CLASSIFICATION OF AVIAN PATHOGENIC E. COLI (APEC) AND E. COLI FROM COMMERCIAL CHICKEN INTO PHYLOGENETIC GROUPS A, B1, B2 AND D

AC05

Ana Lívia da Silva Ferreira (1) ferreira.analivia@gmail.com, Renata K. T. Kobayashi (1), Marilda Carlos Vidotto (1).

Escherichia coli can be classified into three main groups: commensal, intestinal pathogenic and extraintestinal pathogenic strains (ExPEC). The last group involves APEC (avian pathogenic E. coli) and UPEC (uropathogenic E. coli), and for having diverse virulence factors both of them are capable of living in almost all anatomic sites. There are similarities between these two groups, although not well documented yet. Among the diseases E. coli can cause, there are septicemia, diarrhea, urinary tract infections and neonatal meningitis. The phylogenetic analysis shows that they can be divided into 4 phylogenetic groups: A, B1, B2 and D. The virulent extra-intestinal E. coli belong mainly to group B2 and D and the commensal strains, to group A. In the present work, 246 E. coli samples (180 were APEC isolates and 66 were isolated from commercial chicken) were classified into the phylogenetic groups A, B1, B2 and D, by the polymerase chain reaction, using the short cycle. This methodology consists on the amplification of three primers: ChuA, Yja and Tsp. Of all 246 samples, 69 belonged to group A (28,05%); 80 belonged to group B1 (32,52%); 50 belonged to group B2 (20,33%) and 47, to group D (19,10%). Of the 180 APEC samples, 52 (28,89%) belonged to group A; 62 (34,44%), to group B1; 37 (20,56%), to group B2 and 29 (16,11%), to group D. However, among the 66 commercial chicken samples, 17 (25,76%) belonged to group A; 18 (27,27%), to group B1; 13 (19,70%), to group B2 and 18 (27,27%), to group D. Among APECs, the most prevalent groups were B2 and D, which confirms APEC’s pathogenicity, since B2 and D are the two most pathogenic groups. The major percentage of the commercial chicken isolates belong to groups A and B1 (nonpathogenic), however a significant part of these samples are compatible to groups B2 and D. The phylogenetic analysis can help us to understand the similarities between the virulence factor and the colonization standard of APEC and UPEC.