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McCoy R, Oldroyd S, Yang W, Wang K, Hoven D, Bulmer D, Zilbauer M, Owens RM. In Vitro Models for Investigating Intestinal Host-Pathogen Interactions. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306727. [PMID: 38155358 PMCID: PMC10885678 DOI: 10.1002/advs.202306727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/01/2023] [Indexed: 12/30/2023]
Abstract
Infectious diseases are increasingly recognized as a major threat worldwide due to the rise of antimicrobial resistance and the emergence of novel pathogens. In vitro models that can adequately mimic in vivo gastrointestinal physiology are in high demand to elucidate mechanisms behind pathogen infectivity, and to aid the design of effective preventive and therapeutic interventions. There exists a trade-off between simple and high throughput models and those that are more complex and physiologically relevant. The complexity of the model used shall be guided by the biological question to be addressed. This review provides an overview of the structure and function of the intestine and the models that are developed to emulate this. Conventional models are discussed in addition to emerging models which employ engineering principles to equip them with necessary advanced monitoring capabilities for intestinal host-pathogen interrogation. Limitations of current models and future perspectives on the field are presented.
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Affiliation(s)
- Reece McCoy
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Sophie Oldroyd
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Woojin Yang
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| | - Kaixin Wang
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Darius Hoven
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - David Bulmer
- Department of PharmacologyUniversity of CambridgeCambridgeCB2 1PDUK
| | - Matthias Zilbauer
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| | - Róisín M. Owens
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
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2
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Morgaan HA, Omar HMG, Zakaria AS, Mohamed NM. Repurposing carvacrol, cinnamaldehyde, and eugenol as potential anti-quorum sensing agents against uropathogenic Escherichia coli isolates in Alexandria, Egypt. BMC Microbiol 2023; 23:300. [PMID: 37872476 PMCID: PMC10591344 DOI: 10.1186/s12866-023-03055-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/11/2023] [Indexed: 10/25/2023] Open
Abstract
BACKGROUND Urinary tract infections represent one of the most frequent hospital and community-acquired infections with uropathogenic Escherichia coli (UPEC) being the main causative agent. The global increase in the emergence of multidrug-resistant (MDR) UPEC necessitates exploring novel approaches. Repurposing natural products as anti-quorum sensing (QS) agents to impede bacterial virulence is gaining momentum nowadays. Hence, this study investigates the anti-QS potentials of carvacrol, cinnamaldehyde, and eugenol against E. coli isolated from urine cultures of Egyptian patients. RESULTS Antibiotic susceptibility testing was performed for 67 E. coli isolates and 94% of the isolates showed MDR phenotype. The usp gene was detected using PCR and accordingly, 45% of the isolates were categorized as UPEC. Phytochemicals, at their sub-inhibitory concentrations, inhibited the swimming and twitching motilities of UPEC isolates, with eugenol showing the highest inhibitory effect. The agents hindered the biofilm-forming ability of the tested isolates, at two temperature sets, 37 and 30 °C, where eugenol succeeded in significantly inhibiting the biofilm formation by > 50% at both investigated temperatures, as compared with untreated controls. The phytochemicals were shown to downregulate the expression of the QS gene (luxS) and critical genes related to motility, asserting their anti-QS potential. Further, the combinatory activity of the phytoproducts with five antibiotics was assessed by checkerboard assay. The addition of the phytoproducts significantly reduced the minimum inhibitory concentrations of the antibiotics and generated several synergistic or partially synergistic combinations, some of which have not been previously explored. CONCLUSIONS Overall, carvacrol, cinnamaldehyde, and eugenol could be repurposed as potential anti-QS agents, which preferentially reduce the QS-based communication and attenuate the cascades of gene expression, thus decreasing the production of virulence factors in UPEC, and eventually, subsiding their pathogenicity. Furthermore, the synergistic combinations of these agents with antibiotics might provide a new perspective to circumvent the side effects brought about by high antibiotic doses, thereby paving the way for overcoming antibiotic resistance.
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Affiliation(s)
- Hadeer A Morgaan
- Microbiology and Immunology Department, Faculty of Pharmacy, Alexandria University, El-Khartoom Square, Azarita, Alexandria, Egypt
| | - Hoda M G Omar
- Microbiology and Immunology Department, Faculty of Pharmacy, Alexandria University, El-Khartoom Square, Azarita, Alexandria, Egypt
| | - Azza S Zakaria
- Microbiology and Immunology Department, Faculty of Pharmacy, Alexandria University, El-Khartoom Square, Azarita, Alexandria, Egypt
| | - Nelly M Mohamed
- Microbiology and Immunology Department, Faculty of Pharmacy, Alexandria University, El-Khartoom Square, Azarita, Alexandria, Egypt.
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3
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Samanta P, Doerksen RJ. Identifying FmlH lectin-binding small molecules for the prevention of Escherichia coli-induced urinary tract infections using hybrid fragment-based design and molecular docking. Comput Biol Med 2023; 163:107072. [PMID: 37329611 PMCID: PMC10810094 DOI: 10.1016/j.compbiomed.2023.107072] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 04/26/2023] [Accepted: 05/27/2023] [Indexed: 06/19/2023]
Abstract
Nearly 50% of women are affected by urinary tract infections (UTIs) during their lifetimes. The most common agent to cause UTIs is Uropathogenic Escherichia coli (UPEC). UPEC expresses fibers known as chaperone-usher pathway pili with adhesins that specifically bind to receptors as they colonize various host tissues. UPEC uses an F9/Yde/Fml pilus, tipped with FmlH, which interacts with terminal galactoside/galactosaminoside units in glycoproteins in the epithelial cells of the bladder and kidney. The extensive use of traditional antibiotics has led to the rise of various antibiotic-resistant strains of UPEC. An alternative therapeutic approach is to use an anti-adhesion strategy mediated by competitive tight-binding FmlH inhibitors. In the current study, we have applied various computational modeling techniques, including fragment-based e-pharmacophore virtual screening, molecular docking, molecular dynamics simulations and binding free energy calculations for the design of small molecules that exhibit binding to FmlH. Our modeling protocol successfully predicted ligand moieties, such as a thiazole group, which were previously found as components of UPEC adhesin pili inhibitors, thereby validating our designed screening protocol. The screening protocol developed here could be utilized for design of ligands for other homologous protein targets. We also identified several novel galactosaminoside-containing molecules that, according to the computational modeling, are predicted to interact strongly with FmlH and hence we predict will be good FmlH inhibitors. Additionally, we have prepared and supplied a database of ∼190K small molecules obtained from virtual screening, which can serve as an excellent resource for the discovery of novel FmlH inhibitors.
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Affiliation(s)
- Priyanka Samanta
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS, 38677-1848, USA
| | - Robert J Doerksen
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS, 38677-1848, USA; Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS, 38677-1848, USA.
