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Herrera-Espejo S, Domínguez-Miranda JL, Rodríguez-Mogollo JI, Pachón J, Cordero E, Pachón-Ibáñez ME. Effects of pH on the Pathogenicity of Escherichia coli and Klebsiella pneumoniae on the Kidney: In Vitro and In Vivo Studies. Int J Mol Sci 2024; 25:7925. [PMID: 39063167 PMCID: PMC11277208 DOI: 10.3390/ijms25147925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Urine pH reflects the functional integrity of the body and may influence the virulence of uropathogenic Escherichia coli and Klebsiella pneumoniae, the main causes of urinary tract infections (UTIs). This study evaluated the effects of acidic pH on the pathogenicity of uropathogenic E. coli and K. pneumoniae strains, in vitro and in vivo. Four uropathogenic E. coli and four K. pneumoniae strains were used. Biofilm formation, growth competition indices, motility, and adhesion and invasion of human renal cells were analyzed in media with acidic, neutral, and alkaline pH. A murine lower UTI model was used, with urine adjusted to acidic, neutral, or alkaline pH. At acidic pH, E. coli and K. pneumoniae exhibited higher bacterial concentrations in the kidneys and systemic symptoms, including bacteremia. Alkaline urine pH did not affect bacterial concentrations of any strain. In mice with UTIs caused by E. coli Nu14 and K. pneumoniae HUVR42 and acidic urine pH, histopathological studies of the kidneys showed acute inflammation affecting the urothelium and renal parenchyma, which are traits of acute pyelonephritis. These results indicate that acidic pH could increase the pathogenicity of E. coli and K. pneumoniae in murine models of lower UTI, promoting renal infection and acute inflammation.
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Affiliation(s)
- Soraya Herrera-Espejo
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, Institute of Biomedicine of Seville (IBiS), Virgen del Rocio University Hospital/CSIC/University of Seville, 41013 Seville, Spain; (S.H.-E.); (J.I.R.-M.); (M.E.P.-I.)
| | | | - Juan Ignacio Rodríguez-Mogollo
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, Institute of Biomedicine of Seville (IBiS), Virgen del Rocio University Hospital/CSIC/University of Seville, 41013 Seville, Spain; (S.H.-E.); (J.I.R.-M.); (M.E.P.-I.)
| | - Jerónimo Pachón
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocio University Hospital/CSIC/University of Seville, 41013 Seville, Spain
- Department of Medicine, School of Medicine, University of Seville, 41004 Seville, Spain
| | - Elisa Cordero
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, Institute of Biomedicine of Seville (IBiS), Virgen del Rocio University Hospital/CSIC/University of Seville, 41013 Seville, Spain; (S.H.-E.); (J.I.R.-M.); (M.E.P.-I.)
- Department of Medicine, School of Medicine, University of Seville, 41004 Seville, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - María Eugenia Pachón-Ibáñez
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, Institute of Biomedicine of Seville (IBiS), Virgen del Rocio University Hospital/CSIC/University of Seville, 41013 Seville, Spain; (S.H.-E.); (J.I.R.-M.); (M.E.P.-I.)
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
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LeCuyer TE, Sellon RK, Byrne BA, Daniels JB, Diaz-Campos DV, Hendrix GK, Burbick CR, Besser TE, Davis MA. Multicenter molecular investigation of recurrent Escherichia coli bacteriuria in dogs. Vet Microbiol 2024; 288:109914. [PMID: 38113575 DOI: 10.1016/j.vetmic.2023.109914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 11/09/2023] [Accepted: 11/12/2023] [Indexed: 12/21/2023]
Abstract
Escherichia coli is the most common cause of recurrent urinary tract infection (UTI) in dogs. UTI recurrence comprises of persistent, unresolved E. coli infection or reinfection with a different strain of E. coli. Differentiating between these processes is clinically important but is often impossible with routine diagnostics. We tested the hypothesis that most recurrent canine E. coli bacteriuria is due to recurrence of the same E. coli strain involved in the initial infection. Molecular typing was performed on 98 urinary E. coli isolated from dogs with recurrent bacteriuria from five veterinary diagnostic laboratories in the United States. Of the 42 dogs in this study with multiple E. coli bacteriuria observations, a single strain of E. coli caused recurrent bacteriuria in 26 (62 %) dogs, in some cases on multiple occasions for prolonged periods of time (up to eight months). A single E. coli strain was detected during both subclinical bacteriuria and clinically-apparent UTI in three dogs. Isolates with the P-fimbrial adhesin genes papA and papC were associated with recurrence by the same strain of E. coli. Multiple isolations of a single strain of E. coli associated with recurrent bacteriuria suggests that E. coli may be maintained within the urinary tract of some dogs for prolonged periods of time. In some patients, the same strain can cause both clinical UTI and subclinical bacteriuria. This indicates that in dogs, the urinary bladder may serve as a subclinical, long-term reservoir of E. coli that may cause clinical UTI in the future.
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Affiliation(s)
- Tessa E LeCuyer
- Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA; Washington Animal Disease Diagnostic Laboratory, Washington State University, Pullman, WA, USA.
| | - Rance K Sellon
- Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Barbara A Byrne
- Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Joshua B Daniels
- Veterinary Clinical Sciences, College of Veterinary Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Dubraska V Diaz-Campos
- Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA; Washington Animal Disease Diagnostic Laboratory, Washington State University, Pullman, WA, USA
| | - G Kenitra Hendrix
- Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA; Indiana Animal Disease Diagnostic Laboratory, West Lafayette, IN, USA
| | - Claire R Burbick
- Veterinary Diagnostic Laboratory, North Dakota State University, Fargo, ND, USA
| | - Thomas E Besser
- Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Margaret A Davis
- Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA; Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
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Whelan S, Lucey B, Finn K. Uropathogenic Escherichia coli (UPEC)-Associated Urinary Tract Infections: The Molecular Basis for Challenges to Effective Treatment. Microorganisms 2023; 11:2169. [PMID: 37764013 PMCID: PMC10537683 DOI: 10.3390/microorganisms11092169] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
Urinary tract infections (UTIs) are among the most common bacterial infections, especially among women and older adults, leading to a significant global healthcare cost burden. Uropathogenic Escherichia coli (UPEC) are the most common cause and accounts for the majority of community-acquired UTIs. Infection by UPEC can cause discomfort, polyuria, and fever. More serious clinical consequences can result in urosepsis, kidney damage, and death. UPEC is a highly adaptive pathogen which presents significant treatment challenges rooted in a complex interplay of molecular factors that allow UPEC to evade host defences, persist within the urinary tract, and resist antibiotic therapy. This review discusses these factors, which include the key genes responsible for adhesion, toxin production, and iron acquisition. Additionally, it addresses antibiotic resistance mechanisms, including chromosomal gene mutations, antibiotic deactivating enzymes, drug efflux, and the role of mobile genetic elements in their dissemination. Furthermore, we provide a forward-looking analysis of emerging alternative therapies, such as phage therapy, nano-formulations, and interventions based on nanomaterials, as well as vaccines and strategies for immunomodulation. This review underscores the continued need for research into the molecular basis of pathogenesis and antimicrobial resistance in the treatment of UPEC, as well as the need for clinically guided treatment of UTIs, particularly in light of the rapid spread of multidrug resistance.
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Affiliation(s)
- Shane Whelan
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland;
| | - Brigid Lucey
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland;
| | - Karen Finn
- Department of Analytical, Biopharmaceutical and Medical Sciences, Atlantic Technological University Galway City, Dublin Road, H91 T8NW Galway, Ireland
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Govindarajan DK, Kandaswamy K. Virulence factors of uropathogens and their role in host pathogen interactions. Cell Surf 2022; 8:100075. [PMID: 35198842 PMCID: PMC8841375 DOI: 10.1016/j.tcsw.2022.100075] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/01/2022] [Accepted: 02/06/2022] [Indexed: 12/26/2022] Open
Abstract
Gram-positive and Gram-negative bacterial pathogens are commonly found in Urinary Tract Infection (UTI), particularly infected in females like pregnant women, elder people, sexually active, or individuals prone to other risk factors for UTI. In this article, we review the expression of virulence surface proteins and their interaction with host cells for the most frequently isolated uropathogens: Escherichia coli, Enterococcus faecalis, Proteus mirabilis, Klebsiella pneumoniae, and Staphylococcus saprophyticus. In addition to the host cell interaction, surface protein regulation was also discussed in this article. The surface protein regulation serves as a key tool in differentiating the pathogen isotypes. Furthermore, it might provide insights on novel diagnostic methods to detect uropathogen that are otherwise easily overlooked due to limited culture-based assays. In essence, this review shall provide an in-depth understanding on secretion of virulence factors of various uropathogens and their role in host-pathogen interaction, this knowledge might be useful in the development of therapeutics against uropathogens.
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Affiliation(s)
| | - Kumaravel Kandaswamy
- Corresponding author at: Department of Biotechnology, Kumaraguru College of Technology (KCT), Chinnavedampatti, Coimbatore 641049, Tamil Nadu, India.
