engleski

Helicobacter pylori genotypes and resistance rates are associated with treatment failure in Croatian patients

The aim of this study was to evaluate in a matched groups (according to age, gender, treatment, clinical diagnosis)of patients contribution of cagA and vacA status, resistance to antibiotics and clinical diagnosis to treatment failure. A total of 82 Patients with H.pylori infection and peptic ulcer disease or gastritis.40 patients with H.pylori isolates before and after unsuccesful eradication, of them 38 with one isolate before and after therapy and 2 patients who received 2 different therapy regimens, with 2 isolates before and2 isolates after therapy ; 42 patients (control group) with succesful erdication. Methods: H.pylori was cultivated from gastric biopsies from antrum and corpus, taken before and after treatment.MICs to amoxycillin, tetracycline, azithromycin and metronidazol were determined bxy agar dilution method. DNA was isolated from H.pylori culture and vacA, cagA and RAPD were done by PCR.Products were visualised electrophoretically. Data were analysed with SPSS version 8.0. Results: Resistance to metronidazol irrespective of therapy significantly influences treatment outcome (p-0, 001 for whole group). Sensitivity results for other antibiotics do not correlate with treatmentoutcome. VacA subtypes could not be connected with treatment outcome.Cag+ strains significantly reduce eradication success (p=0, 0012). It could not be found relation between molecular virulence markers and clinical diagnosis. predictive factors for erdication success are cagA positive status and resistance to metronidazol irrespective of clinical diagnosis and therapy. Conclusion: Reinfection as causative factor for treatment failure was not detected by RAPD. H.pylori extreme genetic diversity has been confirmed. Also it has not been found relation between specific genotypes and clinical diagnosis. Significant predictors for treatment failure are cag+ status and resistance to metronidazol, probably with additional mutagenic effect which potentionaly leads to other mutatuins which can contribute to treatment failure. Further investigations should confirme these facts.

H.pylori; genotyping; resistance

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