Biologically synthesized silver nanoparticles as potent antibacterial effective against multidrug-resistant
C Campo-Beleño1, R A Villamizar-Gallardo2, L E López-Jácome3
1Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Abstract:
Pseudomonas aeruginosa is one of the most worrisome infectious bacteria due to its intrinsic and acquired resistance against several antibiotics and the recalcitrance of its infections; hence, the development of novel antimicrobials effective against multidrug-resistant P. aeruginosa is mandatory. In this work, silver nanoparticles obtained by green synthesis using a leaf extract and fungi were tested against a battery of clinical strains from cystic fibrosis, pneumonia and burnt patients, some of them with multidrug resistance. Both nanoparticles showed a potent antibacterial effect, causing severe damage to the cell wall, membrane and DNA, and inducing the production of reactive oxygen species. Moreover, the nanoparticles derived from fungi showed synergistic antibacterial effects with the antibiotics meropenem and levofloxacin for some clinical strains and both kinds of nanoparticles were nontoxic for larvae of the moth Galleria mellonella, encouraging further research for their implementation in the treatment of P. aeruginosa infections.
Insights
Green synthesized silver nanoparticles show potent antibacterial effects against multidrug-resistant Pseudomonas aeruginosa. These novel antimicrobials are non-toxic and offer a promising alternative for treating challenging P. aeruginosa infections.
Area of Science:
- Nanotechnology
- Microbiology
- Infectious Diseases
Background:
- Pseudomonas aeruginosa infections are difficult to treat due to antibiotic resistance.
- Multidrug-resistant (MDR) P. aeruginosa poses a significant global health threat.
- Novel antimicrobial strategies are urgently needed.
Purpose of the Study:
- To evaluate the efficacy of green synthesized silver nanoparticles (AgNPs) against clinical strains of P. aeruginosa.
- To investigate the antibacterial mechanisms of AgNPs.
- To assess the synergistic effects of AgNPs with conventional antibiotics and their in vivo toxicity.
Main Methods:
- Green synthesis of silver nanoparticles using leaf extract and fungi.
- Testing AgNPs against a panel of clinical P. aeruginosa isolates (cystic fibrosis, pneumonia, burn patients).
- Assessing antibacterial activity, cell damage, reactive oxygen species (ROS) production, synergistic effects with meropenem and levofloxacin, and Galleria mellonella larval toxicity.
Main Results:
- Both leaf- and fungi-derived AgNPs exhibited potent antibacterial activity against P. aeruginosa.
- AgNPs caused significant damage to bacterial cell walls, membranes, and DNA, and induced ROS production.
- Fungi-derived AgNPs showed synergistic effects with meropenem and levofloxacin against some strains.
- Both types of AgNPs demonstrated no toxicity in Galleria mellonella larvae.
Conclusions:
- Green synthesized silver nanoparticles are effective against multidrug-resistant P. aeruginosa.
- AgNPs offer a novel therapeutic approach with potential synergistic activity and low toxicity.
- Further research is warranted for the clinical application of these AgNPs in treating P. aeruginosa infections.
