Characteristics associated with pathogenicity of avian septicaemic Escherichia coli strains.
Seventeen strains of E. coli, isolated from chickens with colisepticaemia, were studied with respect to their pathogenic characteristics including: serum resistance, toxin production, pathogenicity for one-day-old chicks, colicin production, adherence to and invasiveness of HeLa cells, plasmid DNA profile and SDS-PAGE electrophoresis of membrane proteins, as well as electron microscope studies and hemagglutination tests for fimbriae. We concluded that the adherence to and the invasiveness of HeLa cells were not related to the pathogenicity of these strains for chickens. Plasmid profiles were not related to the bactericidal activity of the serum. Toxin production was correlated to the highest levels of pathogenicity. Some of the strains had mannose-resistant fimbriae. SDS-PAGE of membrane proteins of all the strains which were either not pathogenic or which had a very high LD50 lacked two major protein subunits of 40.7 kDa and 28.8 kDa found only in pathogenic strains.
Fantinatti
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Departamento de Microbiologia e Imunologia, IB Universidade Estadual de Campinas, São Paulo, Brazil.
Silveira
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WD
Castro
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AF
D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification; D001427:Bacterial Toxins / Q000096:biosynthesis; D002645:Chickens; D002522:Chlorocebus aethiops; D003087:Colicins / Q000096:biosynthesis; D004926:Escherichia coli / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D006367:HeLa Cells; D006386:Hemagglutination Tests; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification; D008970:Molecular Weight; D010957:Plasmids / Q000302:isolation & purification; D011201:Poultry Diseases / Q000382:microbiology*; D018805:Sepsis / Q000382:microbiology / Q000662:veterinary*; D014709:Vero Cells; D014774:Virulence
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003087:Colicins; D008565:Membrane Proteins