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Abstract
Many antibiotic resistant uropathogenic Escherichia coli (UPEC) strains belong to clones defined by their multilocus sequence type (ST), with ST131 being the most dominant. Although we have a good understanding of resistance development to fluoroquinolones and third-generation cephalosporins by ST131, our understanding of the virulence repertoire that has contributed to its global dissemination is limited. Here we show that the genes encoding Afa/Dr fimbriae, a group of adhesins strongly associated with UPEC that cause gestational pyelonephritis and recurrent cystitis, are found in approximately one third of all ST131 strains. Sequence comparison of the AfaE adhesin protein revealed a unique allelic variant carried by 82.9% of afa-positive ST131 strains. We identify the afa regulatory region as a hotspot for the integration of insertion sequence (IS) elements, all but one of which alter afa transcription. Close investigation demonstrated that the integration of an IS1 element in the afa regulatory region leads to increased expression of Afa/Dr fimbriae, promoting enhanced adhesion to kidney epithelial cells and suggesting a mechanism for altered virulence. Finally, we provide evidence for a more widespread impact of IS1 on ST131 genome evolution, suggesting that IS dynamics contribute to strain level microevolution that impacts ST131 fitness. IMPORTANCE E. coli ST131 is the most common antibiotic resistant UPEC clone associated with human urinary tract and bloodstream infections. Understanding the features of ST131 that have driven its global dissemination remains a critical priority if we are to counter its increasing antibiotic resistance. Here, we utilized a large collection of ST131 isolates to investigate the prevalence, regulation, and function of Afa/Dr fimbriae, a well-characterized UPEC colonization and virulence factor. We show that the afa genes are found frequently in ST131 and demonstrate how the integration of IS elements in the afa regulatory region modulates Afa expression, presenting an example of altered virulence capacity. We also exploit a curated set of ST131 genomes to map the integration of the antibiotic resistance-associated IS1 element in the ST131 pangenome, providing evidence for its widespread impact on ST131 genome evolution.
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A Kadry A, M Al-Kashef N, M El-Ganiny A. Distribution of genes encoding adhesins and biofilm formation capacity among Uropathogenic Escherichia coli isolates in relation to the antimicrobial resistance. Afr Health Sci 2020; 20:238-247. [PMID: 33402912 PMCID: PMC7750046 DOI: 10.4314/ahs.v20i1.29] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background Escherichia coli is the most predominant pathogen involved in UTIs. Mainly, fimbrial surface appendages are implicated in adherence to urothelium besides non-fimbrial proteins. Objectives to determine prevalence of genes encoding fimbrial and non-fimbrial proteins among Uropathogenic Escherichia coli (UPEC). Furthermore, distribution of these genes and biofilm formation capacity were investigated in relation to antimicrobial resistance. Methods Antimicrobial susceptibility of 112 UPEC isolates was performed using disc diffusion method. ESBL production was confirmed by double disc synergy test. Genes encoding fimbrial and non-fimbrial proteins were detected using PCR and biofilm formation was investigated using microtitre plate assay. Results UPEC isolates exhibited high resistance against doxycyclines (88.39 %), β-lactams (7.14–86.6%), sulphamethoxazole-trimethoprim (53.75%) and fluoro-quinolones (50%). Fifty percent of tested isolates were ESBL producers. PapGII gene was statistically more prevalent among pyelonephritis isolates. SfaS, focG and picU genes were statistically associated with fluoroquinolone (FQs) sensitive isolates and Dr/afaBC gene was statistically associated with ESBL production. Moreover, non-MDR isolates produced sturdier biofilm. Conclusion PapGII adhesin variant seems to have a critical role in colonization of upper urinary tract. There is a possible link between antimicrobial resistance and virulence being capable of affecting the distribution of some genes besides its negative impact on biofilm formation.
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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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Werneburg GT, Thanassi DG. Pili Assembled by the Chaperone/Usher Pathway in Escherichia coli and Salmonella. EcoSal Plus 2018; 8:10.1128/ecosalplus.ESP-0007-2017. [PMID: 29536829 PMCID: PMC5940347 DOI: 10.1128/ecosalplus.esp-0007-2017] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Indexed: 12/12/2022]
Abstract
Gram-negative bacteria assemble a variety of surface structures, including the hair-like organelles known as pili or fimbriae. Pili typically function in adhesion and mediate interactions with various surfaces, with other bacteria, and with other types of cells such as host cells. The chaperone/usher (CU) pathway assembles a widespread class of adhesive and virulence-associated pili. Pilus biogenesis by the CU pathway requires a dedicated periplasmic chaperone and integral outer membrane protein termed the usher, which forms a multifunctional assembly and secretion platform. This review addresses the molecular and biochemical aspects of the CU pathway in detail, focusing on the type 1 and P pili expressed by uropathogenic Escherichia coli as model systems. We provide an overview of representative CU pili expressed by E. coli and Salmonella, and conclude with a discussion of potential approaches to develop antivirulence therapeutics that interfere with pilus assembly or function.
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Affiliation(s)
- Glenn T. Werneburg
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
- Center for Infectious Diseases, Stony Brook University, Stony Brook, NY, USA
| | - David G. Thanassi
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
- Center for Infectious Diseases, Stony Brook University, Stony Brook, NY, USA
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9
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Tong YQ, Sun M, Chi Y. Prophylactic herbal therapy prevents experimental ascending urinary tract infection in mice. Chin J Integr Med 2016; 22:774-7. [DOI: 10.1007/s11655-016-2601-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Indexed: 10/21/2022]
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10
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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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Strengths and Limitations of Model Systems for the Study of Urinary Tract Infections and Related Pathologies. Microbiol Mol Biol Rev 2016; 80:351-67. [PMID: 26935136 DOI: 10.1128/mmbr.00067-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Urinary tract infections (UTIs) are some of the most common bacterial infections worldwide and are a source of substantial morbidity among otherwise healthy women. UTIs can be caused by a variety of microbes, but the predominant etiologic agent of these infections is uropathogenic Escherichia coli (UPEC). An especially troubling feature of UPEC-associated UTIs is their high rate of recurrence. This problem is compounded by the drastic increase in the global incidence of antibiotic-resistant UPEC strains over the past 15 years. The need for more-effective treatments for UTIs is driving research aimed at bettering our understanding of the virulence mechanisms and host-pathogen interactions that occur during the course of these infections. Surrogate models of human infection, including cell culture systems and the use of murine, porcine, avian, teleost (zebrafish), and nematode hosts, are being employed to define host and bacterial factors that modulate the pathogenesis of UTIs. These model systems are revealing how UPEC strains can avoid or overcome host defenses and acquire scarce nutrients while also providing insight into the virulence mechanisms used by UPEC within compromised individuals, such as catheterized patients. Here, we summarize our current understanding of UTI pathogenesis while also giving an overview of the model systems used to study the initiation, persistence, and recurrence of UTIs and life-threatening sequelae like urosepsis. Although we focus on UPEC, the experimental systems described here can also provide valuable insight into the disease processes associated with other bacterial pathogens both within the urinary tract and elsewhere within the host.
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12
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Gupta P, Song B, Neto C, Camesano TA. Atomic force microscopy-guided fractionation reveals the influence of cranberry phytochemicals on adhesion of Escherichia coli. Food Funct 2016; 7:2655-66. [DOI: 10.1039/c6fo00109b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Characterization of cranberry juice fractions for their role in anti-adhesive properties against pathogenicE. coliusing Atomic Force Microscopy (AFM).
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Affiliation(s)
- Prachi Gupta
- Department of Chemical Engineering
- Worcester Polytechnic Institute
- Worcester
- USA
| | - Biqin Song
- Department of Chemistry and Biochemistry
- University of Massachusetts-Dartmouth
- North Dartmouth
- USA
| | - Catherine Neto
- Department of Chemistry and Biochemistry
- University of Massachusetts-Dartmouth
- North Dartmouth
- USA
| | - Terri A. Camesano
- Department of Chemical Engineering
- Worcester Polytechnic Institute
- Worcester
- USA
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Chahales P, Thanassi DG. Structure, Function, and Assembly of Adhesive Organelles by Uropathogenic Bacteria. Microbiol Spectr 2015; 3:10.1128/microbiolspec.UTI-0018-2013. [PMID: 26542038 PMCID: PMC4638162 DOI: 10.1128/microbiolspec.uti-0018-2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Indexed: 01/02/2023] Open
Abstract
Bacteria assemble a wide range of adhesive proteins, termed adhesins, to mediate binding to receptors and colonization of surfaces. For pathogenic bacteria, adhesins are critical for early stages of infection, allowing the bacteria to initiate contact with host cells, colonize different tissues, and establish a foothold within the host. The adhesins expressed by a pathogen are also critical for bacterial-bacterial interactions and the formation of bacterial communities, including biofilms. The ability to adhere to host tissues is particularly important for bacteria that colonize sites such as the urinary tract, where the flow of urine functions to maintain sterility by washing away non-adherent pathogens. Adhesins vary from monomeric proteins that are directly anchored to the bacterial surface to polymeric, hair-like fibers that extend out from the cell surface. These latter fibers are termed pili or fimbriae, and were among the first identified virulence factors of uropathogenic Escherichia coli. Studies since then have identified a range of both pilus and non-pilus adhesins that contribute to bacterial colonization of the urinary tract, and have revealed molecular details of the structures, assembly pathways, and functions of these adhesive organelles. In this review, we describe the different types of adhesins expressed by both Gram-negative and Gram-positive uropathogens, what is known about their structures, how they are assembled on the bacterial surface, and the functions of specific adhesins in the pathogenesis of urinary tract infections.
