Subpathotypes Of Avian Pathogenic Escherichia Coli (apec) Exist As Defined By Their Syndromes And Virulence Traits

Avian pathogenic Escherichia coli (APEC) strains cause different types of systemic extraintestinal infections in poultry, collectively termed colibacillosis, which can cause significant economic losses in the poultry industry. To date, there have been no descriptions of genes or characteristics that allow for the classification of avian strains pathotypes responsible for causing specific diseases in their hosts. In this study we aimed to characterize avian E. coli strains representing 4 groups, including one of commensal strains (AFEC - Avian Fecal Escherichia coli) and 3 groups of APEC strains, where each group is responsible for causing a different disease syndrome in their respective hosts (septicemia, omphalitis and swollen head syndrome). We chose to examine several biological characteristics of these strains including: adhesion to eukaryotic cells, pathogenicity levels according to the lethal dose (50%) assay, phylogenetic group and virulence gene profiles. The comparison of strains based on these genotypic and phenotypic traits, using multivariate statisticals tools and complex networks, allowed us to infer information about the population structure of the studied groups. Our results indicate that APEC strains do not constitute a unique homogeneous group, but rather a structured set of subgroups, where each one is associated with a specific infectious syndrome which can possibly be used to define pathotypes or subpathotypes within APEC strains. These results offer new possibilities with which to study the genes responsible for various pathogenetic processes within APEC strains, and for vaccine development. It may be important to consider these subgroups when developing a vaccine in an effort for obtain cross protection, which has not yet been successfully accomplished when working with APEC strains.5SUPPL.15564Kaper, J.B., Nataro, J.P., Mobley, H.L.T., Pathogenic Escherichia coli (2004) Nat Rev Microbiol, pp. 123-140Dho-Moulin, M., Fairbrother, J.M., Avian pathogenic Escherichia coli (APEC) (1999) Vet Res, 30, pp. 299-316Barnes, H.J., Nolan, L.K., Vaillancourt, J.F., Colibacillosis (2008) Diseases of Poultry, pp. 691-732. , In: Saif YM, Fadly AM, Glisson JR, McDougald LR, Nolan LK, Swayne DE Eds., 12th ed. Ames, Blackwell PublishingDziva, F., Stevens, M.P., Colibacillosis in poultry: Unravelling the molecular basis of virulence of avian pathogenic Escherichia coli in their natural hosts (2008) Avian Pathol, 37, pp. 355-366Johnson, T.J., Wannemuehler, Y., Doetkott, C., Johnson, S.J., Rosen-Berger, S.C., Nolan, L.K., Identification of minimal predictors of avian pathogenic Escherichia coli virulence for use as a rapid diagnostic tool (2008) J Clin Microbiol, 46, pp. 3987-3996Rodriguez-Siek, K.E., Giddings, C.W., Doetkott, C., Johnson, T.J., Nolan, L.K., Characterizing the APEC pathotype (2005) Vet Res, 36, pp. 241-256Johnson, T.J., Kariyawasam, S., Wannemuehler, Y., The genome sequence of avian pathogenic Escherichia coli strain O1:K1:H7 shares strong similarities with human extraintestinal pathogenic E (2007) Coli Genomes. J Bacteriol, 189, pp. 3228-3236Sambrook, J., Fritsch, E.F., Maniats, T., (1989) Molecular Cloning - a Labora-tory Manual, , 2nd ed. New York: Cold Spring Harbor Laboratory PressClermont, O., Bonacorsi, S., Bingen, E., Rapid and simple determination of Escherichia coli phylogenetic group (2000) Appl Environ Microbiol, 66, pp. 4555-4558Dho-Moulin, M., Lafont, J.P., Escherichia coli colonization of the trachea in poultry: Comparison of virulent and avirulent strains in gnotoxenic chickens (1982) Avian Dis, 26, pp. 