Table 3: Animal evidence that biofilm delays wound healing from porcine, murine and rabbit ear wound models
From: Biofilm delays wound healing: A review of the evidence
Model | Biofilm species | Observations | Reference |
|---|---|---|---|
Porcine acute wound | S. aureus | Challenge with antimicrobial agents confirmed the recalcitrance of biofilm bacteria | Serralta et al. (2001)[34] |
Porcine acute wound | S. aureus | Indirect evidence of delayed healing, with polymorphonucleocytes observed on the surface of, but not within, biofilm | Davis et al. (2008)[35] |
Porcine acute wound | Methicillin-resistant S. aureus (MRSA) | Greater healing delays were observed due to biofilm formed by passaged MRSA strains than by parent strains; passaged strain was observed to form more biofilm than parent strain | Roche et al. (2012)[36] |
Porcine partial-thickness wound | MRSA, P . aeruginosa | Interactions between MRSA and P. aeruginosa were observed, delaying healing due to suppression of epithelialization and expression of virulence factors | Pastar et al. (2013)[37] |
Murine burn | P. aeruginosa | A biofilm-forming factor established in vitro was a key virulence factor in vivo | Rashid et al. (2000)[38] |
Murine burn | P. aeruginosa | Microscopic biofilm that was not readily removed by rinsing with saline | Schaber et al. (2007)[39] |
Murine diabetic chronic wound | P. aeruginosa | (In vitro then inoculated) biofilm significantly delayed healing compared to controls; health parameters in biofilm-colonized mice were normal | Zhao et al. (2010)[40] |
Murine diabetic chronic wound | P. aeruginosa | (In vitro then inoculated) biofilm-colonized wounds had high levels of inflammatory cells; 8 weeks for all biofilm-colonized wounds to heal, compared to 4 weeks for controls | Zhao et al. (2012)[41] |
Murine diabetic chronic wound | P. aeruginosa | Biofilm significantly delayed wound healing, even in diabetic mice treated with insulin | Watters et al. (2012)[42] |
Murine chronically infected surgical wound | P. aeruginosa | Biofilm was highly resistant to antibiotics and undiluted sodium hypochlorite once established over several days | Wolcott et al. (2010)[32] |
Murine chronically infected surgical wound | S. aureus, P. aeruginosa, Enterococcus faecalis, Finegoldia magna | (In vitro then inoculated) polymicrobial biofilm was maintained for 12 days, and delayed healing more than P. aeruginosa biofilm, as measured by wound closure | Dalton et al. (2011)[43] |
Murine splinted wound | S. aureus or Staphylococcus epidermidis | Biofilms significantly delayed epithelialization; inhibition of biofilm restored normal wound healing | Schierle et al. (2009)[44] |
Rabbit ear wound | S. aureus | Biofilm and active infection significantly delayed epithelialization and granulation tissue formation; biofilm-colonized wounds expressed significantly lower levels of inflammatory cytokines than infected wounds | Gurjala et al. (2011)[22] |
Rabbit ear wound | P. aeruginosa | Biofilm significantly delayed epithelialization and granulation tissue formation; debridement, lavage and silver sulphadiazine in combination were more effective at restoring healing than individua treatments | Seth et al. (2012a)[45] |
Rabbit ischemic ear wound | Klebsiella pneumoniae | Biofilm formed readily in ischemic wounds but not in non-ischemic wounds where neutrophils and macrophages were seen | Seth et al. (2012b)[46] |
Rabbit ischemic ear wound | K. pneumoniae, S. aureus, P. aeruginosa | K. pneumoniae biofilm was least virulent, P. aeruginosa biofilm most virulent, measured by healing inhibition and inflammatory responses; EPS-deficient P. aeruginosa did not delay healing | Seth et al. (2012c)[47] |
Rabbit ear wound | S. aureus, P. aeruginosa | Two-species biofilm elicited significantly elevated inflammatory response and impaired epithelialization and granulation tissue formation compared to single-species biofilm | Seth et al. (2012d)[48] |