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Affiliation(s)
- Peter Chahales
- Center for Infectious Diseases and Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794
| | - David G Thanassi
- Center for Infectious Diseases and Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794
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14
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Abstract
Blood group antigens represent polymorphic traits inherited among individuals and populations. At present, there are 34 recognized human blood groups and hundreds of individual blood group antigens and alleles. Differences in blood group antigen expression can increase or decrease host susceptibility to many infections. Blood groups can play a direct role in infection by serving as receptors and/or coreceptors for microorganisms, parasites, and viruses. In addition, many blood group antigens facilitate intracellular uptake, signal transduction, or adhesion through the organization of membrane microdomains. Several blood groups can modify the innate immune response to infection. Several distinct phenotypes associated with increased host resistance to malaria are overrepresented in populations living in areas where malaria is endemic, as a result of evolutionary pressures. Microorganisms can also stimulate antibodies against blood group antigens, including ABO, T, and Kell. Finally, there is a symbiotic relationship between blood group expression and maturation of the gastrointestinal microbiome.
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Affiliation(s)
- Laura Cooling
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
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Pathogenesis of human diffusely adhering Escherichia coli expressing Afa/Dr adhesins (Afa/Dr DAEC): current insights and future challenges. Clin Microbiol Rev 2015; 27:823-69. [PMID: 25278576 DOI: 10.1128/cmr.00036-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The pathogenicity and clinical pertinence of diffusely adhering Escherichia coli expressing the Afa/Dr adhesins (Afa/Dr DAEC) in urinary tract infections (UTIs) and pregnancy complications are well established. In contrast, the implication of intestinal Afa/Dr DAEC in diarrhea is still under debate. These strains are age dependently involved in diarrhea in children, are apparently not involved in diarrhea in adults, and can also be asymptomatic intestinal microbiota strains in children and adult. This comprehensive review analyzes the epidemiology and diagnosis and highlights recent progress which has improved the understanding of Afa/Dr DAEC pathogenesis. Here, I summarize the roles of Afa/Dr DAEC virulence factors, including Afa/Dr adhesins, flagella, Sat toxin, and pks island products, in the development of specific mechanisms of pathogenicity. In intestinal epithelial polarized cells, the Afa/Dr adhesins trigger cell membrane receptor clustering and activation of the linked cell signaling pathways, promote structural and functional cell lesions and injuries in intestinal barrier, induce proinflammatory responses, create angiogenesis, instigate epithelial-mesenchymal transition-like events, and lead to pks-dependent DNA damage. UTI-associated Afa/Dr DAEC strains, following adhesin-membrane receptor cell interactions and activation of associated lipid raft-dependent cell signaling pathways, internalize in a microtubule-dependent manner within urinary tract epithelial cells, develop a particular intracellular lifestyle, and trigger a toxin-dependent cell detachment. In response to Afa/Dr DAEC infection, the host epithelial cells generate antibacterial defense responses. Finally, I discuss a hypothetical role of intestinal Afa/Dr DAEC strains that can act as "silent pathogens" with the capacity to emerge as "pathobionts" for the development of inflammatory bowel disease and intestinal carcinogenesis.
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16
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Sanchez-Villamil J, Navarro-Garcia F. Role of virulence factors on host inflammatory response induced by diarrheagenic Escherichia coli pathotypes. Future Microbiol 2015; 10:1009-33. [DOI: 10.2217/fmb.15.17] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
ABSTRACT Pathogens are able to breach the intestinal barrier, and different bacterial species can display different abilities to colonize hosts and induce inflammation. Inflammatory response studies induced by enteropathogens as Escherichia coli are interesting since it has acquired diverse genetic mobile elements, leading to different E. coli pathotypes. Diarrheagenic E. coli secrete toxins, effectors and virulence factors that exploit the host cell functions to facilitate the bacterial colonization. Many bacterial proteins are delivered to the host cell for subverting the inflammatory response. Hereby, we have highlighted the specific processes used by E. coli pathotypes, by that subvert the inflammatory pathways. These mechanisms include an arrangement of pro- and anti-inflammatory responses to favor the appropriate environmental niche for the bacterial survival and growth.
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Affiliation(s)
- Javier Sanchez-Villamil
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Ap. Postal 14–740, 07000, México DF, Mexico
| | - Fernando Navarro-Garcia
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Ap. Postal 14–740, 07000, México DF, Mexico
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17
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Zalewska-Pia Tek B, Pia Tek R, Olszewski M, Kur J. Identification of antigen Ag43 in uropathogenic Escherichia coli Dr+ strains and defining its role in the pathogenesis of urinary tract infections. MICROBIOLOGY-SGM 2015; 161:1034-1049. [PMID: 25743156 DOI: 10.1099/mic.0.000072] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/03/2015] [Indexed: 11/18/2022]
Abstract
Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) are amongst the most common bacterial infectious diseases in the developed world. The urovirulence of UPEC is mainly associated with the surface-exposed fimbrial adhesins and adhesins of the autotransporter (AT) family. The best studied of these proteins is antigen Ag43 mediating cell aggregation, adhesion and biofilm development as the causes of chronic UTIs. The E. coli IH11128 Dr(+) (dra (+)) strain of the Dr/Afa(+) family of adhesins possesses two major surface-exposed virulence factors: Dr fimbrial polyadhesin and DraD protein (fimbrial tip subunit or protein component of the adhesive sheath). Here, we identified for the first time, to our knowledge, the agn43 gene encoding Ag43 in the WT clinical isolate of UPEC Dr(+) as a new virulence factor not yet tested. We also found that Dr fimbrial expression, which like Ag43 is under the control of a phase-variable mechanism, did not exclude Ag43 surface presentation. However, the presence of Dr fimbriae supported by other structures on the cell surface caused a physical neutralization of Ag43-mediated autoaggregation during in vitro growth. The fimbrial bundling further increased the distance between the adjacent Ag43(+) cells, thus preventing head-to-tail association between surface-exposed Ag43 subunits and their interactions with the host cells. The investigations showed that Ag43 did not act as a specific adhesin and invasin, conversely to the major virulence factors of E. coli Dr(+), but played significant roles in the viability and metabolic activity of bacterial cells forming biofilm, and in the survival of bacteria within invaded epithelial cells.
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Affiliation(s)
- Beata Zalewska-Pia Tek
- Department of Molecular Biotechnology and Microbiology, Gdansk University of Technology, ul. G. Narutowicza 11/12, 80-233Gdansk, Poland
| | - Rafał Pia Tek
- Department of Molecular Biotechnology and Microbiology, Gdansk University of Technology, ul. G. Narutowicza 11/12, 80-233Gdansk, Poland
| | - Marcin Olszewski
- Department of Molecular Biotechnology and Microbiology, Gdansk University of Technology, ul. G. Narutowicza 11/12, 80-233Gdansk, Poland
| | - Józef Kur
- Department of Molecular Biotechnology and Microbiology, Gdansk University of Technology, ul. G. Narutowicza 11/12, 80-233Gdansk, Poland
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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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Banadakoppa M, Goluszko P, Liebenthal D, Nowicki BJ, Nowicki S, Yallampalli C. PI3K/Akt pathway restricts epithelial adhesion of Dr + Escherichia coli by down-regulating the expression of decay accelerating factor. Exp Biol Med (Maywood) 2014; 239:581-94. [PMID: 24599886 DOI: 10.1177/1535370214522183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The urogenital microbial infection in pregnancy is an important cause of maternal and neonatal morbidity and mortality. Uropathogenic Escherichia coli strains which express Dr fimbriae (Dr+) are associated with unique gestational virulence and they utilize cell surface decay accelerating factor (DAF or CD55) as one of the cellular receptor before invading the epithelial cells. Previous studies in our laboratory established that nitric oxide reduces the rate of E. coli invasion by delocalizing the DAF protein from cell surface lipid rafts and down-regulating its expression. The phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) cell signal pathway plays an important role in host-microbe interaction because many bacteria including E. coli activate this pathway in order to establish infection. In the present study, we showed that the PI3K/Akt pathway negatively regulated the expression of DAF on the epithelial cell surface and thus inhibited the adhesion of Dr(+) E. coli to epithelial cells. Initially, using two human cell lines Ishikawa and HeLa which differ in constitutive activity of PI3K/Akt, we showed that DAF levels were associated with the PI3K/Akt pathway. We then showed that the DAF gene expression was up-regulated and the Dr(+) E. coli adhesion increased after the suppression of PI3K/Akt pathway in Ishikawa cells using inhibitor LY294002, and a plasmid which allowed the expression of PI3K/Akt regulatory protein PTEN. The down-regulation of PTEN protein using PTEN-specific siRNA activated the PI3K/Akt pathway, down-regulated the DAF, and decreased the adhesion of Dr(+) E. coli. We conclude that the PI3K/Akt pathway regulated the DAF expression in a nitric oxide independent manner.
