Prospective multicentre study on antimicrobial resistance of Helicobacter pylori in Germany

One-quarter of German adults are colonized with Helicobacter pylori but only one-fifth of these present with symptoms and may develop complications including peptic ulcer disease, gastric adenocarcinoma or mucosa-associated lymphoid tissue lymphoma. German and European guidelines recommend to eradicate the bacteria by administration of an empirical antimicrobial chemotherapy that consists of two antimicrobials in combination with a proton pump inhibitor (PPI). Successful eradication of H. pylori, however, is substantially impaired by increasing antimicrobial resistance. Hence, knowledge of risk factors leading to antimicrobial resistance is critical to avoid administration of ineffective antimicrobials. – 5 A recent European multicentre study reported primary resistances of 6.9% for clarithromycin and 14.9% for levofloxacin in Germany. These figures, however, were based on a low number of samples collected over a short period of time in a single microbiological centre (MC) only. To continuously keep the resistance development of H. pylori under surveillance, the German National Reference Centre (NRC) for H. pylori established a network of 17 microbiological laboratories and launched the nationwide multicentre study ResiNet in 2001. The aims of ResiNet are as follows: (i) to collect prospective and systematic data on the prevalence of antimicrobial resistance in H. pylori depending on age, sex, country of origin, underlying diseases and previous unsuccessful eradication attempts; and (ii) to identify risk factors for the development of resistance. To ensure comparable and reliable results, antimicrobial susceptibility testing was standardized by using identical culture media lots and identical standard operating procedures at the participating study centres.