Title: Enzymatic degradation of in vitro Staphylococcus aureus biofilms supplemented with human plasma

Abstract

Enzymatic debridement is a therapeutic strategy used clinically to remove necrotic tissue from wounds. Some of the enzymes utilized for debridement have been tested against bacterial pathogens, but the effectiveness of these agents in dispersing clinically relevant biofilms has not been fully characterized. Here, we developed an in vitro Staphylococcus aureus biofilm model that mimics wound-like conditions and employed this model to investigate the antibiofilm activity of four enzymatic compounds. Human plasma at concentrations of 0%–50% was supplemented into growth media and used to evaluate biofilm biomass accumulation over 24 hours and 48 hours in one methicillin-sensitive and five methicillin-resistant strains of S. aureus. Supplementation of media with 10% human plasma resulted in the most robust biofilms in all six strains. The enzymes α-amylase, bromelain, lysostaphin, and papain were then tested against S. aureus biofilms cultured in 10% human plasma. Quantification of biofilms after 2 hours and 24 hours of treatment using the crystal violet assay revealed that lysostaphin decreased biomass by up to 76%, whereas α-amylase, bromelain, and papain reduced biomass by up to 97%, 98%, and 98%, respectively. Scanning electron microscopy confirmed that the dispersal agents detached the biofilm exopolysaccharide matrix and bacteria from the growth surface. Lysostaphinmore » caused less visible dispersal of the biofilms, but unlike the other enzymes, induced morphological changes indicative of bacterial cell damage. Overall, our results indicate that use of enzymes may be an effective means of eradicating biofilms and a promising strategy to improve treatment of multidrug-resistant bacterial infections.« less

Authors:

Millenbaugh, Nancy ^[1]; Watters, Chase ^[2]; Burton, Tarea ^[1]; Kirui, Dickson ^[1]

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+ Show Author Affiliations

1. Joint Base San Antonio-Fort Sam Houston, TX (United States). Naval Medical Research Unit San Antonio. Maxillofacial Injury and Disease Dept.
2. Joint Base San Antonio-Fort Sam Houston, TX (United States). Naval Medical Research Unit San Antonio. Maxillofacial Injury and Disease Dept.; Naval Medical Research Center, Silver Spring, MD (United States). Wound Infections Dept.

Publication Date:

Wed Apr 27 00:00:00 EDT 2016

Research Org.:

Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1627994

Grant/Contract Number:  

SC0014664

Resource Type:

Accepted Manuscript

Journal Name:

Infection and drug resistance

Additional Journal Information:

Journal Volume: 9; Journal ID: ISSN 1178-6973

Publisher:

Dove Press

Country of Publication:

United States

Language:

English

Subject:

60 APPLIED LIFE SCIENCES; Infectious Diseases; Pharmacology & Pharmacy; MRSA; α-amylase; bromelain; lysostaphin; papain