Antimicrobial‐resistant Helicobacter pylori in Japan: Report of nationwide surveillance for 2018–2020

Background Antimicrobial therapy is necessary to eradicate Helicobacter pylori infection. The emergence of antimicrobial‐resistant bacteria poses a threat to continued treatment with antimicrobial agents. For those who prescribe antimicrobial therapy, it is necessary to constantly monitor the emergence of antimicrobial‐resistant bacteria. Method H. pylori clinical isolates were collected in Japan from August 2018 to December 2020 for antimicrobial susceptibility testing. The agar dilution method was used for the determination of the minimum inhibitory concentration (MIC) of clarithromycin (CLR), amoxicillin (AMX), metronidazole (MNZ), and sitafloxacin (STX). Results MICs for 938 H. pylori isolates were examined. The primary resistance rates of H. pylori clinical isolates for CLR, AMX, MNZ, and STX in Japan were 35.5%, 2.7%, 4.2%, and 27.6%, respectively. The primary resistance rates for CLR, AMX, and MNZ were significantly higher than those of the 2002–2005 isolates. The resistance rate for CLR was significantly higher in females (males: 30.7%, females: 41.5%, p