Characteristics and Trends of Clarithromycin-Resistant <i>Helicobacter pylori</i> Isolates in Japan over a Decade

Abstract

Clarithromycin has been administered to patients in Japan since 1991. Clarithromycin-resistant Helicobacter pylori strains have been on the rise in Japan. We obtained H. pylori isolates between 1989 and 2000 and examined mutations of the 23S rRNA gene, which are closely associated with clarithromycin resistance. Isolates were obtained from 356 patients with H. pylori infection treated at the Hiroshima University. Sixty-one of the patients received clarithromycin-based H. pylori eradication therapy. Mutations of the 23S rRNA gene were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) followed by sequencing analysis. Mutant strains were found in 42 of the 356 patients (11.8%). The prevalence of mutant strains increased from 0 to 20.4% during the 12-year study period. The prevalence increased to more than 10% by 1995 and then to more 20% after 1999. The H. pylori eradication rate was significantly higher in patients with wild-type strains than in patients with mutant strains (72.0 vs. 36.4%, p = 0.024). Our data indicate that clarithromycin-resistant H. pylori strains have increased rapidly since 1995 and that the effectiveness of clarithromycin-based H. pylori eradication therapies may soon be compromised. Other new therapies may be necessary as first-line treatments in Japan.

Molecular Detection of H. pylori Using Adherent Gastric Mucous to Biopsy Forceps

“…However, it was unfortunately only approved as first eradication regimen in Japan. Our eradication rate was similar to the previous Japanese reports ,, and relatively higher compared to the results of Korean studies (0~12.5%) investigating the small number of subjects with 23S rRNA A2143G mutant ,. As a rapid increase in CAM resistance led to a fall in cure rates to 80% or less, CAM must be avoided as H. pylori eradication regimen unless the CAM susceptibility can be confirmed.…”

Antimicrobial resistance of in Poland: a multicentre study

“…It has also been suggested that a combination of MTZ and CL promotes the selection of secondary CL resistance more readily than regimens containing CL and AMX [19]. Helicobacter pylori resistance to CL has been reported to be increasing in many countries [20,21], which is associated with an extensive therapeutic use of macrolides. Our study showed high rates both of overall and primary H. pylori resistance to CL, with great variations between the centres (ranging from 0% to 33%).…”

Diagnosis of Helicobacter pylori Infection

“…They observed an increase in macrolide resistance from 0 to 20.4% over the 12 years follow‐up period. The eradication rate was 72% for susceptible strains and 36.4% for resistant strains [8].…”