Marked susceptibility of South African Helicobacter pylori strains to ciprofloxacin and amoxicillin: Clinical implications

Abstract

Objectives. Helicobacter pylori-associated infection is common in South Africa, as in other developing countries. Antibiotic resistance is recognised as a major cause of treatment failure. We studied the susceptibility and resistance patterns of H. pylori to guide empiric treatment and prevent the emergence of resistance.

Methods. Two hundred H. pylori strains obtained from gastric biopsies of patients presenting with gastric-related morbidities attending Livingstone Hospital, Port Elizabeth, were evaluated for their susceptibility to seven antibiotics – metronidazole, clarithromycin, tetracycline, amoxicillin, gentamicin, ciprofloxacin and erythromycin. H. pylori was isolated following standard microbiology procedures, and susceptibility determined using the Kirby-Bauer disc diffusion and agar dilution methods. Comparisons of antimicrobial resistance rates with sex of the patients were determined using the chi-square test; a p-value of <0.05 was considered significant.

Results. Marked susceptibility was observed for ciprofloxacin (100%) and amoxicillin (97.5%), and good activity for clarithromycin (80%) and gentamicin (72.5%). However, marked resistance (95.5%) was observed for metronidazole. The minimal inhibitory concentration (MIC) ranged from 0.0625 µg/ml to 8 µg/ml. The lowest MIC, with a range of 0.0625 - 1 µg/ml, was recorded for ciprofloxacin, while the highest (5 - 8 µg/ml) was noted for gentamicin.

Conclusion. Multidrug resistance was commonly encountered – a finding of clinical significance that calls for continuous surveillance of antibiograms to guide empiric treatment. We advocate the inclusion of ciprofloxacin in the treatment regimen of H. pylori infection in our study environment.