Prevalence of primary Helicobacter pylori resistance to several antimicrobials in a Saudi Teaching Hospital.

OBJECTIVE To determine the resistance rate of the most commonly used antimicrobial agents amongst Helicobacter pylori isolates. METHODS The agar disk diffusion method (Kirby Bauer) was utilized to determine the susceptibility of 223 H. pylori strains isolated before treatment. Isolates were tested against metronidazole (5 micrograms), clarithromycin (15 micrograms), amoxycillin (10 micrograms), and tetracycline (30 micrograms). RESULTS The resistance rate was 80% for metronidazole and 4% for clarithromycin. Tetracycline and amoxycillin showed very low degree of resistance with 1 (0.4%) and 3 (1.3%) of the strains resistant to these antibiotics, respectively. Age, sex and ethnicity had a remarkable effect on the resistance rate. CONCLUSION The results indicate that metronidazole and clarithromycin should not be used as the only antimicrobial agents in the treatment of H. pylori infection. Susceptibility testing using the disk diffusion method is cost-effective in the screening of antimicrobial resistance against H. pylori.