Escherichia coli isolated from pyometra and cystitis in the same animal exhibit a wide phenotypic similarity.

AIMS: Pyometra and cystitis caused by Escherichia coli are common diseases identified in canine or feline females. The origin of pyometra infection remains uncertain, and effective prevention strategies for this disease are still unknown. This study aimed to provide a phenotypic characterization, including antimicrobial resistance and virulence profiles, of endometrial pathogenic (EnPEC) and uropathogenic (UPEC) E. coli strains isolated simultaneously from the same animal. METHODS AND RESULTS: Sixteen E. coli strains, from eight different animals, were analyzed in this study. The antimicrobial susceptibility profile of EnPEC and UPEC strains was determined using the disc diffusion method, which showed a similar susceptibility profile among strains (EnPEC and UPEC) from the same animal. The virulence profile of the strains was assessed through biofilm formation, as well as serum resistance abilities. EnPEC and UPEC strains from the same animal exhibited slight variations in their virulence and antimicrobial resistance capabilities. Overall, most of the strain pairs showed a high similarity in their ability to establish biofilms and survive in serum complement activity. CONCLUSIONS: Overall, strains of E. coli isolated from both pyometra and cystitis in the same animal, despite presenting distinct clinical diseases, exhibit a wide phenotypic similarity, suggesting a common origin for the strains.

Comparative genetic and pathogenic approaches of Escherichia coli isolated simultaneously from pyometra and urine of bitches.

Escherichia coli (E. coli) are widely related to pyometra and cystitis in dogs, and these infections can occur simultaneously. The goal of this study was to determine genetic and pathogenic insights of 14 E. coli isolated simultaneously from pyometra content and bladder urine of seven bitches. To achieve this, in silico and in vitro comparative analyses were conducted. Whole-genome comparisons demonstrated that E. coli isolated from pyometra and urine of the same animal were predominantly genetic extraintestinal E. coli clones belonging to the same Sequence Type and phylogroup. The E. coli clones identified in this study included ST372, ST457, ST12, ST127, ST646, and ST961. Five isolates (35.7%) belonged to the ST12 complex. Except for two E. coli, all other isolates belonged to the B2 Clermont phylogroup. Interestingly, some genomes of E. coli from urine carried more virulence genes than those E. coli from pyometra. Both pyometra and urine E. coli isolates demonstrated a strong affinity for adhering to HeLa and T24 cells, with a low affinity for invading them. However, certain isolates from urine exhibited a greater tendency to adhere to T24 cells in qualitative and quantitative assays compared to isolates from pyometra. In conclusion, this study revealed the high genomic similarity between pyometra and urine E. coli isolates, as well as the virulent capacity of both to colonize endometrial and urothelial cells. The findings of this study underscore the importance of concurrently managing both infections clinically and could potentially contribute to future resources for the prevention of cystitis and pyometra.