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Affiliation(s)
- Manu Banadakoppa
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas 77030, USA
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Arikawa K, Meraz IM, Nishikawa Y, Ogasawara J, Hase A. Interleukin-8 Secretion by Epithelial Cells Infected with Diffusely AdherentEscherichia coliPossessing Afa Adhesin-Coding Genes. Microbiol Immunol 2013; 49:493-503. [PMID: 15965296 DOI: 10.1111/j.1348-0421.2005.tb03754.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Escherichia coli that adhere sparsely to human epithelial (HEp-2) cells are known as diffusely adherent E. coli(DAEC) and considered potentially diarrheagenic. The role of the afimbrial adhesive sheath (Afa)-identified originally as a uropathogenic factor-in diffuse adhesion is now understood. However, the role of DAEC in diarrheal disease remains controversial. Recently, ability to induce interleukin-8 (IL-8) secretion from intestinal epithelial cells has been suggested as one of the properties of enterovirulent bacteria. In this study, we examined whether DAEC strains possessing Afa genes induced IL-8 in cultures of human carcinoma epithelial cells (e.g., HEp-2, Caco-2, and T84). Nineteen afa-positive DAEC strains were examined for their ability to induce IL-8 secretion, and only 7 strains (37%; 7/19) induced IL-8 as much as enteroaggregative E. coli did. No marked differences in adhesion were observed between high and low inducers. Diffusive adhesiveness itself is unlikely to be sufficient to induce IL-8. All high inducers were motile and others were nonmotile. Additional stimulation by flagella may be required to cause high levels of chemokine induction. Motility or presence of flagella can be an important criterion to predict DAEC diarrheagenicity at clinical laboratories.
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Affiliation(s)
- Kentaro Arikawa
- Department of Food and Human Health Sciences, Graduate School of Human Life Science, Osaka City University, Japan
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Biochemical characteristic of biofilm of uropathogenic Escherichia coli Dr + strains. Microbiol Res 2013; 168:367-378. [DOI: 10.1016/j.micres.2013.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 12/21/2012] [Accepted: 01/02/2013] [Indexed: 11/18/2022]
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Chandra M, Cheng P, Rondeau G, Porwollik S, McClelland M. A single step multiplex PCR for identification of six diarrheagenic E. coli pathotypes and Salmonella. Int J Med Microbiol 2013; 303:210-6. [PMID: 23562277 DOI: 10.1016/j.ijmm.2013.02.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 02/01/2013] [Accepted: 02/03/2013] [Indexed: 11/19/2022] Open
Abstract
E. coli is generally a commensal but includes some highly pathogenic strains carrying additional genes in plasmids and/or the chromosome. Based on these genes the pathogenic strains are divided into pathotypes including enteropathogenic (EPEC), enterohemorrhagic (EHEC), enterotoxigenic (ETEC), enteroaggregative (EAEC), enteroinvasive (EIEC) and diffusely adherent (DAEC) E. coli. Here, previously developed multiplex PCR strategies for these strains were integrated into one single step multiplex that differentiates all these E. coli pathotypes, usually based on multiple characteristic PCR products. This multiplex PCR works reliably for colony PCR. Two additional markers were added: one to detect most Enterobacteriacea, which acts as a positive control for successful PCR, and one to distinguish Salmonella. The multiplex correctly classified a set of 45 reference strains by colony PCR and 71 (45+26) strains by in silico PCR. It was then used to interrogate 44 clinical strains from bovine hosts resulting in detection of EAEC and DAEC determinants.
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Affiliation(s)
- Mudit Chandra
- Department of Veterinary Microbiology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, India
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Role of Uropathogenic Escherichia coli Virulence Factors in Development of Urinary Tract Infection and Kidney Damage. Int J Nephrol 2012; 2012:681473. [PMID: 22506110 PMCID: PMC3312279 DOI: 10.1155/2012/681473] [Citation(s) in RCA: 203] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 11/02/2011] [Accepted: 12/01/2011] [Indexed: 01/17/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) is a causative agent in the vast majority of urinary tract infections (UTIs), including cystitis and pyelonephritis, and infectious complications, which may result in acute renal failure in healthy individuals as well as in renal transplant patients. UPEC expresses a multitude of virulence factors to break the inertia of the mucosal barrier. In response to the breach by UPEC into the normally sterile urinary tract, host inflammatory responses are triggered leading to cytokine production, neutrophil influx, and the exfoliation of infected bladder epithelial cells. Several signaling pathways activated during UPEC infection, including the pathways known to activate the innate immune response, interact with calcium-dependent signaling pathways. Some UPEC isolates, however, might possess strategies to delay or suppress the activation of components of the innate host response in the urinary tract. Studies published in the recent past provide new information regarding how virulence factors of uropathogenic E. coli are involved in activation of the innate host response. Despite numerous host defense mechanisms, UPEC can persist within the urinary tract and may serve as a reservoir for recurrent infections and serious complications. Presentation of the molecular details of these events is essential for development of successful strategies for prevention of human UTIs and urological complications associated with UTIs.
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Wroblewska-Seniuk K, Nowicki S, Lebouguénec C, Nowicki B, Yallampalli C. Maternal/fetal mortality and fetal growth restriction: role of nitric oxide and virulence factors in intrauterine infection in rats. Am J Obstet Gynecol 2011; 205:83.e1-7. [PMID: 21481839 PMCID: PMC3143246 DOI: 10.1016/j.ajog.2011.02.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 01/26/2011] [Accepted: 02/14/2011] [Indexed: 10/18/2022]
Abstract
OBJECTIVE The mechanism of infection-related deaths of pregnant rats and intrauterine growth restriction are not understood. We assessed whether nitric oxide (NO) has differential effects on infection with Escherichia coli Dr/Afa mutants that lack either AfaE or AfaD invasins. STUDY DESIGN Sprague-Dawley rats were infected intrauterinally with the clinical strain of E coli AfaE(+)D(+) or 1 of its isogenic mutants in the presence or absence of the NO synthesis inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). Maternal/fetal mortality rates, fetoplacental weight, and infection rates were evaluated. RESULTS Maternal and/or fetal death was associated with the presence of at least 1 virulence factor (AfaE(+)D(+)>AfaE(+)D(-)>AfaE(-)D(+)) and was increased by L-NAME treatment. The fetal and placental weights were lower than controls and were further reduced by L-NAME treatment. CONCLUSION These results demonstrate that NO enhanced AfaE- and AfaD-mediated virulence and plays an important role in Dr/Afa(+)E coli gestational tropism.
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Affiliation(s)
- Katarzyna Wroblewska-Seniuk
- Department of neonatal Infectious Diseases, Chair of Neonatology, Poznan University of Medical Sciences, Poznan, Poland
| | - Stella Nowicki
- Departments of Obstetrics & Gynecology and Microbiology & Immunology Meharry Medical College, Nashville, Tennessee, USA
| | - Chantal Lebouguénec
- Institut Pasteur, Unité Pathogénie Bactérienne des Muqueuses, Département de Microbiologie, F-75015 Paris, France
- Institut Pasteur, Unité Biologie des Bactéries Pathogènes à Gram Positif, Département de Microbiologie, F-75015 Paris, France
- CNRS, URA2172, F-75015 Paris, France
| | - Bogdan Nowicki
- Departments of Obstetrics & Gynecology and Microbiology & Immunology Meharry Medical College, Nashville, Tennessee, USA
| | - Chandra Yallampalli
- Department of Obstetrics & Gynecology, The University of Texas Medical Branch at Galveston, Galveston, Texas, USA
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Smith A, van Rooyen JP, Argo E, Cash P. Proteomic analysis of Escherichia coli associated with urinary tract infections. Proteomics 2011; 11:2283-93. [DOI: 10.1002/pmic.201000626] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 02/27/2011] [Accepted: 03/07/2011] [Indexed: 11/09/2022]
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The DraC usher in Dr fimbriae biogenesis of uropathogenic E. coli Dr+ strains. Arch Microbiol 2010; 192:351-63. [DOI: 10.1007/s00203-010-0564-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 02/12/2010] [Accepted: 03/10/2010] [Indexed: 10/19/2022]
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Chew BH, Lange D. Ureteral stent symptoms and associated infections: a biomaterials perspective. Nat Rev Urol 2009; 6:440-8. [PMID: 19597512 DOI: 10.1038/nrurol.2009.124] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ureteral stents are commonly used in the field of urology, and, given their indwelling nature, are often a nidus for infection and a cause of discomfort. To minimize symptoms, the urologic surgeon should first consider whether a stent needs to be placed at all. Softer stents do not seem to improve patient comfort. Stents that are too long, specifically those that cross the midline of the bladder, significantly increase the frequency of stent-related symptoms. Administering alpha blockers while the stent is indwelling can reduce these symptoms. Antibiotic prophylaxis or concomitant antibiotic administration does not seem to reduce the incidence of stent-related urinary tract infection. At present, drug-eluting stents have shown the most promise for inhibiting bacterial adhesion and biofilm formation. Future stent designs that maintain drainage of the kidney and ureter while minimizing inflammation and contact with the urothelium will improve patient outcomes. By better understanding the basic pathways of bacterial adhesion to biomaterials, new stents and medications that target these mechanisms can be developed to eliminate bacterial adhesion and infection in patients with ureteral stents.
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Affiliation(s)
- Ben H Chew
- Department of Urologic Sciences, University of British Columbia, Vancouver, Canada.
