Filogrupos e fatores de virulência de estirpes de Escherichia coli obtidas do conteúdo uterino e de fezes de cadelas com piometra

Abstract

Several bacterial agents are associated with the occurrence of pyometra in female dogs, but the extraintestinal pathogenic E. coli (ExPEC) pathotype is the most common, being associated with 82 to 100% of the cases. The aim of the present study was to determine the frequency of phylogenetic groups and virulence factors associated with isolated E. coli strains with uterine content and feces of 55 female dogs, totalizing 110 clinical samples. A total of 225 E. coli strains were isolated and divided into three categories: 90 (40%) isolated from uterine content, 75 (33.3%) isolates from feces of E. coli piometra bitches and 60 (26.6%) of female feces in which pyometra was not caused by E. coli. In the uterine content, predominated strains of E. coli belonging to phylogroup B2 and positive for adhesion-associated virulence factor genes (papC, papG and sfaS) and toxin production (hlyA, cnf-1 and usp). Similarly, high frequencies of strains belonging to phylogroup B2 were identified in the feces of E. coli piometra female dogs, while female dogs with non-E. coli uterine infection more often eliminated strains of phylogroup B1. The fimbria virulence factors type P (papC and papG) and specific uropathogenic protein (usp), previously associated with pyometra in previous studies, were identified with higher frequency in feces of E. coli piometra bitches (p ≤ 0.05). Therefore, the present study demonstrates that phylogroup B2 ExPEC strains are commonly found to cause pyometra in dogs. In addition, the high frequency of strains of phylogroup B2 and carriers of virulence genes papC, papG and usp in the feces of E. coli-associated pyometra dogs suggests that colonization by these strains may be related to a higher risk of pyometra by E. coli in these animals.