Showing papers on "Escherichia coli published in 2022"
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TL;DR: In this paper , the effect of shapes and sizes on cytotoxicity towards normal and cancer cells and antibacterial activity toward two kinds of bacteria was studied by synthesizing ZnO nano-and microparticles.
Abstract: Abstract The aim of our work was the synthesis of ZnO nano- and microparticles and to study the effect of shapes and sizes on cytotoxicity towards normal and cancer cells and antibacterial activity toward two kinds of bacteria. We fabricated ZnO nano- and microparticles through facile chemical and physical routes. The crystal structure, morphology, textural properties, and photoluminescent properties were characterized by powder X-ray diffraction, electron microscopies, nitrogen adsorption/desorption measurements, and photoluminescence spectroscopy. The obtained ZnO structures were highly crystalline and monodispersed with intensive green emission. ZnO NPs and NRs showed the strongest antibacterial activity against Escherichia coli and Staphylococcus aureus compared to microparticles due to their high specific surface area. However, the ZnO HSs at higher concentrations also strongly inhibited bacterial growth. S. aureus strain was more sensitive to ZnO particles than the E. coli. ZnO NPs and NRs were more harmful to cancer cell lines than to normal ones at the same concentration.
62 citations
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TL;DR: In this article , the main mechanism of action (MOA) of ZnO NPs has not been fully elucidated by using X-ray diffraction, FT-IR spectroscopy and scanning electron microscopy.
Abstract: Zinc oxide nanoparticles (ZnO NPs) are one of the most widely used nanoparticulate materials due to their antimicrobial properties, but their main mechanism of action (MOA) has not been fully elucidated. This study characterized ZnO NPs by using X-ray diffraction, FT-IR spectroscopy and scanning electron microscopy. Antimicrobial activity of ZnO NPs against the clinically relevant bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and the Gram-positive model Bacillus subtilis was evaluated by performing resazurin microtiter assay (REMA) after exposure to the ZnO NPs at concentrations ranging from 0.2 to 1.4 mM. Sensitivity was observed at 0.6 mM for the Gram-negative and 1.0 mM for the Gram-positive cells. Fluorescence microscopy was used to examine the interference of ZnO NPs on the membrane and the cell division apparatus of B. subtilis (amy::pspac-ftsZ-gfpmut1) expressing FtsZ-GFP. The results showed that ZnO NPs did not interfere with the assembly of the divisional Z-ring. However, 70% of the cells exhibited damage in the cytoplasmic membrane after 15 min of exposure to the ZnO NPs. Electrostatic forces, production of Zn2+ ions and the generation of reactive oxygen species were described as possible pathways of the bactericidal action of ZnO. Therefore, understanding the bactericidal MOA of ZnO NPs can potentially help in the construction of predictive models to fight bacterial resistance.
48 citations
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TL;DR: The biosynthesized SeNPs using extract of baker’s yeast extract exhibit antimicrobial activities and could be a useful efficacious antimicrobial agent in the preservation of food and medical field.
45 citations
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TL;DR: In this paper , a defined community of 104 bacterial species composed of the most common taxa from the human gut microbiota (hCom1) was constructed and characterized in vitro, and mice were colonized with hCom1 and then challenged with a human fecal sample.
45 citations
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TL;DR: In this article , the catalytic effectiveness of AgNPs and AuNPs was studied in the popular nanocatalyst reaction, nitroaromatic reduction, and dye degradation.
