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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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Butler D, Ambite I, Wan MLY, Tran TH, Wullt B, Svanborg C. Immunomodulation therapy offers new molecular strategies to treat UTI. Nat Rev Urol 2022; 19:419-437. [PMID: 35732832 PMCID: PMC9214477 DOI: 10.1038/s41585-022-00602-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2022] [Indexed: 12/13/2022]
Abstract
Innovative solutions are needed for the treatment of bacterial infections, and a range of antibacterial molecules have been explored as alternatives to antibiotics. A different approach is to investigate the immune system of the host for new ways of making the antibacterial defence more efficient. However, the immune system has a dual role as protector and cause of disease: in addition to being protective, increasing evidence shows that innate immune responses can become excessive and cause acute symptoms and tissue pathology during infection. This role of innate immunity in disease suggests that the immune system should be targeted therapeutically, to inhibit over-reactivity. The ultimate goal is to develop therapies that selectively attenuate destructive immune response cascades, while augmenting the protective antimicrobial defence but such treatment options have remained underexplored, owing to the molecular proximity of the protective and destructive effects of the immune response. The concept of innate immunomodulation therapy has been developed successfully in urinary tract infections, based on detailed studies of innate immune activation and disease pathogenesis. Effective, disease-specific, immunomodulatory strategies have been developed by targeting specific immune response regulators including key transcription factors. In acute pyelonephritis, targeting interferon regulatory factor 7 using small interfering RNA or treatment with antimicrobial peptide cathelicidin was protective and, in acute cystitis, targeting overactive effector molecules such as IL-1β, MMP7, COX2, cAMP and the pain-sensing receptor NK1R has been successful in vivo. Furthermore, other UTI treatment strategies, such as inhibiting bacterial adhesion and vaccination, have also shown promise. Hyperactivation of innate immunity is a disease determinant in urinary tract infections (UTIs). Modulation of innate immunity has promise as a therapy for UTIs. In this Review, the authors discuss potential mechanisms and immunomodulatory therapeutic strategies in UTIs. Excessive innate immune responses to infection cause symptoms and pathology in acute pyelonephritis and acute cystitis. Innate immunomodulation therapy is, therefore, a realistic option for treating these conditions. Targeting excessive innate immune responses at the level of transcription has been successful in animal models. Innate immunomodulation therapy reduces excessive inflammation and tissue pathology and accelerates bacterial clearance from infected kidneys and bladders in mice. Innate immunomodulation therapy also accelerates the clearance of antibiotic-resistant bacterial strains.
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Affiliation(s)
- Daniel Butler
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Ines Ambite
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Murphy Lam Yim Wan
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Thi Hien Tran
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Björn Wullt
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Catharina Svanborg
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
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Dahlberg T, Baker JL, Bullitt E, Andersson M. Unveiling molecular interactions that stabilize bacterial adhesion pili. Biophys J 2022; 121:2096-2106. [PMID: 35491503 PMCID: PMC9247471 DOI: 10.1016/j.bpj.2022.04.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/09/2022] [Accepted: 04/27/2022] [Indexed: 11/29/2022] Open
Abstract
Adhesion pili assembled by the chaperone-usher pathway are superelastic helical filaments on the surface of bacteria, optimized for attachment to target cells. Here, we investigate the biophysical function and structural interactions that stabilize P pili from uropathogenic bacteria. Using optical tweezers, we measure P pilus subunit-subunit interaction dynamics and show that pilus compliance is contour-length dependent. Atomic details of subunit-subunit interactions of pili under tension are shown using steered molecular dynamics (sMD) simulations. sMD results also indicate that the N-terminal "staple" region of P pili, which provides interactions with pilins that are four and five subunits away, significantly stabilizes the helical filament structure. These data are consistent with previous structural data, and suggest that more layer-to-layer interactions could compensate for the lack of a staple in type 1 pili. This study informs our understanding of essential structural and dynamic features of adhesion pili, supporting the hypothesis that the function of pili is critically dependent on their structure and biophysical properties.
