Occurrence of virulence-related sequences and phylogenetic analysis of commensal and pathogenic avian Escherichia coli strains (APEC)

Autor(es)

de Campos, Tatiana Amabile ^[1] ; Lago, Juliana Carvalhaes ^[1] ; Nakazato, Gerson ^[1] ; Stehling, Eliana Guedes ^[1] ; Brocchi, Marcelo ^[1] ; Pestana de Castro, Antonio Fernando ^[2] ; da Silveira, Wanderley Dias ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Depto Microbiol & Imunol, Inst Biol, BR-13081862 Campinas, SP - Brazil

^[2] Univ Sao Paulo, Dept Microbiol, Inst Ciencias Biomed 2, BR-05505900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Pesquisa Veterinária Brasileira; v. 28, n. 10, p. 533-540, OCT 2008.
• Citações Web of Science: 6

Resumo

The presence of iron uptake (irp-2, fyuA, sitA, fepC, iucA), adhesion (iha, lpfA(O157/O141), lpfA(O157/O154), eta, toxB) and invasion (inv, ial-related DNA sequences and assignment to the four main Escherichia coli phylogenetic groups (A, B1, B2 e D) were determined in 30 commensal E coli strains isolated from healthy chickens and in 49 APEC strains isolated from chickens presenting clinical signs of septicemia (n=24) swollen head syndrome (n=14) and omphalitis (n=11) by PCR. None of the strains presented DNA sequences related to the inv, ial, efa, and toxB genes. DNA sequences related to lpfA(O157/O154), iucA, fepC, and irp-2 genes were significantly found among pathogenic strains, where iucA gene was associated with septicemia and swollen head syndrome and fepC and irp-2 genes were associated with swollen head syndrome strains. Phylogenetic typing showed that commensal and omphalitis strains belonged mainly to phylogenetic Group A and swollen head syndrome to phylogenetic Group D. Septicemic strains were assigned in phylogenetic Groups A and D. These data could suggest that clonal lineage of septicemic APEC strains have a multiple ancestor origin; one from a pathogenic bacteria ancestor and other from a non-pathogenic ancestor that evolved by the acquisition of virulence related sequences through horizontal gene transfer. Swollen head syndrome may constitute a pathogenic clonal group. By the other side, omphalitis strains probably constitute a non-pathogenic clonal group, and could cause omphalitis as an opportunistic infection. The sharing of virulence related sequences by human pathogenic E coli and APEC strains could indicate that APEC strains could be a source of virulence genes to human strains and could represent a zoonotic risk. (AU)

• Processo FAPESP: 03/08407-0 - Genotipagem e identificação da clonalidade, através de amplificação, restrição e sequenciamento dos genes CoA e SPA de S. aureus e S. epidermidis, na epidemiologia das infecções hospitalares: comparação com PFGE e Multiplex-PC
• Beneficiário: Wanderley Dias da Silveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular