scholarly journals Sex Differences in Population Dynamics during Formation of Kidney Bacterial Communities by Uropathogenic Escherichia coli

2021 ◽  
Vol 89 (4) ◽  
Author(s):  
Lisa K. McLellan ◽  
Allyssa L. Daugherty ◽  
David A. Hunstad
Keyword(s):  
Escherichia Coli ◽  
Population Dynamics ◽  
Bacterial Communities ◽  
High Titer ◽  
Etiologic Agent ◽  
Population Diversity ◽  
Content Type ◽  
Tubular Lumen ◽  
Renal Tubular ◽  
Tract Infections

ABSTRACT Uropathogenic Escherichia coli (UPEC), the primary etiologic agent of urinary tract infections (UTIs), encounters a restrictive population bottleneck within the female mammalian bladder. Its genetic diversity is restricted during establishment of cystitis because successful UPEC must invade superficial bladder epithelial cells prior to forming clonal intracellular bacterial communities (IBCs). In this study, we aimed to understand UPEC population dynamics during ascending pyelonephritis, namely, formation of kidney bacterial communities (KBCs) in the renal tubular lumen and nucleation of renal abscesses. We inoculated the bladders of both male and female C3H/HeN mice, a background which features vesicoureteral reflux; we have previously shown that in this model, males develop severe, high-titer pyelonephritis and renal abscesses much more frequently than females. Mice were infected with 40 isogenic, PCR-tagged (“barcoded”) UPEC strains, and tags remaining in bladder and kidneys were ascertained at intervals following infection. In contrast to females, males maintained a majority of strains within both the bladder and kidneys throughout the course of infection, indicating only a modest host-imposed bottleneck on overall population diversity during successful renal infection. Moreover, the diverse population in the infected male kidneys obscured any restrictive bottleneck in the male bladder. Finally, using RNA in situ hybridization following mixed infections with isogenic UPEC bearing distinct markers, we found that despite their extracellular location (in the urinary space), KBCs are clonal in origin. This finding indicates that even with bulk reflux of infected bladder urine into the renal pelvis, successful ascension of UPEC to establish the tubular niche is an uncommon event.

scholarly journals Genome Sequence of Multidrug-Resistant Escherichia coli EC302/04, Isolated from a Human Tracheal Aspirate

2012 ◽  
Vol 194 (23) ◽  
pp. 6691-6692 ◽  
Author(s):  
Wing-Sze Ho ◽  
Han-Ming Gan ◽  
Kien-Pong Yap ◽  
Ganeswrie Balan ◽  
Chew Chieng Yeo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genome Sequence ◽  
Respiratory Tract Infections ◽  
Tracheal Aspirate ◽  
Multidrug Resistant ◽  
Etiologic Agent ◽  
Lower Respiratory Tract Infections ◽  
Content Type ◽  
E Coli ◽  
Tract Infections

ABSTRACTEscherichia coliis an important etiologic agent of lower respiratory tract infections (LRTI). Multidrug-resistantE. coliEC302/04 was isolated from a tracheal aspirate, and its genome sequence is expected to provide insights into antimicrobial resistance as well as adaptive and virulence mechanisms ofE. coliinvolved in LRTI.

scholarly journals Purine Biosynthesis Metabolically Constrains Intracellular Survival of Uropathogenic Escherichia coli

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Carrie L. Shaffer ◽  
Ellisa W. Zhang ◽  
Anne G. Dudley ◽  
Beverly R. E. A. Dixon ◽  
Kirsten R. Guckes ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Bacterial Communities ◽  
De Novo ◽  
Intracellular Survival ◽  
Purine Biosynthesis ◽  
Purine Nucleotides ◽  
Content Type ◽  
Tract Infections

ABSTRACT The ability to de novo synthesize purines has been associated with the intracellular survival of multiple bacterial pathogens. Uropathogenic Escherichia coli (UPEC), the predominant cause of urinary tract infections, undergoes a transient intracellular lifestyle during which bacteria clonally expand into multicellular bacterial communities within the cytoplasm of bladder epithelial cells. Here, we characterized the contribution of the conserved de novo purine biosynthesis-associated locus cvpA-purF to UPEC pathogenesis. Deletion of cvpA-purF, or of purF alone, abolished de novo purine biosynthesis but did not impact bacterial adherence properties in vitro or in the bladder lumen. However, upon internalization by bladder epithelial cells, UPEC deficient in de novo purine biosynthesis was unable to expand into intracytoplasmic bacterial communities over time, unless it was extrachromosomally complemented. These findings indicate that UPEC is deprived of purine nucleotides within the intracellular niche and relies on de novo purine synthesis to meet this metabolic requirement.