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4
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Zhou Y, Zhou Z, Zheng L, Gong Z, Li Y, Jin Y, Huang Y, Chi M. Urinary Tract Infections Caused by Uropathogenic Escherichia coli: Mechanisms of Infection and Treatment Options. Int J Mol Sci 2023; 24:10537. [PMID: 37445714 DOI: 10.3390/ijms241310537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Urinary tract infections (UTIs) are common bacterial infections that represent a severe public health problem. They are often caused by Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumonia), Proteus mirabilis (P. mirabilis), Enterococcus faecalis (E. faecalis), and Staphylococcus saprophyticus (S. saprophyticus). Among these, uropathogenic E. coli (UPEC) are the most common causative agent in both uncomplicated and complicated UTIs. The adaptive evolution of UPEC has been observed in several ways, including changes in colonization, attachment, invasion, and intracellular replication to invade the urothelium and survive intracellularly. While antibiotic therapy has historically been very successful in controlling UTIs, high recurrence rates and increasing antimicrobial resistance among uropathogens threaten to greatly reduce the efficacy of these treatments. Furthermore, the gradual global emergence of multidrug-resistant UPEC has highlighted the need to further explore its pathogenesis and seek alternative therapeutic and preventative strategies. Therefore, a thorough understanding of the clinical status and pathogenesis of UTIs and the advantages and disadvantages of antibiotics as a conventional treatment option could spark a surge in the search for alternative treatment options, especially vaccines and medicinal plants. Such options targeting multiple pathogenic mechanisms of UPEC are expected to be a focus of UTI management in the future to help combat antibiotic resistance.
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Affiliation(s)
- Yang Zhou
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
- School of Pharmaceutical Sciences, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
| | - Zuying Zhou
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
- School of Pharmaceutical Sciences, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
| | - Lin Zheng
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
- School of Pharmaceutical Sciences, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
| | - Zipeng Gong
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
| | - Yueting Li
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
| | - Yang Jin
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
| | - Yong Huang
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
- School of Pharmaceutical Sciences, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
| | - Mingyan Chi
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
- School of Pharmaceutical Sciences, Guizhou Medical University, 4 Beijing Road, Guiyang 550004, China
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5
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Holban AM, Gregoire CM, Gestal MC. Conquering the host: Bordetella spp. and Pseudomonas aeruginosa molecular regulators in lung infection. Front Microbiol 2022; 13:983149. [PMID: 36225372 PMCID: PMC9549215 DOI: 10.3389/fmicb.2022.983149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/17/2022] [Indexed: 11/27/2022] Open
Abstract
When bacteria sense cues from the host environment, stress responses are activated. Two component systems, sigma factors, small RNAs, ppGpp stringent response, and chaperones start coordinate the expression of virulence factors or immunomodulators to allow bacteria to respond. Although, some of these are well studied, such as the two-component systems, the contribution of other regulators, such as sigma factors or ppGpp, is increasingly gaining attention. Pseudomonas aeruginosa is the gold standard pathogen for studying the molecular mechanisms to sense and respond to environmental cues. Bordetella spp., on the other hand, is a microbial model for studying host-pathogen interactions at the molecular level. These two pathogens have the ability to colonize the lungs of patients with chronic diseases, suggesting that they have the potential to share a niche and interact. However, the molecular networks that facilitate adaptation of Bordetella spp. to cues are unclear. Here, we offer a side-by-side comparison of what is known about these diverse molecular mechanisms that bacteria utilize to counteract host immune responses, while highlighting the relatively unexplored interactions between them.
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Affiliation(s)
- Alina M. Holban
- Research Institute of the University of Bucharest (ICUB), Bucharest, Romania
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Courtney M. Gregoire
- Department of Microbiology and Immunology, Louisiana State University Health Science Center, Shreveport, LA, United States
| | - Monica C. Gestal
- Department of Microbiology and Immunology, Louisiana State University Health Science Center, Shreveport, LA, United States
- *Correspondence: Monica C. Gestal, ;
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6
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Sun L, Chen Y, Duan Y, Ma F. Electrogenerated Chemiluminescence Biosensor Based on Functionalized Two-Dimensional Metal-Organic Frameworks for Bacterial Detection and Antimicrobial Susceptibility Assays. ACS APPLIED MATERIALS & INTERFACES 2021; 13:38923-38930. [PMID: 34369161 DOI: 10.1021/acsami.1c11949] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The emergence of antibiotic resistance has prompted the development of rapid antimicrobial susceptibility testing (AST) technologies to guide antibiotic prescription. A novel electrochemiluminescence (ECL) biosensor developed can quantitatively measure the binding between the lectin and lipopolysaccharide (LPS) on Gram-negative bacteria for bacterial determination and to characterize the antimicrobial activities of β-lactam and non-β-lactam antibiotics to normal and antibiotic-resistant bacteria. The biosensor utilizes ruthenium complex tagged concanavalin A (Ru-Con A) coated on NH2-MIL-53(Al) interface for LPS binding measurements. The decreased ECL signal obtained was directly proportional to increasing Escherichia coli (E. coli) BL21 concentrations. The sensitivity displayed logarithmic dependence in the range of (50-5.0) × 104 cells/mL, with a detection limit of 16 cells/mL. The minimum inhibitory concentration (MIC) values of antibiotics for normal E. coli BL21 were 0.02-0.2, 2-4, 0.002-0.02, and 0.2-1 mg/L for levofloxacin hydrochloride (LVX), tetracycline (TCY), imipenem (IPM), and cefpirome (CPO), respectively. The increased MIC values (8-16 and 4 mg/L for IMP and CPO, respectively) in New Delhi metallo-β-lactamase-1 expressing E. coli BL21 (NDM-1-E. coli BL21) indicated greater resistance to β-lactams in NDM-1-E. coli BL21 compared with normal E. coli BL21. Therefore, the changed ECL signal because of binding between LPS with the lectin has a relation with the type of antibiotic and bacterial strains, making the ECL biosensor promote clinical practicability and facilitate antibiotic stewardship.
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Affiliation(s)
- Lina Sun
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi 710127, People's Republic of China
| | - Yu Chen
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi 710127, People's Republic of China
| | - Yuhong Duan
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi 710127, People's Republic of China
| | - Fen Ma
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi 710127, People's Republic of China
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7
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Discovery of Bacterial Fimbria-Glycan Interactions Using Whole-Cell Recombinant Escherichia coli Expression. mBio 2021; 12:mBio.03664-20. [PMID: 33622724 PMCID: PMC8545135 DOI: 10.1128/mbio.03664-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chaperone-usher (CU) fimbriae are the most abundant Gram-negative bacterial fimbriae, with 38 distinct CU fimbria types described in Escherichia coli alone. Some E. coli CU fimbriae have been well characterized and bind to specific glycan targets to confer tissue tropism. For example, type 1 fimbriae bind to α-d-mannosylated glycoproteins such as uroplakins in the bladder via their tip-located FimH adhesin, leading to colonization and invasion of the bladder epithelium. Despite this, the receptor-binding affinity of many other E. coli CU fimbria types remains poorly characterized. Here, we used a recombinant E. coli strain expressing different CU fimbriae, in conjunction with glycan array analysis comprising >300 glycans, to dissect CU fimbria receptor specificity. We initially validated the approach by demonstrating the purified FimH lectin-binding domain and recombinant E. coli expressing type 1 fimbriae bound to a similar set of glycans. This technique was then used to map the glycan binding affinity of six additional CU fimbriae, namely, P, F1C, Yqi, Mat/Ecp, K88, and K99 fimbriae. The binding affinity was determined using whole-bacterial-cell surface plasmon resonance. This work describes new information in fimbrial specificity and a rapid and scalable system to define novel adhesin-glycan interactions that underpin bacterial colonization and disease.
