scholarly journals Defining Genomic Islands and Uropathogen-Specific Genes in Uropathogenic Escherichia coli

2007 ◽  
Vol 189 (9) ◽  
pp. 3532-3546 ◽  
Author(s):  
Amanda L. Lloyd ◽  
David A. Rasko ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Iron Acquisition ◽  
Genomic Islands ◽  
Comparative Genomic ◽  
Upec Strain ◽  
E Coli ◽  
Strain Collection ◽  
Tract Infections ◽  
K 12

ABSTRACT Uropathogenic Escherichia coli (UPEC) strains are responsible for the majority of uncomplicated urinary tract infections, which can present clinically as cystitis or pyelonephritis. UPEC strain CFT073, isolated from the blood of a patient with acute pyelonephritis, was most cytotoxic and most virulent in mice among our strain collection. Based on the genome sequence of CFT073, microarrays were utilized in comparative genomic hybridization (CGH) analysis of a panel of uropathogenic and fecal/commensal E. coli isolates. Genomic DNA from seven UPEC (three pyelonephritis and four cystitis) isolates and three fecal/commensal strains, including K-12 MG1655, was hybridized to the CFT073 microarray. The CFT073 genome contains 5,379 genes; CGH analysis revealed that 2,820 (52.4%) of these genes were common to all 11 E. coli strains, yet only 173 UPEC-specific genes were found by CGH to be present in all UPEC strains but in none of the fecal/commensal strains. When the sequences of three additional sequenced UPEC strains (UTI89, 536, and F11) and a commensal strain (HS) were added to the analysis, 131 genes present in all UPEC strains but in no fecal/commensal strains were identified. Seven previously unrecognized genomic islands (>30 kb) were delineated by CGH in addition to the three known pathogenicity islands. These genomic islands comprise 672 kb of the 5,231-kb (12.8%) genome, demonstrating the importance of horizontal transfer for UPEC and the mosaic structure of the genome. UPEC strains contain a greater number of iron acquisition systems than do fecal/commensal strains, which is reflective of the adaptation to the iron-limiting urinary tract environment. Each strain displayed distinct differences in the number and type of known virulence factors. The large number of hypothetical genes in the CFT073 genome, especially those shown to be UPEC specific, strongly suggests that many urovirulence factors remain uncharacterized.

scholarly journals Iron Acquisition of Urinary Tract Infection Escherichia coli Involves Pathogenicity in Caenorhabditis elegans

2021 ◽  
Vol 9 (2) ◽  
pp. 310
Author(s):  
Masayuki Hashimoto ◽  
Yi-Fen Ma ◽  
Sin-Tian Wang ◽  
Chang-Shi Chen ◽  
Ching-Hao Teng
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Caenorhabditis Elegans ◽  
Large Scale ◽  
Iron Acquisition ◽  
Infection Model ◽  
High Throughput Analysis ◽  
E Coli ◽  
C Elegans ◽  
Tract Infections

Uropathogenic Escherichia coli (UPEC) is a major bacterial pathogen that causes urinary tract infections (UTIs). The mouse is an available UTI model for studying the pathogenicity; however, Caenorhabditis elegans represents as an alternative surrogate host with the capacity for high-throughput analysis. Then, we established a simple assay for a UPEC infection model with C. elegans for large-scale screening. A total of 133 clinically isolated E. coli strains, which included UTI-associated and fecal isolates, were applied to demonstrate the simple pathogenicity assay. From the screening, several virulence factors (VFs) involved with iron acquisition (chuA, fyuA, and irp2) were significantly associated with high pathogenicity. We then evaluated whether the VFs in UPEC were involved in the pathogenicity. Mutants of E. coli UTI89 with defective iron acquisition systems were applied to a solid killing assay with C. elegans. As a result, the survival rate of C. elegans fed with the mutants significantly increased compared to when fed with the parent strain. The results demonstrated, the simple assay with C. elegans was useful as a UPEC infectious model. To our knowledge, this is the first report of the involvement of iron acquisition in the pathogenicity of UPEC in a C. elegans model.

scholarly journals Comparative Genomics of Escherichia coli Strains Causing Urinary Tract Infections

