In silico phylogenetic and virulence gene profile analyses of avian pathogenic Escherichia coli genome sequences

Abstract

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.

Characterization of avian pathogenic Escherichia coli isolated from free-range helmeted guineafowl

“…There was similarity among isolates which share the same ST as well as between isolates with different STs. In general, phylogenetic analysis by MLST has shown that, in fact, APEC constitutes a heterogeneous group, fact that was also observed in another study 41 …”

“…In general, phylogenetic analysis by MLST has shown that, in fact, APEC constitutes a heterogeneous group, fact that was also observed in another study. 41 …”