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8
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Damalanka VC, Maddirala AR, Janetka JW. Novel approaches to glycomimetic design: development of small molecular weight lectin antagonists. Expert Opin Drug Discov 2021; 16:513-536. [PMID: 33337918 DOI: 10.1080/17460441.2021.1857721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Introduction: The direct binding of carbohydrates or those presented on glycoproteins or glycolipids to proteins is the primary effector of many biological responses. One class of carbohydrate-binding proteins, lectins are important in all forms of life. Their functions in animals include regulating cell adhesion, glycoprotein synthesis, metabolism, and mediating immune system response while in bacteria and viruses a lectin-mediated carbohydrate-protein interaction between host cells and the pathogen initiates pathogenesis of the infection.Areas covered: In this review, the authors outline the structural and functional pathogenesis of lectins from bacteria, amoeba, and humans. Mimics of a carbohydrate are referred to as glycomimetics, which are much smaller in molecular weight and are devised to mimic the key binding interactions of the carbohydrate while also allowing additional contacts with the lectin. This article emphasizes the various approaches used over the past 10-15 years in the rational design of glycomimetic ligands.Expert opinion: Medicinal chemistry efforts enabled by X-ray structural biology have identified small-molecule glycomimetic lectin antagonists that have entered or are nearing clinical trials. A common theme in these strategies is the use of biaryl ring systems to emulate the carbohydrate interactions with the lectin.
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Affiliation(s)
- Vishnu C Damalanka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis USA
| | - Amarendar Reddy Maddirala
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis USA
| | - James W Janetka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis USA
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9
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Escherichia coli O157:H7 F9 Fimbriae Recognize Plant Xyloglucan and Elicit a Response in Arabidopsis thaliana. Int J Mol Sci 2020; 21:ijms21249720. [PMID: 33352760 PMCID: PMC7766294 DOI: 10.3390/ijms21249720] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/04/2020] [Accepted: 12/14/2020] [Indexed: 11/16/2022] Open
Abstract
Fresh produce is often a source of enterohaemorrhagic Escherichia coli (EHEC) outbreaks. Fimbriae are extracellular structures involved in cell-to-cell attachment and surface colonisation. F9 (Fml) fimbriae have been shown to be expressed at temperatures lower than 37 °C, implying a function beyond the mammalian host. We demonstrate that F9 fimbriae recognize plant cell wall hemicellulose, specifically galactosylated side chains of xyloglucan, using glycan arrays. E. coli expressing F9 fimbriae had a positive advantage for adherence to spinach hemicellulose extract and tissues, which have galactosylated oligosaccharides as recognized by LM24 and LM25 antibodies. As fimbriae are multimeric structures with a molecular pattern, we investigated whether F9 fimbriae could induce a transcriptional response in model plant Arabidopsis thaliana, compared with flagella and another fimbrial type, E. coli common pilus (ECP), using DNA microarrays. F9 induced the differential expression of 435 genes, including genes involved in the plant defence response. The expression of F9 at environmentally relevant temperatures and its recognition of plant xyloglucan adds to the suite of adhesins EHEC has available to exploit the plant niche.
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10
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Starks CM, Miller MM, Broglie PM, Cubbison J, Martin SM, Eldridge GR. Optimization and qualification of an assay that demonstrates that a FimH vaccine induces functional antibody responses in women with histories of urinary tract infections. Hum Vaccin Immunother 2020; 17:283-292. [PMID: 32701396 PMCID: PMC7872045 DOI: 10.1080/21645515.2020.1770034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Recurrent urinary tract infections (rUTI) are a serious disease associated with morbidities and mortality. Resistance to the standard of care antibiotics is now widespread because of the continued use of antibiotics among people who suffer from rUTI. We are therefore developing a vaccine to prevent recurrences among patients with rUTI. The antigen of the vaccine is FimH, a bacterial adhesin protein, and the vaccine is adjuvanted with a TLR-4 agonist. In a Phase 1 clinical study evaluating the vaccine, immunized individuals produced FimH-binding antibodies. Here we describe the optimization, qualification, and use of an assay to assess the functionality of these anti-FimH antibodies. The suitability of the assay for its intended purpose was demonstrated by selectivity, specificity, sensitivity, and intra-assay and inter-assay precision. The acceptance criteria were achieved for all parameters including intra-assay precision with ≤10% relative standard deviations and inter-assay precision with ≤25% relative standard deviations. The results presented herein suggest this functional assay will be important for supporting the vaccine’s efficacy in future human studies. Furthermore and of great significance, these results prove that vaccine-induced functional antibodies can be elicited in rUTI patients against an essential virulence factor, FimH.
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Affiliation(s)
- Courtney M Starks
- Sequoia Sciences, Inc., 1912 Innerbelt Business Center Drive , St. Louis, MO, USA
| | | | | | | | - Steven M Martin
- Sequoia Sciences, Inc., 1912 Innerbelt Business Center Drive , St. Louis, MO, USA
| | - Gary R Eldridge
- Sequoia Sciences, Inc., 1912 Innerbelt Business Center Drive , St. Louis, MO, USA
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11
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Weiss GL, Stanisich JJ, Sauer MM, Lin CW, Eras J, Zyla DS, Trück J, Devuyst O, Aebi M, Pilhofer M, Glockshuber R. Architecture and function of human uromodulin filaments in urinary tract
infections. Science 2020; 369:1005-1010. [DOI: 10.1126/science.aaz9866] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 04/22/2020] [Accepted: 06/18/2020] [Indexed: 12/28/2022]
Abstract
Uromodulin is the most abundant protein in human urine, and it forms
filaments that antagonize the adhesion of uropathogens; however, the filament
structure and mechanism of protection remain poorly understood. We used
cryo–electron tomography to show that the uromodulin filament consists of a
zigzag-shaped backbone with laterally protruding arms. N-glycosylation mapping and
biophysical assays revealed that uromodulin acts as a multivalent ligand for the
bacterial type 1 pilus adhesin, presenting specific epitopes on the regularly
spaced arms. Imaging of uromodulin-uropathogen interactions in vitro and in
patient urine showed that uromodulin filaments associate with uropathogens and
mediate bacterial aggregation, which likely prevents adhesion and allows clearance
by micturition. These results provide a framework for understanding uromodulin in
urinary tract infections and in its more enigmatic roles in physiology and
disease.
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Affiliation(s)
- Gregor L. Weiss
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Jessica J. Stanisich
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Maximilian M. Sauer
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Chia-Wei Lin
- Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, CH-8093 Zürich, Switzerland
| | - Jonathan Eras
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Dawid S. Zyla
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Johannes Trück
- University Children’s Hospital Zürich, Steinwiesstrasse 75, CH-8032 Zürich, Switzerland
| | - Olivier Devuyst
- Institute of Physiology, Mechanisms of Inherited Kidney Disorders, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
- Division of Nephrology, UCLouvain Medical School, Brussels, Belgium
| | - Markus Aebi
- Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, CH-8093 Zürich, Switzerland
| | - Martin Pilhofer
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
| | - Rudi Glockshuber
- Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, CH-8093 Zürich, Switzerland
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OXA-181-Producing Extraintestinal Pathogenic Escherichia coli Sequence Type 410 Isolated from a Dog in Portugal. Antimicrob Agents Chemother 2020; 64:AAC.02298-19. [PMID: 31964797 DOI: 10.1128/aac.02298-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 01/17/2020] [Indexed: 12/18/2022] Open
Abstract
Two multidrug-resistant and carbapenemase-producing Escherichia coli clones of sequence type 410 were isolated from fecal samples of a dog with skin infection on admission to an animal hospital in Portugal and 1 month after discharge. Whole-genome sequencing revealed a 126,409-bp Col156/IncFIA/IncFII multidrug resistance plasmid and a 51,479-bp IncX3 bla OXA-181-containing plasmid. The chromosome and plasmids carried virulence genes characteristic for uropathogenic E. coli, indicating that dogs may carry multidrug-resistant E. coli isolates related to those causing urinary tract infections in humans.