Abstract: In this paper, the application of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) synthesized using a biomimetic lipid, N-myristoyltaurine (N14T) was evaluated in common fields. The catalytic effectiveness of AgNPs and AuNPs was studied in the popular nanocatalyst reaction, nitroaromatic reduction, and dye degradation. Both NPs display catalytic activity in the nitroaromatic compound and organic dyes reduction reaction involving sodium borohydride and the rate constant is estimated as 10-3 s-1. Strikingly, the reaction initiation time (t0) and completion time (tc) differ significantly between AgNPs and AuNPs. Analyzing the reaction kinetic profile revealed that the reaction carried out with AuNPs showed a shorter t0 and tc, suggesting a better catalyst than AgNPs. In addition, the efficiency of the NPs was examined in Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa). In difference to the catalytic study, AuNPs display poor antibacterial activity. Whereas AgNPs kill the tested bacteria at 250 μM via disturbing bacterial membrane integrity and produce excess reactive oxygen species. The toxicology study carried out with zebrafish animal model reveals that both AgNPs and AuNPs are non-toxic. The findings suggest that each nanomaterial possesses unique physicochemical properties irrespective of stabilization with the same molecules.
44 citations
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TL;DR: An emissive Ru(II) metallacycle (herein referred to as 1) that is excited by 808-nm laser and emits at a wavelength of ∼1,000 nm via coordination-driven self-assembly is presented, broads the applications of supramolecular photosensitizers through the strategy of lengthening their wavelengths.
Abstract: Significance Bacterial infection is the major risk to public health. Developing emissive metal–based photosensitizers against bacterial infections draws continued interest in biomedicine. The most important issue is extending the absorption and emission wavelengths of metal-based photosensitizers to ameliorate the efficiency of in vivo imaging and phototherapy. To address this, we rationally designed a long-wavelength–emissive ruthenium (II) metallacycle (herein referred to as 1) that has superior optical penetration (∼7 mm) and satisfactory reactive oxygen species–generation performance. Complex 1 has promising broad-spectrum antibacterial activity and low toxicity to mammalian cells. Moreover, 1 enables high-performance, in vivo, fluorescent imaging-guided phototherapy of Staphylococcus aureus–infected mice, with ignorable adverse effects, thus demonstrating that 1 could be a good platform for pathogen phototheranostics.
38 citations
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TL;DR: In this article , a suite of soybean straw biochars were fabricated under different pyrolysis temperatures (600-1000 °C), which were utilized as peroxydisulfate (PS) activators for TC degradation and TC resistant Escherichia coli (E. coli) disinfection.
36 citations
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TL;DR: The study showed that the NMR-based metabolomics is promising in elucidating the metabolic changes of various E. coli strains in pea sprouts during an antimicrobial process, and provides clue for controlling “big six” contamination in fresh produce.
34 citations
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TL;DR: The results suggested the potential of AIE NPs acting as broad-spectrum antimicrobial materials, which provided a strategy for treating different microorganisms.
Abstract: Phototheranostics is a potential area for precision medicine, which has received increasing attention for antibacterial applications. Integrating all phototheranostic modalities in a single molecule and achieving precise spatial colocalization is a challenging task because of the complexity of energy dissipation and molecular design. Here, a type of quaternary amine functionalized aggregation-induced emission (AIE), AIEgen, was synthesized and used to produce singlet oxygen (1O2) and heat, which were used to eradicate the bacteria. With the introduction of the positive charge in AIEgen, AIE nanoparticles (AIE NPs) could selectively target bacteria. Notably, the AIE NPs displayed obvious antibacterial performance against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The antibacterial rates of AIE NPs were as high as 99.9% and 99.8% for S. aureus and E. coli, respectively. Therefore, our results suggested the potential of AIE NPs acting as broad-spectrum antimicrobial materials, which provided a strategy for treating different microorganisms.
34 citations
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TL;DR: In this article , the authors analyzed the overall metabolic responses of Escherichia coli biofilms to the combined stresses of ultrasound and low concentration acidic electrolysed water (LcAEW, free available chlorine: 4 mg/L).
