Resistotype of Helicobacter pylori isolates

The impact on eradication outcome

Alfizah Hanafiah, Ahmad Norazah, Razlan Hamizah, Mohamed Ramelah

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Antibiotic resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. The aim of this study was to determine the phenotype and genotype of antibiotic-resistant strains of H. pylori in the Malaysian population and to evaluate the impact of antibiotic resistance to eradication outcome. One hundred and sixty-one H. pylori isolates were analysed in this study. Metronidazole, clarithromycin, fluoroquinolone, amoxicillin and tetracycline susceptibilities were determined by Etest. PCR followed by DNA sequencing was carried out to determine mutations. The medical records of the patients infected with resistant strains were reviewed to determine the eradication outcome. Metronidazole resistance was encountered in 36.6% of H. pylori isolates, whereas clarithromycin and fluoroquinolone resistance was observed in 1.2 and 1.9% of isolates, respectively. All strains tested were susceptible to amoxicillin and tetracycline. Frameshift and nonsense mutations in rdxA and frxA genes resulting in stop codons contributed to metronidazole resistance, which leads to reduced eradication efficacy. A2142G and A2143G mutations of 23S rRNA were identified as causing failure of the eradication therapy. Mutation at either codon 87 or 91 of the gyrA gene was identified in fluoroquinolone-resistant strains. However, the effect of resistance could not be assessed. This study showed that frameshift and nonsense mutations in rdxA or frxA genes and point mutations in the 23S rRNA affected the efficacy of H. pylori eradication therapy.

Original languageEnglish
Pages (from-to)703-709
Number of pages7
JournalJournal of Medical Microbiology
Volume63
Issue numberPART 5
DOIs
Publication statusPublished - 2014

Fingerprint

Helicobacter pylori
Fluoroquinolones
Metronidazole
Frameshift Mutation
Clarithromycin
Nonsense Codon
Amoxicillin
Microbial Drug Resistance
Tetracycline
Mutation
Disk Diffusion Antimicrobial Tests
Genes
Terminator Codon
DNA Sequence Analysis
Point Mutation
Codon
Medical Records
Therapeutics
Genotype
Anti-Bacterial Agents

ASJC Scopus subject areas

  • Microbiology (medical)
  • Microbiology

Cite this

Resistotype of Helicobacter pylori isolates : The impact on eradication outcome. / Hanafiah, Alfizah; Norazah, Ahmad; Hamizah, Razlan; Ramelah, Mohamed.

In: Journal of Medical Microbiology, Vol. 63, No. PART 5, 2014, p. 703-709.

Research output: Contribution to journalArticle

Hanafiah, Alfizah ; Norazah, Ahmad ; Hamizah, Razlan ; Ramelah, Mohamed. / Resistotype of Helicobacter pylori isolates : The impact on eradication outcome. In: Journal of Medical Microbiology. 2014 ; Vol. 63, No. PART 5. pp. 703-709.
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