2011 ◽  
Vol 77 (10) ◽  
pp. 3268-3278 ◽  
Author(s):  
Rebecca Munk Vejborg ◽  
Viktoria Hancock ◽  
Mark A. Schembri ◽  
Per Klemm
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Asymptomatic Bacteriuria ◽  
Genomic Islands ◽  
Comparative Genomic ◽  
Specific Gene ◽  
Virulence Determinants ◽  
Content Type ◽  
Tract Infections

ABSTRACTThe virulence determinants of uropathogenicEscherichia colihave been studied extensively over the years, but relatively little is known about what differentiates isolates causing various types of urinary tract infections. In this study, we compared the genomic profiles of 45 strains from a range of different clinical backgrounds, i.e., urosepsis, pyelonephritis, cystitis, and asymptomatic bacteriuria (ABU), using comparative genomic hybridization analysis. A microarray based on 31 completeE. colisequences was used. It emerged that there is little correlation between the genotypes of the strains and their disease categories but strong correlation between the genotype and the phylogenetic group association. Also, very few genetic differences may exist between isolates causing symptomatic and asymptomatic infections. Only relatively few genes that could potentially differentiate between the individual disease categories were identified. Among these were two genomic islands, namely, pathogenicity island (PAI)-CFT073-serUand PAI-CFT073-pheU, which were significantly more associated with the pyelonephritis and urosepsis isolates than with the ABU and cystitis isolates. These two islands harbor genes encoding virulence factors, such as P fimbriae (pyelonephritis-associated fimbriae) and an important immunomodulatory protein, TcpC. It seems that both urovirulence and growth fitness can be attributed to an assortment of genes rather than to a specific gene set. Taken together, urovirulence and fitness are the results of the interplay of a mixture of factors taken from a rich menu of genes.

scholarly journals Genomic characterization of asymptomatic Escherichia coli isolated from the neobladder

Microbiology ◽  
2011 ◽  
Vol 157 (4) ◽  
pp. 1088-1102 ◽  
Author(s):  
Jason W. Sahl ◽  
Amanda L. Lloyd ◽  
Julia C. Redman ◽  
Thomas A. Cebula ◽  
David P. Wood ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Severe Disease ◽  
Comparative Genomic ◽  
Trauma Studies ◽  
Ileal Neobladder ◽  
E Coli ◽  
Genomic Characterization ◽  
Tract Infections ◽  
Ileal Tissue

The replacement of the bladder with a neobladder made from ileal tissue is the prescribed treatment in some cases of bladder cancer or trauma. Studies have demonstrated that individuals with an ileal neobladder have recurrent colonization by Escherichia coli and other species that are commonly associated with urinary tract infections; however, pyelonephritis and complicated symptomatic infections with ileal neobladders are relatively rare. This study examines the genomic content of two E. coli isolates from individuals with neobladders using comparative genomic hybridization (CGH) with a pan-E. coli/Shigella microarray. Comparisons of the neobladder genome hybridization patterns with reference genomes demonstrate that the neobladder isolates are more similar to the commensal, laboratory-adapted E. coli and a subset of enteroaggregative E. coli than they are to uropathogenic E. coli isolates. Genes identified by CGH as exclusively present in the neobladder isolates among the 30 examined isolates were primarily from large enteric isolate plasmids. Isolations identified a large plasmid in each isolate, and sequencing confirmed similarity to previously identified plasmids of enteric species. Screening, via PCR, of more than 100 isolates of E. coli from environmental, diarrhoeagenic and urinary tract sources did not identify neobladder-specific genes that were widely distributed in these populations. These results taken together demonstrate that the neobladder isolates, while distinct, are genomically more similar to gastrointestinal or commensal E. coli, suggesting why they can colonize the transplanted intestinal tissue but rarely progress to acute pyelonephritis or more severe disease.

scholarly journals Modulation of Host Innate Immune Response in the Bladder by Uropathogenic Escherichia coli