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Nowicki S, Izban MG, Pawelczyk E, Agboto VK, Pratap S, Olson G, Nowicki B. Preterm labor: CD55 in maternal blood leukocytes. Am J Reprod Immunol 2009; 61:360-7. [PMID: 19341386 DOI: 10.1111/j.1600-0897.2009.00702.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
PROBLEM Intrauterine inflammation is a frequent and significant factor associated with the pathogenesis of preterm labor/birth (PTL/PTB). However, it remains unclear whether the intrauterine inflammatory responses activate the maternal peripheral circulation. We explored the association between PTL/PTB and the 'activation' of the peripheral circulatory system by determining whether CD55 mRNA expression within peripheral WBCs differed between PTL and control patients not in labor. METHOD OF STUDY RNA was purified from white blood cells collected from pregnant women with preterm labor (n = 45), and from pregnant (n = 30) control women. CD55 gene expression was evaluated by quantitative PCR. RESULTS The mean CD55 mRNA level within the PTL group (0.77 +/- 0.03) was 1.48-fold higher than that observed (0.52 +/- 0.02) within the control group (P < 0.0001); 71% of PTL patients and only 6.7% of control subjects expressed elevated CD55 mRNA. The receiver operating characteristics (with 95% CI) of CD55 as a marker for PTL were as follows: Sensitivity, 69% (53-82%); Specificity, 93% (78-99%); Positive Predictive Value, 94% (80-99%); and Negative Predictive Value, 67% (51-80%). In the patient population that delivered prematurely (before 37 weeks), 81% expressed elevated CD55 mRNA levels with a mean of 0.78 +/- 0.03 and 95% CI of 0.71-0.84. The receiver operating characteristics were as follows: Sensitivity, 73% (54-88%); Specificity, 86% (71-95%); Positive Predictive Value, 81.5% (62-94%); and Negative Predictive Value, 80% (64-91%). CONCLUSION Here we report for the first time that CD55 mRNA expression was elevated in the peripheral WBCs of subjects with preterm labor compared with control gestationally-matched pregnant woman and that elevated leukocyte CD55 may be a useful predictor of subsequent PTB.
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Affiliation(s)
- Stella Nowicki
- Departments of Obstrics and Gynocology, and Microbial Pathogenesis and Immune Response, Meharry Medical College, 1005 Dr. D.B. Todd, Jr. Blvd., Nashville, TN 37208, USA.
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Pettigrew DM, Roversi P, Davies SG, Russell AJ, Lea SM. A structural study of the interaction between the Dr haemagglutinin DraE and derivatives of chloramphenicol. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2009; 65:513-22. [PMID: 19465765 PMCID: PMC2685729 DOI: 10.1107/s0907444909005113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Accepted: 02/12/2009] [Indexed: 12/02/2022]
Abstract
Dr adhesins are expressed on the surface of uropathogenic and diffusely adherent strains of Escherichia coli. The major adhesin subunit (DraE/AfaE) of these organelles mediates attachment of the bacterium to the surface of the host cell and possibly intracellular invasion through its recognition of the complement regulator decay-accelerating factor (DAF) and/or members of the carcinoembryonic antigen (CEA) family. The adhesin subunit of the Dr haemagglutinin, a Dr-family member, additionally binds type IV collagen and is inhibited in all its receptor interactions by the antibiotic chloramphenicol (CLM). In this study, previous structural work is built upon by reporting the X-ray structures of DraE bound to two chloramphenicol derivatives: chloramphenicol succinate (CLS) and bromamphenicol (BRM). The CLS structure demonstrates that acylation of the 3-hydroxyl group of CLM with succinyl does not significantly perturb the mode of binding, while the BRM structure implies that the binding pocket is able to accommodate bulkier substituents on the N-acyl group. It is concluded that modifications of the 3-hydroxyl group would generate a potent Dr haemagglutinin inhibitor that would not cause the toxic side effects that are associated with the normal bacteriostatic activity of CLM.
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Affiliation(s)
- David M. Pettigrew
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
| | - Pietro Roversi
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
| | - Stephen G. Davies
- Department of Chemistry, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, England
| | - Angela J. Russell
- Department of Chemistry, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, England
| | - Susan M. Lea
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
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Urothelial cultures support intracellular bacterial community formation by uropathogenic Escherichia coli. Infect Immun 2009; 77:2762-72. [PMID: 19451249 DOI: 10.1128/iai.00323-09] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) causes most community-acquired and nosocomial urinary tract infections (UTI). In a mouse model of UTI, UPEC invades superficial bladder cells and proliferates rapidly, forming biofilm-like structures called intracellular bacterial communities (IBCs). Using a gentamicin protection assay and fluorescence microscopy, we developed an in vitro model for studying UPEC proliferation within immortalized human urothelial cells. By pharmacologic manipulation of urothelial cells with the cholesterol-sequestering drug filipin, numbers of intracellular UPEC CFU increased 8 h and 24 h postinfection relative to untreated cultures. Enhanced UPEC intracellular proliferation required that the urothelial cells, but not the bacteria, be filipin treated prior to infection. However, neither UPEC frequency of invasion nor early intracellular trafficking events to a Lamp1-positive compartment were modulated by filipin. Upon inspection by fluorescence microscopy, cultures with enhanced UPEC intracellular proliferation exhibited large, dense bacterial aggregates within cells that resembled IBCs but were contained with Lamp1-positive vacuoles. While an isogenic fimH mutant was capable of forming these IBC-like structures, the mutant formed significantly fewer than wild-type UPEC. Similar to IBCs, expression of E. coli iron acquisition systems was upregulated by intracellular UPEC. Expression of other putative virulence factors, including hlyA, cnf1, fliC, kpsD, and the biofilm adhesin yfaL also increased, while expression of fimA decreased and that of flu did not change. These results indicate that UPEC differentially regulates virulence factors in the intracellular environment. Thus, immortalized urothelial cultures that recapitulate IBC formation in vitro represent a novel system for the molecular and biochemical characterization of the UPEC intracellular life cycle.
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Dhakal BK, Kulesus RR, Mulvey MA. Mechanisms and consequences of bladder cell invasion by uropathogenic Escherichia coli. Eur J Clin Invest 2008; 38 Suppl 2:2-11. [PMID: 18616559 DOI: 10.1111/j.1365-2362.2008.01986.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Strains of uropathogenic Escherichia coli (UPEC) are the major cause of urinary tract infections worldwide. Multiple studies over the past decade have called into question the dogmatic view that UPEC strains act as strictly extracellular pathogens. Rather, bacterial expression of filamentous adhesive organelles known as type 1 pili and Afa/Dr fibrils enable UPEC to invade host epithelial cells within the urinary tract. Entry into bladder epithelial cells provides UPEC with a protected niche where the bacteria can persist quiescently for long periods, unperturbed by host defences and protected from many antibiotic treatments. Alternately, internalized UPEC can rapidly multiply, forming large intracellular inclusions that can contain several thousand bacteria. Initial work aimed at defining the host and bacterial factors that modulate the entry, intracellular trafficking, and eventual resurgence of UPEC suggests a high degree of host-pathogen crosstalk. Targeted disruption of these processes may provide a novel means to prevent and treat recurrent, relapsing and chronic infections within the urinary tract.
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Affiliation(s)
- B K Dhakal
- Division of Cell Biology and Immunology, Pathology Department, University of Utah, Salt Lake City, Utah 84112-0565, USA
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Complicated catheter-associated urinary tract infections due to Escherichia coli and Proteus mirabilis. Clin Microbiol Rev 2008; 21:26-59. [PMID: 18202436 DOI: 10.1128/cmr.00019-07] [Citation(s) in RCA: 477] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Catheter-associated urinary tract infections (CAUTIs) represent the most common type of nosocomial infection and are a major health concern due to the complications and frequent recurrence. These infections are often caused by Escherichia coli and Proteus mirabilis. Gram-negative bacterial species that cause CAUTIs express a number of virulence factors associated with adhesion, motility, biofilm formation, immunoavoidance, and nutrient acquisition as well as factors that cause damage to the host. These infections can be reduced by limiting catheter usage and ensuring that health care professionals correctly use closed-system Foley catheters. A number of novel approaches such as condom and suprapubic catheters, intermittent catheterization, new surfaces, catheters with antimicrobial agents, and probiotics have thus far met with limited success. While the diagnosis of symptomatic versus asymptomatic CAUTIs may be a contentious issue, it is generally agreed that once a catheterized patient is believed to have a symptomatic urinary tract infection, the catheter is removed if possible due to the high rate of relapse. Research focusing on the pathogenesis of CAUTIs will lead to a better understanding of the disease process and will subsequently lead to the development of new diagnosis, prevention, and treatment options.