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Affiliation(s)
| | - Joseph L Baker
- Department of Chemistry, The College of New Jersey, Ewing, New Jersey
| | - Esther Bullitt
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts.
| | - Magnus Andersson
- Department of Physics, Umeå University, Umeå, Sweden; Umeå Centre for Microbial Research (UCMR), Umeå, Sweden.
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Ambite I, Butler D, Wan MLY, Rosenblad T, Tran TH, Chao SM, Svanborg C. Molecular determinants of disease severity in urinary tract infection. Nat Rev Urol 2021; 18:468-486. [PMID: 34131331 PMCID: PMC8204302 DOI: 10.1038/s41585-021-00477-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2021] [Indexed: 02/06/2023]
Abstract
The most common and lethal bacterial pathogens have co-evolved with the host. Pathogens are the aggressors, and the host immune system is responsible for the defence. However, immune responses can also become destructive, and excessive innate immune activation is a major cause of infection-associated morbidity, exemplified by symptomatic urinary tract infections (UTIs), which are caused, in part, by excessive innate immune activation. Severe kidney infections (acute pyelonephritis) are a major cause of morbidity and mortality, and painful infections of the urinary bladder (acute cystitis) can become debilitating in susceptible patients. Disease severity is controlled at specific innate immune checkpoints, and a detailed understanding of their functions is crucial for strategies to counter microbial aggression with novel treatment and prevention measures. One approach is the use of bacterial molecules that reprogramme the innate immune system, accelerating or inhibiting disease processes. A very different outcome is asymptomatic bacteriuria, defined by low host immune responsiveness to bacteria with attenuated virulence. This observation provides the rationale for immunomodulation as a new therapeutic tool to deliberately modify host susceptibility, control the host response and avoid severe disease. The power of innate immunity as an arbitrator of health and disease is also highly relevant for emerging pathogens, including the current COVID-19 pandemic.
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Affiliation(s)
- Ines Ambite
- grid.4514.40000 0001 0930 2361Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Daniel Butler
- grid.4514.40000 0001 0930 2361Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Murphy Lam Yim Wan
- grid.4514.40000 0001 0930 2361Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Therese Rosenblad
- grid.4514.40000 0001 0930 2361Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Thi Hien Tran
- grid.4514.40000 0001 0930 2361Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Sing Ming Chao
- Nephrology Service, Department of Paediatrics, KK Hospital, Singapore, Singapore
| | - Catharina Svanborg
- grid.4514.40000 0001 0930 2361Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
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Simões E Silva AC, Oliveira EA, Mak RH. Urinary tract infection in pediatrics: an overview. J Pediatr (Rio J) 2020; 96 Suppl 1:65-79. [PMID: 31783012 PMCID: PMC9432043 DOI: 10.1016/j.jped.2019.10.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/12/2019] [Accepted: 10/16/2019] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE This review aimed to provide a critical overview on the pathogenesis, clinical findings, diagnosis, imaging investigation, treatment, chemoprophylaxis, and complications of urinary tract infection in pediatric patients. SOURCE OF DATA Data were obtained independently by two authors, who carried out a comprehensive and non-systematic search in public databases. SUMMARY OF FINDINGS Urinary tract infection is the most common bacterial infection in children. Urinary tract infection in pediatric patients can be the early clinical manifestation of congenital anomalies of the kidney and urinary tract (CAKUT) or be related to bladder dysfunctions. E. coli is responsible for 80-90% of community-acquired acute pyelonephritis episodes, especially in children. Bacterial virulence factors and the innate host immune systems may contribute to the occurrence and severity of urinary tract infection. The clinical presentation of urinary tract infections in children is highly heterogeneous, with symptoms that can be quite obscure. Urine culture is still the gold standard for diagnosing urinary tract infection and methods of urine collection in individual centers should be determined based on the accuracy of voided specimens. The debate on the ideal imaging protocol is still ongoing and there is tendency of less use of prophylaxis. Alternative measures and management of risk factors for recurrent urinary tract infection should be emphasized. However, in selected patients, prophylaxis can protect from recurrent urinary tract infection and long-term consequences. According to population-based studies, hypertension and chronic kidney disease are rarely associated with urinary tract infection. CONCLUSION Many aspects regarding urinary tract infection in children are still matters of debate, especially imaging investigation and indication of antibiotic prophylaxis. Further longitudinal studies are needed to establish tailored approach of urinary tract infection in childhood.
