Comparative studies on the antimicrobial activity of peritoneal and ascitic fluids in human beings.

The antibacterial activity of peritoneal fluid obtained from 28 women undergoing laparoscopy was compared with that of ascitic fluid obtained from 11 patients with various pathologic conditions. Similar antibacterial activity was found in these two types of fluid. The activity varied from bactericidal to bacteriostatic and was directed mainly against gram-negative bacilli-Escherichia coli, Proteus mirabilis and Bacteroides fragilis. Candida albicans was inhibited by many of the fluids, but the activity against gram-positive cocci was much less marked. Lysozyme was present in the fluids but was not solely responsible for the antimicrobial activity. The results of this study suggest the presence of at least three groups of thermostable antibacterial substances, two of which are bactericidal and one, bacteriostatic. One of the bactericidal factors is complement-dependent.