Bacterial virulence phenotypes of Escherichia coli and host susceptibility determine risk for urinary tract infections

Abstract

Urinary tract infections (UTIs) are caused by uropathogenic Escherichia coli (UPEC) strains. In contrast to many enteric E. coli pathogroups, no genetic signature has been identified for UPEC strains. We conducted a high-resolution comparative genomic study using E. coli isolates collected from the urine of women suffering from frequent recurrent UTIs. These isolates were genetically diverse and varied in urovirulence, or the ability to infect the bladder of a mouse model of cystitis. Importantly, we found no set of genes, including previously defined putative urovirulence factors (PUFs), that were predictive of urovirulence. In addition, in some patients, the E. coli strain causing a recurrent UTI had fewer PUFs than the supplanted strain. In competitive experimental infections in mice, the supplanting strain was more efficient at colonizing the mouse bladder than the supplanted strain. Despite the lack of a clear genomic signature for urovirulence, comparative transcriptomic and phenotypic analyses revealed that the expression of key conserved functions during culture, such as motility and sugar metabolism, could be used to predict subsequent mouse bladder colonization. Taken together, our findings suggest that UTI risk and outcome may be determined by complex interactions between host susceptibility and the urovirulence potential of diverse bacterial strains.

FIMBRIAE AND FLAGELLA MEDIATED SURFACE MOTILITY AND THE EFFECT OF GLUCOSE ON NONPATHOGENIC AND UROPATHOGENICESCHERICHIA COLI

“…The flhDC promoter region of these strains was sequenced after PCR amplification and shown to lack insertion elements. About 75% of UPEC strains are in group B2 of the Clermont classification scheme (32, 33), but the strains in this study—UTI89, PNK_004, and PNK_006—were in groups B2, D, and A, respectively. Although the NPEC-S strains and PNK_006 are in the same clade, they have different types of surface motility, which indicates that membership in a specific group cannot account for the difference in surface motility.…”

Urinary microbes and postoperative urinary tract infection risk in urogynecologic surgical patients

“…This finding should cause us to reconsider “pathogenicity” since, at the genomic level these bacteria are identical (at least by the sequence of the 16S rRNA gene). For E. coli , other investigators have recently shown that there is no genomic difference between strains associated with UTI or no UTI; the investigators report that the differences appear related to transcription rather than core genetics 24 .…”

Identification and characterization of OmpT‐like proteases in uropathogenic Escherichia coli clinical isolates

“…Previous studies have suggested that OmpT from the UPEC strain CFT073 is involved in adhesion, invasion, and/or inactivation of AMPs (Brannon et al, 2013;He et al, 2015). While the presence of ompT is associated with virulent strains, its precise contribution remains unclear, as UPEC clinical isolates have highly variable genetic sequences (Schreiber et al, 2017). In addition, we previously observed large differences in OmpT protein activity due to differential ompT expression (Thomassin, Brannon, Gibbs, et al, 2012;Thomassin, Brannon, Kaiser, et al, 2012), suggesting that the presence of the ompT gene may not entirely correlate with its activity levels in different UPEC clinical isolates.…”