1721. Dakinís Solution Alters Macrophage Viability and Function In Vitro
Session: Poster Abstract Session: Studies of the Interface of Host-Microbial Interaction
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • Cardile IDSA Dakin's 2013 final.pdf (1.6 MB)
  • Background: Dakins solution (DS), buffered sodium hypochlorite, is utilized as a topical antimicrobial for war wounds and is commercially available at 0.5%, 0.25%, and 0.125%.  DS can be toxic to human cells, but the effects on immune cells are not well documented. To examine whether DS might hinder the local immune response to infection, we evaluated macrophage viability and phagocytosis in vitro following DS exposure.

    Methods: Viability was assessed by treating confluent monolayers of murine macrophages (J774A.1, ATCC) with DS at six concentrations via fluorescent assay (CellTiter-Fluor™).  Viability was defined as percentage relative to control non-treated cells. To assess phagocytosis, macrophages were treated with DS at the same six concentrations, and the DS was neutralized with 0.2M sodium thiosulfate. Macrophages were then incubated with S. aureus(UAMS-1, ATCC) at a ratio of 10 bacteria/cell for 30min, and washed with phosphate-buffered saline. Cells were incubated in medium with gentamicin (200µg/mL) for 30min, lysed, and serially diluted to enumerate bacteria. Percent phagocytosis was determined relative to non-treated, control cells.  Statistical analysis was performed via ANOVA.

    Results:

    Treatment of macrophages with DS at concentrations > 0.0025% reduced viability, and resulted in significantly impaired phagocytosis.

    Viability (%)

     

     

    Phagocytosis

     

    Time Exposed (min)

    % DS

    % Phagocytosis

    % DS

    0.5

    1

    5

    10

    15

    30

    Control

    100

    0.000025

    97.6 +1.1

    95.4+1

    91.3+1.3

    90.5+2

    91.5+1

    89.6+1

    0.125

    13*

    0.00025

    92.6+3.5

    90.8+1.2

    84.5+1.4

    83.1+1.8

    84.1+1

    81.2+0.9

    0.025

    42*

    0.0025

    80.8+1.7

    74.7+1.3

    65.8+2.9

    60.6+0.4

    63.6+0.7

    58.7+0.1

    0.0025

    58*

    0.025

    12.4+0.1

    2.4+0.1

    3.2+0.3

    4.8+3.5

    3.6+2.9

    2.1+0.8

    0.00025

    73

    0.125

    1.2 +0.1

    1.5+0.1

    2.0+0.3

    2.4+0.3

    2.1+0.3

    1.2+0.4

    0.000025

    78

    0.25

    1.2+ 0.7

    1.6+0.1

    2.0+0.1

    1.9+0.1

    1.6+0.1

    1.6+0.3

     

    *P-value < 0.05 compared to control (0.2M Sodium thiosulfate) 

    Conclusion: DS at clinically utilized concentrations (0.025-0.25%) was detrimental to macrophage survival and function in vitro.  Dilution to < 0.00025% was required to attenuate these effects.  This is in agreement with prior data indicating that use of 0.00025% DS balances dose dependent toxicity with efficacy.  The optimal concentration for clinical use will be determined with future in vivo experiments.

    Anthony P. Cardile, DO1, Carlos J. Sanchez Jr., PhD2, Brady J. Hurtgen, PhD2, Desiree Romano2, Sharanda Hardy2, Joseph Wenke, PhD3, Clinton K. Murray, MD1 and Kevin S. Akers, MD1,4, (1)Infectious Disease Service, San Antonio Military Medical Center, Fort Sam Houston, TX, (2)Department of Extremity Trauma, United States Army Institute of Surgical Research, Fort Sam Houston, TX, (3)Extremity Trauma and Regenerative Medicine, US Army Institute of Surgical Research, Fort Sam Houston, TX, (4)US Army Institute of Surgical Research, Fort Sam Houston, TX

    Disclosures:

    A. P. Cardile, None

    C. J. Sanchez Jr., None

    B. J. Hurtgen, None

    D. Romano, None

    S. Hardy, None

    J. Wenke, None

    C. K. Murray, None

    K. S. Akers, None

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