scholarly journals Kinetics of Uropathogenic Escherichia coli Metapopulation Movement during Urinary Tract Infection

mBio ◽  
2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Matthew S. Walters ◽  
M. Chelsea Lane ◽  
Patrick D. Vigil ◽  
Sara N. Smith ◽  
Seth T. Walk ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Population Dynamics ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Quantitative Real Time Pcr ◽  
Content Type ◽  
E Coli ◽  
Tract Infections ◽  
Kinetics Of

ABSTRACTThe urinary tract is one of the most frequent sites of bacterial infection in humans. UropathogenicEscherichia coli(UPEC) strains are the leading cause of urinary tract infections (UTIs) and are responsible for greater than 80% of uncomplicated cases in adults. Infection of the urinary tract occurs in an ascending manner, with colonization of the bladder leading to possible kidney infection and bacteremia. The goal of this study was to examine the population dynamics of UPECin vivousing a murine model of ascending UTI. To track individual UPEC lineages within a host, we constructed 10 isogenic clones of UPEC strain CFT073 by inserting unique signature tag sequences between thepstSandglmSgenes at the attTn7 chromosomal site. Mice were transurethrally inoculated with a mixture containing equal numbers of unique clones. After 4 and 48 h, the tags present in the bladders, kidneys, and spleens of infected mice were enumerated using tag-specific primers and quantitative real-time PCR. The results indicated that kidney infection and bacteremia associated with UTI are most likely the result of multiple rounds of ascension and dissemination from motile UPEC subpopulations, with a distinct bottleneck existing between the kidney and bloodstream. The abundance of tagged lineages became more variable as infection progressed, especially after bacterial ascension to the upper urinary tract. Analysis of the population kinetics of UPEC during UTI revealed metapopulation dynamics, with lineages that constantly increased and decreased in abundance as they migrated from one organ to another.IMPORTANCEUrinary tract infections are some of the most common infections affecting humans, andEscherichia coliis the primary cause in most uncomplicated cases. These infections occur in an ascending manner, with bacteria traveling from the bladder to the kidneys and potentially the bloodstream. Little is known about the spatiotemporal population dynamics of uropathogenicE. coliwithin a host. Here we describe a novel approach for tracking lineages of isogenic taggedE. colistrains within a murine host by the use of quantitative real-time PCR. Understanding thein vivopopulation dynamics and the factors that shape the bacterial population may prove to be of significant value in the development of novel vaccines and drug therapies.

scholarly journals Occurrence of Antimicrobial-Resistant Escherichia coli and Salmonella enterica in the Beef Cattle Production and Processing Continuum

2014 ◽  
Vol 81 (2) ◽  
pp. 713-725 ◽  
Author(s):  
John W. Schmidt ◽  
Getahun E. Agga ◽  
Joseph M. Bosilevac ◽  
Dayna M. Brichta-Harhay ◽  
Steven D. Shackelford ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Generation Cephalosporin ◽  
Resistant Bacteria ◽  
Processing Plant ◽  
Cattle Production ◽  
Content Type ◽  
E Coli ◽  
Beef Processing ◽  
Tract Infections

ABSTRACTSpecific concerns have been raised that third-generation cephalosporin-resistant (3GCr)Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COTr)E. coli, 3GCrSalmonella enterica, and nalidixic acid-resistant (NALr)S. entericamay be present in cattle production environments, persist through beef processing, and contaminate final products. The prevalences and concentrations of these organisms were determined in feces and hides (at feedlot and processing plant), pre-evisceration carcasses, and final carcasses from three lots of fed cattle (n= 184). The prevalences and concentrations were further determined for strip loins from 103 of the carcasses. 3GCrSalmonellawas detected on 7.6% of hides during processing and was not detected on the final carcasses or strip loins. NALrS. entericawas detected on only one hide. 3GCrE. coliand COTrE. coliwere detected on 100.0% of hides during processing. Concentrations of 3GCrE. coliand COTrE. colion hides were correlated with pre-evisceration carcass contamination. 3GCrE. coliand COTrE. coliwere each detected on only 0.5% of final carcasses and were not detected on strip loins. Five hundred and 42 isolates were screened for extraintestinal pathogenicE. coli(ExPEC) virulence-associated markers. Only two COTrE. coliisolates from hides were ExPEC, indicating that fed cattle products are not a significant source of ExPEC causing human urinary tract infections. The very low prevalences of these organisms on final carcasses and their absence on strip loins demonstrate that current sanitary dressing procedures and processing interventions are effective against antimicrobial-resistant bacteria.