Abstract: This study aimed to better understand the overall metabolic responses of Escherichia coli biofilms to the combined stresses of ultrasound and low concentration acidic electrolysed water (LcAEW, free available chlorine: 4 mg/L). The inactivation kinetics of all E. coli strains (ATCC 25922, ATCC 35150 and ATCC 43895) were simulated well by the modified Weibull model (R2: 0.81–0.97; RMSE: 0.04–0.71). By analysing metabolite profiles, ultrasound mainly disrupted nucleotide metabolism in E. coli cells within biofilms, as most intracellular nucleotide-related compounds (e.g., uridine, ATP, ADP) showed decreased trend especially in ATCC 25922 and ATCC 35150. Increased contents of most amino acids and decreased contents of most carbohydrates were shown in all strains after LcAEW treatment. Under combined treatment, adaptive strategies like glutamate decarboxylase system and mixed acid fermentation were activated to different extents among the three strains. These findings revealed that NMR-based metabolomics technology is promising in identifying strain-specific metabolic responses of biofilms to different antimicrobial treatments, providing guidance for future mechanism studies related to food contact surface sanitisation.
33 citations
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TL;DR: In this article , the authors examined the sanitising efficacy of a 10-min low-concentration electrolysed water (LcEW) treatment against eight Escherichia coli serotypes (the “big six”) using pea sprouts as the food matrix.
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TL;DR: In this paper , the authors used native E. coli as chassis for transgene delivery to impact host physiology and found that the reintroduction of these strains induces perpetual engraftment in the intestine.
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TL;DR: The ability of broad-spectrum β-lactamases to reduce the susceptibility to ceftazidime-avibactam (CZA), ceftolozane-tazobactam(C/T), imipenem-relebactam, meropenem-vaborbactsam, aztreonam-avIBactam and cefiderocol (FDC) was evaluated both in Pseudomonas aeruginosa
Abstract: The ability of broad-spectrum β-lactamases to reduce the susceptibility to ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C/T), imipenem-relebactam, meropenem-vaborbactam, aztreonam-avibactam (AZA), and cefiderocol (FDC) was evaluated both in Pseudomonas aeruginosa and in Escherichia coli using isogenic backgrounds. Although metallo-β-lactamases conferred resistance in most cases, except for AZA, several clavulanic-acid-inhibited extended-spectrum β-lactamases (PER, BEL, SHV) had a significant impact on the susceptibility to CZA, C/T, and FDC. ABSTRACT The ability of broad-spectrum β-lactamases to reduce the susceptibility to ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C/T), imipenem-relebactam, meropenem-vaborbactam, aztreonam-avibactam (AZA), and cefiderocol (FDC) was evaluated both in Pseudomonas aeruginosa and in Escherichia coli using isogenic backgrounds. Although metallo-β-lactamases conferred resistance in most cases, except for AZA, several clavulanic-acid-inhibited extended-spectrum β-lactamases (PER, BEL, SHV) had a significant impact on the susceptibility to CZA, C/T, and FDC.
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TL;DR: The in vivo inactivation and following recovery during storage suggested that the combination treatment presented a potential inactivation process for organic vegetables or sprouts.
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TL;DR: Results indicate a synergistic effect between the self-propulsion provided by the enzyme and the photocatalytic activity induced under light stimuli, and the design of efficient light-driven microrobots with promising applications in microbiology and biomedicine.
Abstract: Urinary-based infections affect millions of people worldwide. Such bacterial infections are mainly caused by Escherichia coli (E. coli) biofilm formation in the bladder and/or urinary catheters. Herein, the authors present a hybrid enzyme/photocatalytic microrobot, based on urease-immobilized TiO2 /CdS nanotube bundles, that can swim in urea as a biocompatible fuel and respond to visible light. Upon illumination for 2 h, these microrobots are able to remove almost 90% of bacterial biofilm, due to the generation of reactive radicals, while bare TiO2 /CdS photocatalysts (non-motile) or urease-coated microrobots in the dark do not show any toxic effect. These results indicate a synergistic effect between the self-propulsion provided by the enzyme and the photocatalytic activity induced under light stimuli. This work provides a photo-biocatalytic approach for the design of efficient light-driven microrobots with promising applications in microbiology and biomedicine.