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Kur M, Piatek R, Kur J. A two-plasmid Escherichia coli system for expression of Dr adhesins. Protein Expr Purif 2007; 55:361-7. [PMID: 17543539 DOI: 10.1016/j.pep.2007.04.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 04/12/2007] [Accepted: 04/17/2007] [Indexed: 11/24/2022]
Abstract
This paper presents a very efficient expression system for production of Dr adhesins. The system consists of two plasmids. One is the pACYCpBAD-DraC-C-His, which contains the draC gene under the control of the arabinose promoter (pBAD), encoding the DraC usher. The second is the pET30b-syg-DraBE, which contains the draB and draE genes under the control of the T7lac promoter, encoding the DraB chaperone and the DraE adhesin, respectively. Those plasmids have different origin of replication and can therefore coexist in one cell. Since different promoters are present, the protein expression can be controlled. The Dr adhesion expression system constructed opens up a lot of possibilities, and could be very useful in experiments focusing on understanding the biogenesis of Gram-negative bacteria adhesins. For this purpose we showed that the AfaE-III adhesin (98.1% identity between the DraE and the AfaE-III adhesins, with three divergent amino acids within the sequences) was able to pass through the DraC channel in the Escherichia coli BL21(DE3) strain. Immunoblotting analysis and immunofluorescence microscopy showed the presence of AfaE-III on the bacterial cell surface. In addition, the system described can be useful for displaying the immune-relevant sectors of foreign proteins on the bacterial cell. The heterologous epitope sequence of the HSV1 glycoprotein D was inserted into the draE gene in place of the N-terminal region of surface exposed domain 2. Chimeric proteins were exposed on the bacterial surface as evidenced by immunoblotting and immunofluorescence microscopy. The effective display of peptide segments on Dr fimbriae expressed at the bacterial cell surface, can be used for the development of a fimbrial vaccine.
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Affiliation(s)
- Marta Kur
- Gdańsk University of Technology, Chemical Faculty, Department of Microbiology, Narutowicza 11/12, 80-952 Gdańsk, Poland
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34
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Rice JC, Peng T, Kuo YF, Pendyala S, Simmons L, Boughton J, Ishihara K, Nowicki S, Nowicki BJ. Renal allograft injury is associated with urinary tract infection caused by Escherichia coli bearing adherence factors. Am J Transplant 2006; 6:2375-83. [PMID: 16869795 DOI: 10.1111/j.1600-6143.2006.01471.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Urinary tract infections are the most common infection in renal transplant patients and Escherichia coli (E. coli) is the most common clinical isolate. Although acute allograft injury (AAI) secondary to urinary tract infection (UTI) has been reported, the incidence of AAI associated with UTI, the virulence factors express by uropathic E. coli and whether virulence factors are associated with renal allograft outcome have not been described. We collected E. coli from our renal transplant patients with UTI, determined O:H serotypes, P and Dr fimbriae expression and the clinical presentation and allograft function during the UTI and post-UTI period. Pyelonephritis occurred in 40% of our patients, 82% of which had AAI (>20% increase in SCr). Sixty-two percent of E. coli isolates that expressed P fimbriae were associated with AAI, whereas only 29% that did not express P fimbriae had AAI (p = 0.03). The pattern of P fimbriae and O serotypes differed from reported isolates, as the P fimbriae PapG class II and the O25 serotype were the most common. Dr adhesin was expressed on 7 isolates, including 2 of 3 with urosepsis. We propose a unique pattern of uropathogenic serotypes and adherence factors contribute to acute allograft injury in renal transplant patients with UTI.
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Affiliation(s)
- J C Rice
- Department of Internal Medicine, The University of Texas Medical Branch at Galveston, Texas, USA.
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35
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Li K, Feito MJ, Sacks SH, Sheerin NS. CD46 (Membrane Cofactor Protein) Acts as a Human Epithelial Cell Receptor for Internalization of Opsonized UropathogenicEscherichia coli. THE JOURNAL OF IMMUNOLOGY 2006; 177:2543-51. [PMID: 16888016 DOI: 10.4049/jimmunol.177.4.2543] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Escherichia coli is a common urinary pathogen whose uptake into epithelial cells is mediated by attachment through type 1 fimbriae. In this study, we show by using using human urinary tract epithelial cells that maximal internalization of E. coli is achieved only when bacteria are opsonized with complement. The concentrations of complement proteins in the urine rise sufficiently during infection to allow bacterial opsonization. The complement regulatory protein, CD46 (membrane cofactor protein), acts in cohort with fimbrial adhesion to promote the uptake of pathogenic E. coli. This uptake is inhibited by RNA interference to lower the expression of CD46 and by soluble CD46 that will competitively inhibit opsonized bacteria binding to cell surface CD46. We propose that efficient internalization of uropathogenic E. coli by the human urinary tract depends on cooperation between fimbrial-mediated adhesion and C3 receptor (CD46)-ligand interaction. Complement receptor-ligand interaction could pose a new target for interrupting the cycle of reinfection due to intracellular bacteria.
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Affiliation(s)
- Ke Li
- Department of Nephrology and Transplantation, Guy's Hospital, King's College London, United Kingdom
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36
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Capasso M, Durrant LG, Stacey M, Gordon S, Ramage J, Spendlove I. Costimulation via CD55 on Human CD4+T Cells Mediated by CD97. THE JOURNAL OF IMMUNOLOGY 2006; 177:1070-7. [PMID: 16818763 DOI: 10.4049/jimmunol.177.2.1070] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Decay-accelerating factor (CD55) is a complement regulatory protein, which is expressed by most cells to protect them from complement-mediated attack. CD55 also binds CD97, an EGF-TM7 receptor constitutively expressed on granulocytes and monocytes and rapidly up-regulated on T and B cells upon activation. Early results suggested that CD55 could further enhance T cell proliferation induced by phorbol ester treatment. The present study demonstrates that coengagement of CD55, using either cross-linking mAbs or its natural ligand CD97, and CD3 results in enhanced proliferation of human peripheral blood CD4(+) T cells, expression of the activation markers CD69 and CD25, and secretion of IL-10 and GM-CSF. Recently, an increase in T cell responsiveness in CD55(-/-) mice was shown to be mediated by a lack of complement regulation. In this study, we show that direct stimulation of CD55 on CD4(+) T cells with CD97 can modulate T cell activation but does not interfere with CD55-mediated complement regulation. Our results support a multifaceted role for CD55 in human T cell activation, constituting a further link between innate and adaptive immunity.
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Affiliation(s)
- Melania Capasso
- Academic Department of Clinical Oncology, Institute of Infection, Immunity and Inflammation, University of Nottingham, City Hospital, Nottingham NG5 1PB, United Kingdom
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37
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Xie J, Foxman B, Zhang L, Marrs CF. Molecular epidemiologic identification of Escherichia coli genes that are potentially involved in movement of the organism from the intestinal tract to the vagina and bladder. J Clin Microbiol 2006; 44:2434-41. [PMID: 16825361 PMCID: PMC1489509 DOI: 10.1128/jcm.00397-06] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Revised: 04/10/2006] [Accepted: 05/10/2006] [Indexed: 11/20/2022] Open
Abstract
A first step in urinary tract infection (UTI) pathogenesis in the otherwise healthy host is the movement of uropathogenic Escherichia coli from the intestinal tract to the urinary tract. We conducted a genomic subtraction to isolate genetic regions associated with this movement. A representative UTI isolate present in the rectum, vagina, and bladder of a woman with UTI was chosen as the tester; the driver was a phylogenetically distant rectal isolate (based on pulsed-field gel electrophoresis analysis) with a profile of uropathogenic virulence genes similar to that of the tester. Tester-specific regions identified by the subtraction were screened, using DNA dot blot hybridization, against a collection of 88 uropathogens isolated from the rectum, urine, and/or vagina of women with UTIs and 54 E. coli isolates from the same women that were found only in the rectum. Twelve genetic regions occurred more often in multisite isolates than in rectal site-only isolates. Eleven of these 12 genetic regions are homologous to regions in the sequenced uropathogenic E. coli CFT073 strain.
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Affiliation(s)
- Jingping Xie
- Department of Epidemiology, University of Michigan School of Public Health, 109 Observatory Street, Ann Arbor, MI 48109-2029, USA
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38
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Diard S, Toribio AL, Boum Y, Vigier F, Kansau I, Bouvet O, Servin A. Environmental signals implicated in Dr fimbriae release by pathogenic Escherichia coli. Microbes Infect 2006; 8:1851-8. [PMID: 16815721 DOI: 10.1016/j.micinf.2006.02.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 02/21/2006] [Accepted: 02/21/2006] [Indexed: 10/24/2022]
Abstract
Afa/Dr diffusely adhering Escherichia coli have been shown to cause urinary tract infections and enteric infections. Virulence of Dr-positive IH11128 bacteria is associated with the presence of Dr fimbriae. In this report, we show for the first time that the Dr fimbriae are released in the extracellular medium in response to multiple environmental signals. Production and secretion of Dr fimbriae are clearly thermoregulated. A comparison of the amounts of secreted fimbriae showed that the secretion is drastically increased during anaerobic growth in minimal medium. The effect of anaerobiosis on secretion seemed to depend on both the growth phase and the culture medium. The secretion was maximal during the logarithmic-phase growth and corresponded to 27 and 57% of total Dr fimbriae produced by bacteria grown in mineral medium+glucose and LB broth, respectively. Thus, the anaerobic environment of the colon would favour the secretion of Dr fimbriae during bacterial multiplication. The controlled release of the Dr fimbriae, which is carried out in the absence of cellular lysis, appears independent of the action of proteases or a process of maturation. The mechanism employed in the liberation of Dr fimbriae thus seems different from that described for the adhesins FHA and Hap of Bordetella pertussis and Haemophilus influenzae.
