Investigation of the effect of silver nanoparticles alone and their combination with clarithromycin on H. pylori isolates

Abstract Helicobacter pylori is a common bacterial pathogen responsible for gastrointestinal diseases worldwide. Clarithromycin has been considered the best tolerable and safe antibiotic in treating H. pylori infection, but increased levels of clarithromycin resistance have reduced the effectiveness of the recommended treatment regimens. So alternative treatment approaches such as nanotechnology have been considered recently. This study aimed to determine the effect of silver nanoparticles (Ag-NP) alone and their combination with clarithromycin on H. pylori isolates. Gastric biopsy specimens were collected from 163 patients with different gastrointestinal signs referred to the endoscopy ward of Beheshti Hospital in Kashan, Iran. H. Pylori strains were isolated from 40 patients out of 163 (24.5%). Minimum inhibitory concentration (MIC) of clarithromycin on H. pylori isolates was determined by the Epsilometer test. The effect of the combination of Ag-NP with clarithromycin on the growth inhibition of clarithromycin-sensitive and resistant H. pylori isolates was determined by the checkerboard titration method. The clarithromycin resistance rate to H. pylori was 42.5%. The MIC of Ag-NP in clarithromycin-sensitive was 31.25-125 µg/ml and resistant H. pylori isolates ranged from 62.5-250 µg/ml. Due to the combination of Ag-NP with clarithromycin, 70.58% of clarithromycin-resistant isolates and 78.26% of clarithromycin-sensitive isolates showed a synergistic effect. A significant difference was observed in comparing the MIC of clarithromycin in combination with Ag-NP and clarithromycin or Ag-NP alone. The MIC clarithromycin was decreased in the presence of Ag-NP against clarithromycin sensitive, and resistant H. Pylori isolates.