Antibiotics resistance of Helicobacter pylori at the San Ignacio University Hospital in Bogota

Abstract

Objectives: to determine the frequency of resistance of Helicobacter pylori (H. pylori) to amoxicillin, clarithromycin, tetracyclin and metronidazole at the San Ignacio University Hospital in Bogotá, and to look for correlation between the presence of resistance and previous antibiotic use.

Material and methods: samples for H. pylori cultures were taken from 115 patients who underwent endoscopy because of dyspeptic symptoms. Resistance to antibiotics was determined by means of susceptibility discs. Information was collected on previous antibiotic and imidazole intake, and associations with resistance evaluated by means of contingency tables and Fischer"(TM) s exact test.

Results: 84 positive cultures for H. pylori were obtained. Resistance to metronidazole was found in 97,6% of cultures, followed by resistance to tetracycline (85,7%), to clarithromycin (63,1%) and to amoxicillin (9,5%). No relationship was found between previous use of antibiotics or imidazoles and the resistance to studied antibiotics. No associations were found between antibiotic resistance and other variables like age, sex or endoscopic findings. There was an increased probability of resistance to clarithromycin if there was also resistance to tetracycline (RR 4.25, IC 1.18-15.19 p= 0.001).

Conclusions: resistances of H. pylori to metronidazol and to tetracycline are above 85%, and to clarithromycin above 60% in the studied population. History of previous intake of antibiotics does not increase the probability of resistance. Since these antibiotics are amongst the most widely used for eradication of H. pylori, the clinical impact of these findings in the effectiveness of eradication regimens must be evaluated with clinical trials.