<p>Molecular characterization and prevalence of antibiotic resistance in <em>Helicobacter pylori</em> isolates in Kuala Lumpur, Malaysia</p>

Abstract

Aims and objectivesHelicobacter pylori has been classified as high priority pathogen by the WHO in 2017. The emergence of antibiotic-resistant strains is one of the main causes of treatment failure in H. pylori infection. This study determined and characterized primary and secondary resistances in H. pylori in Malaysia.Materials and methodsGastric biopsies from antrum (n=288) and corpus (n=283) were obtained from 288 patients who underwent endoscopy at Universiti Kebangsaan Malaysia Medical Center (UKMMC), Kuala Lumpur, Malaysia. Antibiotic susceptibility to six classes of antibiotics was determined by the E-test. Mutations conferring in resistance in functional genes were identified by PCR and sequencing.ResultsOverall resistance rates to metronidazole, clarithromycin and levofloxacin were 59.3% (35/59), 35.6% (21/59) and 25.4% (15/59), respectively. Secondary isolates showed significantly higher resistance rates to clarithromycin compared to the primary isolates. Mixed infection with susceptible and resistant isolates was observed in 16.2% (6/37) of cases, of which 83.3% (n=5) had infection with the same strain. 41% (18/44) of isolates were resistant to more than one class of antibiotics of which 50% (9/18) were multidrug-resistant, two being primary and seven being secondary isolates. Mutations in rdxA, 23S rRNA and gyrA genes were associated with resistance to metronidazole, clarithromycin and levofloxacin, respectively.ConclusionThe high level of resistance to metronidazole, clarithromycin and levofloxacin seen in H. pylori isolates in our setting warrants the need for continuous surveillance and highlights caution in use of antibiotics generally used as first-line therapy in H. pylori eradication regimen.

Molecular Assessment of Resistance to Clarithromycin in Helicobacter pylori Strains Isolated from Patients with Dyspepsia by Fluorescent In Situ Hybridization in the Center of Iran

“…In our study, A2143G was the most common type of mutation in strains. This finding verified previous studies by other researchers [7,26]. Furthermore, 9.5% of clarithromycin-resistant H. pylori strains lacked the studied mutations.…”

“…Another finding of this research indicated that 69.2% of strains with A2143G mutation had the MIC of 8 to 256 μg/mL; however, 83.3% of strains with A2144G mutation had a MIC of 0.5 to 8 μg/mL. Hanafiah et al reported that more than 40% of strains with A2143G mutation had a MIC of 64 to >256 μg/mL [7]. The association of MIC values and point mutations in 23S rRNA gene was first determined by Versalovic et al who suggested the MIC value of 64 μg/mL as a cutoff point between high and low levels of antibiotic resistance, and they had high-level resistance in 84% of strains with the A2143G mutations and low-level resistance in 58% of A2144G mutations [28].…”

“…Based on the Maastricht V consensus reports, the above treatment is appropriate in countries with less than 15% resistance to clarithromycin. There are numerous, important factors (human and bacterial) in reducing the effect of H. pylori treatment, of which the antibiotic resistance seems to be the most significant [7,8].…”

Searching for an optimal therapy for H pylori eradication: High‐dose proton‐pump inhibitor dual therapy with amoxicillin vs. standard triple therapy for 14 days

“…This will explain the relatively high eradication rates we achieved with the 2‐week STT in our present study. However, a recent paper looking at the background primary resistance of H pylori strains in the same area has shown an increase in prevalence rate to 12.2% 11 from 6.8% in a previous study from our group 9 . Increasing clarithromycin resistance rates will impact adversely on the success of clarithromycin‐containing treatment regimens in the future and needs to be monitored closely in every locality.…”

<p>Eradication Treatment of <em>Helicobacter pylori</em> Infection Based on Molecular Pathologic Antibiotic Resistance</p>

“…[13][14][15] For the antibiotic resistance in H. pylori infection, bacterial culture and disc diffusion method are recommended by the Clinical Laboratory Standard Institute (CLSI). [16][17][18] However, compared with H. pylori culture, molecular pathological detection based on molecular markers, such as real-time polymerase chain reaction (PCR) and conventional PCR analysis, is a very simple and economic approach which also takes less time. Our study was designed to determine the effect and safety of H. pylori eradication therapy based on the results of molecular pathologic antibiotic resistance.…”