The development of an effective rat model of incisional
surgical site infection (SSI) has so far proven difficult. In this study, we created a novel incisional SSI model and validated it in terms of both macroscopic and microscopic aspects including its response to treatment using antimicrobial
wound-dressing,
Aquacel Ag(®).
Wounds were created on the dorsum of rats. 3-0
Vicryl(®) threads inoculated with Escherichia coli were inserted in the
wound beds in the
infection group (n = 6). The
wounds were closed for two days to induce
infection and then opened and covered with
polypropylene sheets during the study.
Aquacel Ag was placed under the
polypropylene sheet in the infected
wounds of the
Aquacel Ag group rats (n = 6). The
wounds in the control group (n = 6) contained sterile
Vicryl thread that had not been inoculated with E. coli. The macroscopic appearance,
wound area, bacterial counts, and histology of each group were evaluated. The
infection group demonstrated significantly lower wound healing (p < 0.001), greater bacterial counts (median [interquartile range] ratings, 2.15 × 10(7) [0.51 × 10(7)-53.40 × 10(7)] vs 2.07 × 10(4) [0.60 × 10(4)-4.45 × 10(4)] CFU/g, respectively; p < 0.01), and severer histological
inflammation (p < 0.001) than the control group. The
Aquacel Ag group was only able to show significantly better wound healing than the
infection group (p < 0.001). The new incisional SSI model exhibited all clinical manifestations of incisional SSI. It could be utilized to assess the effectiveness of newly developed treatments for incisional SSI.