Negative pressure wound therapy reduces the motility of Pseudomonas aeruginosa and enhances wound healing in a rabbit ear biofilm infection model

Abstract

Pseudomonas aeruginosa motility, virulence factors and biofilms are known to be detrimental to wound healing. The efficacy of negative pressure wound therapy (NPWT) against P. aeruginosa has been little studied, either in vitro or in vivo. The present study evaluated the effect of negative pressure (NP) on P. aeruginosa motility in vitro, and the effect of NPWT on virulence factors and biofilms in vivo. P. aeruginosa motility was quantified under different levels of NP (atmospheric pressure, − 75, − 125, − 200 mmHg) using an in vitro model. Swimming, swarming and twitching motility were significantly inhibited by NP (− 125 and − 200 mmHg) compared with atmospheric pressure (p = 0.05). Virulence factors and biofilm components were quantified in NPWT and gauze treated groups using a rabbit ear biofilm model. Biofilm structure was studied with fluorescence microscopy and scanning electron microscopy. Additionally, viable bacterial counts and histological wound healing parameters were measured. Compared with the control, NPWT treatment resulted in a significant reduction in expression of all virulence factors assayed including exotoxin A, rhamnolipid and elastase (p = 0.01). A significant reduction of biofilm components (eDNA) (p = 0.01) was also observed in the NPWT group. The reduction of biofilm matrix was verified by fluorescence- and scanning electron-microscopy. NPWT lead to better histologic parameters (p = 0.01) and decreased bacterial counts (p = 0.05) compared with the control. NPWT treatment was demonstrated to be an effective strategy to reduce virulence factors and biofilm components, which may explain the increased wound healing observed.

Biofilm-Innate Immune Interface: Contribution to Chronic Wound Formation

“…It has also been shown to control infection and modulate immune responses. In animal models, NPWT has been shown to have anti-biofilm effects (186)(187)(188). It has also been shown to modulate growth factor, cytokine expression, and matrix metalloproteinases to support healing (189,190).…”

Fixierung von Hauttransplantaten mit Vakuumversiegelung: Eine sinnvolle Option?

“…In addition, some authors have postulated a reduction in the bacterial load of the wound. Thus, Wang et al showed a relevant reduction in Pseudomonas aeruginosa under NPWT [7]. Li et al reported similar results in respect of Staphylococcus aureus [14].…”

Artificial sweeteners inhibit multidrug‐resistant pathogen growth and potentiate antibiotic activity

“…Motility, and twitching in particular for A. baumannii , is a central facet of virulence and facilitates bacterial dissemination to the bloodstream or other niches within an infected host (Guoqi et al , 2018 ; Maslova et al , 2021 ). As mentioned above, almost all genes involved in T4P assembly and control of protrusion/retraction dynamics were significantly downregulated in the presence of ace‐K according to our dRNA‐seq data.…”