Accession Number:

AD1023479

Title:

Gold Nanoparticle-Assisted Laser Therapy for the Disruption of Methicillin-Resistant Staphylococcus aureus Biofilms

Descriptive Note:

Technical Report,06 Apr 2015,03 Oct 2016

Corporate Author:

Naval Medical Research Unit San Antonio JBSA Fort Sam Houston United States

Personal Author(s):

• Kirui,Dickson
• Burton,Tarea
• Weber,Gregor
• Millenbaugh,Nancy

Report Date:

2016-11-28

Pagination or Media Count:

27.0

Abstract:

The purpose of this study was to develop a method to destroy bacterial biofilms using energy absorbing gold nanoparticles GNPs in combination with pulsed laser irradiation. Methicillin-resistant Staphylococcus aureus MRSA biofilms were cultured in vitro for 24 hours and then treated with 0, 62.5, 125, 250, or 500 micro gmL of GNPs for 1 to 5 hours. Biofilms were then exposed to 10 to 110 laser pulses 532 nm, 8 ns, 1 Hz or sham exposed. The crystal violet assay for biofilm biomass revealed that optimal dispersion of MRSA biofilms was achieved after treatment with 500 micro gmL of GNPs for 5 h followed by 50 laser pulses. Treatment of the biofilms with a combination of GNPs and laser irradiation led to a 63 - 8 reduction in colony forming units CFUs relative to controls and a 79 - 10 dispersion of biofilms as evidenced by confocal microscopy. Conversely, biofilms treated with 50 laser pulses alone or GNPs alone showed no discernible dispersion or reduction in CFUs compared to untreated controls. These results demonstrate the use of GNP-assisted laser therapy as a potential strategy to disrupt biofilms and, therefore, enhance the therapeutic efficacy of mainstay antibiotic regimens.

Descriptors:

• metallic nanoparticles
• gold
• pulsed lasers
• PHOTOTHERMAL ENERGY
• INFECTION
• DRUG RESISTANCE
• anti bacterial agents
• laser pulses
• antibiotics
• confocal laser scanning microscopy

Subject Categories:

• Microbiology
• Lasers and Masers
• Miscellaneous Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE