The Prevalence of Antimicrobial Resistance to Helicobacter Pylori in the South of Ireland

Aim: To determine the level of antimicrobial resistance to H. pylori amongst patients attending for endoscopy at a University Teaching Hospital in the South of Ireland.

Methods: Ethical approval was received. At Endoscopy, a CLO test was taken, along with antral and corpus biopsies, which were placed in labeled transport media, and transported immediately to microbiology laboratory for culture and antibiotic susceptibility testing. Antimicrobial susceptibility testing to antibiotics commonly used in eradication treatments (clarithromycin, metronidazole, amoxicillin, and tetracycline) was performed by Etest.

Results: A total of 146 patients had biopsies cultured, mean age 50yrs(19–91yrs) and there were 47(32%) positive by culture and/or Clo test. There were 10(22.7%) false negative Clo tests and 3(6.8%) false negative culture (CLO positive, culture negative) results. Clarithromycin resistance was present in 3(6.8%) of isolates and metronidazole in 7 (18.18%). There was no amoxicillin or tetracycline resistance detected in our patient cohort.

Conclusion: Our resistance levels are quite low relative to comparable data from other countries with rates as high as 50% are quoted for metronidazole resistance and 12% for clarithromycin resistance. Resistance was distributed almost equally among male and female (ratio 6:4). Routine culture for H. pylori is not currently recommended but should be considered in patients with refractory infection, as the incidence of resistance is higher in this group.