Helicobacter Pylori Resistance to Metronidazole and Clarithromycin in Dyspeptic Patients in Iran

Iranian Red Crescent Medical Journal 07/2010; 12(4).
Source: DOAJ


Background: The resistance of H. pylori to the recently available antibiotic treatment regimens has been a growingproblem. The prevalence of high antibiotic resistance of H. pylori is the most common reason of its eradicationfailure. The purpose of the present study is to determine the prevalence of antibiotic resistance among H.pylori strains isolated from Iranian patients.Method: We investigated the prevalence of H. pylori resistance to metronidazole, clarithromycin, amoxicillin, andtetracycline among 128 H. pylori isolates from Iranian patients. After the culture of biopsy specimens and identification,susceptibility tests was performed with Modified Disk Diffusion Method (MDDM) and E. test.Results: Resistance rates to metronidazole, clarithromycin, amoxicillin and tetracycline were 64%, 23%, 2.5%and 0%, respectively. Seventy two percent of the metronidazole resistance strains had MIC>256mg/ml (High-Level-Resistance).Discussion: Due to the increasing rate of antibiotic resistance in H. pylori strains and in order to decrease thetreatment cost, testing of susceptibility to metronidazole and clarithromycin is recommended.

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Available from: Amin Talebi Bezmin Abadi
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    • "Metronidazole resistance occurs by rdxA gene (which encodes an oxygen-insensitive NADPH nitroreductase), inactivation of frxA (NADPH flavin oxidoreductase), fdxB (ferrodoxin-like protein). The mechanism of intrinsic metronidazole resistance is related to the decreasing drug uptake or increased drug efflux.[927] H. pylori resistance to metronidazole in developed countries is about 35% and in some areas almost all strains resistant to metronidazole.[1416] "
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    ABSTRACT: Helicobacter pylori (H. pylori) resistance to antibiotics has become a global problem and is an important factor in determining the outcome of treatment of infected patients. The purpose of this study was to determine the H. pylori resistance to clarithromycin, metronidazole, and amoxicillin in gastrointestinal disorders patients. In this study, a total of 260 gastric antrum biopsy specimens were collected from patients with gastrointestinal disorders who referred to Endoscopy Section of the Isfahan Hospitals. The E-test and Modified Disk Diffusion Method (MDDM) were used to verify the prevalence of antibiotic resistance in 78 H. pylori isolates to the clarithromycin, metronidazole, and amoxicillin. H. pylori resistance to clarithromycin, metronidazole, and amoxicillin were 15.3, 55.1, and 6.4%, respectively. In this study, we had one multidrug resistance (MDR) isolates from patient with gastritis and peptic ulcer disease. Information on antibiotic susceptibility profile plays an important role in empiric antibiotic treatment and management of refractive cases. According to the results obtained in this study, H. pylori resistance to clarithromycin and metronidazole was relatively high. MDR strains are emerging and will have an effect on the combination therapy.
    Full-text · Article · Dec 2013 · Journal of research in medical sciences
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    • "H. pylori resistance to clarithromycin is attributed to A2143G and A2144G transition mutations in the 23s rRNA gene, a mutation which results in a decrease in the affinity of clarithromycin binding to the ribosome. In Europe, the prevalence of clarithromycin-resistant H. pylori seems to range between 10-45%,[1118–20] a rate which is lower in other countries of the world.[92122] Our results showed that there was no point mutation in clarithromycin-susceptible strains of H. pylori. "
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    ABSTRACT: Resistance to clarithromycin in H. pylori isolates is accepted as a main cause of treatment failure in developing countries. We aimed to determine the prevalence of clarithromycin-resistant strains isolated from dyspeptic patients in northern Iran, furthermore we aimed to assess the relationship between clinical outcomes of infection with point mutations. A total of 147 consecutive patients infected with H. pylori were included for determining the status of resistant H. pylori strains. With upper gastroscopy, three antral biopsies were taken from each patient, first section for rapid urea test, second for pathology and third section was used for bacterial culture in microbiologic lab. The antimicrobial susceptibility tests in this examination were agar dilution, in accordance with clinical and laboratory standards institue guidelines. Restriction fragment length polymorphism-PCR (RFLP-PCR) method was applied to determine the frequency of point mutations in 23s rRNA gene. Statistical analysis was performed using SPSS software (15.0) (SPSS, Inc., Chicago, Ill). Chi-square and Fisher's exact tests were applied to our analysis. A P value less than 5% was considered as statistically significant. Our results showed that there was no point mutation in clarithromycin-susceptible strains of H. pylori. The important findings in our study indicate that A2143G is the most prevalent point mutation (30/32: 93.7%) attributed in clarithromycin resistance among the H. pylori strains. The current study concluded that clarithromycin could still be involved in the empirical treatment of H. pylori infection, although a high frequency of A2143G mutation may increase the concerns regarding treatment failure.
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