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TL;DR: In this article , copper oxide nanoparticles (CuONPs) have been synthesized from the live cell filtrate of the fungus Penicillium chrysogenum, and the created CuONPs were characterized via several techniques, namely Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM), and energy-dispersive Xray spectroscope (EDX).
Abstract: Mycosynthesis of nanoparticle (NP) production is a potential ecofriendly technology for large scale production. In the present study, copper oxide nanoparticles (CuONPs) have been synthesized from the live cell filtrate of the fungus Penicillium chrysogenum. The created CuONPs were characterized via several techniques, namely Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the biosynthesized CuONPs were performed against biofilm forming Klebsiella oxytoca ATCC 51,983, Escherichia coli ATCC 35,218, Staphylococcus aureus ATCC 25,923, and Bacillus cereus ATCC 11,778. The anti-bacterial activity result was shown with the zone of inhibition determined to be 14 ± 0.31 mm, 16 ± 0.53 mm, 11 ± 0.57 mm, and 10 ± 0.57 mm respectively. Klebsiella oxytoca and Escherichia coli were more susceptible to CuONPs with minimal inhibitory concentration (MIC) values 6.25 and 3.12 µg/mL, respectively, while for Staphylococcus aureus and Bacillus cereus, MIC value was 12.5 and 25 μg/mL, respectively. The minimum biofilm inhibition concentration (MBIC) result was more evident, that the CuONPs have excellent anti-biofilm activity at sub-MIC levels reducing biofilm formation by 49% and 59% against Klebsiella oxytoca and Escherichia coli, while the results indicated that the MBIC of CuONPs on Bacillus cereus and Staphylococcus aureus was higher than 200 μg/mL and 256 μg/mL, respectively, suggesting that these CuONPs could not inhibit mature formatted biofilm of Bacillus cereus and Staphylococcus aureus in vitro. Overall, all the results were clearly confirmed that the CuONPs have excellent anti-biofilm ability against Klebsiella oxytoca and Escherichia coli. The prepared CuONPs offer a smart approach for biomedical therapy of resistant microorganisms because of its promoted antimicrobial action, but only for specified purposes.
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TL;DR: In this paper, the effects of biochar (BC) on the horizontal transfer of ARG-carrying plasmids to Escherichia coli via transformation were systematically investigated and it was shown that BC could significantly inhibit the transformation of ARGs and the inhibition degree increased with pyrolysis temperature.
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TL;DR: In this article , eight kinds of chitosan fibers were selected to characterize and analyze their composition, surface morphology, and mechanical properties, and the relationship between antibacterial activity and molecular weight and degree of deacetylation was established.
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TL;DR: In this article , the effects of biochar (BC) on the horizontal transfer of ARG-carrying plasmids to Escherichia coli via transformation were systematically investigated and it was shown that BC could significantly inhibit the transformation of ARGs and the inhibition degree increased with pyrolysis temperature.
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TL;DR: In this article , the authors investigated the kinetics of the inactivation of Escherichia coli in organic broccoli sprouts by mild heat (MH) and lactic acid (LA).
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TL;DR: In this article , a pan-genomic analysis of a global collection of 752 Escherichia coli isolates from diverse sources was performed to identify a large ST58 sub-lineage characterized by near ubiquitous carriage of ColV plasmids, which carry genes encoding virulence factors, and by a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island.
Abstract: Escherichia coli ST58 has recently emerged as a globally disseminated uropathogen that often progresses to sepsis. Unlike most pandemic extra-intestinal pathogenic E. coli (ExPEC), which belong to pathogenic phylogroup B2, ST58 belongs to the environmental/commensal phylogroup B1. Here, we present a pan-genomic analysis of a global collection of 752 ST58 isolates from diverse sources. We identify a large ST58 sub-lineage characterized by near ubiquitous carriage of ColV plasmids, which carry genes encoding virulence factors, and by a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island. This sub-lineage includes three-quarters of all ExPEC sequences in our study and has a broad host range, although poultry and porcine sources predominate. By contrast, strains isolated from cattle often lack ColV plasmids. Our data indicate that ColV plasmid acquisition contributed to the divergence of the major ST58 sub-lineage, and different sub-lineages inhabit poultry, swine and cattle.
