title: Living in Sofia is associated with a risk for antibiotic resistance in Helicobacter pylori: a Bulgarian study.
abstract: The aim of the retrospective study was to evaluate geographic regions and residence places as possible risk factors for primary Helicobacter pylori antibiotic resistance in Bulgaria. Data from Sofia region, exhibiting the highest living density, were compared to those from other residence places. In total, 588 H. pylori strains from untreated adults who filled a questionnaire were evaluated. Strain susceptibility was assessed by a breakpoint susceptibility test. Resistance rates to metronidazole and clarithromycin have been found to increase, and that to tetracycline has been found to decrease over years. Clarithromycin resistance was 1.7-fold higher in Sofia inhabitants (23.5 %) than elsewhere (13.8 %) and 4.7-fold higher than that in villages (5.0 %). Moreover, the clarithromycin resistance rate was 2.6-fold lower in northern region (8.2 %) than in southern region (21.7 %). On multivariate analysis, sex and residence place were independent predictors for metronidazole resistance. Men were at lower risk for metronidazole resistance compared with women [odds ratio (OR) 0.703; 95 % confidence interval (CI) 0.499-0.990]. Importantly, Sofia inhabitants were at higher risk for the resistance compared with those living elsewhere (OR 1.453; 95 % CI 1.009-2.093). In conclusion, living in Sofia was associated with a risk for antibiotic resistance in H. pylori-positive adults. Living density could be associated with H. pylori resistance rates.
authors.affiliation: Department of Medical Microbiology, Medical University of Sofia, Zdrave Street 2, 1431, Sofia, Bulgaria, l.boyanova@hotmail.com.
authors.forename: Lyudmila
authors.initials: L
authors.lastname: Boyanova
authors.forename: Juliana
authors.initials: J
authors.lastname: Ilieva
authors.forename: Galina
authors.initials: G
authors.lastname: Gergova
authors.forename: Ivailo
authors.initials: I
authors.lastname: Evstatiev
authors.forename: Rossen
authors.initials: R
authors.lastname: Nikolov
authors.forename: Ivan
authors.initials: I
authors.lastname: Mitov
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002031:Bulgaria / Q000453:epidemiology; D017291:Clarithromycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D011795:Surveys and Questionnaires; D013752:Tetracycline / Q000494:pharmacology; D019371:Topography, Medical; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D008795:Metronidazole; D013752:Tetracycline; D017291:Clarithromycin