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Affiliation(s)
- Stéphane Diard
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 510, Faculté de Pharmacie, Université Paris XI, F-92296 Châtenay-Malabry, France
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39
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Mager DL. Bacteria and cancer: cause, coincidence or cure? A review. J Transl Med 2006; 4:14. [PMID: 16566840 PMCID: PMC1479838 DOI: 10.1186/1479-5876-4-14] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Accepted: 03/28/2006] [Indexed: 01/28/2023] Open
Abstract
Research has found that certain bacteria are associated with human cancers. Their role, however, is still unclear. Convincing evidence links some species to carcinogenesis while others appear promising in the diagnosis, prevention or treatment of cancers. The complex relationship between bacteria and humans is demonstrated by Helicobacter pylori and Salmonella typhi infections. Research has shown that H. pylori can cause gastric cancer or MALT lymphoma in some individuals. In contrast, exposure to H. pylori appears to reduce the risk of esophageal cancer in others. Salmonella typhi infection has been associated with the development of gallbladder cancer; however S. typhi is a promising carrier of therapeutic agents for melanoma, colon and bladder cancers. Thus bacterial species and their roles in particular cancers appear to differ among different individuals. Many species, however, share an important characteristic: highly site-specific colonization. This critical factor may lead to the development of non-invasive diagnostic tests, innovative treatments and cancer vaccines.
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Affiliation(s)
- D L Mager
- The Forsyth Institute, 140 The Fenway, Boston, MA, USA.
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40
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Wroblewska-Seniuk K, Selvarangan R, Hart A, Pladzyk R, Goluszko P, Jafari A, du Merle L, Nowicki S, Yallampalli C, Le Bouguénec C, Nowicki B. Dra/AfaE adhesin of uropathogenic Dr/Afa+ Escherichia coli mediates mortality in pregnant rats. Infect Immun 2005; 73:7597-601. [PMID: 16239563 PMCID: PMC1273835 DOI: 10.1128/iai.73.11.7597-7601.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Revised: 06/02/2005] [Accepted: 08/04/2005] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli bearing adhesins of the Dr/Afa family frequently causes urogenital infections during pregnancy in humans and has been associated with mortality in pregnant rats. Two components of the adhesin, Dra/AfaE and Dra/AfaD, considered virulence factors, are responsible for bacterial binding and internalization. We hypothesize that gestational mortality caused by Dr/Afa+ E. coli is mediated by one of these two proteins, Dra/AfaE or Dra/AfaD. In this study, using afaE and/or afaD mutants, we investigated the role of the afaE and afaD genes in the mortality of pregnant rats from intrauterine infection. Sprague-Dawley rats, on the 17th day of pregnancy, were infected with the E. coli afaE+ afaD and afaE afaD+ mutants. The clinical E. coli strain (afaE+ afaD+) and the afaE afaD double mutant were used as positive and negative controls, respectively. The mortality rate was evaluated 24 h after infection. The highest maternal mortality was observed in the group infected with the afaE+ afaD+ strain, followed by the group infected with the afaE+ afaD strain. The mortality was dose dependent. The afaE afaD double mutant did not cause maternal mortality, even with the highest infection dose. The in vivo studies corresponded with the invasion assay, where the afaE+ strains were the most invasive (afaE+ afaD strain > afaE+ afaD+ strain), while the afaE mutant strains (afaE afaD+ and afaE afaD strains) seemed to be noninvasive. This study shows for the first time that the afaE gene coding for the AfaE subunit of Dr/Afa adhesin is involved in the lethal outcome of gestational infection in rats. This lethal effect associated with AfaE correlates with the invasiveness of afaE+ E. coli strains in vitro.
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Affiliation(s)
- K Wroblewska-Seniuk
- Department of Obstetrics and Gynecology, Meharry University, Nashville, TN 37208, USA
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41
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Marrs CF, Zhang L, Foxman B. Escherichia coli mediated urinary tract infections: are there distinct uropathogenic E. coli (UPEC) pathotypes? FEMS Microbiol Lett 2005; 252:183-90. [PMID: 16165319 DOI: 10.1016/j.femsle.2005.08.028] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 08/18/2005] [Accepted: 08/18/2005] [Indexed: 11/29/2022] Open
Abstract
A variety of virulence genes are associated with Escherichia coli mediated urinary tract infections. Particular sets of virulence factors shared by bacterial strains directing them through a particular pathogenesis process are called a "pathotype." Comparison of co-occurrence of potential urinary tract infection (UTI) virulence genes among different E. coli isolates from fecal and UTI collections provides evidence for multiple pathotypes of uropathogenic E. coli, but current understanding of critical genetic differences defining the pathotypes is limited. Discovery of additional E. coli genes involved in uropathogenesis and determination of their distribution and co-occurrences will further define UPEC pathotypes and allow for a more detailed analysis of how these pathotypes might differ in how they cause disease.
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Affiliation(s)
- Carl F Marrs
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, 48109-2029, USA.
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42
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Das M, Hart-Van Tassell A, Urvil PT, Lea S, Pettigrew D, Anderson KL, Samet A, Kur J, Matthews S, Nowicki S, Popov V, Goluszko P, Nowicki BJ. Hydrophilic domain II of Escherichia coli Dr fimbriae facilitates cell invasion. Infect Immun 2005; 73:6119-26. [PMID: 16113333 PMCID: PMC1231115 DOI: 10.1128/iai.73.9.6119-6126.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Revised: 09/07/2004] [Accepted: 04/05/2005] [Indexed: 11/20/2022] Open
Abstract
Uropathogenic and diarrheal Escherichia coli strains expressing adhesins of the Dr family bind to decay-accelerating factor, invade epithelial cells, preferentially infect children and pregnant women, and may be associated with chronic or recurrent infections. Thus far, no fimbrial domain(s) that facilitates cell invasion has been identified. We used alanine scanning mutagenesis to replace selected amino acids in hydrophilic domain II of the structural fimbrial subunit DraE and evaluated recombinant mutant DraE for attachment, invasion, and intracellular compartmentalization. The mutation of amino acids V28, T31, G33, Q34, T36, and P40 of DraE reduced or abolished HeLa cell invasion but did not affect attachment. Electron micrographs showed a stepwise entry and fusion of vacuoles containing Escherichia coli mutants T36A and Q34A or corresponding beads with lysosomes, whereas vacuoles with wild-type Dr adhesin showed no fusion. Mutants T31A and Q34A, which were deficient in invasion, appeared to display a reduced capacity for clustering decay-accelerating factor. Our findings suggest that hydrophilic domain II may be involved in cell entry. These data are consistent with the interpretation that in HeLa cells the binding and invasion phenotypes of Dr fimbriae may be separated.
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Affiliation(s)
- Margaret Das
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-1062, USA
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43
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Zalewska B, Piątek R, Bury K, Samet A, Nowicki B, Nowicki S, Kur J. A surface-exposed DraD protein of uropathogenic Escherichia coli bearing Dr fimbriae may be expressed and secreted independently from DraC usher and DraE adhesin. Microbiology (Reading) 2005; 151:2477-2486. [PMID: 16000738 DOI: 10.1099/mic.0.28083-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The dra gene cluster, expressed by uropathogenic Escherichia coli strains, determines bacterial attachment and invasion. The Dr fimbrial structures formed at the bacterial cell surface are composed of DraE subunits. The Dr fimbriae-coding cluster contains six open reading frames – draA, draB, draC, draD, draP and draE – among which the draE gene encodes the structural fimbrial subunit DraE. Very little is known about E. coli surface expression of the draD gene product. The expression of DraD and its role in the biogenesis of Dr fimbriae were determined by constructing mutants in the dra operon and by immunoblot and immunofluorescence experiments. In this study, DraD was found to be a surface-exposed protein. The expression of DraD was independent of the DraC usher and DraE fimbrial subunits. Polymerization of DraE fimbrial subunits into fimbrial structures did not require expression of the DraD protein.
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Affiliation(s)
- Beata Zalewska
- Department of Microbiology, Gdańsk University of Technology, ul. G. Narutowicza 11/12, 80-952 Gdańsk, Poland
| | - Rafał Piątek
- Department of Microbiology, Gdańsk University of Technology, ul. G. Narutowicza 11/12, 80-952 Gdańsk, Poland
| | - Katarzyna Bury
- Department of Microbiology, Gdańsk University of Technology, ul. G. Narutowicza 11/12, 80-952 Gdańsk, Poland
| | - Alfred Samet
- Department of Clinical Microbiology, Public Hospital No. 1, Gdańsk, Poland
| | - Bogdan Nowicki
- Department of Obstetrics and Gynecology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Stella Nowicki
- Department of Obstetrics and Gynecology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Józef Kur
- Department of Microbiology, Gdańsk University of Technology, ul. G. Narutowicza 11/12, 80-952 Gdańsk, Poland
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Taylor PR, Martinez-Pomares L, Stacey M, Lin HH, Brown GD, Gordon S. Macrophage receptors and immune recognition. Annu Rev Immunol 2005; 23:901-44. [PMID: 15771589 DOI: 10.1146/annurev.immunol.23.021704.115816] [Citation(s) in RCA: 936] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Macrophages express a broad range of plasma membrane receptors that mediate their interactions with natural and altered-self components of the host as well as a range of microorganisms. Recognition is followed by surface changes, uptake, signaling, and altered gene expression, contributing to homeostasis, host defense, innate effector mechanisms, and the induction of acquired immunity. This review covers recent studies of selected families of structurally defined molecules, studies that have improved understanding of ligand discrimination in the absence of opsonins and differential responses by macrophages and related myeloid cells.
