Effects of simultaneous co-treatment with a de novo cationic antimicrobial peptide and silver nanoparticles on biofilm biomass and lasR, algD, and tpbB gene expression in Pseudomonas aeruginosa
Year: 2026
Type: article
Abstract: Pseudomonas aeruginosa is a major opportunistic and multidrug-resistant pathogen associated with chronic biofilm-related infections. This study aimed to design a de novo cationic antimicrobial peptide and evaluate its combined effects with silver nanoparticles (AgNPs) on biofilm biomass and biofilm-related gene expression and virulence gene expression in a standard P. aeruginosa strain. A 20-amino-acid linear peptide (RRFFKKAAHVGKHVGKAARR) was designed using AntiBP2, DBAASP, and AI4AMP and selected based on its predicted net positive charge (+ 8), moderate hydrophobicity (~ 45%), amphipathic helical structure, and low hemolytic potential. Commercial AgNPs (ARMINANO) were used to prepare a stock solution of 1024 ug/mL. MIC, biofilm biomass by crystal violet assay, and expression of lasR, algD, and tpbB were evaluated in the presence of peptide (64–128 ug/mL), AgNPs (4 ug/mL), and simultaneous co-treatment with the peptide and AgNPs. Gene expression was analyzed by RT-qPCR using the 2^-DDCt method with gyrB as the reference gene. The peptide significantly reduced biofilm biomass after 24 h (0.93 to 0.72; p = 0.0004). AgNPs alone produced the greatest reduction in biofilm biomass (0.24; p < 0.001), whereas simultaneous co-treatment also reduced biofilm biomass (0.41). All treatments significantly downregulated lasR , algD , and tpbB ( p < 0.0001). Under the tested conditions, the designed peptide, AgNPs, and their simultaneous co-treatment reduced biofilm biomass and downregulated selected biofilm- and virulence-associated genes in P. aeruginosa .
Source: BMC Microbiology
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,990
OpenAlex ID: W7214519434
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