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Affiliation(s)
- Ana Cristina Simões E Silva
- Universidade Federal de Minas Gerais (UFMG), Faculdade de Medicina, Laboratório Interdisciplinar de Investigação Médica, Departamento de Pediatria, Unidade de Nefrologia Pediátrica, Belo Horizonte, MG, Brazil.
| | - Eduardo A Oliveira
- Universidade Federal de Minas Gerais (UFMG), Faculdade de Medicina, Laboratório Interdisciplinar de Investigação Médica, Departamento de Pediatria, Unidade de Nefrologia Pediátrica, Belo Horizonte, MG, Brazil
| | - Robert H Mak
- University of California, Rady Children's Hospital San Diego, Division of Pediatric Nephrology, San Diego, United States
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Klarström Engström K, Zhang B, Demirel I. Human renal fibroblasts are strong immunomobilizers during a urinary tract infection mediated by uropathogenic Escherichia coli. Sci Rep 2019; 9:2296. [PMID: 30783129 PMCID: PMC6381130 DOI: 10.1038/s41598-019-38691-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/03/2019] [Indexed: 12/29/2022] Open
Abstract
To prevent the onset of urosepsis and reduce mortality, a better understanding of how uropathogenic Escherichia coli (UPEC) manages to infiltrate the bloodstream through the kidneys is needed. The present study elucidates if human renal interstitial fibroblasts are part of the immune response limiting a UPEC infection, or if UPEC has the ability to modulate the fibroblasts for their own gain. Microarray results showed that upregulated genes were associated with an activated immune response. We also found that chemokines released from renal fibroblasts upon a UPEC infection could be mediated by LPS and triacylated lipoproteins activating the TLR2/1, TLR4, MAPK, NF-κB and PKC signaling pathways. Furthermore, UPEC was also shown to be able to adhere and invade renal fibroblasts, mediated by the P-fimbriae. Furthermore, it was found that renal fibroblasts were more immunoreactive than renal epithelial cells upon a UPEC infection. However, both renal fibroblasts and epithelial cells were equally efficient at inducing neutrophil migration. In conclusion, we have found that human renal fibroblasts can sense UPEC and mobilize a host response with neutrophil migration. This suggests that renal fibroblasts are not only structural cells that produce and regulate the extracellular matrix, but also highly immunoreactive cells.
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Affiliation(s)
| | - Boxi Zhang
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Isak Demirel
- iRiSC - Inflammatory Response and Infection Susceptibility Centre, Faculty of Medicine and Health, Örebro University, Örebro, Sweden. .,School of Medical Sciences, Örebro University, Örebro, Sweden.
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Zeiger RS. Allergic and Nonallergic Rhinitis. Classification and Pathogenesis: Part II. Nonallergic Rhinitis. ACTA ACUST UNITED AC 2018. [DOI: 10.2500/105065889782009705] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Part I of this review classified and defined the causes of chronic rhinitis, describing in detail the etiology and pathophysiology of allergic rhinitis. Part II focuses on the nonallergic (non-IgE) causes of chronic rhinitis, concentrating on their clinical presentations, differential characteristics, and known or speculative pathophysiology. A comprehensive understanding of the allergic and nonallergic conditions associated with symptomatic rhinitis should aid the clinician in the appropriate diagnosis and treatment of patients with chronic rhinitis.
