Experimental Modeling of General Purulent Peritonitis

Abstract

General purulent peritonitis takes one of the first places in the structure of purulent complications. Despite the im provement of methods of diagnosis and treatment, mortality in postoperative purulent peritonitis remains quite high.

Aim of the study: develop a reproducible model of postoperative general peritonitis to study the pathophysiological mechanisms of its development and the development of pathogenetically substantiated therapy.

Materials and methods. The study was performed on 18 Wistar male rats aged 6 months, weighing 250–300 grams. Animals underwent laparotomy and modeling of postoperative general peritonitis according to the proposed method. Hospital strains of Escherichia coli BRLS 109 and Bacteroides fragilis 109 (strain ISCST1982, registered in Genbank), which we isolated from patients with acute appendicitis, with a total volume of 1.0 ml per animal, were used as infectious agents. Animals were taken out of the experiment under anesthesia with compliance with the rules of euthanasia at 1st, 3rd, 7th days after surgery. For morphological studies, samples of a fragment of the abdominal wall and cecum were taken. Bacteriological studies were performed on the 3rd, 7th day from the beginning of the experiment.

Results. It was established that all animals developed peritonitis with the progression of purulent-destructive changes in the abdominal cavity and the development of adhesions, which was confirmed by the data of the morphological method of research. According to the results of bacteriological studies on the 3rd day, exudate infection was detected in all rats (in 100 % of observations). E. coli BLS were isolated in all cases at concentrations of 103–104 CFU/ml. The strain B. fragilis is inoculated in 3 animals at a concentration of 103 CFU/ml, which made 50 %. By the 7th day, only an aerobic E. coli strain of BLS was detected in peritoneal exudate at concentrations of 103 CFU/ml in the complete absence of growth of B. fragilis.

Conclusion. We have developed a model of postoperative general peritonitis, which allows us to study the dynamics of the development of the inflammatory process in the abdominal cavity and, in terms of its clinical manifestations, is close to a real human disease. The reproducibility of the model is 100 %, which is confirmed by microbiological and morphological data.