Nanogold for In Vitro Inhibition of Salmonella Strains

Abstract EN

The pathogenic strains of Salmonella typhi, paratyphi, and typhimurium are the major cause of typhoid and food poisoning in children and adults in developing countries.

According to WHO estimation, 22 million cases of typhoid fever and 200,000 related deaths occur worldwide each year with an additional 6 million cases of paratyphoid fever estimated to occur annually with the highest incidence in children, resulting in a high death rate.

The high use of antibiotics has also given rise to drug-resistant strains.

Hence, it was of importance to assess the inhibition and quick detection of pathogenic strains of Salmonella.

This study aims to investigate the chemically synthesized gold nanoparticles (GNPs) for its antibacterial activity against clinical isolates of S.

typhi and S.

paratyphi including food sample isolates.

The GNPs were characterized using visible color change, UV-Vis spectrophotometry, FTIR, XRD, DLS, FESEM, TEM, and zeta potential.

The plasmon peak at 525 nm and 535 nm confirmed the synthesis of gold nanoparticles.

The size of the chemically synthesized gold nanoparticles (GNPs) were in the range of 40-60 nm, while FESEM and TEM images revealed that the GNPs were spherical in shape.

For antimicrobial activities, five of the Salmonella strains were isolated from fish and egg samples, while the other seven were S.

typhi and S.

paratyphi from clinical samples.

The inhibition factor for GNPs showed higher inhibition against S.

paratyphi, while the inhibition factor for S.

typhi were found to be higher than Ciprofloxacin-30.

This is the first study of the antibacterial efficacy of GNPs against pathogenic strains of Salmonella.

The obtained results suggest that nanobioconjugated gold may be of interest in the detection of typhoid and high potential use in areas in biomedicine as an alternative to antibiotics.