The Inhibition Activity of Silver Nanoparticles Compared with D-Glycin and Imipenem Effect on the Biofilm Formation by Food-origin Salmonella

Abstract

Since decades silver was depended worldwide as a treatment to a lot of diseases
ranging from burn infections, anthrax, and typhoid fever to bacterial conjunctivitis
in stillbirth, but its effectiveness against biofilms is still undetermined. Salmonella is
a major cause of food poisoning outbreaks especially in the third world countries.
Thus, in the present study; the antimicrobial activity of silver nanoparticles (Ag-
NPs) against Salmonella enterica biofilm was examined; their activity was
compared with amino acid; D-Glycin and imipenem antibiotic. The result of the
study revealed that Ag-NPs exhibited considerable antimicrobial property against
Salmonella enterica biofilm where the minimum inhibitory concentration (MIC)
was found at 50 μg/ml while MIC of D-glycin and imipenem were 50mM and
4μg/ml respectively. The isolates ability to form biofilm was assayed using the
tissue culture plate (TCP) assay, all the isolates were biofilm producers but with a
different thickness degrees. It was found that both of Ag-NPs and imipenem
inhibited Salmonella biofilm formation, but the inhibition by Ag-NPs was more than
the antibiotic imipenem, whereas D-Glycin increased the ability of Salmonella
isolates to form biofilm.