Apoptosis of murine peritoneal macrophages induced by an avian pathogenic strain of Escherichia coli

• Published in: FEMS microbiology letters Vol. 179; no. 1; pp. 73 - 78
• Main Authors: Rodrigues, V.S, Vidotto, M.C, Felipe, I, Santos, D.S, Gaziri, L.C.J
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-10-1999; Blackwell; Oxford University Press
• Subjects: Animals; Apoptosis; Bacteria; Bacteriology; Biological and medical sciences; Cells, Cultured; Chickens; Colicin V; Cytochalasin D; E coli; Escherichia coli; Escherichia coli - pathogenicity; Escherichia coli - physiology; Escherichia coli Infections - physiopathology; Escherichia coli Infections - veterinary; Fundamental and applied biological sciences. Psychology; In Situ Nick-End Labeling; Macrophage; Macrophages; Macrophages, Peritoneal - cytology; Macrophages, Peritoneal - microbiology; Macrophages, Peritoneal - physiology; Mice; Microbiology; pathogenesis; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Peritoneum; Phagocytosis; Poultry Diseases - microbiology; Poultry Diseases - physiopathology; Pretreatment; Septicemia; Shigella flexneri - physiology; Colicin V; Macrophage; Apoptosis; Escherichia coli; Rodentia; Host agent relation; Pathogenicity; Vertebrata; Mammalia; Mouse; Cell death; Bacteria; Veterinary; Aves; Clinical isolate; Enterobacteriaceae; Peritoneum
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.1999.tb08710.x

The mechanisms used by avian strains of Escherichia coli to invade the respiratory epithelia, leading to septicemia in poultry, are not well-established. In this work, we show that resident murine peritoneal macrophages infected in vitro with an avian strain of E. coli underwent apoptosis 4 h after infection (55.6% of apoptosis in infected cells versus 3.5% in non-infected cells). Heat-inactivated bacteria did not induce apoptosis and the inhibition of phagocytosis by pretreatment of cells with cytochalasin D reduced the number of apoptotic cells from 55.6 to 13.9% (P < 0.05), showing that the bacteria must be intracellularly located and viable to induce apoptosis. Therefore, these data suggest that induction of macrophage apoptosis may be a pathogenic mechanism employed by avian E. coli to circumvent the host defenses and invade the respiratory epithelia.