Background: Antibiotic resistance of H.pylori is the main cause of failure of most current eradication regimens. As antimicrobial susceptibility testing (AST) is not always performed, it is important to have surveys to infer the treatments which can be used. For this purpose, European surveys were performed in 1998, 2008 and we report here the results of 2018.
Materials/methods: Centres were recruited on a voluntary basis, one for each small country and several for larger countries. The protocol was to include 50 adult patients who had not received previous eradication treatment.
Information collected included demographic, clinical, and endoscopic results as well as AST results (clarithromycin, levofloxacin, metronidazole, amoxicillin, tetracycline, rifampicin) performed by Etest or disk diffusion according to a standardised procedure. Control strains were provided. A 10% random sample was sent from each centre to the coordinating centre. The Amplidiag® H.pylori+ClariR kit (Mobidiag) was used for clarithromycin testing and AST for the other antibiotics. A univariate and multivariate analysis were also carried out to define the risk factors of antibiotic resistance.
Results: The crude data show 1,234 H.pylori positive patients included in 24 centres from 18 countries. H.pylori resistance was present in 21.3% for clarithromycin, 16.0% for levofloxacin, 39.1% for metronidazole, 0.4% for amoxicillin , 2% for rifampicin compounds and none for tetracycline. The random selection of 142 strains showed an excellent concordance of results (>95%). The main discrepancies were linked to the presence of double populations not detected by Etest. In the multivariate analysis, the risk factors for resistance were essentially linked to the region of birth: Southern Europe for clarithromycin (OR:3.7, 95%CI [1.4-9.5]) and outside Europe for metronidazole (OR:2.7, 95%CI [1.2-6.2]).
Conclusions: These results indicate a global and continuous rise in H.pylori primary resistance to clarithromycin but lower than in the previous decade (9.9% in 1998, 17.5% in 2008, and 21.3% in 2018), a slight increase to levofloxacin, and a more important increase for metronidazole (from 33.1 to 39.5% since 2008). The risk factors for resistance were similar to those found 10 years ago.
Acknowledgments: The authors acknowledge bioMérieux for providing Etests and Mobidiag for providing PCR kits.