazole Resistance in Clinical Isolates of Helicobacter pylori in Croatia

The aim of the study was to evaluate the prevalence og primary azithromycin, clarithromycin and metronidazole resistance among H. Pylori isolates during 1996-1999. Gastric biopsies of 534 patients from the Clinical Hospital Merkur presenting with upper gastrodudenal pathology from 1996 to 1999 were cultured fro H. Pylori isolation on standard media. Minimal inhibitory concentrations (MICs) were determined by agar dilution according to NCCLS M7-A4 and M100-S. Incoulum was adjusted to the turbidity of a 2 McFarland standard. After 3 days of incubation plates were examined for visible growth. The MIC was defined as the lowest concetration of antimacrobial agent that prevented visible growth after incubation at 35C in microbiotic atmosphere fro 72h. A single colony or faint hase was taken as no growth. Results: A total of 534 H. Pylori isolates take before eradication theraphy were tested. The MIC of azithromycin range between 0.06 mg/L and less then 128 mg/L, with a median MIC of 0.25 mg/L. Primary resistance to azithromicin was 7.8 per cent (1996), 8.5 per cent (1997), 7.7 per cent (1998) and 9.2 per cent (1999). The MIC of clarithromycin ranged between 0.03 mg/L and less then 128 mg/L, with a median MIC 0.125 mg/L. Primary resistance to clarithromycin was 5.6 per cent (1996), 8.5 per cent (1997), 7.4 per cent (1998) and 8.2 per cent (1999). The MICs of metronidazole ranged between 0.5 mg/L and less then 128 mg/L, with median MIC of 1 mg/L. Primary resistance to metronidazole was 32.8 per cent (1996), 46.2 per cent (1997), 47.1 per cent (1998) and 48.9 per cent (1999). Conclusion: An increase in prevalence of primary azithromycin and clarithromycin resistance during the past 4 years was not observed. Increase in primary resistance to metronidazole is important becouse approximately half of Helicobacter pylori isolates are resistant to metronidazole. Becouse of constant resitance rates azithromycin or clarithromycin based triple regimens provide a sufficient efficacy for eradication of Helicobacter pylori infections in Croatia. This study also emphasis the need for community surveillance of Helicobacter pylori sensitivity as in other important infectious diseases.

Helicobacter pylori; therapy; resistance; metronidazole

nije evidentirano