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Affiliation(s)
- Robert S. Zeiger
- Department of Allergy-Immunology, Kaiser Permanente Medical Center; University of California, San Diego, San Diego, San Diego, CA
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Susceptibility to Urinary Tract Infection: Benefits and Hazards of the Antibacterial Host Response. Microbiol Spectr 2017; 4. [PMID: 27337480 DOI: 10.1128/microbiolspec.uti-0019-2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A paradigm shift is needed to improve and personalize the diagnosis of infectious disease and to select appropriate therapies. For many years, only the most severe and complicated bacterial infections received more detailed diagnostic and therapeutic attention as the efficiency of antibiotic therapy has guaranteed efficient treatment of patients suffering from the most common infections. Indeed, treatability almost became a rationale not to analyze bacterial and host parameters in these larger patient groups. Due to the rapid spread of antibiotic resistance, common infections like respiratory tract- or urinary-tract infections (UTIs) now pose new and significant therapeutic challenges. It is fortunate and timely that infectious disease research can offer such a wealth of new molecular information that is ready to use for the identification of susceptible patients and design of new suitable therapies. Paradoxically, the threat of antibiotic resistance may become a window of opportunity, by encouraging the implementation of new diagnostic and therapeutic approaches. The frequency of antibiotic resistance is rising rapidly in uropathogenic organisms and the molecular and genetic understanding of UTI susceptibility is quite advanced. More bold translation of the new molecular diagnostic and therapeutic tools would not just be possible but of great potential benefit in this patient group. This chapter reviews the molecular basis for susceptibility to UTI, including recent advances in genetics, and discusses the consequences for diagnosis and therapy. By dissecting the increasingly well-defined molecular interactions between bacteria and host and the molecular features of excessive bacterial virulence or host-response malfunction, it is becoming possible to isolate the defensive from the damaging aspects of the host response. Distinguishing "good" from "bad" inflammation has been a long-term quest of biomedical science and in UTI, patients need the "good" aspects of the inflammatory response to resist infection while avoiding the "bad" aspects, causing chronicity and tissue damage.
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Conover MS, Ruer S, Taganna J, Kalas V, De Greve H, Pinkner JS, Dodson KW, Remaut H, Hultgren SJ. Inflammation-Induced Adhesin-Receptor Interaction Provides a Fitness Advantage to Uropathogenic E. coli during Chronic Infection. Cell Host Microbe 2016; 20:482-492. [PMID: 27667696 PMCID: PMC5294914 DOI: 10.1016/j.chom.2016.08.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/10/2016] [Accepted: 08/19/2016] [Indexed: 02/04/2023]
Abstract
Uropathogenic E. coli (UPEC) is the dominant cause of urinary tract infections, clinically described as cystitis. UPEC express CUP pili, which are extracellular fibers tipped with adhesins that bind mucosal surfaces of the urinary tract. Here we identify the role of the F9/Yde/Fml pilus for UPEC persistence in the inflamed urothelium. The Fml adhesin FmlH binds galactose β1-3 N-acetylgalactosamine found in core-1 and -2 O-glycans. Deletion of fmlH had no effect on UPEC virulence in an acute mouse model of cystitis. However, FmlH provided a fitness advantage during chronic cystitis, which is manifested as persistent bacteriuria, high bladder bacterial burdens, and chronic inflammation. In situ binding confirmed that FmlH bound avidly to the inflamed, but not the naive bladder. In accordance with its pathogenic profile, vaccination with FmlH significantly protected mice from chronic cystitis. Thus, UPEC employ separate CUP pili to adapt to the rapidly changing niche during bladder infection.