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Urinary tract infections: microbial pathogenesis, host-pathogen interactions and new treatment strategies. Nat Rev Microbiol 2020; 18:211-226. [PMID: 32071440 DOI: 10.1038/s41579-020-0324-0] [Citation(s) in RCA: 213] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2020] [Indexed: 12/14/2022]
Abstract
Urinary tract infections (UTIs) are common, recurrent infections that can be mild to life-threatening. The continued emergence of antibiotic resistance, together with our increasing understanding of the detrimental effects conferred by broad-spectrum antibiotic use on the health of the beneficial microbiota of the host, has underscored the weaknesses in our current treatment paradigm for UTIs. In this Review, we discuss how recent microbiological, structural, genetic and immunological studies have expanded our understanding of host-pathogen interactions during UTI pathogenesis. These basic scientific findings have the potential to shift the strategy for UTI treatment away from broad-spectrum antibiotics targeting conserved aspects of bacterial replication towards pathogen-specific antibiotic-sparing therapeutics that target core determinants of bacterial virulence at the host-pathogen interface.
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14
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Rapid Bladder Interleukin-10 Synthesis in Response to Uropathogenic Escherichia coli Is Part of a Defense Strategy Triggered by the Major Bacterial Flagellar Filament FliC and Contingent on TLR5. mSphere 2019; 4:4/6/e00545-19. [PMID: 31776239 PMCID: PMC6881718 DOI: 10.1128/msphere.00545-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Interleukin-10 is part of the immune response to urinary tract infection (UTI) due to E. coli, and it is important in the early control of infection in the bladder. Defining the mechanism of engagement of the immune system by the bacteria that enables the protective IL-10 response is critical to exploring how we might exploit this mechanism for new infection control strategies. In this study, we reveal part of the bacterial flagellar apparatus (FliC) is an important component that is sensed by and responsible for induction of IL-10 in the response to UPEC. We show this response occurs in a TLR5-dependent manner. Using infection prevention and control trials in mice infected with E. coli, this study also provides evidence that purified FliC might be of value in novel approaches for the treatment of UTI or in preventing infection by exploiting the FliC-triggered bladder transcriptome. Urinary tract infection (UTI) caused by uropathogenic Escherichia coli (UPEC) engages interleukin-10 (IL-10) as an early innate immune response to regulate inflammation and promote the control of bladder infection. However, the mechanism of engagement of innate immunity by UPEC that leads to elicitation of IL-10 in the bladder is unknown. Here, we identify the major UPEC flagellar filament, FliC, as a key bacterial component sensed by the bladder innate immune system responsible for the induction of IL-10 synthesis. IL-10 responses of human as well as mouse bladder epithelial cell-monocyte cocultures were triggered by flagella of three major UPEC representative strains, CFT073, UTI89, and EC958. FliC purified to homogeneity induced IL-10 in vitro and in vivo as well as other functionally related cytokines, including IL-6. The genome-wide innate immunological context of FliC-induced IL-10 in the bladder was defined using RNA sequencing that revealed a network of transcriptional and antibacterial defenses comprising 1,400 genes that were induced by FliC. Of the FliC-responsive bladder transcriptome, altered expression of il10 and 808 additional genes were dependent on Toll-like receptor 5 (TLR5), according to analysis of TLR5-deficient mice. Examination of the potential of FliC and associated innate immune signature in the bladder to boost host defense, based on prophylactic or therapeutic administration to mice, revealed significant benefits for the control of UPEC. We conclude that detection of FliC through TLR5 triggers rapid IL-10 synthesis in the bladder, and FliC represents a potential immune modulator that might offer benefit for the treatment or prevention of UPEC UTI. IMPORTANCE Interleukin-10 is part of the immune response to urinary tract infection (UTI) due to E. coli, and it is important in the early control of infection in the bladder. Defining the mechanism of engagement of the immune system by the bacteria that enables the protective IL-10 response is critical to exploring how we might exploit this mechanism for new infection control strategies. In this study, we reveal part of the bacterial flagellar apparatus (FliC) is an important component that is sensed by and responsible for induction of IL-10 in the response to UPEC. We show this response occurs in a TLR5-dependent manner. Using infection prevention and control trials in mice infected with E. coli, this study also provides evidence that purified FliC might be of value in novel approaches for the treatment of UTI or in preventing infection by exploiting the FliC-triggered bladder transcriptome.
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15
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Classical chaperone-usher (CU) adhesive fimbriome: uropathogenic Escherichia coli (UPEC) and urinary tract infections (UTIs). Folia Microbiol (Praha) 2019; 65:45-65. [DOI: 10.1007/s12223-019-00719-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 05/20/2019] [Indexed: 12/17/2022]
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16
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Acharya D, Sullivan MJ, Duell BL, Eveno T, Schembri MA, Ulett GC. Physical Extraction and Fast Protein Liquid Chromatography for Purifying Flagella Filament From Uropathogenic Escherichia coli for Immune Assay. Front Cell Infect Microbiol 2019; 9:118. [PMID: 31069177 PMCID: PMC6491459 DOI: 10.3389/fcimb.2019.00118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 04/03/2019] [Indexed: 01/17/2023] Open
Abstract
Flagella are expressed on the surface of a wide range of bacteria, conferring motility and contributing to virulence and innate immune stimulation. Host-pathogen interaction studies of the roles of flagella in infection, including due to uropathogenic Escherichia coli (UPEC), have used various methods to purify and examine the biology of the major flagella subunit protein, FliC. These studies have offered insight into the ways in which flagella proteins interact with host cells. However, previous methods used to extract and purify FliC, such as mechanical shearing, ultracentrifugation, heterologous expression in laboratory E. coli strains, and precipitation-inducing chemical treatments have various limitations; as a result, there are few observations based on highly purified, non-denatured FliC in the literature. This is especially relevant to host-pathogen interaction studies such as immune assays that are designed to parallel, as closely as possible, naturally-occurring interactions between host cells and flagella. In this study, we sought to establish a new, carefully optimized method to extract and purify non-denatured, native FliC from the reference UPEC strain CFT073 to be suitable for immune assays. To achieve purification of FliC to homogeneity, we used a mutant CFT073 strain containing deletions in four major chaperone-usher fimbriae operons (type 1, F1C and two P fimbrial gene clusters; CFT073Δ4). A sequential flagella extraction method based on mechanical shearing, ultracentrifugation, size exclusion chromatography, protein concentration and endotoxin removal was applied to CFT073Δ4. Protein purity and integrity was assessed using SDS-PAGE, Western blots with anti-flagellin antisera, and native-PAGE. We also generated a fliC-deficient strain, CFT073Δ4ΔfliC, to enable the concurrent preparation of a suitable carrier control to be applied in downstream assays. Innate immune stimulation was examined by exposing J774A.1 macrophages to 0.05-1 μg of purified FliC for 5 h; the supernatants were analyzed for cytokines known to be induced by flagella, including TNF-α, IL-6, and IL-12; the results were assessed in the context of prior literature. Macrophage responses to purified FliC encompassed significant levels of several cytokines consistent with prior literature reports. The purification method described here establishes a new approach to examine highly purified FliC in the context of host-pathogen interaction model systems.