787-797Scaletsky, I.C.A., Silva, M.L.M., Trabulsi, L.R., Distinctive patterns of adherence of enteropathogenic Escherichia coli to HeLa cells (1984) Infect Immun, 45, pp. 534-536Silveira, W.D., Fantinatti, F., Castro, A.P., Tranposon mutagenesis and membrane protein studies in an avian colisepticemic Escherichia coli strain (1994) Brazil J Genetics, 17, pp. 9-14Reed, L.J., Muench, H., A simple method for estimating fifty per centend points (1938) Am J Hyg, 27, pp. 493-497Hill, T., Lewicki, P., Statistics Methods and Applications (2007) Stat Soft IncGirvan, M., Newman, M.E.J., Community structure in social and biological networks (2002) Proc Natl Acad Sci USA, 99, pp. 7821-7826Guimerà, R., Sales-Pardo, M., Modularity from fluctuations in random graphs and complex networks (2004) Phys Rev, 70, p. 025101. , Amaral LANGuimerà, R., Amaral, L.A.N., Functional cartography of complex metabolic networks (2005) Nature, 433, pp. 895-900Delicato, E.R., Brito, B.G., Gaziri, L.C., Vidotto, M.C., Virulence-associated genes in Escherichia coli isolates from poultry with colibacillosis (2003) Vet Microbiol, 94, pp. 97-103Mokady, D., Gophna, U., Ron, E.Z., Extensive gene diversity in septi-cemic Escherichia coli Strains (2005) J Clin Microbiol, 43, pp. 66-73Stocki, S.L., Babiuk, L.A., Rawlyk, N.A., Potter, A.A., Allan, B.J., Identification of genomic differences between Escherichia coli strains pathogenic for poultry and E. Coli K-12 MG1655 Using Suppression Subtractive Hybridization Analysis (2002) Microb Pathog, 33, pp. 289-298Okeke, I.N., Scaletsky, I.C.A., Soars, E.H., Macfarlane, L.R., Torres, A.G., Molecular epidemiology of the iron utilization genes of enteroag-gregative Escherichia coli (2004) J Clin Microbiol, 42, pp. 36-44Schubert, S., Rakin, A., Karch, H., Carniel, E., Heesemann, J., Prevalence of the high-pathogenicity island of Yersinia species among Escherichia coli strains that are pathogenic to humans (1998) Infect Immun, 66, pp. 480-485Ye, C., Xu, J., Prevalence of iron transport gene on pathogenicity-associated island of uropathogenic Escherichia coli in E. Coli O157:H7 Containing Shiga Toxin Gene (2001) J Clin Microbiol, 39, pp. 2300-2305Runyen-Janecky, L.J., Reeves, S.A., Gonzales, E.G., Payne, S.M., Contribution of the Shigella flexneri Sit, Iuc, and Feo iron acquisition systems to iron acquisition in vitro and in cultured cells (2003) Infect Immun, 71, pp. 1919-1928Marc, D., Dho-Moulin, M., Analysis of the fim cluster of an avian O2 strain of Escherichia coli: Serogroup-specific sites within fimA and nucleotide sequence of fimI (1996) J Med Microbiol, 44, pp. 444-452Bouguenec, L.C., Archambaud, M., Labigne, A., Rapid and specific detection of the pap, afa, and sfa adhesin-encoding operons in uro-pathogenic Escherichia coli strains by polymerase chain reaction (1992) J Clin Microbiol, 30, pp. 1189-1193Maurer, J.J., Brown, T.P., Steffens, W.L., Thayer, S.G., The occurrence of ambient temperature-regulated adhesins, curli, and the temperature-sensitive hemagglutinin tsh among Avian Escherichia coli (1998) Avian Dis, 42, pp. 106-118Szalo, I.M., Goffaux, F., Pirson, V., Piérard, D., Ball, H., Mainil, J., Presence in bovine enteropathogenic (EPEC) and enterohaemorrhagic (EHEC) Escherichia coli of genes encoding for putative adhesins of human EHEC strains (2002) Res Microbiol, 153, pp. 653-658Toma, C., Espinosa, E.M., Song, T., Distribution of putative adhesins in different seropathotypes of Shiga toxin-producing Escherichia coli (2004) J Clin Microbiol, 42, pp. 4937-4946Schmidt, H., Zhang, W.L., Hemmrich, U., Identification and characterization of a novel genomic island integrated at selC in locus of enterocyte effacement-negative, Shiga toxin-producing Escherichia coli (2000) Infect Immun, 69, pp. 6863-687