scholarly journals Single Clinical Isolates from Acute Uncomplicated Urinary Tract Infections Are Representative of Dominant In Situ Populations

mBio ◽  
2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Dana Willner ◽  
Serene Low ◽  
Jason A. Steen ◽  
Narelle George ◽  
Graeme R. Nimmo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Clinical Isolates ◽  
Content Type ◽  
E Coli ◽  
Strain Diversity ◽  
Amplicon Pyrosequencing ◽  
Culture Independent ◽  
Tract Infections

ABSTRACTUrinary tract infections (UTIs) are one of the most commonly acquired bacterial infections in humans, and uropathogenicEscherichia colistrains are responsible for over 80% of all cases. The standard method for identification of uropathogens in clinical laboratories is cultivation, primarily using solid growth media under aerobic conditions, coupled with morphological and biochemical tests of typically a single isolate colony. However, these methods detect only culturable microorganisms, and characterization is phenotypic in nature. Here, we explored the genotypic identity of communities in acute uncomplicated UTIs from 50 individuals by using culture-independent amplicon pyrosequencing and whole-genome and metagenomic shotgun sequencing. Genus-level characterization of the UTI communities was achieved using the 16S rRNA gene (V8 region). Overall UTI community richness was very low in comparison to other human microbiomes. We strain-typedEscherichia-dominated UTIs using amplicon pyrosequencing of the fimbrial adhesin gene,fimH. There were nine highly abundantfimHtypes, and each UTI sample was dominated by a single type. Molecular analysis of the corresponding clinical isolates revealed that in the majority of cases the isolate was representative of the dominant taxon in the community at both the genus and the strain level. Shotgun sequencing was performed on a subset of eightE. coliurine UTI and isolate pairs. The majority of UTI microbial metagenomic sequences mapped to isolate genomes, confirming the results obtained using phylogenetic markers. We conclude that for the majority of acute uncomplicatedE. coli-mediated UTIs, single cultured isolates are diagnostic of the infection.IMPORTANCEIn clinical practice, the diagnosis and treatment of acute uncomplicated urinary tract infection (UTI) are based on analysis of a single bacterial isolate cultured from urine, and it is assumed that this isolate represents the dominant UTI pathogen. However, these methods detect only culturable bacteria, and the existence of multiple pathogens as well as strain diversity within a single infection is not examined. Here, we explored bacteria present in acute uncomplicated UTIs using culture-independent sequence-based methods.Escherichia coliwas the most common organism identified, and analysis ofE. colidominant UTI samples and their paired clinical isolates revealed that in the majority of infections the cultured isolate was representative of the dominant taxon at both the genus and the strain level. Our data demonstrate that in most cases single cultured isolates are diagnostic of UTI and are consistent with the notion of bottlenecks that limit strain diversity during UTI pathogenesis.

scholarly journals Amdinocillin (Mecillinam) Resistance Mutations in Clinical Isolates and Laboratory-Selected Mutants of Escherichia coli

2015 ◽  
Vol 59 (3) ◽  
pp. 1718-1727 ◽  
Author(s):  
Elisabeth Thulin ◽  
Martin Sundqvist ◽  
Dan I. Andersson
Keyword(s):  
Escherichia Coli ◽  
Clinical Isolates ◽  
Cysteine Biosynthesis ◽  
Resistance Mutations ◽  
Content Type ◽  
E Coli ◽  
Major Mechanism ◽  
Laboratory Selection ◽  
Lactam Antibiotic ◽  
Tract Infections

ABSTRACTAmdinocillin (mecillinam) is a β-lactam antibiotic that is used mainly for the treatment of uncomplicated urinary tract infections. The objectives of this study were to identify mutations that confer amdinocillin resistance on laboratory-isolated mutants and clinical isolates ofEscherichia coliand to determine why amdinocillin resistance remains rare clinically even though resistance is easily selected in the laboratory. Under laboratory selection, frequencies of mutation to amdinocillin resistance varied from 8 × 10−8to 2 × 10−5per cell, depending on the concentration of amdinocillin used during selection. Several genes have been demonstrated to give amdinocillin resistance, but here eight novel genes previously unknown to be involved in amdinocillin resistance were identified. These genes encode functions involved in the respiratory chain, the ribosome, cysteine biosynthesis, tRNA synthesis, and pyrophosphate metabolism. The clinical isolates exhibited significantly greater fitness than the laboratory-isolated mutants and a different mutation spectrum. ThecysBgene was mutated (inactivated) in all of the clinical isolates, in contrast to the laboratory-isolated mutants, where mainly other types of more costly mutations were found. Our results suggest that the frequency of mutation to amdinocillin resistance is high because of the large mutational target (at least 38 genes). However, the majority of these resistant mutants have a low growth rate, reducing the probability that they are stably maintained in the bladder. Inactivation of thecysBgene and a resulting loss of cysteine biosynthesis are the major mechanism of amdinocillin resistance in clinical isolates ofE. coli.

