Antibiotic Resistance Among Helicobacter Pylori Strains Isolated From Patients With Histopathological Changes of the Gastric Tissue Towards Metronidazole, Clarithromycin, and Ciprofloxacin Publisher



Bayati S¹ ; Amirmozafari N¹ ; Alebouyeh M^{2, 3} ; Farzi N² ; Daryani NE⁴ ; Zali MR⁵ Show Affiliations
Source: Archives of Clinical Infectious Diseases Published:2019

Abstract

Background: The extent of antibiotic resistance among Helicobacter pylori strains influences current clinical therapeutic regimens in each region. Objectives: This cross-sectional study aimed to determine the resistance property and minimum inhibitory concentration (MIC50-90) of Helicobacter pylori strains toward metronidazole, clarithromycin, and ciprofloxacin in patients with distinct gastric histopathological changes in Tehran, Iran. Methods: This study was conducted on 170 patients suffering from gastric complications in three hospitals in Tehran from October 2014 until March 2015. Two separate biopsy samples were collected from each patient and used for pathological and microbiological examinations. Antimicrobial susceptibility tests were performed by agar dilution method according to the CLSI guidelines. The MIC values and susceptibility to varying concentrations of metronidazole (4 to 64 µg/mL), ciprofloxacin (0.5 to 16 µg/mL), and clarithromycin (0.25 to 16 µg/mL) were determined based on EUCAST recommendations. Results: Our results indicated the infection with H. pylori in a frequency of 32% (55/170) among the study patients (female, 51% and male, 49%). Endoscopic findings indicated that 42% of the patients suffered from peptic ulcers, 33% from duodenal ulcers, and 25% with a non-ulcer disease. Pathological findings indicated 58% of the patients had chronic gastritis, 33% had active chronic gastritis, and 9% suffered from intestinal metaplasia. In terms of antibiotic susceptibility, nearly 76.3%, 49%, and 45.5% of the strains were resistant to metronidazole, clarithromycin, and ciprofloxacin, respectively. The MIC values at which the growth of 50% and 90% of the strains was inhibited (MIC50-90) were 32-64 µg/mL for metronidazole, 0.5-16 µg/mL for clarithromycin, and 2-16 µg/mL for ciprofloxacin. Conclusions: The overall resistance levels were relatively high among the study patients. Accordingly, the administration of other anti-Helicobacter drugs, as well as more appropriate therapeutic regimens based on laboratory results, is recommended in patients with a history of treatment failure. © 2019, Archives of Clinical Infectious Diseases.