The time at which infected postoperative wounds demonstrate increased strength.

It was again shown in this study that laparotomy wounds purposely infected with a known inoculum of live gram-negative bacteria exhibited greater tensile strength than did those in the normal control group. The organisms used were Escherichia coli and Pseudomonas aeruginosa. The phenomenon was not present during the first ten days after wounding but was quite evident in wounds tested at 14 and 21 days. By histologic examination, there was evidence of much more new collagen in the wounds that exhibited increased strength.