Prevalence of Helicobacter pylori resistance to clarithromycin determined by 23S ribosomal RNA analysis in Jordan. Diab AF1, Diab FH2, Nassar SS3. Faculty of Medicine, University of Jordan1; Departments of Medicine2 and Laboratory Medicine3, Khaldi Medica

Background: Antimicrobial resistance is a growing problem in Helicobacter pylori treatment. This study was intended to evaluate the prevalence of clarithromycin resistance, using a polymerase chain reaction (PCR) technique on gastric specimens, from adult Jordanian patients with Helicobacter pylori infection.   Materials and Methods: Gastric biopsy specimens were taken from gastric antrum and body during routine upper gastrointestinal endoscopies, and were tested with Rapid Urea test for H. pylori. Only specimens that were positive for H. pylori by the rapid Urea test were included in the study. A total of 50 specimens tested positive for H. pylori, and were further tested using the Seeplex® ClaR-H. pylori ACE detection kit, a dual priming oligonucleotide (DPO) methodology from Seegene Inc., Seoul, Korea, to determine the frequency of point mutations in 23s rRNA gene, known to confer resistance to clarithromycin (A2142G and A2143G point mutations).   Results: Out of a total of 50 gastric specimens that tested positive for H. pylori by rapid urease test, 49 were confirmed positive for H. pylori by PCR technique. Point mutations were found in 11 specimens (8 had A2143G point mutation, and 3 had A2142G point mutation).   Conclusion: Prevalence of clarithromycin resistant strains of H. pylori in Jordan was 22.4%. A2143G was the most prevalent point mutation. This high rate of clarithromycin resistant strains should be taken into consideration when prescribing eradication regimens. This is the first study to investigate H. pylori resistance to clarithromycin in Jordan.