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Affiliation(s)
- Matt S Conover
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ségolène Ruer
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Joemar Taganna
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Vasilios Kalas
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Henri De Greve
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Jerome S Pinkner
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Karen W Dodson
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Han Remaut
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
| | - Scott J Hultgren
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Puthia M, Ambite I, Cafaro C, Butler D, Huang Y, Lutay N, Rydström G, Gullstrand B, Swaminathan B, Nadeem A, Nilsson B, Svanborg C. IRF7inhibition prevents destructive innate immunity—A target for nonantibiotic therapy of bacterial infections. Sci Transl Med 2016; 8:336ra59. [DOI: 10.1126/scitranslmed.aaf1156] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/08/2016] [Indexed: 12/16/2022]
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Abstract
Purpose of review Urinary tract infections (UTIs) are common, dangerous and interesting. Susceptible individuals experience multiple, often clustered episodes, and in a subset of patients, infections progress to acute pyelonephritis (APN), sometimes accompanied by uro-sepsis. Others develop asymptomatic bacteriuria (ABU). Here, we review the molecular basis for these differences, with the intention to distinguish exaggerated host responses that drive disease from attenuated responses that favour protection and to highlight the genetic basis for these extremes, based on knock-out mice and clinical studies. Recent findings The susceptibility to UTI is controlled by specific innate immune signalling and by promoter polymorphisms and transcription factors that modulate the expression of genes controlling these pathways. Gene deletions that disturb innate immune activation either favour asymptomatic bacteriuria or create acute morbidity and disease. Promoter polymorphisms and transcription factor variants affecting those genes are associated with susceptibility in UTI-prone patients. Summary It is time to start using genetics in UTI-prone patients, to improve diagnosis and to assess the risk for chronic sequels such as renal malfunction, hypertension, spontaneous abortions, dialysis and transplantation. Furthermore, the majority of UTI patients do not need follow-up, but for lack of molecular markers, they are unnecessarily investigated.
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Abstract
Asymptomatic bacteriuria (ASB) is a common finding and frequently detected in premenopausal nonpregnant women, institutionalized patients, patients with diabetes mellitus, and the ambulatory elderly population. Despite clear recommendations regarding diagnosis and management of ASB in these populations from the Infectious Diseases Society of America (IDSA), there remains an alarming rate of antimicrobial overuse. This article reviews definitions of ASB, epidemiology of ASB, literature surrounding ASB in diabetic patients, risk factors of ASB, microbiologic data regarding bacterial virulence, use of ASB strains for treatment of symptomatic urinary tract infection, and approaches to addressing translational barriers to implementing IDSA recommendations regarding diagnosis and management of ASB.
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Affiliation(s)
- Matthew Ferroni
- Department of Urology, University of Pittsburgh Medical Center, 300 Halket Street, Suite 4710, Pittsburgh, PA 15213, USA
| | - Aisha Khalali Taylor
- Department of Urology, University of Pittsburgh Medical Center, 300 Halket Street, Suite 4710, Pittsburgh, PA 15213, USA.
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P1PK, GLOB, and FORS Blood Group Systems and GLOB Collection: Biochemical and Clinical Aspects. Do We Understand It All Yet? Transfus Med Rev 2014; 28:126-36. [DOI: 10.1016/j.tmrv.2014.04.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 04/15/2014] [Accepted: 04/17/2014] [Indexed: 01/09/2023]
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Prosser JI, Cole JA, Nielsen J, Bavoil PM, Häggblom MM. Most influential FEMS publications. FEMS Microbiol Lett 2014; 354:83-4. [PMID: 24842770 DOI: 10.1111/1574-6968.12444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
A selection of influential FEMS publications to celebrate the 40th anniversary of FEMS.
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Affiliation(s)
- James I Prosser
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK.
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Abstract
Urinary tract infections (UTIs) are among the most common of bacterial infections in humans. Although a number of Gram-negative bacteria can cause UTIs, most cases are due to infection by uropathogenic E. coli (UPEC). Genomic studies have shown that UPEC encode a number of specialized activities that allow the bacteria to initiate and maintain infections in the environment of the urinary tract. Proteomic analyses have complemented the genomic data and have documented differential patterns of protein synthesis for bacteria growing ex vivo in human urine or recovered directly from the urinary tracts of infected mice. These studies provide valuable insights into the molecular basis of UPEC pathogenesis and have aided the identification of putative vaccine targets. Despite the substantial progress that has been achieved, many future challenges remain in the application of proteomics to provide a comprehensive view of bacterial pathogenesis in both acute and chronic UTIs.
