Efficacy of Polyhexamethylene Biguanide-containing Antimicrobial Foam Dressing Against MRSA Relative to Standard Foam Dressing
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Abstract: Many modern foam wound dressings possess a variety of attributes that are designed to create a supportive wound-healing environment. These attributes include absorbing exudate, providing optimum moisture balance at the wound surface, and preventing maceration of surrounding tissue. However, studies suggest that controlling wound bioburden should also be targeted when developing wound therapeutics. Thus, traditional foam dressings may absorb a copious amount of fluid, but may also provide an environment where microbes can grow unchallenged, leading to an increase in wound bioburden. However, antimicrobial foam dressings may prevent or reduce microbial growth, increasing the potential for wound healing. Studies reported herein evaluated the efficacy of 0.5% polyhexamethylene biguanide (PHMB) treated dressings to prevent the growth of methicillin-resistant Staphylococcus aureus (MRSA). An antimicrobial foam (Kendall™ AMD, Covidien, Mansfield, MA), which contains PHMB and a standard foam dressing (Copa™, Covidien, Mansfield, MA), which contains no PHMB (control), were directly inoculated with clinical isolate of MRSA and placed on a growth medium for selected time intervals. The presence or absence of microbial growth was quantified using plate counts and was visually assessed using scanning electron microscopy. At all time points, the antimicrobial foam dressing significantly reduced the MRSA growth compared to the control dressing. Similar results were also obtained in the microscopic evaluations.
Address correspondence to:
Kelly R. Kirker, PhD
Montana State University
Center for Biofilm Engineering
366 EPS Building
Bozeman, MT 59717
Phone: 406-994-4770
Email: Kelly.Kirker@biofilm.montana.edu
Polyhexamethylene biguanide (PHMB), also known as polyaminopropyl biguanide (PAPB) or polyhexanide, is a broad-spectrum antimicrobial agent used in a variety of products including contact lens cleaning solutions, skin disinfectant solutions, and wound dressings. The antimicrobial activity of PHMB is attributed to its disruption of the bacterial cell wall. This polymeric biguanide reacts with acidic membrane lipids and induces aggregation, leading to increased membrane fluidity and permeability, and eventual organism death. Polyhexamethylene biguanide has also been reported to bind bacterial DNA, alter its transcription, and cause lethal DNA damage.1 Wound care products containing PHMB include Kerlix™ AMD, Excilon™ AMD, Telfa™ AMD (all from Covidien, Mansfield, MA) and XCell® Cellulose Wound Dressing (Xylos, Corp., Langhorne, PA).
The efficacy of the AMD dressings against gram-positive and gram-negative bacteria as well as yeast and fungi has been demonstrated in several in-vitro and in-vivo studies.2–5 Kerlix AMD (PHMB-impregnated gauze) was exposed to several bacterial pathogens isolated from veterinary patients. Using a disk diffusion antimicrobial susceptibility test, the PHMB-impregnated gauze significantly inhibited the growth of 4 out of 4 gram-positive organisms, and 6 of 6 gram-negative species compared to untreated gauze.4 Furthermore, after direct inoculation of the Kerlix AMD dressings and 24 hours of incubation, there was no recovery of any colony forming units (CFU).
1. Allen MJ, White GF, Morby AP. The response of Escherichia coli to exposure to the biocide polyhexamethylene biguanide. Microbiology. 2006;152(Pt 4):989–1000.
2. Cazzaniga AL, Serralta V, Davis S, Orr R, Eaglstein WH, Mertz PM. The effect of an antimicrobial gauze dressing impregnated with 0.2-percent polyhexamethylene biguanide as a barrier to prevent Pseudomonas aeruginosa wound invasion. WOUNDS. 2002;14(5):169–176.
3. Gallant-Behm CL, Yin HQ, Liu S, et al. Comparison of in vitro disc diffusion and time kill-kinetic assays for the evaluation of antimicrobial wound dressing efficacy. Wound Repair Regen. 2005;13(4):412–421.
4. Lee WR, Tobias KM, Bemis DA, Rohrbach BW. In vitro efficacy of a polyhexamethylene biguanide-impregnated gauze dressing against bacteria found in veterinary patients. Vet Surg. 2004;33(4):404–411.
5. Motta GJ, Trigilia D. The effect of an antimicrobial drain sponge dressing on specific bacterial isolates at tracheostomy sites. Ostomy Wound Manage. 2005;51(1):60–66.
6. Motta GJ, Milne CT, Corbett LQ. Impact of antimicrobial gauze on bacterial colonies in wounds that require packing. Ostomy Wound Manage. 2004;50(8):48–62.
7. Mueller SW, Krebsbach LE. Impact of an antimicrobial-impregnated gauze dressing on surgical site infections including methicillin-resistant Staphylococcus aureus infections. Am J Infect Control. 2008;36(9):651–655.
8. Davis SC, Ricotti C, Cazzaniga A, Welsh E, Eaglstein WH, Mertz PM. Microscopic and physiologic evidence for biofilm-associated wound colonization in vivo. Wound Repair Regen. 2008;16(1):23–29.
9. Donlan RM, Costerton JW. Biofilms: survival mechanisms of clinically relevant microorganisms. Clin Microbiol Rev. 2002;15(2):167–193.
10. James GA, Swogger E, Wolcott R, et al. Biofilms in chronic wounds. Wound Repair Regen. 2008;16(1):37–44.
11. Parsek MR, Singh PK. Bacterial biofilms: an emerging link to disease pathogenesis. Annu Rev Microbiol. 2003;57:677–701.
12. Bjarnsholt T, Kirketerp-Møller K, Jensen PØ, et al. Why chronic wounds will not heal: a novel hypothesis. Wound Repair Regen. 2008;16(1):2–10.
13. Dowd SE, Sun Y, Secor PR, et al. Survey of bacterial diversity in chronic wounds using pyrosequencing, DGGE, and full ribosome shotgun sequencing. BMC Microbiol. 2008;8:43.
14. Percival SL, Bowler PG, Dolman J. Antimicrobial activity of silver-containing dressings on wound microorganisms using an in vitro biofilm model. Int Wound J. 2007;4(2):186–191.
15. Sun Y, Dowd SE, Smith E, Rhoads DD, Wolcott RD. In vitro multispecies Lubbock chronic wound biofilm model. Wound Repair Regen. 2008;16(6):805–813.
