Prevalence of Primary Resistance of Helicobacter pylori to Clarithromycin and Levofloxacin in Southern Spain

BACKGROUND: The eradication of Helicobacter pylori (HP) using clarithromycin (CLA)-based triple therapy depends on the resistance of HP to antibiotics. The Maastricht III conference recommends the implementation of locoregional surveillance programmes for primary resistance of HP to CLA. In Andalusia, there are no previous data in this respect. The aim of this study was to determine the prevalence of the primary resistance of HP to CLA and levofloxacin (LF) in southern Spain. METHODS: Multicentre cross sectional study was carried out in 6 hospitals in Andalusia. Patients of both sexes numbering 401 were included (male 48%), aged 18-80 years and naïve to HP eradication. Resistance of HP to CLA (CLAr) and LF (LFr) was assessed by determining mutations by PCR: mutations of the 23S rRNA gene define CLAr and mutations of the gene gyrA define LFr. Four hundred one gastric samples were collected. CLAr was detected in 72 patients (17.9%) and LFr was detected in 56 patients (13.9%). Heteroresistance was detected for both antibiotics: CLA 37/72 (51.3%) and LF 28/56 (50%). Variability for CLAr was detected among the centres, ranging from 11.5% to 24.7% without statistical significance (p = 0.12). Female sex was related to CLAr. CONCLUSIONS: In Andalusia, there is a high rate of primary CLAr and LFr. CLA-based triple therapy should be avoided as the primary eradication regimen in this region. There is a wide variability in the rate of CLAr among centres.