Quantitative Study of Wound Infection in Irradiated Mice

Summary

Bacterial infection of simple wounds was studied directly and quantitatively in adult mice given 6·5 Gy ⁶⁰Co. Three days later, when neutropenia was evident, the skin and the medial gluteus muscle of anaesthetized mice were incised. A suspension of Staphylococcus aureusEscherichia coliKlebsiella pneumoniae or Streptococcus pyogenes was inoculated into the wound. Bacteria per mg muscle were enumerated 3, 4 or 7 days later. The geometric means of bacteria per mg were greater in irradiated than in non-irradiated mice. Phagocytic cells were present in the wounded tissue. Hence sublethal ionizing radiation enhanced the susceptibility of mice to infections of wounds by these four bacterial species.