Accession Number:

ADA621777

Title:

Disruption of Methicillin-resistant Staphylococcus aureus Biofilms with Enzymatic Therapeutics

Descriptive Note:

Technical rept. Mar 2014-Apr 2015

Corporate Author:

NAVAL MEDICAL RESEARCH UNIT (SAN ANTONIO) FORT SAM HOUSTON TX

Report Date:

2015-04-29

Pagination or Media Count:

25.0

Abstract:

The purpose of this study was to establish an in vitro Staphylococcus aureus biofilm model that mimics wound-like conditions and employ this model to evaluate the anti-biofilm activity of four enzymatic compounds. Varying concentrations of human plasma from 0-50 were supplemented into growth media to evaluate biomass accumulation in 2 laboratory and 4 clinical multi-drug resistant S. aureus strains. Supplementation with 10 human plasma resulted in the most robust and reproducible biofilms in all 6 strains. The enzymes papain, bromelain, alpha-amylase, and lysostaphin were then tested on the 6 S. aureus strains in the 10 human plasma biofilm model, and biofilm biomass was quantified using the crystal violet assay. All four enzymes significantly reduced biomass compared to controls in all strains after 2 and 24 hours of treatment. Lysostaphin decreased biomass by up to 76, whereas the other agents reduced biomass by up to 94-98 in the 6 bacterial strains. Visualization of the biofilms with confocal laser scanning microscopy and scanning electron microscopy confirmed that the dispersal agents detached the biofilm matrix and bacteria from the growth surface, and lysostaphin, but not the other enzymes, induced changes in cell morphology indicative of bacterial cell damage. Overall, our results indicate use of enzymes may be an effective means of eradicating biofilms and a promising strategy to improve treatment of multidrug resistant bacterial infections.

Subject Categories:

  • Biochemistry
  • Biology
  • Microbiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE