Project description:Recurrent urinary tract infections (rUTI) are a costly clinical problem affecting millions of women worldwide each year. The majority of rUTI cases are caused by uropathogenic Escherichia coli (UPEC). Data from humans and mouse models indicate that some instances of rUTI are caused by UPEC emerging from latent reservoirs in the bladder. Some studies have reported that women with vaginal dysbiosis, typically characterized by high levels of Gardnerella vaginalis and other anaerobes, are at increased risk of UTI. Multiple studies have detected G. vaginalis in urine collected by transurethral catheterization (to limit vaginal contamination), suggesting that some women experience routine urinary tract exposures. We recently reported that inoculation of G. vaginalis into the bladder triggers rUTI from UPEC bladder reservoirs in a mouse model. Here we performed whole bladder RNAseq to identify host pathways involved in G. vaginalis-induced rUTI. We identified multiple host pathways differentially expressed following G. vaginalis exposure. At the gene and transcript level, we identified upregulation of the orphan nuclear receptor Nur77 (aka Nr4a1) and Nur77-regulated genes. Pilot data from Nur77 knockout mice suggests that Nur77 is necessary for G. vaganalis exposure to trigger rUTI.
Project description:More than half of women will experience a urinary tract infection (UTI) with uropathogenic Escherichia coli (UPEC) causing ~80% of uncomplicated cases. Iron acquisition systems are essential for uropathogenesis, and UPEC encode functionally redundant iron acquisition systems, underlining their importance. However, a recent UPEC clinical isolate, HM7 lacks this functional redundancy and instead encodes a sole siderophore, enterobactin. To determine if E. coli HM7 possesses unidentified iron acquisition systems, we performed RNA-sequencing under iron-limiting conditions and demonstrated the ferric citrate uptake system (fecABCDE and fecIR) was highly upregulated. Importantly, there are high levels of citrate within urine, some of which is bound to iron, and the fec system is highly enriched in UPEC isolates compared to commensal or fecal strains. Therefore, we hypothesized that HM7 and other similar strains use the fec system to acquire iron in the host. Deletion of both enterobactin biosynthesis and ferric citrate uptake (ΔentB/ΔfecA) abrogates use of ferric citrate as an iron source and fecA provides an advantage in pooled human urine in absence of enterobactin. However, in a UTI mouse model, fecA is a fitness factor independent of enterobactin production, likely due to the action of host Lipocalin-2 chelating ferrienterobactin. These findings indicate that ferric citrate uptake is used as an iron source when siderophore efficacy is limited, such as in the host during UTI. Defining these novel compensatory mechanisms and understanding the nutritional hierarchy of preferred iron sources within the urinary tract are important in the search for new approaches to combat UTI.
Project description:Uropathogenic Escherichia coli utilize a variety of adherence factors that assist in colonization of the host urinary tract. TosA (type one secretion) is a non-fimbrial adhesin that is predominately expressed during murine urinary tract infection (UTI), binds to kidney epithelial cells, and promotes survival during invasive infections. The tosRCBDAEF operon encodes the secretory machinery necessary for TosA localization to the E. coli cell surface, as well as the transcriptional regulator TosR. TosR binds upstream of the tos operon and, in a concentration dependent manner, either induces or represses tosA expression. TosR is a member of the PapB family of fimbrial regulators that can participate in crosstalk between fimbrial operons. TosR also binds upstream of the pap operon and suppresses PapA production. However, the scope of TosR-mediated crosstalk is understudied and may be underestimated. To quantify the global effects of TosR-mediated regulation on the E. coli CFT073 genome, we induced expression of tosR, collected mRNA, and performed RNA-Seq. These findings show that production of TosR affected the expression of genes involved with adhesins, including P, F1C, and Auf; nitrate/nitrite transport; microcin secretion; and promoted biofilm formation.
Project description:Urinary tract infections (UTIs) are a very common bacterial infectious disease in humans, and uropathogenic Escherichia coli (UPEC) are the most frequent cause of UTIs. During infection, UPEC must cope with a variety of stressful conditions in the urinary tract. Here, we demonstrated that the small RNA (sRNA) RyfA of UPEC strains was required for resistance to oxidative and osmotic stresses. Inactivation of ryfA in UPEC strain CFT073 decreased urinary tract colonization in CBA/J mice and the ryfA mutant also had reduced production of type 1 and P fimbriae, which are known to be important for UTI. Transcriptomic analysis of the ryfA mutant showed changes in expression of genes associated with general stress responses, metabolism, biofilm formation and genes coding for cell surface proteins. Furthermore, loss of ryfA also reduced UPEC survival in human macrophages. Thus, ryfA plays a key regulatory role in UPEC adaptation to stress, that contributes to UTI and survival in macrophages.
Project description:Uropathogenic Escherichia coli (UPEC) are the most common cause of urinary tract infection (UTI). UPEC normally reside in the intestine, and during establishment of UTI, it undergoes metabolic adaptations, first to urine and then upon tissue invasion to the bladder cell interior. In order to understand these adaptations, we used quantitative proteomic profiling to characterize protein expression of UPEC strain UTI89 growing in human urine and when inside J82 bladder cells. In order to facilitate detection of UPEC proteins over the excess amount of eukaryotic proteins in bladder cells, we developed a method where proteins from UTI89 grown in MOPS and urine was spiked-in to enhance detection of bacterial proteins. More than 2000 E. coli proteins were detected. During growth in urine, proteins associated with iron acquisition and several amino acid uptake and biosynthesis systems, in particular arginine metabolism, were significantly upregulated. During growth in J82 cells, proteins related to iron uptake and arginine metabolisms were upregulated together with proteins involved in sulphur compound turnover. Results suggested that UPEC experience a richer environment in bladder cells compared to urine. There was no direct correlation between upregulated proteins and proteins reported to be essential for infections, showing that upregulation during growth does not signify that the proteins are essential for growth under a condition.
Project description:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
Project description:Strains of urinary tract associated E. coli both recent isolates and from the ECOR collection and non pathogenic E. coli strains were analyzed. Replicates were performed to establish the reproduciblity, then single experiments were performed there on.