INTRA-ABDOMINAL ABSCESS FORMATION IN MICE - QUANTITATIVE STUDIES ON BACTERIA AND ABSCESS-POTENTIATING AGENTS

  • 1 January 1983
    • journal article
    • research article
    • Vol. 64  (4) , 345-353
Abstract
A model of intra-abdominal (IA) abscess formation was developed in mice. I.p. injection of a mixture of a potentiating agent (autoclaved colonic and cecal contents (ACC), 0.2 mg dry wt/mouse or sterile bran, 1 mg dry wt/mouse), Escherichia coli (1 .times. 106 colony forming units (cfu)/mouse) and Bacteroides fragilis (5 .times. 108 cfu/mouse) induced abscesses in 98% of mice inoculated. The abscesses persisted for at least 4 wk in 60% of inoculated animals and for 10 wk in 36%. From 1-5 abscesses/mouse were found. Abscess formation was quantified by weighing the dissected abscesses and by culturing bacteria from them. Histologically, the abscesses were characterized by a central region of polymorphonuclear leukocytes, often with a thin mononuclear phagocyte infiltrate surrounding it, and an outer wall of vascularized connective tissue. Fluorescent antibody studies demonstrated that antigens from both bacterial species were distributed throughout the abscess. At the concentrations used, neither ACC nor sterile bran induced formation in the absence of viable bacteria.