2007 ◽  
Vol 75 (11) ◽  
pp. 5353-5360 ◽  
Author(s):  
Benjamin K. Billips ◽  
Sarah G. Forrestal ◽  
Matthew T. Rycyk ◽  
James R. Johnson ◽  
David J. Klumpp ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Response ◽  
Urinary Tract ◽  
Innate Immune Response ◽  
Bacterial Colonization ◽  
Innate Immune ◽  
Upec Strain ◽  
Chemokine Production ◽  
E Coli ◽  
K 12

ABSTRACT Uropathogenic Escherichia coli (UPEC), the most frequent cause of urinary tract infection (UTI), is associated with an inflammatory response which includes the induction of cytokine/chemokine secretion by urothelial cells and neutrophil recruitment to the bladder. Recent studies indicate, however, that UPEC can evade the early activation of urothelial innate immune response in vitro. In this study, we report that infection with the prototypic UPEC strain NU14 suppresses tumor necrosis factor alpha (TNF-α)-mediated interleukin-8 (CXCL-8) and interleukin-6 (CXCL-6) secretion from urothelial cell cultures compared to infection with a type 1 piliated E. coli K-12 strain. Furthermore, examination of a panel of clinical E. coli isolates revealed that 15 of 17 strains also possessed the ability to suppress cytokine secretion. In a murine model of UTI, NU14 infection resulted in diminished levels of mRNAs encoding keratinocyte-derived chemokine, macrophage inflammatory peptide 2, and CXCL-6 in the bladder relative to infection with an E. coli K-12 strain. Furthermore, reduced stimulation of inflammatory chemokine production during NU14 infection correlated with decreased levels of bladder and urine myeloperoxidase and increased bacterial colonization. These data indicate that a broad phylogenetic range of clinical E. coli isolates, including UPEC, may evade the activation of innate immune response in the urinary tract, thereby providing a pathogenic advantage.

scholarly journals Epigenetic Mechanisms Regulate Innate Immunity against Uropathogenic and Commensal-Like Escherichia coli in the Surrogate Insect Model Galleria mellonella

2017 ◽  
Vol 85 (10) ◽  
Author(s):  
Miriam Heitmueller ◽  
André Billion ◽  
Ulrich Dobrindt ◽  
Andreas Vilcinskas ◽  
Krishnendu Mukherjee
Keyword(s):  
Escherichia Coli ◽  
Innate Immunity ◽  
Urinary Tract ◽  
Histone Acetylation ◽  
Galleria Mellonella ◽  
Epigenetic Mechanisms ◽  
Upec Strain ◽  
Content Type ◽  
E Coli ◽  
Tract Infections

ABSTRACT Innate-immunity-related genes in humans are activated during urinary tract infections (UTIs) caused by pathogenic strains of Escherichia coli but are suppressed by commensals. Epigenetic mechanisms play a pivotal role in the regulation of gene expression in response to environmental stimuli. To determine whether epigenetic mechanisms can explain the different behaviors of pathogenic and commensal bacteria, we infected larvae of the greater wax moth, Galleria mellonella, a widely used model insect host, with a uropathogenic E. coli (UPEC) strain that causes symptomatic UTIs in humans or a commensal-like strain that causes asymptomatic bacteriuria (ABU). Infection with the UPEC strain (CFT073) was more lethal to larvae than infection with the attenuated ABU strain (83972) due to the recognition of each strain by different Toll-like receptors, ultimately leading to differential DNA/RNA methylation and histone acetylation. We used next-generation sequencing and reverse transcription (RT)-PCR to correlate epigenetic changes with the induction of innate-immunity-related genes. Transcriptomic analysis of G. mellonella larvae infected with E. coli strains CFT073 and 83972 revealed strain-specific variations in the class and expression levels of genes encoding antimicrobial peptides, cytokines, and enzymes controlling DNA methylation and histone acetylation. Our results provide evidence for the differential epigenetic regulation of transcriptional reprogramming by UPEC and ABU strains of E. coli in G. mellonella larvae, which may be relevant to understanding the different behaviors of these bacterial strains in the human urinary tract.

scholarly journals Adaptation of Arginine Synthesis among Uropathogenic Branches of the Escherichia coli Phylogeny Reveals Adjustment to the Urinary Tract Habitat

