Bacteriological autopsy. I. A methodological study.
The two aims of this investigation were: 1. To compare a swab culture technique with an imprint method in bacteriological autopsy. 2. To examine the influence of body manipulation on culture. Specimens were taken from the lungs and the spleen in 42 autopsies. For imprint a piece of sterile blotting paper was used. Point 1. Good qualitative agreement was found between the two methods. Print cultures enabled a quantitation at low numbers of bacteria. However, in most cases when growth was present the colonies were confluent, which did not allow counting. The lung cultures were 67%/69% positive (swab/print). For the spleen, the positive rate was 21%/42% (swab/print). In the cases representing the difference, only a few colonies grew on the print plates. Culture by means of a swab was found to give the same information as culture by imprint. Swabs are easier to handle but should be processed within a couple of hours. Point 2. In ten autopsies, cultures were taken with organs in situ after the organ block was removed and after an ordinary autopsy had been performed. A scoring system was used to compare the results. There was a clear correlation between positive cultures and manipulation of the organs. The specimens should be taken with the organs in situ.