High secondary resistance to quinolones in German Helicobacter pylori clinical isolates.

Objectives: The aim of this study was to update data on levofloxacin/ciprofloxacin and triple resistance (resistance to metronidazole, clarithromycin and levofloxacin/ciprofloxacin) in Helicobacter pylori clinical isolates and to identify the impact of prior eradication therapies on their development.

Methods: We tested the antimicrobial susceptibility to amoxicillin, metronidazole, clarithromycin, levofloxacin/ciprofloxacin, tetracycline and rifampicin of 5296 clinical H. pylori strains isolated between 2006 and 2011.

Identification and molecular characterization of triple- and quadruple-resistant Helicobacter pylori clinical isolates in Germany.

Objectives: The aim of this study was to estimate the frequency of triple- and quadruple-resistant Helicobacter pylori isolated in Germany, to characterize those isolates molecular genetically and to identify risk factors for the development of multiresistance.

Methods: Antimicrobial susceptibility to metronidazole, clarithromycin, amoxicillin, tetracycline, ciprofloxacin/levofloxacin and rifampicin in 1118 clinical isolates obtained between July 2006 and December 2007 was tested by the Etest method. For patients harbouring triple- or quadruple-resistant strains (n = 169), data on prior eradication therapies and underlying diseases were collected and evaluated.