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TL;DR: The E. coli population is dominated by diverse sequence types with varied geographic distributions, warranting ongoing genomic surveillance.
Abstract: The E. coli population is dominated by diverse sequence types with varied geographic distributions, warranting ongoing genomic surveillance.
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28 Jun 2022
TL;DR: In this paper , Aminoglycosides, a well-known class of antibiotics produced by Streptomyces, are potent inhibitors of phage infection in widely divergent bacterial hosts.
Abstract: In response to viral predation, bacteria have evolved a wide range of defense mechanisms, which rely mostly on proteins acting at the cellular level. Here, we show that aminoglycosides, a well-known class of antibiotics produced by Streptomyces, are potent inhibitors of phage infection in widely divergent bacterial hosts. We demonstrate that aminoglycosides block an early step of the viral life cycle, prior to genome replication. Phage inhibition was also achieved using supernatants from natural aminoglycoside producers, indicating a broad physiological significance of the antiviral properties of aminoglycosides. Strikingly, we show that acetylation of the aminoglycoside antibiotic apramycin abolishes its antibacterial effect but retains its antiviral properties. Altogether, our study expands the knowledge of aminoglycoside functions, suggesting that aminoglycosides not only are used by their producers as toxic molecules against their bacterial competitors but also could provide protection against the threat of phage predation at the community level. IMPORTANCE Predation by phages is a major driver of bacterial evolution. As a result, elucidating antiphage strategies is crucial from both fundamental and therapeutic standpoints. While protein-mediated defense mechanisms, like restriction-modification systems or CRISPR/Cas, have been extensively studied, much less is known about the potential antiphage activity of small molecules. Focusing on the model bacteria Escherichia coli and Streptomyces venezuelae, our findings revealed significant antiphage properties of aminoglycosides, a major class of translation-targeting antibiotics produced by Streptomyces. Further, we demonstrate that supernatants from natural aminoglycoside producers protect bacteria from phage propagation, highlighting the physiological relevance of this inhibition. Suppression of phage infection by aminoglycosides did not result from the indirect inhibition of bacterial translation, suggesting a direct interaction between aminoglycosides and phage components. This work highlights the molecular versatility of aminoglycosides, which have evolved to efficiently block protein synthesis in bacterial competitors and provide protection against phages.
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TL;DR: In this article , the role of nano-composite-laced carbon nanotubes (SWCNTs) in the prevention of bacterial infection by inhibiting biofilm formation, showing the potential to be utilized as catheter coatings.
Abstract: Abstract Zinc oxide-silver (ZnO–Ag), and zinc oxide-gold (ZnO–Au) nano-composites were prepared through wet chemical process and laced into single-walled carbon nanotubes (SWCNTs) to yield ZnO–Ag-SWCNTs, and ZnO–Au-SWCNTs hybrids. These nano-composite-laced SWCNTs hybrids were characterized using Raman spectroscopic, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. The hybrids were evaluated for their effects on phagocytic cells and bactericidal activity against the gram-negative bacteria E. coli. Their phagocytic cell activities and intracellular killing actions were found to be significantly increased, as the ZnO–Ag-SWCNTs and ZnO–Au-SWCNTs nano-hybrids induced widespread clearance of Escherichia coli. An increase in the production of reactive oxygen species (ROS) also led to upregulated phagocytosis, which was determined mechanistically to involve the phagocyte NADPH oxidase (NOX2) pathway. The findings emphasized the roles of ZnO–Ag- and ZnO–Au-decorated SWCNTs in the prevention of bacterial infection by inhibiting biofilm formation, showing the potential to be utilized as catheter coatings in the clinic.
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TL;DR: In this article , the authors applied whole-genome sequence analysis to 982 animal-derived Escherichia coli samples collected in China from the 1970s to 2019, finding that the number of AMR genes per isolate doubled, including those conferring resistance to critically important agents for both veterinary (florfenicol and norfloxacin) and human medicine (colistin, cephalosporins and meropenem).
