Comparison of methods to detect the in vitro activity of silver nanoparticles (AgNP) against multidrug resistant bacteria

作者：Emerson Danguy Cavassin, Luiz Francisco Poli de Figueiredo, José Pinhata Otoch, Marcelo Martins Seckler, Roberto Angelo de Oliveira, Fabiane Fantinelli Franco, Valéria S. Marangoni, Valtencir Zucolotto, Anna S. Levin, Sílvia Figueiredo Costa · 发表于：Journal of Nanobiotechnology · 年份：2015 · DOI：10.1186/s12951-015-0120-6 · 被引用次数：298 · 研究领域：Nanoparticles: synthesis and applications、Antibiotics Pharmacokinetics and Efficacy、Cancer Research and Treatment

BACKGROUND: Multidrug resistant microorganisms are a growing challenge and new substances that can be useful to treat infections due to these microorganisms are needed. Silver nanoparticle may be a future option for treatment of these infections, however, the methods described in vitro to evaluate the inhibitory effect are controversial. RESULTS: This study evaluated the in vitro activity of silver nanoparticles against 36 susceptible and 54 multidrug resistant Gram-positive and Gram-negative bacteria from clinical sources. The multidrug resistant bacteria were oxacilin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp., carbapenem- and polymyxin B-resistant A. baumannii, carbapenem-resistant P. aeruginosa and carbapenem-resistant Enterobacteriaceae. We analyzed silver nanoparticles stabilized with citrate, chitosan and polyvinyl alcohol and commercial silver nanoparticle. Silver sulfadiazine and silver nitrate were used as control. Different methods were used: agar diffusion, minimum inhibitory concentration, minimum bactericidal concentration and time-kill. The activity of AgNPs using diffusion in solid media and the MIC methods showed similar effect against MDR and antimicrobial-susceptible isolates, with a higher effect against Gram-negative isolates. The better results were achieved with citrate and chitosan silver nanoparticle, both with MIC90 of 6.75 μg mL(-1), which can be due the lower stability of these particles and, consequently, release of Ag...