Avian pathogenic Escherichia coli (APEC) infections are responsible for significant losses in the poultry industry worldwide. A zoonotic risk has been attributed to APEC strains because they present similarities to extraintestinal pathogenic E. coli (ExPEC) associated with illness in humans, mainly urinary tract infections and neonatal meningitis. Here, we present in silico analyses with pathogenic E. coli genome sequences, including recently available APEC genomes. The phylogenetic tree, based on multi-locus sequence typing (MLST) of seven housekeeping genes, revealed high diversity in the allelic composition. Nevertheless, despite this diversity, the phylogenetic tree was able to cluster the different pathotypes together. An in silico virulence gene profile was also determined for each of these strains, through the presence or absence of 83 well-known virulence genes/traits described in pathogenic E. coli strains. The MLST phylogeny and the virulence gene profiles demonstrated a certain genetic similarity between Brazilian APEC strains, APEC isolated in the United States, UPEC (uropathogenic E. coli) and diarrheagenic strains isolated from humans. This correlation corroborates and reinforces the zoonotic potential hypothesis proposed to APEC.342129133Barnes, H., Nolan, L., Vaillancourt, J., Colibacillosis (2008) Diseases of Poultry, pp. 691-732. , In: Saif Y. (Ed.), 12th ed. Blackwell Publishing, Ames. 1409pBergholz, T.M., Wick, L.M., Qi, W., Riordan, J.T., Ouellette, L.M., Whittam, T.S., Global transcriptional response of Escherichia coli O157:H7 to growth transitions in glucose minimal medium (2007) BMC Microbiol, 7, p. 97Chaudhuri, R.R., Sebaihia, M., Hobman, J.L., Webber, M.A., Leyton, D.L., Goldberg, M.D., Cunningham, A.F., Henderson, I.R., Complete genome sequence and comparative metabolic profiling of the prototypical enteroaggregative Escherichia coli strain 042 (2010) PLoS One, 5, pp. e8801Chen, S.L., Hung, C.S., Xu, J., Reigstad, C.S., Magrini, V., Sabo, A., Blasiar, D., Gordon, J.I., Identification of genes subject to positive selection in uropathogenic strains of Escherichia coli: a comparative genomics approach (2006) Proc. Natl Acad. Sci. USA, 103, pp. 5977-5982Crossman, L.C., Chaudhuri, R.R., Beatson, S.A., Wells, T.J., Desvaux, M., Cunningham, A.F., Petty, N.K., Henderson, I.R., A commensal gone bad: complete genome sequence of the prototypical enterotoxigenic Escherichia coli strain H10407 (2010) J. Bacteriol, 192, pp. 5822-5831Dho-Moulin, M., Fairbrother, J.M., Avian pathogenic Escherichia coli (APEC) (1999) Vet. Res, 30, pp. 299-316Dziva, F., Hauser, H., Connor, T.R., Van Diemen, P.M., Prescott, G., Langridge, G.C., Eckert, S., Stevens, M.P., Sequencing and functional annotation of avian pathogenic Escherichia coli serogroup O78 strains reveal the evolution of E (2013) coli lineages pathogenic for poultry via distinct mechanisms. Infect. Immun, 81, pp. 838-849Dziva, F., Stevens, M., Colibacillosis in poultry: unravelling the molecular basis of virulence of avian pathogenic Escherichia coli in their natural hosts (2008) Avian Pathol, 37, pp. 355-366Edgar, R.C., Muscle: a multiple sequence alignment method with reduced time and space complexity (2004) BMC Bioinformatics, 5, p. 113Ewers, C., Janssen, T., Kiessling, S., Philipp, H.C., Wieler, L.H., Rapid detection of virulence-associated genes in avian pathogenic Escherichia coli by multiplex polymerase chain reaction (2005) Avian Dis., 49, pp. 269-273Ewers, C., Li, G., Wilking, H., Kieling, S., Alt, K., Antão, E.M., Laturnus, C., Wieler, L.H., Avian pathogenic, uropathogenic, and newborn meningitis--causing Escherichia coli: How closely related are they? (2007) Int. J. Med. Microbiol, 297, pp. 163-176Gregersen, R.H., Christensen, H., Ewers, C., Bisgaard, M., Impact of Escherichia coli vaccine on parent stock mortality, first week mortality of broilers and population diversity of E (2010) coli in vaccinated flocks. Avian Pathol, 39, pp. 287-295Iguchi, A., Thomson, N.R., Ogura, Y., Saunders, D., Ooka, T., Henderson, I.R., Harris, D., Frankel, G., Complete genome sequence and comparative genome analysis of enteropathogenic Escherichia coli O127:H6 strain E2348/69 (2009) J. Bacteriol, 191, pp. 347-354Johnson, T., Johnson, S.J., Nolan, L.K., Complete DNA sequence of a ColBM plasmid from avian pathogenic Escherichia coli suggests that it evolved from closely related ColV virulence plasmids (2006) J. Bacteriol, 188, pp. 5975-5983Johnson, T.J., Wannemeuhler, Y.M., Scaccianoce, J.A., Johnson, S.J., Nolan, L.K., Complete DNA sequence, comparative genomics, and prevalence of an IncHI2 plasmid occurring among extraintestinal pathogenic Escherichia coli isolates (2006) Antimicrob. Agents Chemother, 50, pp. 3929-3933Johnson, T.J., Kariyawasam, S., Wannemuehler, Y., Mangiamele, P., Johnson, S.J., Doetkott, C., Skyberg, J.A., Nolan, L.K., 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. 