In Vitro Investigation of Antibacterial Enhancement Using Silver and Gold Nanoparticles Against Multidrug-resistance Staphylococcus aureus

Abstract

The aim of this study is to investigate the antibacterial enhancement of silver and gold nanoparticles against multidrug-resistance Staphylococcus. A total of 75 multidrug-resistant S. aureus were isolated from 200 different clinical samples from patients in Arbil, Iraq. All isolates were tested for their resistance against ten different types of antimicrobials. Isolates were treated with silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) by the disc diffusion method. Treated isolates were tested for their minimum minimum inhibitory concentration (MIC) by using the broth microdilution method. The antibacterial activity of nanoparticles against isolates significantly increased the zone 3.6±36 mm for AuNPs and 1.78±25 mm for AgNPs. All isolates were sensitive to Imipenem, Ceftriaxone, and Ciprofloxacin, whereas highest rate of was seen among Trimethoprim, Azithromycin, Amikacin, Tetracycline, Aztreonam, Pipracycline, and Vancomycin. The fractional inhibitory concentration index (FICI) result revealed that 0.91 was from Azithromycin with AgNPs and 1 from Vancomycin with AgNPs, while the FICI results for AuNPs were 0.94 for Vancomycin with AuNPs, 1 for Imipenem. The synergistic effect between the Imipenem and AgNPs were as follows: the FICI value reached 0.45, and 0.62 Imipenem and AuNPs.