The synergistic effect of biosynthesized gold nanoparticles with antibiotic against clinical isolates

الملخص EN

Background: Antibiotic resistance is a life threating problem and the need for an alternative is increasing worldwide.

Objective of this study is: Detecting the combination effect of AuNps with Amoxicillin/clavulanate (AMC) antibiotic against antibiotic resistant clinical bacterial isolates.

Materials and methods: Gold nanoparticles were biosynthesized using food origin Citrobacter freundii isolate (C2) which was isolated from chicken meat samples by pour plate method and identified using cultural characteristics, biochemical tests and the identification to the species level was completed by Vitek-2 system and this identification was confirmed by sequencing of the 16 s r RNA.

The biosynthesis of gold nanoparticles was optimized in order to achieve the finest AuNps with a diameter range (30-60) nm.

and the biosynthesized gold nanoparticles were characterized by visual observation and then characterized using various characterization techniques: Uv-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR) analysis, atomic force microscopy (AFM) analysis and scanning Electron Microscope (SEM).

The combination effect of AuNps with AMC antibiotic was detected against clinical bacterial isolates.

Results: The results revealed the biosynthesized AuNPs were roughly spherical and poly-dispersed, and they were highly effective with concentration (62.5 µg/ml) that inhibit the bacterial growth, MIC values of AMC antibiotic against clinical isolates were determined as 500 µg/ml, while the combination of gold nanoparticles and AMC had wide spectrum of antibacterial activity against different isolates of the bacteria that used in this study.

Conclusion: There was a significant synergistic effect between the biosynthesized gold nanoparticles when used in combination with antibiotic where the minimum inhibitory concentrations of the combination (AuNps/AMC) were less than its concentration when each of them (AuNps) or (AMC) used separately.