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Affiliation(s)
- Dhruba Acharya
- School of Medical Science, Griffith University, Southport, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Matthew J Sullivan
- School of Medical Science, Griffith University, Southport, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Benjamin L Duell
- School of Medical Science, Griffith University, Southport, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Tanguy Eveno
- Institute for Glycomics, Griffith University, Southport, QLD, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, University of Queensland, St. Lucia, QLD, Australia
| | - Glen C Ulett
- School of Medical Science, Griffith University, Southport, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
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17
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Day CJ, Hartley-Tassell LE, Seib KL, Tiralongo J, Bovin N, Savino S, Masignani V, Jennings MP. Lectin activity of Pseudomonas aeruginosa vaccine candidates PSE17-1, PSE41-5 and PSE54. Biochem Biophys Res Commun 2019; 513:287-290. [PMID: 30954224 DOI: 10.1016/j.bbrc.2019.03.092] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/16/2019] [Indexed: 12/26/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial infections most commonly in immunocompromised, cystic fibrosis (CF) and burns patients. The pilin and Pseudomonas lectins 1 (PA-IL) and 2 (PA-IIL) are known glycan-binding proteins of P. aeruginosa that are involved in adherence to host cells, particularly CF host airways. Recently, new P. aeruginosa surface proteins were identified by reverse vaccinology and tested in vivo as potential vaccine antigens. Three of these, namely PSE17-1, PSE41-5 and PSE54, were screened for glycan binding using glycan arrays displaying glycan structures representative of those found on human cells. Surface plasmon resonance was used to confirm the lectin activity of these proteins, and determined affinities with several host glycans to be in the nanomolar range. PSE17-1 binds hyaluronic acid and sialyl Lewis A and X. PSE41-5 binds terminal β-linked galactose structures, Lewis and ABO blood group antigens. PSE54 binds to ABO blood group antigens and some terminal β-linked galactose. All three proteins are novel lectins of P. aeruginosa with potential roles in infection of host cells.
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Affiliation(s)
- Christopher J Day
- Institute for Glycomics, Griffith University, Gold Coast, QLD, 4222, Australia
| | | | - Kate L Seib
- Institute for Glycomics, Griffith University, Gold Coast, QLD, 4222, Australia
| | - Joe Tiralongo
- Institute for Glycomics, Griffith University, Gold Coast, QLD, 4222, Australia
| | - Nicolai Bovin
- Shemyakin Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | | | | | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, QLD, 4222, Australia.
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18
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Lectin Activity of the TcdA and TcdB Toxins of Clostridium difficile. Infect Immun 2019; 87:IAI.00676-18. [PMID: 30530621 PMCID: PMC6386544 DOI: 10.1128/iai.00676-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 12/04/2018] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile is a major cause of hospital-acquired antibiotic-associated diarrhea. C. difficile produces two cytotoxins, TcdA and TcdB; both toxins are multidomain proteins that lead to cytotoxicity through the modification and inactivation of small GTPases of the Rho/Rac family. Previous studies have indicated that host glycans are targets for TcdA and TcdB, with interactions thought to be with both α- and β-linked galactose. In the current study, screening of glycan arrays with different domains of TcdA and TcdB revealed that the binding regions of both toxins interact with a wider range of host glycoconjugates than just terminal α- and β-linked galactose, including blood groups, Lewis antigens, N-acetylglucosamine, mannose, and glycosaminoglycans. The interactions of TcdA and TcdB with ABO blood group and Lewis antigens were assessed by surface plasmon resonance (SPR). The blood group A antigen was the highest-affinity ligand for both toxins. Free glycans alone or in combination were unable to abolish Vero cell cytotoxicity by TcdB. SPR competition assays indicate that there is more than one glycan binding site on TcdB. Host glycoconjugates are common targets of bacterial toxins, but typically this binding is to a specific structure or related structures. The binding of TcdA and TcdB is to a wide range of host glycans providing a wide range of target cells and tissues in vivo.
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19
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Uropathogenic Escherichia coli and the related virulence factors. GINECOLOGIA.RO 2019. [DOI: 10.26416/gine.26.4.2019.2713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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20
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O'Connell Motherway M, Houston A, O’Callaghan G, Reunanen J, O’Brien F, O’Driscoll T, Casey PG, de Vos WM, van Sinderen D, Shanahan F. A Bifidobacterial pilus-associated protein promotes colonic epithelial proliferation. Mol Microbiol 2018; 111:287-301. [DOI: 10.1111/mmi.14155] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2018] [Indexed: 01/15/2023]
Affiliation(s)
- Mary O'Connell Motherway
- APC Microbiome Ireland, National University of Ireland; Western Road Cork Ireland
- School of Microbiology; National University of Ireland; Western Road Cork Ireland
| | - Aileen Houston
- APC Microbiome Ireland, National University of Ireland; Western Road Cork Ireland
- Department of Medicine; National University of Ireland, Cork University Hospital; Cork Ireland
| | - Grace O’Callaghan
- APC Microbiome Ireland, National University of Ireland; Western Road Cork Ireland
- Department of Medicine; National University of Ireland, Cork University Hospital; Cork Ireland
| | - Justus Reunanen
- Research Programme Unit Immunobiology, Department of Bacteriology and Immunology; Helsinki University; Helsinki Finland
- Cancer and Translational Medicine Research Unit and Biocenter Oulu; University of Oulu; Oulu Finland
| | - Frances O’Brien
- APC Microbiome Ireland, National University of Ireland; Western Road Cork Ireland
| | - Tara O’Driscoll
- APC Microbiome Ireland, National University of Ireland; Western Road Cork Ireland
| | - Patrick G. Casey
- APC Microbiome Ireland, National University of Ireland; Western Road Cork Ireland
| | - Willem M. de Vos
- Research Programme Unit Immunobiology, Department of Bacteriology and Immunology; Helsinki University; Helsinki Finland
- Laboratory of Microbiology; Wageningen University; The Netherlands
| | - Douwe van Sinderen
- APC Microbiome Ireland, National University of Ireland; Western Road Cork Ireland
- School of Microbiology; National University of Ireland; Western Road Cork Ireland
| | - Fergus Shanahan
- APC Microbiome Ireland, National University of Ireland; Western Road Cork Ireland
- Department of Medicine; National University of Ireland, Cork University Hospital; Cork Ireland
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21
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Aas CG, Drabløs F, Haugum K, Afset JE. Comparative Transcriptome Profiling Reveals a Potential Role of Type VI Secretion System and Fimbriae in Virulence of Non-O157 Shiga Toxin-Producing Escherichia coli. Front Microbiol 2018; 9:1416. [PMID: 30008706 PMCID: PMC6033998 DOI: 10.3389/fmicb.2018.01416] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 06/08/2018] [Indexed: 01/18/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) cause both sporadic infections and outbreaks of enteric disease in humans, with symptoms ranging from asymptomatic carriage to severe disease like haemolytic uremic syndrome (HUS). Bacterial virulence factors like subtypes of the Shiga toxin (Stx) and the locus of enterocyte effacement (LEE) pathogenicity island, as well as host factors like young age, are strongly associated with development of HUS. However, these factors alone do not accurately differentiate between strains that cause HUS and those that do not cause severe disease, which is important in the context of diagnosis, treatment, as well as infection control. We have used RNA sequencing to compare transcriptomes of 30 stx2a and eae positive STEC strains of non-O157 serogroups isolated from children <5 years of age. The strains were from children with HUS (HUS group, n = 15), and children with asymptomatic or mild disease (non-HUS group, n = 15), either induced with mitomycin C or non-induced, to reveal potential differences in gene expression levels between groups. When the HUS and non-HUS group were compared for differential expression of protein-encoding gene families, 399 of 6,119 gene families were differentially expressed (log2 fold change ≥ 1, FDR < 0.05) in the non-induced condition, whereas only one gene family was differentially expressed in the induced condition. Gene ontology and cluster analysis showed that several fimbrial operons, as well as a putative type VI secretion system (T6SS) were more highly expressed in the HUS group than in the non-HUS group, indicating a role of these in the virulence of STEC strains causing severe disease.
