High rate of A2142G point mutation associated with clarithromycin resistance among Iranian Helicobacter pylori clinical isolates

Abstract

This study aimed to investigate the clarithromycin resistance and its associated molecular mechanisms among Helicobacter pylori isolates from dyspeptic patients in Shiraz, Iran. From January to May 2014, 100 H. pylori strains were isolated from patients with gastroduodenal disorders. The resistance to clarithromycin was quantitatively evaluated, using Epsilometer (E-test) method. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed on all the isolates to detect A2143G and A2142G mutations in 23S rRNA gene. The H. pylori isolation rate was found to be 31.4%. E-test showed that 20% of isolates were resistant to clarithromycin (MIC ≥ 1 mg/L). MIC of clarithromycin ranged between 0.016 and 24 mg/L. Findings of PCR-RFLP showed that the A2142G was the most (90%) frequently point mutation, followed by the A2143G (10%). No statistically significant difference was found between H. pylori clarithromycin resistance point mutations and patients' gender or age. To the best of our knowledge, this is the first report of high frequency of A2142G point mutation in Iran and probably in other regions of the world. Considering the increasing trend of H. pylori resistance to clarithromycin due to these mutations, it is crucial to investigate the new therapeutic approaches against H. pylori infection.

High Prevalence of Antibiotic Resistance in Iranian Helicobacter pylori Isolates: Importance of Functional and Mutational Analysis of Resistance Genes and Virulence Genotyping

“…In this study, only four mutations including A2143G and C2195T were found in our isolates. In contrast, Khashei et al reported that A2142G was the most (90%) frequent point mutation among the isolates from southwest of Iran a PCR-RFLP method [74]. In addition, we failed to identify additional mutations such as T2183C and A2223G, which are frequently reported to be the cause of clarithromycin resistance in Eastern countries, rather than in Western countries [75].…”

A systematic review and meta‐analysis of genotypic methods for detecting antibiotic resistance in Helicobacter pylori

“…Subgroup analysis based on PCR methods Several PCR-based methods were applied in these 22 studies. Including PCR-RFLP, 34,35,37,[41][42][43][44][45][46] PCR-based sequencing, 40,47-52 fluorescent in situ hybridization (FISH), 36,50,52 scorpion PCR assay, 43,53 GenoType HelicoDR, 51 PCR-line probe assay, 24 LightCycler PCR, 54 denaturing HPLC (DHPLC) assay, 23 and primer-mismatch PCR. 46,55 The pooled sensitivity and specificity for any of these assays were greater than 0.95, except for GenoType HelicoDR, which had a sensitivity of 89.6%.…”

Molecular detection of H. pylori antibiotic‐resistant genes and molecular docking analysis

“…1 Currently, the drugs used for H. pylori eradication are mainly composed of proton pump inhibitors and gastric mucosal protectant in combination with one or two kinds of antibiotics, including clarithromycin (CAM), metronidazole (MNZ), levofloxacin (LVX), and amoxicillin. 3,4 However, a research in Brazil showed the resistance mutation was mainly located in A2147G. 2 At present, bacterial factors are regarded as the main cause for antibiotic resistance.…”