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Affiliation(s)
- Phillip Cash
- Division of Applied Medicine, University of Aberdeen, Foresterhill, Aberdeen AB32 6QX, Scotland
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Ragnarsdóttir B, Svanborg C. Susceptibility to acute pyelonephritis or asymptomatic bacteriuria: host-pathogen interaction in urinary tract infections. Pediatr Nephrol 2012; 27:2017-2029. [PMID: 22327887 DOI: 10.1007/s00467-011-2089-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 11/30/2011] [Accepted: 12/02/2011] [Indexed: 10/14/2022]
Abstract
Our knowledge of the molecular mechanisms of urinary tract infection (UTI) pathogenesis has advanced greatly in recent years. In this review, we provide a general background of UTI pathogenesis, followed by an update on the mechanisms of UTI susceptibility, with a particular focus on genetic variation affecting innate immunity. The innate immune response of the host is critically important in the antibacterial defence mechanisms of the urinary tract, and bacterial clearance normally proceeds without sequelae. However, slight dysfunctions in these mechanisms may result in acute disease and tissue destruction. The symptoms of acute pyelonephritis are caused by the innate immune response, and inflammation in the urinary tract decreases renal tubular function and may give rise to renal scarring, especially in paediatric patients. In contrast, in children with asymptomatic bacteriuria (ABU), bacteria persist without causing symptoms or pathology. Pathogenic agents trigger a response determined by their virulence factors, mediating adherence to the urinary tract mucosa, signalling through Toll-like receptors (TLRs) and activating the defence mechanisms. In ABU strains, such virulence factors are mostly not expressed. However, the influence of the host on UTI severity cannot be overestimated, and rapid progress is being made in clarifying host susceptibility mechanisms. For example, genetic alterations that reduce TLR4 function are associated with ABU, while polymorphisms reducing IRF3 or CXCR1 expression are associated with acute pyelonephritis and an increased risk for renal scarring. It should be plausible to "individualize" diagnosis and therapy by combining information on bacterial virulence and the host response.
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Affiliation(s)
- Bryndís Ragnarsdóttir
- Institute of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology (MIG), Lund University, Sölvegatan 23, 22362, Lund, Sweden
| | - Catharina Svanborg
- Institute of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology (MIG), Lund University, Sölvegatan 23, 22362, Lund, Sweden.
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Ragnarsdóttir B, Lutay N, Grönberg-Hernandez J, Köves B, Svanborg C. Genetics of innate immunity and UTI susceptibility. Nat Rev Urol 2011; 8:449-68. [PMID: 21750501 DOI: 10.1038/nrurol.2011.100] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A functional and well-balanced immune response is required to resist most infections. Slight dysfunctions in innate immunity can turn the 'friendly' host defense into an unpleasant foe and give rise to disease. Beneficial and destructive forces of innate immunity have been discovered in the urinary tract and mechanisms by which they influence the severity of urinary tract infections (UTIs) have been elucidated. By modifying specific aspects of the innate immune response to UTI, genetic variation either exaggerates the severity of acute pyelonephritis to include urosepsis and renal scarring or protects against symptomatic disease by suppressing innate immune signaling, as in asymptomatic bacteriuria (ABU). Different genes are polymorphic in patients prone to acute pyelonephritis or ABU, respectively, and yet discussions of UTI susceptibility in clinical practice still focus mainly on social and behavioral factors or dysfunctional voiding. Is it not time for UTIs to enter the era of molecular medicine? Defining why certain individuals are protected from UTI while others have severe, recurrent infections has long been difficult, but progress is now being made, encouraging new approaches to risk assessment and therapy in this large and important patient group, as well as revealing promising facets of 'good' versus 'bad' inflammation.
