Detection of clarithromycin resistance and 23SrRNA point mutations in clinical isolates of Helicobacter pylori isolates: Phenotypic and molecular methods

Abstract

Background and objectives Peptic ulcer disease, chronic gastritis, and stomach cancer are all caused by H. pylori . The most notable drug for the treatment is the antibiotic clarithromycin, which is currently the drug of choice. H. pylori clarithromycin resistance has been associated with point mutations in 23srRNA, the most prominent of which are A2143 and A2144G . In H. pylori bacteria, methylase synthesis, macrolide-inactivating enzyme activity, and active efflux have all been found to be resistance mechanisms. The goal of the study is to determine how resistant H. pylori is to clarithromycin and what the minimum inhibitory concentration is for various antimicrobials. Furthermore, gastro-endoscopy will be performed on Iraqi patients to detect the presence of A2143G and A2144G point mutations in Helicobacter pylori infections, as diagnosed from the pyloric region and other anatomical regions. Methods One hundred fifteen samples were collected from patients strongly suspected of H. pylori infection presented for upper gastrointestinal endoscopy at Ramadi Teaching Hospitals and Private Clinics for the period from January 2020 until February 2021. Specimens were cultured on brain heart infusion agar containing various antibiotics and were incubated at 37 °C under microaerophilic conditions. For identification of H. pylori, isolates of the biochemical tests and RT-PCR assay were applied. The Epsilometer test was used in the antibiotic susceptibility testing as dependent on the CLSI standard. The Restriction Fragment Length Polymorphism technique was used to determine point mutations. Results In total, 55 (47.8%) Helicobacter pylori isolates were cultured from the 115 biopsy specimens, among which 16 (29.1%), 38 (69.1%), 20 (36.4%), and 40 (72.7%) revealed some degree of resistance to levofloxacin, clarithromycin, ciprofloxacin, and metronidazole, respectively. The frequency of A2144G and A2143 point mutations were 23 (60.5%) and 19 (50%), respectively. Conclusions According to our results , Helicobacter pylori showed high resistance to clarithromycin. Our results demonstrate the requirement for antibiotic susceptibility testing and molecular methods in selecting drug regimens.

Optimizing Helicobacter pylori Treatment: An Updated Review of Empirical and Susceptibility Test-Based Treatments

“…77 A report compared the detection rate of A2144 or A2143 from PCR-RFLP with that of MIC measurement by the agar culture method, and they found that the diagnostic performance was nearly equivalent. 78 Another study compared the diagnostic accuracy of real-time PCR against MIC measurements by culture test, and it showed a high concordance rate; 84.6% of subjects diagnosed with clarithromycin-resistant infections by the culture method also had point mutations in 23S rRNA. 79 DNA gyrase, which is used to break the DNA double helix structure during DNA replication, is required for H. pylori to proliferate.…”

The role of adjuvants in overcoming antibacterial resistance due to enzymatic drug modification

“…Resistance to macrolides has spread to S. pneumoniae and H. influenzae which, as highlighted previously, are on World Health Organisation's priority pathogens list. 145,146 Macrolide esterase (Ere). These enzymes break the ester bond of the macrolide ring to give an inactive linear structure (Scheme 5).…”

“…Resistance to macrolides has spread to S. pneumoniae and H. influenzae which, as highlighted previously, are on World Health Organisation's priority pathogens list. 145,146…”

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis

“…The increasing failure rate of eradication treatment due to the appearance of resistant H. pylori strains contributes to the worldwide prevalence of this infection and subsequent inflammatory and neoplastic disorders. Unfortunately, nowadays, the success of this treatment is less than 80% worldwide ( Kocsmár et al, 2021 ; Hussein, Al-Ouqaili & Majeed, 2022 ).…”