Abstract：Objective To quantitatively analyze the clinical effect of negative pressure wound therapy on Pseudomonas aeruginosa infected wound in a porcine model.Methods Twenty-four Bama miniature pigs were included in this study. All these animals had a wound 5 cm in diameter created on the back and infected with Pseudomonas aeruginosa before they were randomly divided into two groups: negative pressure wound therapy group (NPWT) and sterile gauze treatment group. After the infected model was established, samples were collected for analysis of bacterial count and bacterial invasion depth on day 0, 4, 8, 12 and day16. Wound dressing (weight, 1 g) was also collected for eDNA analysis.Results After treatment, the bacterial count in the NPWT group was lower than that of the control group and the difference was statistically significant from the 8th day (P<0.05). The bacterial counts in the NPWT group and the control group were 1.92±0.79 and 3.50±0.80 respectively(expressed as the logarithm, P<0.001) on the 16th day. The results of eDNA showed that the bacterial count of the NPWT group was significantly lower than that of the control group on the 4th, 8th, 12th and 16th days (P<0.05). With the extension of treatment, the average invasion depth of the two groups was gradually decreased. However, the bacterial invasion depth of the NPWT group was significantly lower than that of the control group on the 4th, 8th, 12th and 16th days (P<0.05). Bacterial invasion depth in the NPWT group and the control group was (18.2±9.7)μm and (40.0±12.3)μm (P<0.01)respectively.Conclusions Compared with conventional gauze treatment group, negative pressure wound therapy can significantly reduce the bacterial count, eDNA amount and invasion depth for Pseudomonas aeruginosa infected wound. This may be one of the mechanisms by which negative pressure wound therapy can promote wound healing.
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