title: Comparison of killing of bacteria by guinea pig neutrophils and monocytes.
abstract: Guinea pig polymorphonuclear neutrophils (PMN's; harvested from the blood and from peritoneal exudates) and monocytes (harvested from the peritoneal cavity with and without stimulation of an exudate) were compared in their capacities to kill three pyogenic bacteria. All combinations of phagocytes and bacteria required heat-labile opsonic factors. No significant differences in killing of the three organisms were observed between blood and peritoneal PMN's or between stimulated and unstimulated monocytes. PMN's killed Staphylococcus aureus more effectively than monocytes after both 1 and 2 hr of incubation (p less than 0.05). Although PMN's appeared to have greater bactericidal activity against Escherichia coli than did monocytes, this differences was significant only after 2 hr of incubation (p less than 0.05). The killing of Bacteroides fragilis by PMN's and monocytes was identical. These data demonstrate that guinea pig exudates provide suitable models for the study of phagocytosis and killing of bacteria and suggest that the relative bactericidal capacities of phagocytes depend not only on the phagocyte but also on the species of pyogenic bacteria being studied. These observations may have important implications in host defense against serious infections.
mesh_terms: D000818:Animals; D001441:Bacteroides fragilis; D001770:Blood Bactericidal Activity; D004926:Escherichia coli; D006168:Guinea Pigs; D007958:Leukocyte Count; D008297:Male; D009000:Monocytes / Q000502:physiology*; D009504:Neutrophils / Q000502:physiology*; D009895:Opsonin Proteins; D010586:Phagocytes / Q000502:physiology; D010587:Phagocytosis; D013211:Staphylococcus aureus
chemical_list: D009895:Opsonin Proteins