ABSTRACT
The presence of specific virulence features conditions severe forms of urinary tract disease, but the frequency and distribution of these highly virulent extraintestinal pathogenic Escherichia coli strains in animals and humans is unclear. We used whole genome sequencing, comparative genomics, histological and clinical data to characterize the genetic basis for pathogenesis and origin of E. coli Ec_151217, a strain (B2, ST83, O83:H5:K5) that caused an extremely aggressive upper urinary tract infection (UTI) in a cat. We show that Ec_151217 and 52% of other highly related ST83 genomes (O6 and O83) identified from different animal species and human infections carry two copies of the hemolysin A operon, though this duplication is infrequent (~1%) among closed ExPEC genomes from multiple sources. Our data enlarges the list of E. coli genetic backgrounds carrying hlyA operon duplication which is potentially involved in severity of UTI, and demonstrates that it seems to occur infrequently amongst ExPEC. Its identification in E. coli lineages (diverse ST83 serotypes) of potential animal-human transmission is of concern and anticipates the need to screen larger collections.