scholarly journals The Extracellular Domain of the β2Integrin β Subunit (CD18) Is Sufficient forEscherichia coliHemolysin andAggregatibacter actinomycetemcomitansLeukotoxin Cytotoxic Activity

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Laura C. Ristow ◽  
Vy Tran ◽  
Kevin J. Schwartz ◽  
Lillie Pankratz ◽  
Andrew Mehle ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Integrin Signaling ◽  
Β Subunit ◽  
Wild Type ◽  
Α Subunit ◽  
Content Type ◽  
Animal Pathogens ◽  
Tract Infections

ABSTRACTTheEscherichia colihemolysin (HlyA) is a pore-forming exotoxin associated with severe complications of human urinary tract infections. HlyA is the prototype of the repeats-in-toxin (RTX) family, which includes LtxA fromAggregatibacter actinomycetemcomitans, a periodontal pathogen. The existence and requirement for a host cell receptor for these toxins are controversial. We performed an unbiased forward genetic selection in a mutant library of human monocytic cells, U-937, for host factors involved in HlyA cytotoxicity. The top candidate was the β2integrin β subunit. Δβ2cell lines are approximately 100-fold more resistant than wild-type U-937 cells to HlyA, but remain sensitive to HlyA at high concentrations. Similarly, Δβ2cells are more resistant than wild-type U-937 cells to LtxA, as Δβ2cells remain LtxA resistant even at >1,000-fold-higher concentrations of the toxin. Loss of any single β2integrin α subunit, or even all four α subunits together, does not confer resistance to HlyA. HlyA and LtxA bind to the β2subunit, but not to αL, αM, or αXin far-Western blots. Genetic complementation of Δβ2cells with either β2or β2with a cytoplasmic tail deletion restores HlyA and LtxA sensitivity, suggesting that β2integrin signaling is not required for cytotoxicity. Finally, β2mutations do not alter sensitivity to unrelated pore-forming toxins, as wild-type or Δβ2cells are equally sensitive toStaphylococcus aureusα-toxin andProteus mirabilisHpmA. Our studies show two RTX toxins use the β2integrin β subunit alone to facilitate cytotoxicity, but downstream integrin signaling is dispensable.IMPORTANCEUrinary tract infections are one of the most common bacterial infections worldwide. UropathogenicEscherichia colistrains are responsible for more than 80% of community-acquired urinary tract infections. Although we have known for nearly a century that severe infections stemming from urinary tract infections, including kidney or bloodstream infections are associated with expression of a toxin, hemolysin, from uropathogenicEscherichia coli, how hemolysin functions to enhance virulence is unknown. Our research defines the interaction of hemolysin with the β2integrin, a human white cell adhesion molecule, as a potential therapeutic target during urinary tract infections. TheE. colihemolysin is the prototype for a toxin family (RTX family) produced by a wide array of human and animal pathogens. Our work extends to the identification and characterization of the receptor for an additional member of the RTX family, suggesting that this interaction may be broadly conserved throughout the RTX toxin family.

scholarly journals The Repeat-In-Toxin Family Member TosA Mediates Adherence of Uropathogenic Escherichia coli and Survival during Bacteremia

2011 ◽  
Vol 80 (2) ◽  
pp. 493-505 ◽  
Author(s):  
Patrick D. Vigil ◽  
Travis J. Wiles ◽  
Michael D. Engstrom ◽  
Lev Prasov ◽  
Matthew A. Mulvey ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Virulence Factors ◽  
Upper Urinary Tract ◽  
Host Cells ◽  
Content Type ◽  
E Coli ◽  
Wide Range ◽  
Novel Target ◽  
Tract Infections

