Alireza Ghanbari - Department of Microbiology, Islamic Azad University, Qom, Iran
Nahid Yarian - Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran.
Ali Javadi - Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

Background and Aim:Helicobacter pylori is a main causes of peptic ulcer. unfortunately, drug resistance in this bacterium has made treatment difficult; therefore new treatment methods are of importance. Using nanotechnology in medicine may be able to help humans in this field in the future Our goal is to construct gold nanoparticles and to conjugate them with commonly used therapies and investigate their anti-helicobacter effect.Methods:gold nanoparticles were synthesized by Turkevich method and analyzed by a spectrophotometer, and electron microscope device; then nanoparticles of gold and clarithromycin were conjugated and the conjugate compounds were reanalyzed. After confirming the conjugation, the antimicrobial effects of gold nanoparticles and the free drugs alone were compared with their conjugated state by disc method.Results:The maximum absorption wavelength of the gold nanoparticles was 522 nm. These particles were seen in almost spherical shape in the electron image and the largest amount was found in the solution of 10.0 nm. In practice, conjugation changed the solution’s color from red to purple and the maximum absorption wavelength of gold nanoparticles to 670 in the conjugated clarithromycin, In analysis with FT-IR, conjugate spectrum changed compared to the free state of antibiotics. Regarding antimicrobial tests, The inhibition zone in conjugate state increased in all antibiotics relative to free mode.Conclusion:According to the findings, gold nanoparticles alone had no antimicrobial effects at low concentrations, but could increase the activity of conjugated antibiotics against Helicobacter pylori, with optimal effect on both sensitive and resistant isolates of Helicobacter pylori.

Anti Helicobacter ,clarithromycin,gold nanoparticle