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 invasiness of HeLa cells were not related to the pathogenicity of these strains for chickens. Plasmid profiles were not related to the bacterial 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. © 1994.411-27586Aycardi, Lafont, Données récentes sur l'étiologie et l'épizootologie de la mycoplasmose de poulet. Conséquences prophylactiques (1969) Bull. Off. Int. Epizoot., 72, pp. 351-380Christensen, Simpson, Beachey, Microbial adherence in infection (1985) Principles and Practice of Infectious Diseases, , Mandell, Douglas, Bennett, 2nd EdnDatta, Hedges, Shaw, Sykes, Richmond, Properties of an R-factor from Pseudomonas aerugninosa (1971) J. Bacteriol., 108, pp. 1244-1249Dean, Ching, Williams, Harden, Test for Escherichia coli enterotoxin using infant mice: application in a study of diarrhea in children in Honolulu (1972) J. Infect. Dis., 125, pp. 407-411Dho, Lafont, Escherichia coli colonization of the trachea in poultry: Comparison of virulent and aviruvent strains in gntotoxenic chickens (1982) Avian Dis., 26, pp. 787-797Dho, Lafont, Adhesive properties and iron uptake ability in Escherichia coli lethal and non-lethal for chicks (1984) Avian Dis., 28, pp. 1016-1025Elwell, Shipley, Plasmid-mediated factors associated with virulence of bacteria to animals (1980) Ann. Rev. Microbiol., 34, pp. 465-496Evans, Silver, Evans, Chase, Gorbach, Plasmid controlled colonization factor associated with virulence in Escherichia coli enterotoxigenic for humans (1975) Infect. Immun., 12, pp. 656-667Gianella, Pathogenesis of Acute Bacterial Diarrheal Disorders (1981) Annual Review of Medicine, 32, pp. 341-357Glantz, Narotsky, Bubash, Escherichia coli Serotypes Isolated from Salpingitis and Chronic Respiratory Disease of Poultry (1962) Avian Diseases, 6, pp. 322-328Grewal, Warner, Williams, An inducible outer membrane protein involved in aerobactin-mediated iron transport by ColV strains of Escherichia coli (1982) FEBS Lett., 140, pp. 27-30Gross, The Development of "Air Sac Disease" (1961) Avian Diseases, 5, pp. 431-439Guinée, Veldkamp, Jansen, Improved minca medium for the detection of K99 antigen in calf enterotoxigenic strains of Escherichia coli (1977) Infect. Immun., 15, pp. 676-678Gyles, DISCUSSION: HEAT-LABILE AND HEAT-STABLE FORMS OF THE ENTEROTOXIN FROM E. COLI STRAINS ENTEROPATHOGENIC FOR PIGS (1971) Annals of the New York Academy of Sciences, 176, pp. 314-322Gyles, Barnum, A heat labile enterotoxin from strains of Escherichia coli enterophatogenic for pigs (1969) J. Infect. Dis., 120, pp. 419-426Gyles, So, Falkow, The enterotoxin plasmids of Escherichia coli (1974) J. Infect. Dis., 130, pp. 40-49Hames, Rickwood, (1982) Gel electrophoresis of proteins: A practical approach, , IRL Press Limited, EnglandHancock, Hantke, Broun, Iron transport in Escherichia coli K-12: involvement of the colicin B receptor and of a citrate-inducible protein (1976) J. Bacteriol., 127, pp. 1370-1375Ichihara, Mizushima, Involvement of outer membrane proteins in enterochelin-mediated iron uptake in Escherichia coli (1977) J. Biochem., 81, pp. 749-756Jones, Rutter, Role of the K88 antigen in the pathogenesis of neonatal diarrhea caused by Escherichia coli in piglets (1972) Infect. Immun., 6, pp. 918-927Kleba, McIntosh, Neilands, Kinetics of biosynthesis of iron-regulated membrane proteins in Escherichia coli (1982) J. Bacteriol., 149, pp. 880-888Laemmli, Cleavage of structural proteins during the assembly of the head of bacteriophage T4 (1970) Nature, 227, pp. 680-685Levine, Escherichia coli that cause diarrhea: enterotoxigenic, enteropathogenic, enteroinvasive, enterophemorrphage, and enteroadherent (1987) J. Infect. Dis., 155, pp. 377-389Lopez-Alvarez, Gyles, Occurrence of the vir plasmids among animal and human strains of invasive Escherichia coli (1980) Am. J. Vet. Res., 41, pp. 769-774Macrina, Kopecko, Jones, Ayers, McCowen, A multiple plasmid-containing Escherichia coli strain: Convenient source of size reference plasmid molecules (1978) Plasmid, 1, pp. 417-420Miller, (1972) Experiments in molecular biology, , Cold Spring Harbor Press, Cold Spring HarborMoll, Manning, Timis, Plasmid-determined resistance to serum bactericidal activity: a major outer membrane protein, the traT gene product, is responsible for plasmid-specified serum resistance in Escherichia coli (1980) Infect. Immun., 28, pp. 359-367Nagaraja, Emery, Newman, Pomeroy, Identification and isolation of somatic pili from pathogenic Escherichia coli of turkeys (1983) Am. J. Vet. Res., 44 (2), pp. 284-287Naveh, Zusman, Skutelsky, Ron, Adherence pili in avian strains of Escherichia coli: effect on pathogenicity (1984) Avian Dis., 28, pp. 651-661Quackenbush, Falkow, Relationship between colicin