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Michael E. Hibbing ◽  
Karen W. Dodson ◽  
Vasilios Kalas ◽  
Swaine L. Chen ◽  
Scott J. Hultgren
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Inoculum Size ◽  
Specific Gene ◽  
Population Bottlenecks ◽  
Founder Population ◽  
Upec Strain ◽  
Content Type ◽  
E Coli ◽  
Tract Infections

ABSTRACT Urinary tract infections (UTIs) are predominantly caused by uropathogenic Escherichia coli (UPEC). UPEC pathogenesis requires passage through a severe population bottleneck involving intracellular bacterial communities (IBCs) that are clonal expansions of a single invading UPEC bacterium in a urothelial superficial facet cell. IBCs occur only during acute pathogenesis. The bacteria in IBCs form the founder population that develops into persistent extracellular infections. Only a small fraction of UPEC organisms proceed through the IBC cycle, regardless of the inoculum size. This dramatic reduction in population size precludes the utility of genomic mutagenesis technologies for identifying genes important for persistence. To circumvent this bottleneck, we previously identified 29 positively selected genes (PSGs) within UPEC and hypothesized that they contribute to virulence. Here, we show that 8 of these 29 PSGs are required for fitness during persistent bacteriuria. Conversely, 7/8 of these PSG mutants showed essentially no phenotype in acute UTI. Deletion of the PSG argI leads to arginine auxotrophy. Relative to the other arg genes, argI in the B2 clade (which comprises most UPEC strains) of E. coli has diverged from argI in other E. coli clades. Replacement of argI in a UPEC strain with a non-UPEC argI allele complemented the arginine auxotrophy but not the persistent bacteriuria defect, showing that the UPEC argI allele contributes to persistent infection. These results highlight the complex roles of metabolic pathways during infection and demonstrate that evolutionary approaches can identify infection-specific gene functions downstream of population bottlenecks, shedding light on virulence and the genetic evolution of pathogenesis. IMPORTANCE Uropathogenic Escherichia coli (UPEC) is the most common cause of human urinary tract infection (UTI). Population bottlenecks during early stages of UTI make high-throughput screens impractical for understanding clinically important later stages of UTI, such as persistence and recurrence. As UPEC is hypothesized to be adapted to these later pathogenic stages, we previously identified 29 genes evolving under positive selection in UPEC. Here, we found that 8 of these genes, including argI (which is involved in arginine biosynthesis), are important for persistence in a mouse model of UTI. Deletion of argI and other arginine synthesis genes resulted in (i) arginine auxotrophy and (ii) defects in persistent UTI. Replacement of a B2 clade argI with a non-B2 clade argI complemented arginine auxotrophy, but the resulting strain remained attenuated in its ability to cause persistent bacteriuria. Thus, argI may have a second function during UTI that is not related to simple arginine synthesis. This study demonstrates how variation in metabolic genes can impact virulence and provides insight into the mechanisms and evolution of bacterial virulence.

scholarly journals In Vitro Reduction of Interleukin-8 Response to Enterococcus faecalis by Escherichia coli Strains Isolated from the Same Polymicrobial Urines

2021 ◽  
Vol 9 (7) ◽  
pp. 1501
Author(s):  
Gabriella Piatti ◽  
Laura De Ferrari ◽  
Anna Maria Schito ◽  
Anna Maria Riccio ◽  
Susanna Penco ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Enterococcus Faecalis ◽  
Interleukin 8 ◽  
Fluoroquinolone Resistance ◽  
Epithelial Cell Line ◽  
E Coli ◽  
Tract Infections ◽  
K 12

