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Updated: Jul 12, 2026
Swine Model of Biofilm Infection and Invisible Wounds
Published on: June 16, 2023
Negative Pressure Wound Therapy Modulates Wound pH and Bacterial Invasion in Pseudomonas aeruginosa-infected Porcine
Zhirui Li1,2, Chen Chen3, Guoqi Wang2,3
1From the Department of Orthopaedics, Hainan Hospital of Chinese PLA General Hospital, Sanya, Hainan, China.
Background:
Pseudomonas aeruginosa infection markedly delays wound healing. Negative pressure wound therapy (NPWT) is widely used for infected wounds, but its effects on wound pH and bacterial invasion remain unclear.
Methods:
A porcine model of full-thickness wounds infected with P. aeruginosa was established. Thirty-six wounds in 18 pigs were treated with NPWT or a gauze dressing. On days 1, 5, 9, and 13 after infection, wound pH, bacterial burden, bacterial invasion depth, inflammatory infiltration, neovascularization, and granulation tissue thickness were assessed.
Results:
Compared with the gauze dressing group, NPWT significantly reduced bacterial counts on days 9 and 13 (P < 0.05 and P < 0.001, respectively). From day 5 onward, wound pH was lower in the NPWT group, with values of 7.82 ± 0.18 versus 8.25 ± 0.19 on day 5; 7.50 ± 0.32 versus 8.20 ± 0.25 on day 9; and 7.23 ± 0.19 versus 7.77 ± 0.23 on day 13. NPWT also reduced bacterial invasion depth at all time points (P < 0.05). Superficial neutrophil aggregation was lower after NPWT on days 5, 9, and 13: 35.60 ± 1.95, 22.40 ± 2.41, and 17.20 ± 1.79 versus 45.20 ± 2.17, 32.80 ± 2.39, and 31.20 ± 2.49, respectively; all P < 0.05. NPWT further enhanced neovascularization and granulation tissue thickness.
Conclusions:
NPWT promotes healing of P. aeruginosa-infected wounds by reducing wound alkalinity, limiting bacterial burden and invasion, attenuating superficial inflammation, and enhancing angiogenesis and granulation tissue formation.
