Oxidative damage to Pseudomonas aeruginosa ATCC 27833 and Staphylococcus aureus ATCC 24213 induced by CuO-NPs

• Published in: Environmental science and pollution research international 2017-09, Vol.24 (27), p.22048-22060
• Main Authors: Ulloa-Ogaz, Ana Laura, Piñón-Castillo, Hilda Amelia, Muñoz-Castellanos, Laila Nayzzel, Athie-García, Martha Samira, Ballinas-Casarrubias, María De Lourdes, Murillo-Ramirez, José Guadalupe, Flores-Ongay, Luis Ángel, Duran, Robert, Orrantia-Borunda, Erasmo
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Antimicrobial agents; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Biomolecules; Cell culture; Cell Wall - drug effects; Chemical Sciences; Copper; Copper - analysis; Copper - toxicity; Copper oxides; Culture media; Cytotoxicity; Damage assessment; Deoxyribonucleic acid; DNA; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Gram-negative bacteria; Intracellular; Intracellular signalling; Light microscopy; Metabolism; Metal Nanoparticles - analysis; Metal Nanoparticles - toxicity; Microorganisms; Microscopy; Minimum inhibitory concentration; Nanoparticles; Nanotechnology; Optical microscopy; Oxidative Stress; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - growth & development; Reactive oxygen species; Reactive Oxygen Species - metabolism; Research Article; Scanning electron microscopy; Staphylococcus aureus; Staphylococcus aureus - drug effects; Staphylococcus aureus - growth & development; Toxicity; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-017-9718-6

The cytotoxicity of nanoparticles (NPs) and their properties are important issues in nanotechnology research. Particularly, NPs affect the metabolism of microorganisms due to NP interactions with some biomolecules. In order to assess the mechanisms underlying NPs toxicity, we studied the damage caused by copper oxide nanoparticles (CuO-NPs) on Staphylococcus aureus ATCC 24213 and Pseudomonas aeruginosa ATCC 27833. Spherical CuO-NPs characterized by their diameter (13 ± 3 nm) were synthesized with a maximum of 254 nm. These NPs reduced cell viability, with a minimum inhibitory concentration (MIC) of 500 and 700 ppm for Staphylococcus aureus and Pseudomonas aeruginosa , respectively. Surfactant was added to reduce the NP agglomeration, but it did not present any effect. The mechanism of CuO-NPs as antimicrobial agent was assessed by analyzing solubilized Cu 2+ , quantifying DNA release in the culture media, and measuring intracellular reactive oxygen species (ROS). CuO-NPs induced severe damage on cells as revealed by confocal optical microscopy and scanning electron microscopy (SEM). Our results indicated that CuO-NPs interacted with bacteria, triggering an intracellular signaling network which produced oxidative stress, leading to ROS generation. Finally, we concluded that CuO-NPs exhibited higher antibacterial activity on Gram-negative bacteria than on Gram-positive ones.