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Affiliation(s)
- Christina G Aas
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Clinic of Laboratory Medicine, Department of Medical Microbiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Finn Drabløs
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Kjersti Haugum
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Clinic of Laboratory Medicine, Department of Medical Microbiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Jan E Afset
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Clinic of Laboratory Medicine, Department of Medical Microbiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
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22
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Structure-based discovery of glycomimetic FmlH ligands as inhibitors of bacterial adhesion during urinary tract infection. Proc Natl Acad Sci U S A 2018; 115:E2819-E2828. [PMID: 29507247 PMCID: PMC5866590 DOI: 10.1073/pnas.1720140115] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Treatment of bacterial infections is becoming a serious clinical challenge due to the global dissemination of multidrug antibiotic resistance, necessitating the search for alternative treatments to disarm the virulence mechanisms underlying these infections. Uropathogenic Escherichia coli (UPEC) employs multiple chaperone-usher pathway pili tipped with adhesins with diverse receptor specificities to colonize various host tissues and habitats. For example, UPEC F9 pili specifically bind galactose or N-acetylgalactosamine epitopes on the kidney and inflamed bladder. Using X-ray structure-guided methods, virtual screening, and multiplex ELISA arrays, we rationally designed aryl galactosides and N-acetylgalactosaminosides that inhibit the F9 pilus adhesin FmlH. The lead compound, 29β-NAc, is a biphenyl N-acetyl-β-galactosaminoside with a Ki of ∼90 nM, representing a major advancement in potency relative to the characteristically weak nature of most carbohydrate-lectin interactions. 29β-NAc binds tightly to FmlH by engaging the residues Y46 through edge-to-face π-stacking with its A-phenyl ring, R142 in a salt-bridge interaction with its carboxylate group, and K132 through water-mediated hydrogen bonding with its N-acetyl group. Administration of 29β-NAc in a mouse urinary tract infection (UTI) model significantly reduced bladder and kidney bacterial burdens, and coadministration of 29β-NAc and mannoside 4Z269, which targets the type 1 pilus adhesin FimH, resulted in greater elimination of bacteria from the urinary tract than either compound alone. Moreover, FmlH specifically binds healthy human kidney tissue in a 29β-NAc-inhibitable manner, suggesting a key role for F9 pili in human kidney colonization. Thus, these glycoside antagonists of FmlH represent a rational antivirulence strategy for UPEC-mediated UTI treatment.
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23
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Abstract
Streptococcus pneumoniae is a leading cause of morbidity and mortality globally. The Pilus-1 proteins, RrgA, RrgB and RrgC of S. pneumoniae have been previously assessed for their role in infection, invasive disease and as possible vaccine candidates. In this study we have investigated the glycan binding repertoire of all three Pilus-1 proteins, identifying that the tip adhesin RrgA has the broadest glycan recognition of the three proteins, binding to maltose/cellobiose, α/β linked galactose and blood group A and H antigens. RrgB only bound mannose, while RrgC bound a subset of glycans also recognized by RrgA. Adherence of S. pneumoniae TIGR4 to epithelial cells was tested using four of the oligosaccharides identified through the glycan array analysis as competitive inhibitors. The blood group H trisaccharide provided the best blocking of S. pneumoniae TIGR4 adherence. Adherence is the first step in disease, and host glycoconjugates are a common target for many adhesins. This study has identified Pilus-1 proteins as new lectins involved in the targeting of host glycosylation by S. pneumoniae.
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24
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Segura A, Auffret P, Klopp C, Bertin Y, Forano E. Draft genome sequence and characterization of commensal Escherichia coli strain BG1 isolated from bovine gastro-intestinal tract. Stand Genomic Sci 2017; 12:61. [PMID: 29046740 PMCID: PMC5634895 DOI: 10.1186/s40793-017-0272-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 09/21/2017] [Indexed: 11/16/2022] Open
Abstract
Escherichia coli is the most abundant facultative anaerobic bacteria in the gastro-intestinal tract of mammals but can be responsible for intestinal infection due to acquisition of virulence factors. Genomes of pathogenic E. coli strains are widely described whereas those of bovine commensal E. coli strains are very scarce. Here, we report the genome sequence, annotation, and features of the commensal E. coli BG1 isolated from the gastro-intestinal tract of cattle. Whole genome sequencing analysis showed that BG1 has a chromosome of 4,782,107 bp coding for 4465 proteins and 97 RNAs. E. coli BG1 belonged to the serotype O159:H21, was classified in the phylogroup B1 and possessed the genetic information encoding "virulence factors" such as adherence systems, iron acquisition and flagella synthesis. A total of 12 adherence systems were detected reflecting the potential ability of BG1 to colonize different segments of the bovine gastro-intestinal tract. E. coli BG1 is unable to assimilate ethanolamine that confers a nutritional advantage to some pathogenic E. coli in the bovine gastro-intestinal tract. Genome analysis revealed the presence of i) 34 amino acids change due to non-synonymous SNPs among the genes encoding ethanolamine transport and assimilation, and ii) an additional predicted alpha helix inserted in cobalamin adenosyltransferase, a key enzyme required for ethanolamine assimilation. These modifications could explain the incapacity of BG1 to use ethanolamine. The BG1 genome can now be used as a reference (control strain) for subsequent evolution and comparative studies.
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Affiliation(s)
- Audrey Segura
- Université Clermont Auvergne, INRA, MEDIS, F-63000 Clermont-Ferrand, France
| | - Pauline Auffret
- Université Clermont Auvergne, INRA, MEDIS, F-63000 Clermont-Ferrand, France
| | - Christophe Klopp
- Plateforme Bioinformatique Toulouse, Midi-Pyrénées UBIA, INRA, Auzeville Castanet-Tolosan, France
| | - Yolande Bertin
- Université Clermont Auvergne, INRA, MEDIS, F-63000 Clermont-Ferrand, France
| | - Evelyne Forano
- Université Clermont Auvergne, INRA, MEDIS, F-63000 Clermont-Ferrand, France
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25
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Sicard JF, Le Bihan G, Vogeleer P, Jacques M, Harel J. Interactions of Intestinal Bacteria with Components of the Intestinal Mucus. Front Cell Infect Microbiol 2017; 7:387. [PMID: 28929087 PMCID: PMC5591952 DOI: 10.3389/fcimb.2017.00387] [Citation(s) in RCA: 279] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/18/2017] [Indexed: 12/19/2022] Open
Abstract
The human gut is colonized by a variety of large amounts of microbes that are collectively called intestinal microbiota. Most of these microbial residents will grow within the mucus layer that overlies the gut epithelium and will act as the first line of defense against both commensal and invading microbes. This mucus is essentially formed by mucins, a family of highly glycosylated protein that are secreted by specialize cells in the gut. In this Review, we examine how commensal members of the microbiota and pathogenic bacteria use mucus to their advantage to promote their growth, develop biofilms and colonize the intestine. We also discuss how mucus-derived components act as nutrient and chemical cues for adaptation and pathogenesis of bacteria and how bacteria can influence the composition of the mucus layer.