Urinary tract infections are often polymicrobial and are mainly due to uropathogenic Escherichia coli (UPEC). We previously demonstrated a link among clinical fluoroquinolone susceptible E. coli reducing in vitro urothelial interleukin-8 (CXCL8) induced by E. coli K-12, polymicrobial cystitis, and pyuria absence. Here, we evaluated whether fifteen clinical fluoroquinolone susceptible UPEC were able to reduce CXCL8 induced by Enterococcus faecalis that had been isolated from the same mixed urines, other than CXCL8 induced by E. coli K-12. We also evaluated the connection between fluoroquinolone susceptibility and pathogenicity by evaluating the immune modulation of isogenic gyrA, a mutant UPEC resistant to ciprofloxacin. Using the 5637 bladder epithelial cell line, we observed that lower CXCL8 induced the most UPEC isolates than K-12 and the corresponding E. faecalis. During coinfections of UPEC/K-12 and UPEC/E. faecalis, we observed lower CXCL8 than during infections caused by K-12 and E. faecalis alone. UPEC strains showed host–pathogen and pathogen–pathogen interaction, which in part explained their persistence in the human urinary tract and coinfections, respectively. Mutant UPEC showed lower modulating activity with respect to the wildtypes, confirming the connection between acquired fluoroquinolone resistance and the decrease of innate microbial properties.

scholarly journals Dissemination and Systemic Colonization of Uropathogenic Escherichia coli in a Murine Model of Bacteremia

mBio ◽  
2010 ◽  
Vol 1 (5) ◽  
Author(s):  
Sara N. Smith ◽  
Erin C. Hagan ◽  
M. Chelsea Lane ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Murine Model ◽  
Systemic Disease ◽  
Content Type ◽  
E Coli ◽  
Bacterial Genes ◽  
Tract Infections ◽  
K 12

ABSTRACTInfection with uropathogenicEscherichia coli(UPEC), the causative agent of most uncomplicated urinary tract infections, proceeds in an ascending manner and, if left untreated, may result in bacteremia and urosepsis. To examine the fate of UPEC after its entry into the bloodstream, we developed a murine model of sublethal bacteremia. CBA/J mice were inoculated intravenously with 1 × 106 CFU of pyelonephritis strainE. coliCFT073 carrying a bioluminescent reporter. Biophotonic imaging, used to monitor the infection over 48 h, demonstrated that the bacteria disseminated systemically and appeared to localize at discrete sites. UPEC was recovered from the spleen, liver, kidneys, lungs, heart, brain, and intestines as early as 20 min postinoculation, peaking at 24 h postinoculation. A nonpathogenicE. coliK-12 strain, however, disseminated at significantly lower levels (P< 0.01) and was cleared from the liver and cecum by 24 h postinoculation. Isogenic mutants lacking type 1 fimbriae, P fimbriae, capsule, TonB, the heme receptors Hma and ChuA, or particularly the sialic acid catabolism enzyme NanA were significantly outcompeted by wild-type CFT073 during bacteremia (P< 0.05), while flagellin and hemolysin mutants were not.IMPORTANCEE. coliis the primary cause of urinary tract infections. In severe cases of kidney infection, bacteria can enter the bloodstream and cause systemic disease. While the ability ofE. colito cause urinary tract infection has been extensively studied, the fate of these bacteria once they enter the bloodstream is largely unknown. Here we used an imaging technique to develop a mouse model ofE. colibloodstream infection and identify bacterial genes that are important for the bacteria to spread to and infect various organs. Understanding how urinary tract pathogens likeE. colicause disease after they enter the bloodstream may aid in the development of protective and therapeutic treatments.

scholarly journals Molecular Analysis of Asymptomatic Bacteriuria Escherichia coli Strain VR50 Reveals Adaptation to the Urinary Tract by Gene Acquisition

2015 ◽  
Vol 83 (5) ◽  
pp. 1749-1764 ◽  
Author(s):  
Scott A. Beatson ◽  
Nouri L. Ben Zakour ◽  
Makrina Totsika ◽  
Brian M. Forde ◽  
Rebecca E. Watts ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Mouse Model ◽  
Molecular Mechanisms ◽  
Asymptomatic Bacteriuria ◽  
Human Bladder ◽  
Content Type ◽  
E Coli ◽  
Tract Infections ◽  
K 12