Abstract: Antimicrobial use in livestock production is linked to the emergence and spread of antimicrobial resistance (AMR), but large-scale studies on AMR changes in livestock isolates remain scarce. Here we applied whole-genome sequence analysis to 982 animal-derived Escherichia coli samples collected in China from the 1970s to 2019, finding that the number of AMR genes (ARGs) per isolate doubled—including those conferring resistance to critically important agents for both veterinary (florfenicol and norfloxacin) and human medicine (colistin, cephalosporins and meropenem). Plasmids of incompatibility groups IncC, IncHI2, IncK, IncI and IncX increased distinctly in the past 50 years, acting as highly effective vehicles for ARG spread. Using antimicrobials of the same class, or even unrelated classes, may co-select for mobile genetic elements carrying multiple co-existing ARGs. Prohibiting or strictly curtailing antimicrobial use in livestock is therefore urgently needed to reduce the growing threat from AMR. Genomic analyses reveal Escherichia coli samples from livestock in China have a third more plasmids than 50 years ago, contributing to the spread of antimicrobial resistance.
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TL;DR: In this article , the authors summarize the latest progress in rationally engineered variants of Escherichia coli Nissle 1917 (EcN) for the treatment of infectious diseases, metabolic disorders, and inflammatory bowel diseases.
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TL;DR: In this paper , the authors review how our knowledge of the ecology and within-host diversity of Escherichia coli has progressed in the 137 years since E. coli was first described and discuss some of the outstanding questions yet to be addressed and prospects for future research.
Abstract: Abstract Escherichia coli has a rich history as biology's ‘rock star’, driving advances across many fields. In the wild, E. coli resides innocuously in the gut of humans and animals but is also a versatile pathogen commonly associated with intestinal and extraintestinal infections and antimicrobial resistance—including large foodborne outbreaks such as the one that swept across Europe in 2011, killing 54 individuals and causing approximately 4000 infections and 900 cases of haemolytic uraemic syndrome. Given that most E. coli are harmless gut colonizers, an important ecological question plaguing microbiologists is what makes E. coli an occasionally devastating pathogen? To address this question requires an enhanced understanding of the ecology of the organism as a commensal. Here, we review how our knowledge of the ecology and within-host diversity of this organism in the vertebrate gut has progressed in the 137 years since E. coli was first described. We also review current approaches to the study of within-host bacterial diversity. In closing, we discuss some of the outstanding questions yet to be addressed and prospects for future research.
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TL;DR: Western-style diet is associated with higher incidence of colorectal cancer containing abundant pks+ E. coli, supporting a potential link between diet, the intestinal microbiota, and coloreCTal carcinogenesis.
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TL;DR: In this paper , a pan-genomic analysis of a global collection of 752 Escherichia coli isolates from diverse sources was performed to identify a large ST58 sub-lineage characterized by near ubiquitous carriage of ColV plasmids, which carry genes encoding virulence factors, and by a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island.
Abstract: Escherichia coli ST58 has recently emerged as a globally disseminated uropathogen that often progresses to sepsis. Unlike most pandemic extra-intestinal pathogenic E. coli (ExPEC), which belong to pathogenic phylogroup B2, ST58 belongs to the environmental/commensal phylogroup B1. Here, we present a pan-genomic analysis of a global collection of 752 ST58 isolates from diverse sources. We identify a large ST58 sub-lineage characterized by near ubiquitous carriage of ColV plasmids, which carry genes encoding virulence factors, and by a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island. This sub-lineage includes three-quarters of all ExPEC sequences in our study and has a broad host range, although poultry and porcine sources predominate. By contrast, strains isolated from cattle often lack ColV plasmids. Our data indicate that ColV plasmid acquisition contributed to the divergence of the major ST58 sub-lineage, and different sub-lineages inhabit poultry, swine and cattle.