A QUANTITATIVE MODEL FOR SUBCUTANEOUS ABSCESS FORMATION IN MICE

  • 1 January 1980
    • journal article
    • research article
    • Vol. 61  (1) , 97-107
Abstract
An experimental model of s.c. encapsulated abscesses was developed in which abscess formation could be assessed by quantitative measurements. Inocula were composed of bacterial broth cultures, autoclaved mouse cecal contents or both in combination. These inocula were injected s.c. on the flank in 2 strains of mice. Large encapsulated abscesses formed in all recipients by day 4 when the inoculum contained Bacteroides fragilis or Staphylococcus aureus combined with cecal contents. Bacterial concentrations/ml of pus at day 6 were 1010.1.+-. 0.02 for B. fragilis and 108.4 .+-. 0.1 for S. aureus. Spontaneous external drainage began by 10-15 days, and complete healing of the lesion occurred by 4-6 wk. The typical histological pattern consisted of a collagen capsule surrounding a rim of neutrophils, enclosing a central area of necrotic cells and fiber from the inoculum. The cross-sectional areas of the capsule, the neutrophil band and the entire abscess were measured in a reproducible manner by planimetry and abscess volumes were calculated. Values for these measurements varied with different inocula and different times after inoculation but were highly consistent for a specified time and inoculum.