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Affiliation(s)
- Jean-Félix Sicard
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Guillaume Le Bihan
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Philippe Vogeleer
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Mario Jacques
- Regroupement de Recherche Pour un Lait de Qualité Optimale (Op+Lait), Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Josée Harel
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
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26
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Aviv G, Elpers L, Mikhlin S, Cohen H, Vitman Zilber S, Grassl GA, Rahav G, Hensel M, Gal-Mor O. The plasmid-encoded Ipf and Klf fimbriae display different expression and varying roles in the virulence of Salmonella enterica serovar Infantis in mouse vs. avian hosts. PLoS Pathog 2017; 13:e1006559. [PMID: 28817673 PMCID: PMC5560535 DOI: 10.1371/journal.ppat.1006559] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/29/2017] [Indexed: 12/18/2022] Open
Abstract
Salmonella enterica serovar Infantis is one of the prevalent Salmonella serovars worldwide. Different emergent clones of S. Infantis were shown to acquire the pESI virulence-resistance megaplasmid affecting its ecology and pathogenicity. Here, we studied two previously uncharacterized pESI-encoded chaperone-usher fimbriae, named Ipf and Klf. While Ipf homologs are rare and were found only in S. enterica subspecies diarizonae and subspecies VII, Klf is related to the known K88-Fae fimbria and klf clusters were identified in seven S. enterica subspecies I serovars, harboring interchanging alleles of the fimbria major subunit, KlfG. Regulation studies showed that the klf genes expression is negatively and positively controlled by the pESI-encoded regulators KlfL and KlfB, respectively, and are activated by the ancestral leucine-responsive regulator (Lrp). ipf genes are negatively regulated by Fur and activated by OmpR. Furthermore, induced expression of both klf and ipf clusters occurs under microaerobic conditions and at 41°C compared to 37°C, in-vitro. Consistent with these results, we demonstrate higher expression of ipf and klf in chicks compared to mice, characterized by physiological temperature of 41.2°C and 37°C, respectively. Interestingly, while Klf was dispensable for S. Infantis colonization in the mouse, Ipf was required for maximal colonization in the murine ileum. In contrast to these phenotypes in mice, both Klf and Ipf contributed to a restrained infection in chicks, where the absence of these fimbriae has led to moderately higher bacterial burden in the avian host. Taken together, these data suggest that physiological differences between host species, such as the body temperature, can confer differences in fimbriome expression, affecting Salmonella colonization and other host-pathogen interplays.
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Affiliation(s)
- Gili Aviv
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Laura Elpers
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | | | - Helit Cohen
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | | | - Guntram A. Grassl
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Galia Rahav
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Michael Hensel
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Ohad Gal-Mor
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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27
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Global transcriptional response of Escherichia coli MG1655 cells exposed to the oxygenated monoterpenes citral and carvacrol. Int J Food Microbiol 2017. [PMID: 28644990 DOI: 10.1016/j.ijfoodmicro.2017.06.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
DNA microarrays were used to study the mechanism of bacterial inactivation by carvacrol and citral. After 10-min treatments of Escherichia coli MG1655 cells with 100 and 50ppm of carvacrol and citral, 76 and 156 genes demonstrated significant transcriptional differences (p≤0.05), respectively. Among the up-regulated genes after carvacrol treatment, we found gene coding for multidrug efflux pumps (acrA, mdtM), genes related to phage shock response (pspA, pspB, pspC, pspD, pspF and pspG), biosynthesis of arginine (argC, argG, artJ), and purine nucleotides (purC, purM). In citral-treated cells, transcription of purH and pyrB and pyrI was 2 times higher. Deletion of several differentially expressed genes confirmed the role of ygaV, yjbO, pspC, sdhA, yejG and ygaV in the mechanisms of E. coli inactivation by carvacrol and citral. These results would indicate that citral and carvacrol treatments cause membrane damage and activate metabolism through the production of nucleotides required for DNA and RNA synthesis and metabolic processes. Comparative transcriptomics of the response of E. coli to a heat treatment, which caused a significant change of the transcription of 1422 genes, revealed a much weaker response to both individual constituents of essential oils (ICs).·Thus, inactivation by citral or carvacrol was not multitarget in nature.
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Conover MS, Ruer S, Taganna J, Kalas V, De Greve H, Pinkner JS, Dodson KW, Remaut H, Hultgren SJ. Inflammation-Induced Adhesin-Receptor Interaction Provides a Fitness Advantage to Uropathogenic E. coli during Chronic Infection. Cell Host Microbe 2016; 20:482-492. [PMID: 27667696 PMCID: PMC5294914 DOI: 10.1016/j.chom.2016.08.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/10/2016] [Accepted: 08/19/2016] [Indexed: 02/04/2023]
Abstract
Uropathogenic E. coli (UPEC) is the dominant cause of urinary tract infections, clinically described as cystitis. UPEC express CUP pili, which are extracellular fibers tipped with adhesins that bind mucosal surfaces of the urinary tract. Here we identify the role of the F9/Yde/Fml pilus for UPEC persistence in the inflamed urothelium. The Fml adhesin FmlH binds galactose β1-3 N-acetylgalactosamine found in core-1 and -2 O-glycans. Deletion of fmlH had no effect on UPEC virulence in an acute mouse model of cystitis. However, FmlH provided a fitness advantage during chronic cystitis, which is manifested as persistent bacteriuria, high bladder bacterial burdens, and chronic inflammation. In situ binding confirmed that FmlH bound avidly to the inflamed, but not the naive bladder. In accordance with its pathogenic profile, vaccination with FmlH significantly protected mice from chronic cystitis. Thus, UPEC employ separate CUP pili to adapt to the rapidly changing niche during bladder infection.
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Affiliation(s)
- Matt S Conover
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ségolène Ruer
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Joemar Taganna
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Vasilios Kalas
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Henri De Greve
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Jerome S Pinkner
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Karen W Dodson
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Han Remaut
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
| | - Scott J Hultgren
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Tan L, Moriel DG, Totsika M, Beatson SA, Schembri MA. Differential Regulation of the Surface-Exposed and Secreted SslE Lipoprotein in Extraintestinal Pathogenic Escherichia coli. PLoS One 2016; 11:e0162391. [PMID: 27598999 PMCID: PMC5012682 DOI: 10.1371/journal.pone.0162391] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 08/22/2016] [Indexed: 11/19/2022] Open
Abstract
Extra-intestinal pathogenic Escherichia coli (ExPEC) are responsible for diverse infections including meningitis, sepsis and urinary tract infections. The alarming rise in anti-microbial resistance amongst ExPEC complicates treatment and has highlighted the need for alternative preventive measures. SslE is a lipoprotein secreted by a dedicated type II secretion system in E. coli that was first identified as a potential vaccine candidate using reverse genetics. Although the function and protective efficacy of SslE has been studied, the molecular mechanisms that regulate SslE expression remain to be fully elucidated. Here, we show that while the expression of SslE can be detected in E. coli culture supernatants, different strains express and secrete different amounts of SslE when grown under the same conditions. While the histone-like transcriptional regulator H-NS strongly represses sslE at ambient temperatures, the variation in SslE expression at human physiological temperature suggested a more complex mode of regulation. Using a genetic screen to identify novel regulators of sslE in the high SslE-expressing strain UTI89, we defined a new role for the nucleoid-associated regulator Fis and the ribosome-binding GTPase TypA as positive regulators of sslE transcription. We also showed that Fis-mediated enhancement of sslE transcription is dependent on a putative Fis-binding sequence located upstream of the -35 sequence in the core promoter element, and provide evidence to suggest that Fis may work in complex with H-NS to control SslE expression. Overall, this study has defined a new mechanism for sslE regulation and increases our understanding of this broadly conserved E. coli vaccine antigen.
