Comparison of quantitative microbiology and histopathology in divided burn-wound biopsy specimens
A. T. McManus, S. H. Kim, W. F. McManus, A. D. Mason Jr and B. A. Pruitt Jr
We examined the association between quantitative microbiologic results and
histopathologic findings in divided biopsy specimens from 200 burned
patients. Microbiologic counts were determined as log10 colony-forming
units per gram of disrupted tissue. Histopathologic results were scored on
a scale of 1 to 6, values of 4 or greater indicating microbial invasion of
viable tissue. Agreement of 96.1% was found between negative cultures,
arbitrarily identified as those with fewer than 5 logs/g, and histologic
absence of invasive infection. In sharp contrast, however, histologic
invasion occurred in only 36% of specimens with positive cultures. Though
low tissue counts are essentially synonymous with negative histologic
findings, quantitative microbiology is not a diagnostic substitute for
histologic examination, since high tissue counts quite commonly do not
indicate invasion. The principal value of quantitative burn-wound biopsies
is the demonstration of predominant burn-wound flora.
