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Updated: Aug 23, 2026
A Delayed Inoculation Model of Chronic Pseudomonas aeruginosa Wound Infection
Published on: February 20, 2020
Early cutaneous alterations in experimental sepsis by Pseudomonas aeruginosa
Haritini Petropoulou1, Evangelos J Giamarellos-Bourboulis, Nicolaos Kavatzas
1Department of Dermatology and Venereology, University of Athens, Medical School, Athens, Greece.
Background:
To evaluate whether histopathologic findings of skin in sepsis by Pseudomonas aeruginosa correlate with the clinical course.
Methods:
Histological alterations after bacterial challenge by one susceptible (A) and two multidrug-resistant isolates (B and C) of P. aeruginosa were studied in 18 rabbits. Sepsis was induced by the intravenous infusion of 1 x 10(8) CFU by a catheter in the right jugular vein; blood was sampled for the estimation of tumor necrosis factor alpha (TNF-alpha) and malondialdehyde (MDA). Skin biopsies were collected along with a subcutaneous fat specimen for culture.
Results:
The mean survival was 0.85, 1.75 and 11.00 days after challenge by isolates A, B and C, respectively. The main histologic findings of skin were: inflammation and swelling of the dermis; thickening of the endothelium and infiltration of vessel wall and lumen by polymorphonuclear leukocytes; extravasation of red blood cells, and necrobiotic changes of the hair follicles. Serum TNF-alpha was elevated in animals challenged by isolate A compared to challenge by isolates B and C. Concentrations of MDA were similar for all isolates. Mean log(10) of viable cells isolated from subcutaneous fat were 5.74, 2.74 and 1.40 after challenge by isolates A, B and C, respectively.
Conclusions:
Prolongation of survival was accompanied by lower serum TNF-alpha, decreased viable cells from subcutaneous fat and intensified inflammatory response in the dermis and subcutaneous tissue. These findings might be of importance for immunomodulatory intervention.
Insights
Histopathologic skin findings in Pseudomonas aeruginosa sepsis correlate with clinical outcomes. Intensified inflammation and lower tumor necrosis factor alpha (TNF-alpha) were observed with prolonged survival in rabbits.
Area of Science:
- Microbiology
- Pathology
- Immunology
Background:
- Sepsis caused by Pseudomonas aeruginosa presents a significant clinical challenge.
- Understanding the correlation between skin histopathology and sepsis progression is crucial for effective treatment.
Purpose of the Study:
- To investigate the relationship between histopathologic skin findings and the clinical course of sepsis induced by Pseudomonas aeruginosa.
- To evaluate the impact of different P. aeruginosa isolates on sepsis severity and host response.
Main Methods:
- Sepsis was induced in 18 rabbits via intravenous infusion of P. aeruginosa.
- Blood samples were analyzed for tumor necrosis factor alpha (TNF-alpha) and malondialdehyde (MDA).
- Skin and subcutaneous fat biopsies were collected for histopathological examination and bacterial culture.
Main Results:
- Survival varied significantly based on the P. aeruginosa isolate, ranging from 0.85 to 11.00 days.
- Histologic findings included dermal inflammation, vascular changes with polymorphonuclear leukocyte infiltration, and necrobiotic alterations.
- Elevated serum TNF-alpha was noted with a more virulent isolate, while subcutaneous bacterial load decreased with prolonged survival.
Conclusions:
- Survival in P. aeruginosa sepsis is linked to specific histopathologic skin changes.
- Lower TNF-alpha levels and reduced bacterial burden in subcutaneous tissue correlate with longer survival.
- These findings suggest potential targets for immunomodulatory interventions in sepsis treatment.