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Affiliation(s)
- P R Taylor
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom, USA
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45
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Abstract
Over the last few years, dramatic increases in our knowledge about diffusely adhering Escherichia coli (DAEC) pathogenesis have taken place. The typical class of DAEC includes E. coli strains harboring AfaE-I, AfaE-II, AfaE-III, AfaE-V, Dr, Dr-II, F1845, and NFA-I adhesins (Afa/Dr DAEC); these strains (i) have an identical genetic organization and (ii) allow binding to human decay-accelerating factor (DAF) (Afa/Dr(DAF) subclass) or carcinoembryonic antigen (CEA) (Afa/Dr(CEA) subclass). The atypical class of DAEC includes two subclasses of strains; the atypical subclass 1 includes E. coli strains that express AfaE-VII, AfaE-VIII, AAF-I, AAF-II, and AAF-III adhesins, which (i) have an identical genetic organization and (ii) do not bind to human DAF, and the atypical subclass 2 includes E. coli strains that harbor Afa/Dr adhesins or others adhesins promoting diffuse adhesion, together with pathogenicity islands such as the LEE pathogenicity island (DA-EPEC). In this review, the focus is on Afa/Dr DAEC strains that have been found to be associated with urinary tract infections and with enteric infection. The review aims to provide a broad overview and update of the virulence aspects of these intriguing pathogens. Epidemiological studies, diagnostic techniques, characteristic molecular features of Afa/Dr operons, and the respective role of Afa/Dr adhesins and invasins in pathogenesis are described. Following the recognition of membrane-bound receptors, including type IV collagen, DAF, CEACAM1, CEA, and CEACAM6, by Afa/Dr adhesins, activation of signal transduction pathways leads to structural and functional injuries at brush border and junctional domains and to proinflammatory responses in polarized intestinal cells. In addition, uropathogenic Afa/Dr DAEC strains, following recognition of beta(1) integrin as a receptor, enter epithelial cells by a zipper-like, raft- and microtubule-dependent mechanism. Finally, the presence of other, unknown virulence factors and the way that an Afa/Dr DAEC strain emerges from the human intestinal microbiota as a "silent pathogen" are discussed.
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Affiliation(s)
- Alain L Servin
- Institut National de la Santé et de la Recherche Médicale, Unité 510, Faculté de Pharmacie Paris XI, Châtenay-Malabry, France.
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46
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Abstract
Entry into host cells is required for many bacterial pathogens to effectively disseminate within a host, avoid immune detection and cause disease. In recent years, many ostensibly extracellular bacteria have been shown to act as opportunistic intracellular pathogens. Among these are strains of uropathogenic Escherichia coli (UPEC), the primary causative agents of urinary tract infections (UTIs). UPEC are able to transiently invade, survive and multiply within the host cells and tissues constituting the urinary tract. Invasion of host cells by UPEC is promoted independently by distinct virulence factors, including cytotoxic necrotizing factor, Afa/Dr adhesins, and type 1 pili. Here we review the diverse mechanisms and consequences of host cell invasion by UPEC, focusing also on the impact of these processes on the persistence and recurrence of UTIs.
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47
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Goluszko P, Goluszko E, Nowicki B, Nowicki S, Popov V, Wang HQ. Vaccination with purified Dr Fimbriae reduces mortality associated with chronic urinary tract infection due to Escherichia coli bearing Dr adhesin. Infect Immun 2005; 73:627-31. [PMID: 15618205 PMCID: PMC538924 DOI: 10.1128/iai.73.1.627-631.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2004] [Revised: 05/13/2004] [Accepted: 09/22/2004] [Indexed: 11/20/2022] Open
Abstract
The vaccination of C3H/HeJ mice with Escherichia coli Dr fimbrial antigen reduced mortality associated with an experimental urinary tract infection due to a homologous strain bearing Dr adhesin. Immune sera with high titers of anti-Dr antibody inhibited bacterial binding to bladders and kidneys but did not affect the rate of renal colonization.
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Affiliation(s)
- Pawel Goluszko
- University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-1062, USA.
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48
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Anderson KL, Billington J, Pettigrew D, Cota E, Simpson P, Roversi P, Chen HA, Urvil P, du Merle L, Barlow PN, Medof ME, Smith RAG, Nowicki B, Le Bouguénec C, Lea SM, Matthews S. An Atomic Resolution Model for Assembly, Architecture, and Function of the Dr Adhesins. Mol Cell 2004; 15:647-57. [PMID: 15327779 DOI: 10.1016/j.molcel.2004.08.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2004] [Revised: 06/04/2004] [Accepted: 06/09/2004] [Indexed: 11/16/2022]
Abstract
Pathogenic bacteria possess adhesion protein complexes that play essential roles in targeting host cells and in propagating infection. Although each family of adhesion proteins is generally associated with a specific human disease, the Dr family from Escherichia coli is a notable exception, as its members are associated with both diarrheal and urinary tract infections. These proteins are reported to form both fimbrial and afimbrial structures at the bacterial cell surface and target a common host cell receptor, the decay-accelerating factor (DAF or CD55). Using the newly solved three-dimensional structure of AfaE, we have constructed a robust atomic resolution model that reveals the structural basis for assembly by donor strand complementation and for the architecture of capped surface fibers.
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Affiliation(s)
- Kirstine L Anderson
- Department of Biological Sciences, Wolfson Laboratories, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
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49
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Selvarangan R, Goluszko P, Singhal J, Carnoy C, Moseley S, Hudson B, Nowicki S, Nowicki B. Interaction of Dr adhesin with collagen type IV is a critical step in Escherichia coli renal persistence. Infect Immun 2004; 72:4827-35. [PMID: 15271945 PMCID: PMC470682 DOI: 10.1128/iai.72.8.4827-4835.2004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Revised: 02/06/2004] [Accepted: 04/21/2004] [Indexed: 12/11/2022] Open
Abstract
The pathogenic mechanism of recurrent or chronic urinary tract infection is poorly understood. Escherichia coli cells bearing Dr fimbriae display unique tropism to the basement membrane (BM)-renal interstitium that enables the bacteria to cause chronic pyelonephritis in experimental mice. The renal receptors for Dr-fimbriated E. coli are type IV collagen and decay-accelerating factor (DAF). We hypothesized that type IV collagen receptor-mediated BM-interstitial tropism is essential for E. coli to cause chronic pyelonephritis. To test the role of the type IV collagen tropism of Dr-fimbriated E. coli in renal persistence, we constructed an isogenic mutant in the DraE adhesin subunit that was unable to bind type IV collagen but retained binding to DAF and examined its virulence in the mouse model. The collagen-binding mutant DrI113T was eliminated from the mouse renal tissues in 6 to 8 weeks, while the parent strain caused persistent renal infection that lasted at least 14 weeks (P < or = 0.02). Transcomplementation with the intact Dr operon restored collagen-binding activity, BM-interstitial tropism, and the ability to cause persistent renal infection. We conclude that type IV collagen binding mediated by DraE adhesin is a critical step for the development of persistent renal infection in a murine model of E. coli pyelonephritis.
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Affiliation(s)
- Rangaraj Selvarangan
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, 77555-1062, USA
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Hudault S, Spiller OB, Morgan BP, Servin AL. Human diffusely adhering Escherichia coli expressing Afa/Dr adhesins that use human CD55 (decay-accelerating factor) as a receptor does not bind the rodent and pig analogues of CD55. Infect Immun 2004; 72:4859-63. [PMID: 15271948 PMCID: PMC470588 DOI: 10.1128/iai.72.8.4859-4863.2004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2004] [Revised: 03/17/2004] [Accepted: 04/05/2004] [Indexed: 11/20/2022] Open
Abstract
Afa/Dr diffusely adhering Escherichia coli (DAEC) bacteria that are responsible for recurrent urinary tract and gastrointestinal infections recognized as a receptor the glycosylphosphatidylinositol (GPI)-anchored protein decay-accelerating factor (DAF; CD55) at the brush border of cultured human intestinal cells. Results show that Afa/Dr DAEC C1845 bacteria were poorly associated with the mucosa of the gastrointestinal tract of infected mice. We conducted experiments with Chinese hamster ovary (CHO) cells stably transfected with mouse (GPI or transmembrane forms), pig, or human CD55 or mouse Crry cDNAs or transfected with empty vector pDR2EF1 alpha. Recombinant E. coli AAEC185 bacteria expressing Dr or F1845 adhesins bound strongly to CHO cells expressing human CD55 but not to the CHO cells expressing mouse (transmembrane and GPI anchored), rat, or pig CD55 or mouse Crry. Positive clustering of CD55 around Dr-positive bacteria was observed in human CD55-expressing CHO cells but not around the rarely adhering Dr-positive bacteria randomly distributed at the cell surface of CHO cells expressing mouse, rat, or pig CD55.
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Affiliation(s)
- Sylvie Hudault
- Institut National de la Santé et de la Recherche Médicale, Unité 510, Faculté de Pharmacie Paris XI, F-92296 ChAtenay-Malabry, France
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