Biology subjects

DeSouza, A.

Publications and source records attributed to DeSouza, A..

2 recordsLinked to original sources

bioRxiv2024

Silversol (a colloidal nanosilver formulation) inhibits growth of antibiotic-resistant Staphylococcus aureus by disrupting its physiology in multiple ways

Antibacterial effect of a colloidal nanosilver formulation Silversol(R) was investigated against an antibiotic-resistant strain of Staphylococcus aureus. Lower concentrations of the test formulation exerted bacteriostatic and, its higher concentrations exerted bactericidal effect against this pathogen. Silversol(R) at sub-lethal concentration was found to disturb multiple physiological traits of S. aureus such as growth, antibiotic susceptibility, membrane permeability, efflux, protein synthesis and export, biofilm and exopolysaccharide production, etc. Transcriptome data revealed the genes coding for transcriptional regulators, efflux machinery, transferases, {beta}-lactam resistance, oxidoreductases, metal homeostasis, virulence factors, and arginine biosynthesis to get expressed differently under influence of the test formulation. Genes (argG and argH) involved in arginine biosynthesis emerged among the major targets of Silversol(R) in S. aureus.

microbiology↗

bioRxiv2023

Identifying molecular targets of a colloidal nanosilver formulation (Silversol) in multidrug resistant Pseudomonas aeruginosa

P. aeruginosa is a notorious pathogen. A multi-drug resistant strain of this bacterium was challenged with a colloidal nano-silver formulation- Silversol(R). Its minimum inhibitory concentration against P. aeruginosa was found to be 1.5 ppm, and at sub-MIC of 1 ppm, it was able to alter quorum-sensing regulated pigmentation, exopolysaccharide synthesis and biofilm formation, antibiotic susceptibility, protein synthesis and export, nitrogen metabolism, and siderophore production in this pathogen. Transcriptome analysis of the silver-exposed P. aeruginosa indicated generation of nitrosative stress and disturbance of iron homeostasis to be the major mechanisms associated with anti-Pseudomonas activity of Silversol(R). Network analysis of the differentially expressed genes in silver-treated bacterium identified ten genes as the potential molecular targets: norB, norD, nirS, nirF, nirM, nirQ, nosZ, nosY, narK1, and norE (all associated with nitrogen metabolism or denitrification). Three of them (norB, narK1, and norE) were also validated through RT-PCR.

microbiology↗