Serum prognostic indicators in experimental Bacteroides peritonitis.

Serum lysozyme and hemolytic complement (CH100) levels were measured in dogs with experimental Bacteroides peritonitis. The CH100 levels showed little change in surviving animals. Nonsurvivors showed a moderate decrease in complement levels shortly after contamination. Both surviving and nonsurviving animals showed a slight initial decrease in lysozyme levels shortly after contamination. In surviving dogs this was followed by an increase to normal levels. In nonsurvivors, levels continued to increase, reaching a threefold magnification just prior to death. As a result of antibiotic therapy, CH100 levels exhibited no major changes; however, dogs deprived of antibiotic showed noticeable and persistent increases in lysozyme levels while treated animals showed only a mild elevation in lysozyme levels. The changes in the level of serum lysozyme may be a good indicator of antibiotic efficacy and approaching death from Bacteroides peritonitis.