The effect of local infection upon wound healing: an experimental study.

Local infection was introduced into rat abdominal wounds using a 10(8) bacterial/ml inoculum. Three groups of infection were used: Staphylococcus aureus, Pseudomonas aeruginosa and a combination group of Escherichia coli and Proteus mirabilis. Infection was shown to delay healing as judged by bursting tests. Fibroblast proliferation was depressed at the wound edges but there was an increase in the total amount of hydroxyproline present. Small vessel angiogenesis was increased in areas of abscess formation but larger vessels were commonly blocked by thrombus or distorted by surrounding inflamed tissue. The possible causes of these effects are discussed.