Bacterial clearance and granulocyte response in experimental peritonitis

Clearance kinetics of Escherichia coli and Bacteroides fragilis from the peritoneal cavity and functional properties of peritoneal and blood polymorphonuclear leukocytes (PMNL) were studied in pigs. The bacteria, approximately 10(10) colony forming units (CFU) of each species, were intraperitoneally injected. Blood and peritoneal exudate were sampled regularly during 24 hr for bacterial quantification and PMNL analysis. The peritoneal concentration of both species fell rapidly in the first 3 hr and then stabilized. Approximately 10(2) CFU/ml remained after 24 hr. Chemotaxis, phagocytosis, and metabolic activation of the peritoneal PMNL showed little change. In some pigs a second bacterial dose was injected 6 hr after the first dose and gave an identical clearance pattern. Exhaustion of the local defence capacity thus was excluded as cause of the impaired bacterial elimination.