Urinary tract infections (UTIs) are among the most common infectious diseases of humans, withEscherichia coliresponsible for >80% of all cases. One extreme of UTI is asymptomatic bacteriuria (ABU), which occurs as an asymptomatic carrier state that resembles commensalism. To understand the evolution and molecular mechanisms that underpin ABU, the genome of the ABUE. colistrain VR50 was sequenced. Analysis of the complete genome indicated that it most resemblesE. coliK-12, with the addition of a 94-kb genomic island (GI-VR50-pheV), eight prophages, and multiple plasmids. GI-VR50-pheVhas a mosaic structure and contains genes encoding a number of UTI-associated virulence factors, namely, Afa (afimbrial adhesin), two autotransporter proteins (Ag43 and Sat), and aerobactin. We demonstrated that the presence of this island in VR50 confers its ability to colonize the murine bladder, as a VR50 mutant with GI-VR50-pheVdeleted was attenuated in a mouse model of UTIin vivo. We established that Afa is the island-encoded factor responsible for this phenotype using two independent deletion (Afa operon and AfaE adhesin) mutants.E. coliVR50afaand VR50afaEdisplayed significantly decreased ability to adhere to human bladder epithelial cells. In the mouse model of UTI, VR50afaand VR50afaEdisplayed reduced bladder colonization compared to wild-type VR50, similar to the colonization level of the GI-VR50-pheVmutant. Our study suggests thatE. coliVR50 is a commensal-like strain that has acquired fitness factors that facilitate colonization of the human bladder.

scholarly journals FIMBRIAE AND FLAGELLA MEDIATED SURFACE MOTILITY AND THE EFFECT OF GLUCOSE ON NONPATHOGENIC AND UROPATHOGENIC ESCHERICHIA COLI

2019 ◽  
Author(s):  
Sankalya Ambagaspitiye ◽  
Sushmita Sudarshan ◽  
Jacob Hogins ◽  
Parker McDill ◽  
Nicole J. De Nisco ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Promoter Region ◽  
Upec Strain ◽  
Surface Movement ◽  
E Coli ◽  
Surface Motility ◽  
The Difference ◽  
Tract Infections

ABSTRACTWe characterized the surface motility of nonpathogenic and pathogenic E. coli strains with respect to the appendage requirement, flagella versus fimbriae, and the glucose requirement. Nonpathogenic lab strains exhibited either slow or fast surface movement. The slow strains required type 1 fimbriae for movement, while the fast strains required flagella and had an insertion in the flhDC promoter region. Surface movement of three uropathogenic E. coli (UPEC) strains was fast and required flagella, but these strains did not have an insertion in the flhDC promoter region. We assessed swimming motility as an indicator of flagella synthesis and found that glucose inhibited swimming of the slow nonpathogenic strains but not of the fast nonpathogenic or pathogenic strains. Fimbriae-based surface motility requires glucose, which inhibits cyclic-AMP (cAMP) and flagella synthesis; therefore, we examined whether surface motility required cAMP. The surface motility of a slow, fimbriae-dominant, nonpathogenic strain did not require cAMP, which was expected because fimbriae synthesis does not require cAMP. In contrast, the surface motility of a faster, flagella-dominant, UPEC strain required cAMP, which was unexpected because swarming was unaffected by the presence of glucose. Electron microscopy verified the presence or absence of fimbriae or flagella. In summary, surface motilities of the nonpathogenic and uropathogenic E. coli strains of this study differed in the appendage used and the effects of glucose on flagella synthesis.IMPORTANCEUropathogenic Escherichia coli strains cause 80-90% of community-acquired urinary tract infections, and recurrent urinary tract infections, which can last for years, and often become antibiotic resistant. Urinary tract infections can be associated with intra-vesical lesions extending from localized trigonitis/cystitis to widely distributed pancystitis: motility may be a factor that distinguishes between these infection patterns. Nonpathogenic and uropathogenic E. coli were shown to exhibit fimbriae- and flagella-dependent surface motility, respectively, and the difference was attributed to altered control of flagella synthesis by glucose. Uropathogenic E. coli strains grow more rapidly in urine than nonpathogenic strains, which implies differences in metabolism. Understanding the basis for glucose-insensitive control of flagella-dependent motility could provide insight into uropathogenic E. coli metabolism and virulence.

Sign in / Sign up

Export Citation Format

Share Document