Identification of antibiotic resistance patterns in strains isolated from gastric biopsies using real-time PCR and genotypic analysis.

Background: is associated with dyspepsia, mucus-associated lymphoid tissue lymphoma, gastritis, and peptic ulcer disease. Treatment in Malta consists of triple therapy, which consists of a proton pump inhibitor and 2 of the antibiotics amoxicillin, clarithromycin, metronidazole and fluoroquinolones. We aimed to determine the resistance rates for clarithromycin and fluoroquinolones in patients with , and its incidence, in patients undergoing an esophagogastroduodenoscopy (EGD) using real-time polymerase chain reaction (RT-PCR).

Methods: Patients undergoing an EGD were recruited. A rapid urease test (RUT) was performed, and 4 gastric biopsies were also taken (2 from antrum, 2 from corpus) and analyzed using RT-PCR. Positive samples were tested for antibiotic resistance using amplification and reverse hybridization techniques.

Results: Two hundred patients (mean age 53.6 [range 20-92] years; 53.1% female) were recruited; the majority were (78%) non-smokers. was identified in 21.0% of the patients. Fluoroquinolone resistance was detected in 21.4% of the patients. Clarithromycin resistance was observed in 26.2%, with dual resistance identified in 4.8% of the patients. A high concordance was present with patients testing negative for with both RUT and RT-PCR (94.3%). Only 57.6% of patients tested positive with both tests. However, 92.9% of RT-PCR positive patients had a positive genotype HelicoDR test.

Conclusions: This data demonstrates a high rate of resistance to both clarithromycin and fluoroquinolones. These should be avoided when treating by utilizing different treatment regimes. Furthermore, we derived important data on the role of RT-PCR, which may be implemented in routine clinical practice.