activity and virulence in Escherichia coli (1984) Infect. Immun., 28, pp. 651-661Reed, Muench, A simple method for estimating fifty per cent endpoints (1938) Am. J. Hyg., 27, pp. 493-497Reynard, Beck, Plasmid mediated resistance to the bactericidal effects of normal rabbit serum (1976) Infect. Immun., 14, pp. 848-850Reynard, Beck, Cunningnam, Effects of antibiotic resistance plasmids on the bactericidal activity of normal rabbit serum (1978) Infect. Immun., 19, pp. 861-866Rosemberg, Young, Iron transport in the enteric bacteria (1974) Microbial iron metabolism: a comprehensive treatise, pp. 67-83. , J.B. Neiland, Academic Press, Inc, New YorkSambrook, Fritsch, Maniatis, (1989) Molecular Cloning: A laboratory Manual, , N. Ford, C. Nolan, M. Ferguson, 2nd Edition, Cold Spring Harbor Laboratory PressScaletsky, Silva, Trabulsi, Distinctive patterns of adherence of enteropathogenic Escherichia coli to HeLa cells (1984) Infect. Immun., 45, pp. 534-536Schnaitnam, Effect of ethylenediaminetetracetic acid, triton X-100 and lysozyme on the morphology and chemical composition of the cell wall of Escherichia coli (1971) J. Bacteriol., 108, pp. 553-563Schnaitman, Solubilization of the cytoplasmic membrane of Escherichia coli by triton X-100 (1971) J. Bacteriol., 108, pp. 545-552Sereny, Experimental Shigella conjunctivitis (1955) Acta Microbial. Acad. Sci. Hung., 2, pp. 293-296Smith, A search for transmissible pathogenic characters in invasive strains of Escherichia coli: the discovery of a plasmid-controlled toxin and a plasmid-controlled lethal character closely associated, or identical, with colicin (1974) V.J. Gen. Microbiol., 83, pp. 11-95Smith, Halls, Studies on Escherichia coli enterotoxin (1967) J. Path. Bact., 93, pp. 531-543Smith, Huggins, Further observations on the association of the colicine V plasmid of Escherichia coli with pathogenicity and with survival in the alimentary tract (1976) J. Gen. Microbiol., 92, pp. 335-350Sojka, (1965) Escherichia coli in domestic animals and poultry, pp. 157-168. , Commonwealth Agricultural Bureaux Farnham Royal, Bucks, EnglandSojka, Carnaghan, Escherichia coli infection in poultry (1961) Res. Vet. Sch., 2, pp. 340-352Srinivasan, Kharole, Kalra, Dwivedi, Colibacillosis in poultry (1979) Indian Vet. J., 56, pp. 629-633Stuart, Greenwood, Luke, Hidroxamate-mediated transport of iron controlled by ColV plasmids (1980) J. Bacteriol., 143, pp. 35-42Suwanichkul, Panigraphy, Biological and Immunological Characterization of Pili of Escherichia coli Serotypes O1, O2, and O78 Pathogenic to Poultry (1986) Avian Diseases, 36, pp. 781-787Suwanichkul, Panigraphy, Diversity of pilus subunits of Escherichia coli isolated from avian species (1988) Avian Dis., 32, pp. 822-825Suwanichkul, Panigraphy, Wagner, Antigenic relatedness and partial amino acid sequences of pili of Escherichia coli serotypes O1, O2, and O78 pathogenic to poultry (1987) Avian Dis., 31, pp. 809-813Truscott, Studies on the chicken-lethal toxin of Escherichia coli (1973) Can. J. Comp. Med., 38, pp. 160-167Tsuji, Joya, Yao, Honda, Miwatani, Purification and characterization of heat-liable enterotoxin isolated from chicken enterotoxigenic Escherichia coli (1988) FEMS Microbiol. Lett., 52, pp. 79-84Valvano, Crosa, Aerobactin iron transport genes commonly encoded by certain ColV plasmids occur in the chromosome of a human invasive strain of Escherichia coli K1 (1984) Infect. Immun., 46, pp. 159-167Vidotto, Muller, Freitas, Alfieri, Guimaråes, Santos, Virulence Factors of Avian Escherichia coli (1991) Avian Diseases, 34, pp. 531-538Warner, Williams, Bindereif, Neilands, ColV plasmid-specified aerobactin synthesis by invasive strains of Escherichia coli (1981) Infect. Immun., 33, pp. 540-545Weinberg, Iron and infection (1978) Microbiol. Rev., 42, pp. 45-66Williams, Novel iron uptake system specified by ColV plasmids: an important component in the virulence of invasive strains of Eschericihia coli (1979) Infect. Immun., 26, pp. 925-932Williams, Carbonetti, Iron, siderophores, and pursuit of virulence: independence of the aerobactin and enterochelin iron uptake systems in Escherichia coli (1986) Infect. Immun., 51, pp. 942-947Williams, Warner, ColV plasmid-mediated, colicin V-independent iron uptake system of invasive strains of Escherichia coli (1980) Infect. Immun., 29, pp. 411-416Yano, Oliveira, Fontes, Almeida, Pestana de Castro, Detection of heat-labile (LT) enterotoxin of enterotoxigenic Escherichia coli by the radial immune hemolysis test: a modification for clinical use (1982) Med. Microbiol. Immunol., 177, pp. 219-228Yano, Tamashiro, Garcia, Pestana de Castro, Detecção de verocitoxina (VT) em amostras de Eschirichia coli isoladas de bezerros com diarréia (1986) Rev. Microbiol., 17, pp. 339-341