ABSTRACTUropathogenicEscherichia coli(UPEC) is responsible for the majority of uncomplicated urinary tract infections (UTI) and represents the most common bacterial infection in adults. UPEC utilizes a wide range of virulence factors to colonize the host, including the novel repeat-in-toxin (RTX) protein TosA, which is specifically expressed in the host urinary tract and contributes significantly to the virulence and survival of UPEC.tosA, found in strains within the B2 phylogenetic subgroup ofE. coli, serves as a marker for strains that also contain a large number of well-characterized UPEC virulence factors. The presence oftosAin anE. coliisolate predicts successful colonization of the murine model of ascending UTI, regardless of the source of the isolate. Here, a detailed analysis of the function oftosArevealed that this gene is transcriptionally linked to genes encoding a conserved type 1 secretion system similar to other RTX family members. TosA localized to the cell surface and was found to mediate (i) adherence to host cells derived from the upper urinary tract and (ii) survival in disseminated infections and (iii) to enhance lethality during sepsis (as assessed in two different animal models of infection). An experimental vaccine, using purified TosA, protected vaccinated animals against urosepsis. From this work, it was concluded that TosA belongs to a novel group of RTX proteins that mediate adherence and host damage during UTI and urosepsis and could be a novel target for the development of therapeutics to treat ascending UTIs.

Gastrointestinal Tract Infections

2017 ◽  
Author(s):  
Marcia B Goldberg ◽  
Molly Paras
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Reactive Arthritis ◽  
The United States ◽  
Etiologic Agent ◽  
Guillain Barre Syndrome ◽  
Gastrointestinal Infections ◽  
Guillain Barré Syndrome ◽  
Guillain Barré ◽  
Tract Infections

Gastrointestinal infections, which present with acute diarrhea, sometimes accompanied by vomiting, are an extremely common medical complaint, with an annual incidence of 0.6 illnesses per person. Transmission can occur from animals to person, from person to person, or by the ingestion of contaminated foodstuffs. In the United States, more than 90% of cases are caused by viruses, with norovirus being by far the most common. Common among bacterial causes of acute gastrointestinal infection are Salmonella, Campylobacter, Shigella, Shiga toxin–producing Escherichia coli, Vibrio, Yersinia, and Clostridium difficile. These infections are typically self-limited, but depending on the etiologic agent and characteristics of the host, antibiotic therapy may be indicated. Certain gastrointestinal infections are associated with significant complications, including reactive arthritis, Guillain-Barré syndrome, or septicemia. This review contains 4 figures, 7 tables, and 60 references. Key words: Campylobacter, Escherichia coli, Guillain-Barré syndrome, reactive arthritis, Shiga toxin, Shigella, Vibrio, Yersinia

scholarly journals Peptidoglycan Sensing Prevents Quiescence and Promotes Quorum-Independent Colony Growth of Uropathogenic Escherichia coli

2020 ◽  
Vol 202 (20) ◽  
Author(s):  
Eric C. DiBiasio ◽  
Hilary J. Ranson ◽  
James R. Johnson ◽  
David C. Rowley ◽  
Paul S. Cohen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Recurrent Infection ◽  
Colony Growth ◽  
Quiescent State ◽  
Content Type ◽  
Tract Infections

ABSTRACT Uropathogenic Escherichia coli (UPEC) is the leading cause of human urinary tract infections (UTIs), and many patients experience recurrent infection after successful antibiotic treatment. The source of recurrent infections may be persistent bacterial reservoirs in vivo that are in a quiescent state and thus are not susceptible to antibiotics. Here, we show that multiple UPEC strains require a quorum to proliferate in vitro with glucose as the carbon source. At low cell density, the bacteria remain viable but enter a quiescent, nonproliferative state. Of the clinical UPEC isolates tested to date, 35% (51/145) enter this quiescent state, including isolates from the recently emerged, multidrug-resistant pandemic lineage ST131 (i.e., strain JJ1886) and isolates from the classic endemic lineage ST73 (i.e., strain CFT073). Moreover, quorum-dependent UPEC quiescence is prevented and reversed by small-molecule proliferants that stimulate colony formation. These proliferation cues include d-amino acid-containing peptidoglycan (PG) tetra- and pentapeptides, as well as high local concentrations of l-lysine and l-methionine. Peptidoglycan fragments originate from the peptidoglycan layer that supports the bacterial cell wall but are released as bacteria grow. These fragments are detected by a variety of organisms, including human cells, other diverse bacteria, and, as we show here for the first time, UPEC. Together, these results show that for UPEC, (i) sensing of PG stem peptide and uptake of l-lysine modulate the quorum-regulated decision to proliferate and (ii) quiescence can be prevented by both intra- and interspecies PG peptide signaling. IMPORTANCE Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs). During pathogenesis, UPEC cells adhere to and infiltrate bladder epithelial cells, where they may form intracellular bacterial communities (IBCs) or enter a nongrowing or slowly growing quiescent state. Here, we show in vitro that UPEC strains at low population density enter a reversible, quiescent state by halting division. Quiescent cells resume proliferation in response to sensing a quorum and detecting external signals, or cues, including peptidoglycan tetra- and pentapeptides.

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