3228-3236Johnson, T.J., Wannemuehler, Y., Doetkott, C., Johnson, S.J., Rosenberger, 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. 3987-3996Johnson, T.J., Wannemuehler, Y., Johnson, S.J., Stell, A.L., Doetkott, C., Johnson, J.R., Kim, K.S., Nolan, L.K., Comparison of extraintestinal pathogenic Escherichia coli strains from human and avian sources reveals a mixed subset representing potential zoonotic pathogens (2008) Appl. Environ. Microbiol, 74, pp. 7043-7050Kaper, J.B., Nataro, J.P., Mobley, H.L.T., Pathogenic Escherichia coli (2004) Natl Rev. Microbiol, 2, pp. 123-140Makino, K., Ishii, K., Yasunaga, T., Hattori, M., Yokoyama, K., Yutsudo, C.H., Kubota, Y., Shinagawa, H., Complete nucleotide sequences of 93-kb and 3.3-kb plasmids of an enterohemorrhagic Escherichia coli O157:H7 derived from Sakai outbreak (1998) DNA Res, 5, pp. 1-9Maturana, V.G., Pace, F., Carlos, C., Mistretta Pires, M., Campos, T.A., Nakazato, G., Guedes Stheling, E., Dias da Silveira, W., Subpathotypes of avian pathogenic Escherichia coli (APEC) exist as defined by their syndromes and virulence traits (2011) Open Microbiol. J, 5, pp. 55-64Miquel, S., Peyretaillade, E., Claret, L., Vallée, A., Dossat, C., Vacherie, B., Zineb, E.H., Darfeuille-Michaud, A., Complete genome sequence of Crohn's disease-associated adherent-invasive E.coli strain LF82 (2010) PLoS One, 5, pp. e12714Moulin-Schouleur, M., Répérant, M., Laurent, S., Brée, A., Mignon-Grasteau, S., Germon, P., Rasschaert, D., Schouler, C., Extraintestinal pathogenic Escherichia coli strains of avian and human origin: link between phylogenetic relationships and common virulence patterns (2007) J. Clin. Microbiol, 45, pp. 3366-3376Olsen, R.H., Stockholm, N.M., Permin, A., Christensen, J.P., Christensen, H., Bisgaard, M., Multi-locus sequence typing and plasmid profile characterization of avian pathogenic Escherichia coli associated with increased mortality in free-range layer flocks (2011) Avian Pathol, 40, pp. 437-444Peigne, C., Bidet, P., Mahjoub-Messai, F., Plainvert, C., Barbe, V., Médigue, C., Frapy, E., Bonacorsi, S., The plasmid of Escherichia coli strain S88 (O45:K1:H7) that causes neonatal meningitis is closely related to avian pathogenic E. coli plasmids and is associated with high-level bacteremia in a neonatal rat meningitis model (2009) Infect. Immun, 77, pp. 2272-2284Perna, N.T., Plunkett, G., Burland, V., Mau, B., Glasner, J.D., Rose, D.J., Mayhew, G.F., Kirkpatrick, H.A., Genome sequence of enterohaemorrhagic Escherichia coli O157:H7 (2001) Nature, 409, pp. 529-533Rodriguez-Siek, K.E., Giddings, C.W., Doetkott, C., Johnson, T.J., Fakhr, M.K., Nolan, L.K., Comparison of Escherichia coli isolates implicated in human urinary tract infection and avian colibacillosis (2005) Microbiol, 151, pp. 2097-2110Rojas, T.C.G., Maluta, R.P., Parizzi, L.P., Koenigkan, L.V., Yang, J., Yu, J., Pereira, G.A., Dias da Silveira, W., Genome sequences of avian pathogenic Escherichia coli strains isolated from Brazilian commercial poultry (2013) Genome Announc, 1, pp. e0011013Rojas, T.C.G., Parizzi, L.P., Tiba, M.R., Chen, L., Pereira, G.A., Sangal, V., Yang, J., Dias da Silveira, W., Draft genome of a Brazilian avian-pathogenic Escherichia coli strain and in silico characterization of virulence--related genes (2012) J. Bacteriol, 194, p. 3023Schouler, C., Schaeffer, B., Brée, A., Mora, A., Dahbi, G., Biet, F., Oswald, E., Moulin-Schouleur, M., Diagnostic strategy for identifying avian pathogenic Escherichia coli based on four patterns of virulence genes (2012) J. Clin. Microbiol, 50, pp. 1673-1678Skyberg, J.A., Horne, S.M., Giddings, C.W., Wooley, R.E., Gibbs, P.S., Nolan, L.K., Characterizing avian Escherichia coli isolates with multiplex polymerase chain reaction (2003) Avian Dis, 47, pp. 1441-1447Welch, R.A., Burland, V., Plunkett, G., Redford, P., Roesch, P., Rasko, D., Buckles, E.L., Blattner, F.R., Extensive mosaic structure revealed by the complete genome sequence of uropathogenic Escherichia coli (2002) Proc. Natl. Acad. Sci. US, 99, pp. 17020-17024Wu, G., Ehricht, R., Mafura, M., Stokes, M., Smith, N., Pritchard, G.C., Woodward, M.J., Escherichia coli isolates from extraintestinal organs of livestock animals harbour diverse virulence genes and belong to multiple genetic lineages (2012) Vet. Microbiol, 160, pp. 197-206