Helicobacter pylori antibiotic resistance and correlation with cagA motifs and homB gene

ABSTRACT

Objectives: Helicobacter pylori (H. pylori) infection caused by antibiotic-resistant strains represents a major public health threat that aggressively promotes gastric cancer progression. Antibiotic resistance evaluation is immensely important to counteract its emergence. Here we merely determine the prevalence of antibiotic resistance in H. pylori isolates and its correlation with cagA motifs and the homB gene.

Methods: The antibiotic resistance pattern was investigated on 128 H. pylori isolated strains utilizing the disk diffusion method and study the correlation between it and the presence of pathogenic genes, cagA EPIYA motifs and homB gene, were accurately detected using the PCR.

Results: The resistance rates to four antibiotics were 70.1% for metronidazole, 35.5% for amoxicillin, 7.2% for clarithromycin and 8.2% for tetracycline. Resistance phenotypes were separated into two groups, single resistance (63.2%) and multi-resistance (12.5%). The prevalence of cagA-ABCC resistant strains and homB⁺ resistant strains was significantly higher in cancer (p = 0.04 and p = 0.01, respectively) than those of other diseases. The prevalence of cagA-homB⁺ resistance strains was 21.8% and had a significant correlation with PUD. A significant relationship was observed between amoxicillin resistant rate with ABC-homB (p = 0.0006).

Conclusion: The Resistance rate to selected antibiotics in Shiraz is higher than years ago. The presence of cagA-homB⁺ is associated with antibiotic resistance and also homB can be used as a marker to antibiotic resistance status prediction in H. pylori isolated in this area.

KEYWORDS:

• Helicobacter pylori
• antibiotic resistance
• cagA-motifs
• EPIYA-motifs
• homB

Acknowledgments

This study was a part of the dissertation of Mohammad Hossain Haddadi, submitted to Shiraz University of Medical Sciences in partial fulfillment of the requirements for the MSc in Microbiology. This study was supported by the Vice-Chancellor for Research, Shiraz University of Medical Sciences (90000214). We acknowledge the staff of the Endoscopy Laboratory of Namazi and Faghihi hospitals, Medical University of Shiraz, for their cooperation. All the staff kindly gave their permission to be acknowledged.

Declaration of interest

The contents of the paper and the opinions expressed within are those of the authors, and it was the decision of the authors to submit the manuscript for publication.

The authors have declared that no competing interests exist.