Molecular diagnosis of Helicobacter pylori antibiotic resistance in the Taif region, Saudi Arabia

Microbiol Immunol. 2019 Jun;63(6):199-205. doi: 10.1111/1348-0421.12686. Epub 2019 Jun 18.

Abstract

Success in eradication of Helicobacter pylori is declining globally because H. pylori has developed resistance against most of the antibiotics proposed for eradication regimens, mainly through point mutations. The present study included 200 patients with dyspepsia attending Taif Hospital. Gastric biopsies were obtained during gastroscopy and subjected to rapid urease testing. Molecular methods were used to confirm diagnoses of H. pylori infection and to identify resistance gene variants of four antibiotics; namely, clarithromycin, metronidazole, fluoroquinolones and tetracycline (23S rRNA, gyrA, rdxA and 16S rRNA respectively). Of all investigated patients, Molecular diagnoses were made in 143 of all investigated patients; thus, the prevalence was .5%. The overall rate of resistance to clarithromycin among the H. pylori-positive patients was high (39.9%) and the rate of resistance significantly greater (48.2%) among the secondary resistance group, secondary resistance being defined as resistance as a result of previous exposure to the relevant antibiotic. The rate of resistance to fluoroquinolones was considered moderate; the difference in rate of resistance between the primary and secondary resistance groups (8.4% and 9.5%, respectively) was not significant Also, there was a low prevalence of both primary and the secondary tetracycline resistance in the study cohort. In contrast, the prevalence of metronidazole resistance was considered high with no significant difference between the two resistance groups. H. pylori showed an increased prevalence of resistance to all four of the commonly used therapeutic agents. Thus, eradication therapy should be based on the regional results of susceptibility testing. Moreover, treatment tailored according to individually determined H. pylori susceptibility may be a reasonable future goal.

Keywords: Helicobacter pylori; antibiotic resistance; molecular diagnosis.

MeSH terms

  • Adult
  • Aged
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics
  • Clarithromycin / pharmacology
  • Cohort Studies
  • DNA Gyrase / genetics
  • Drug Resistance, Multiple, Bacterial / drug effects
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Female
  • Fluoroquinolones / pharmacology
  • Helicobacter Infections / diagnosis*
  • Helicobacter Infections / epidemiology
  • Helicobacter pylori / drug effects
  • Helicobacter pylori / genetics*
  • Helicobacter pylori / isolation & purification*
  • Helicobacter pylori / pathogenicity
  • Humans
  • Male
  • Metronidazole / pharmacology
  • Microbial Sensitivity Tests
  • Middle Aged
  • Molecular Epidemiology
  • Nitroreductases / genetics
  • Pathology, Molecular*
  • Prevalence
  • RNA, Ribosomal, 16S / genetics
  • RNA, Ribosomal, 23S / genetics
  • Saudi Arabia / epidemiology
  • Tetracycline / pharmacology
  • Young Adult

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Fluoroquinolones
  • RNA, Ribosomal, 16S
  • RNA, Ribosomal, 23S
  • Metronidazole
  • Nitroreductases
  • RdxA protein, Helicobacter pylori
  • DNA Gyrase
  • Tetracycline
  • Clarithromycin