Clonal Study Of Avian Escherichia Coli Strains By Flic Conserved-dna-sequence Regions Analysis [estudo Clonal De Escherichia Coli Aviário Por Análise De Seqüências De Dna Conservadas Do Gene Flic]

摘要

The clonal relationship among avian Escherichia coli strains and their genetic proximity with human pathogenic E. coli, Salmonela enterica, Yersinia enterocolitica and Proteus mirabilis, was determined by the DNA sequencing of the conserved 5' and 3'regions fliC gene (flagellin encoded gene). Among 30 commensal avian E. coli strains and 49 pathogenic avian E. coli strains (APEC), 24 commensal and 39 APEC strains harbored fliC gene with fragments size varying from 670bp to 1,900bp. The comparative analysis of these regions allowed the construction of a dendrogram of similarity possessing two main clusters: one compounded mainly by APEC strains and by H-antigens from human E. coli, and another one compounded by commensal avian E. coli strains, S. enterica, and by other H-antigens from human E. coli. Overall, this work demonstrated that fliC conserved regions may be associated with pathogenic clones of APEC strains, and also shows a great similarity among APEC and H-antigens of E. coli strains isolated from humans. These data, can add evidence that APEC strains can exhibit a zoonotic risk. © 2009 Colégio Brasileiro de Patologia Animal.