Molecular detection of Helicobacter pylori resistance to clarithromycin and fluoroquinolones at Mbarara City Health Centre IV, Southwestern Uganda

Introduction: Helicobacter pylori infection is classified as a human carcinogen that is linked to gastric cancer; the third most common cause of cancer death worldwide. Unfortunately, there is an emerging antimicrobial resistance to commonly used antibiotics in the treatment of H. pylori thus knowing the local prevalence rate of resistance using a molecular test is important to describe evidence-based interventions. Objective(s): To determine the prevalence of resistance of H. pylori to clarithromycin and fluoroquinolones using a molecular test at Mbarara City Health Centre IV, Southwestern Uganda. Method s: We conducted a descriptive cross-sectional study from January 2020 to April 2021where informed consents were obtained from patients who presented with gastrointestinal symptoms. An interview-guided questionnaire was used to collect both demographic and clinical data. Each participant was provided with a sterile stool container and given instructions to collect four scoopfuls of stools. The stool specimen was placed in a cool box and transported to the laboratory within 30 minutes of sample collection for H. pylori antigen analysis and those that were positive for H. pylori were stored in a fridge at a temperature of -20ᵒc for a week, then transported to MBN clinical laboratories for DNA Extraction from stool using the QIAamp DNA Stool Mini Kit (Qiagen, Hilden Germany) to identify the presence of H. pylori and point mutations in the genes responsible for resistance to fluoroquinolone and clarithromycin through multiplex amplification, and reverse hybridization. Associations were determined using Chi square with Fisher’s exact test and statistical significance was set at P < 0.05. Stata (version 18) was used for statistical analysis. Results: The prevalence of H. pylori among participants who presented with Gastrointestinal Symptoms (GIS) was 27%. Sanitation, smoking, source of drinking water, and bloody stool were found to be associated with H. pylori infection. The proportion of H. pylori resistant to clarithromycin (CLA) was 40% and that to fluoroquinolones (FLQ) was 70%. All H. pylori resistant samples to CLA showed a mutation in the 23srRNA gene and for all that were resistant to FLQ, a mutation was detected in the gyrase A gene. Conclusion: There was a high prevalence of H. pylori infection among participants who presented with GIS and these were associated with poor sanitation, smoking, source of drinking water, and bloody stool. H. pylori was highly resistant to FLQ followed by CLA hence limiting the treatment options. This calls for precautions while using these drugs in treatment of H. pylori infection Key words: Helicobacter pylori, resistance to clarithromycin and fluoroquinolones