Assessment of wound contamination by wound irrigation. Experimental investigations on quantitative recovery of anaerobic and aerobic bacteria.

The quantitative recovery of E. coli, S. faecalis and B. fragilis from operative abdominal wounds was investigated in pigs in an experimental model suitable for statistical calculations. Wounds were contaminated in groups of ten with different numbers of either a single bacterial species or a mixture of two species. The wound was irrigated with saline 20 minutes after contamination. Significant differences in recovery were found between the bacterial species investigated. Expressed as percentage of the number of bacteria used for contamination, the recovery for a given species was rather low, but it was constant and independent of the degree of contamination. The investigation did not suggest any principle difference in the recovery of anaerobic and aerobic bacteria. The clinical applicability of the method is not yet clarified.