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Affiliation(s)
- Lendl Tan
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Brisbane, Australia
| | - Danilo G. Moriel
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Brisbane, Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, QLD 4059, Brisbane, Australia
| | - Scott A. Beatson
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Brisbane, Australia
| | - Mark A. Schembri
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Brisbane, Australia
- * E-mail:
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Miajlovic H, Mac Aogáin M, Collins CJ, Rogers TR, Smith SGJ. Characterization of Escherichia coli bloodstream isolates associated with mortality. J Med Microbiol 2016; 65:71-79. [PMID: 26518234 DOI: 10.1099/jmm.0.000200] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Extra-intestinal pathogenic Escherichia coli (ExPEC) are the predominant cause of Gramnegative bloodstream infections. In this study, 20 E. coli isolates that were the causative agents of bacteraemia and subsequent mortality were characterized. Whole-genome sequencing was used to define the predominant sequence types (ST) among the isolates and to identify virulence factors associated with pathogenicity of ExPEC. The ability of the isolates to resist killing by both serum and polymorphonuclear leukocytes (PMNLs) was also assessed. In line with global trends, ST131 occurred most frequently among the bloodstream isolates and all isolates of this sequence type were multidrug resistant. Other common STs included ST73 and ST69. All isolates encoded multiple virulence factors across a range of categories, including factors involved in adhesion, immune evasion, iron acquisition and synthesis of toxins. None of these factors could be associated with serum and neutrophil resistance. The majority of isolates were resistant to the bactericidal action of serum and PMNLs, and most of those that were sensitive were isolated from patients with compromised immunity.
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Affiliation(s)
- Helen Miajlovic
- Department of Clinical Microbiology, Sir Patrick Dun Research Laboratory, School of Medicine, Trinity College, Dublin 8, Ireland
| | - Micheál Mac Aogáin
- Department of Clinical Microbiology, Sir Patrick Dun Research Laboratory, School of Medicine, Trinity College, Dublin 8, Ireland
| | - Cathal J Collins
- Department of Clinical Microbiology, Sir Patrick Dun Research Laboratory, School of Medicine, Trinity College, Dublin 8, Ireland
| | - Thomas R Rogers
- Department of Clinical Microbiology, Sir Patrick Dun Research Laboratory, School of Medicine, Trinity College, Dublin 8, Ireland.,Microbiology Department, St James's Hospital, Dublin 8, Ireland
| | - Stephen G J Smith
- Department of Clinical Microbiology, Sir Patrick Dun Research Laboratory, School of Medicine, Trinity College, Dublin 8, Ireland
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Spaulding CN, Hultgren SJ. Adhesive Pili in UTI Pathogenesis and Drug Development. Pathogens 2016; 5:E30. [PMID: 26999218 PMCID: PMC4810151 DOI: 10.3390/pathogens5010030] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 02/15/2016] [Accepted: 03/07/2016] [Indexed: 01/08/2023] Open
Abstract
Urinary tract infections (UTIs) are one of the most common bacterial infections, affecting 150 million people each year worldwide. High recurrence rates and increasing antimicrobial resistance among uropathogens are making it imperative to develop alternative strategies for the treatment and prevention of this common infection. In this Review, we discuss how understanding the: (i) molecular and biophysical basis of host-pathogen interactions; (ii) consequences of the molecular cross-talk at the host pathogen interface in terms of disease progression; and (iii) pathophysiology of UTIs is leading to efforts to translate this knowledge into novel therapeutics to treat and prevent these infections.
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Affiliation(s)
- Caitlin N Spaulding
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Scott J Hultgren
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
- Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Effect of Temperature on Fimbrial Gene Expression and Adherence of Enteroaggregative Escherichia coli. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015. [PMID: 26213951 PMCID: PMC4555238 DOI: 10.3390/ijerph120808631] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The influence of temperature on bacterial virulence has been studied worldwide from the viewpoint of climate change and global warming. The bacterium enteroaggregative Escherichia coli (EAEC) is the causative agent of watery diarrhea and shows an increasing incidence worldwide. Its pathogenicity is associated with the virulence factors aggregative adherence fimbria type I and II (AAFI and AAFII), encoded by aggA and aafA in EAEC strains 17-2 and 042, respectively. This study focused on the effect of temperature increases from 29 °C to 40 °C on fimbrial gene expression using real-time PCR, and on its virulence using an aggregative adherence assay and biofilm formation assay. Incubation at 32 °C caused an up-regulation in both EAEC strains 17-2 and strain 042 virulence gene expression. EAEC strain 042 cultured at temperature above 32 °C showed down-regulation of aafA expression except at 38 °C. Interestingly, EAEC cultured at a high temperature showed a reduced adherence to cells and an uneven biofilm formation. These results provide evidence that increases in temperature potentially affect the virulence of pathogenic EAEC, although the response varies in each strain.
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Ma F, Rehman A, Liu H, Zhang J, Zhu S, Zeng X. Glycosylation of Quinone-Fused Polythiophene for Reagentless and Label-Free Detection of E. coli. Anal Chem 2015; 87:1560-8. [DOI: 10.1021/ac502712q] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Fen Ma
- Department
of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Abdul Rehman
- Department
of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Haiying Liu
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Jingtuo Zhang
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Shilei Zhu
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Xiangqun Zeng
- Department
of Chemistry, Oakland University, Rochester, Michigan 48309, United States
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Lüthje P, Brauner A. Virulence factors of uropathogenic E. coli and their interaction with the host. Adv Microb Physiol 2014; 65:337-72. [PMID: 25476769 DOI: 10.1016/bs.ampbs.2014.08.006] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Urinary tract infections (UTIs) belong to the most common infectious diseases worldwide. The most frequently isolated pathogen from uncomplicated UTIs is Escherichia coli. To establish infection in the urinary tract, E. coli has to overcome several defence strategies of the host, including the urine flow, exfoliation of urothelial cells, endogenous antimicrobial factors and invading neutrophils. Thus, uropathogenic E. coli (UPEC) harbour a number of virulence and fitness factors enabling the bacterium to resist and overcome these different defence mechanisms. There is no particular factor which allows the identification of UPEC among the commensal faecal flora apart from the ability to enter the urinary tract and cause an infection. Many of potential virulence or fitness factors occur moreover with high redundancy. Fimbriae are inevitable for adherence to and invasion into the host cells; the type 1 pilus is an established virulence factor in UPEC and indispensable for successful infection of the urinary tract. Flagella and toxins promote bacterial dissemination, while different iron-acquisition systems allow bacterial survival in the iron-limited environment of the urinary tract. The immune response to UPEC is primarily mediated by toll-like receptors recognising lipopolysaccharide, flagella and other structures on the bacterial surface. UPEC have the capacity to subvert this immune response of the host by means of actively impacting on pro-inflammatory signalling pathways, or by physical masking of immunogenic structures. The large repertoire of bacterial virulence and fitness factors in combination with host-related differences results in a complex interaction between host and pathogen in the urinary tract.
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Affiliation(s)
- Petra Lüthje
- Department of Microbiology, Tumor and Cell Biology, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Annelie Brauner
- Department of Microbiology, Tumor and Cell Biology, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
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