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Affiliation(s)
- Bryndís Ragnarsdóttir
- Section of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Sölvegatan 23, 22362 Lund, Sweden
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Kawamura T, Vartanian AS, Zhou H, Dahlquist FW. The Design Involved in PapI and Lrp Regulation of the pap Operon. J Mol Biol 2011; 409:311-32. [DOI: 10.1016/j.jmb.2011.01.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 01/24/2011] [Accepted: 01/25/2011] [Indexed: 11/30/2022]
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Ragnarsdóttir B, Jönsson K, Urbano A, Grönberg-Hernandez J, Lutay N, Tammi M, Gustafsson M, Lundstedt AC, Leijonhufvud I, Karpman D, Wullt B, Truedsson L, Jodal U, Andersson B, Svanborg C. Toll-like receptor 4 promoter polymorphisms: common TLR4 variants may protect against severe urinary tract infection. PLoS One 2010; 5:e10734. [PMID: 20505764 PMCID: PMC2873976 DOI: 10.1371/journal.pone.0010734] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Accepted: 04/12/2010] [Indexed: 01/07/2023] Open
Abstract
Background Polymorphisms affecting Toll-like receptor (TLR) structure appear to be rare, as would be expected due to their essential coordinator role in innate immunity. Here, we assess variation in TLR4 expression, rather than structure, as a mechanism to diversify innate immune responses. Methodology/Principal Findings We sequenced the TLR4 promoter (4,3 kb) in Swedish blood donors. Since TLR4 plays a vital role in susceptibility to urinary tract infection (UTI), promoter sequences were obtained from children with mild or severe disease. We performed a case-control study of pediatric patients with asymptomatic bacteriuria (ABU) or those prone to recurrent acute pyelonephritis (APN). Promoter activity of the single SNPs or multiple allelic changes corresponding to the genotype patterns (GPs) was tested. We then conducted a replication study in an independent cohort of adult patients with a history of childhood APN. Last, in vivo effects of the different GPs were examined after therapeutic intravesical inoculation of 19 patients with Escherichia coli 83972. We identified in total eight TLR4 promoter sequence variants in the Swedish control population, forming 19 haplotypes and 29 genotype patterns, some with effects on promoter activity. Compared to symptomatic patients and healthy controls, ABU patients had fewer genotype patterns, and their promoter sequence variants reduced TLR4 expression in response to infection. The ABU associated GPs also reduced innate immune responses in patients who were subjected to therapeutic urinary E. coli tract inoculation. Conclusions The results suggest that genetic variation in the TLR4 promoter may be an essential, largely overlooked mechanism to influence TLR4 expression and UTI susceptibility.
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Affiliation(s)
- Bryndís Ragnarsdóttir
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | - Klas Jönsson
- Singapore Immunology Network (SIgN), Biomedical Sciences Institutes, Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Alexander Urbano
- Singapore Immunology Network (SIgN), Biomedical Sciences Institutes, Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Jenny Grönberg-Hernandez
- Department of Urology, Institute for Clinical Sciences Lund, Lund University Hospital, Lund, Sweden
| | - Nataliya Lutay
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | - Martti Tammi
- Department of Biological Sciences, National University of Singapore (NUS), Singapore, Singapore
| | - Mattias Gustafsson
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | - Ann-Charlotte Lundstedt
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | - Irene Leijonhufvud
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | - Diana Karpman
- Department of Pediatrics, Institute of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Björn Wullt
- Department of Urology, Institute for Clinical Sciences Lund, Lund University Hospital, Lund, Sweden
| | - Lennart Truedsson
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | - Ulf Jodal
- Department of Pediatrics, The Queen Silvia Children's Hospital, Gothenburg University, Gothenburg, Sweden
| | - Björn Andersson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Catharina Svanborg
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine Lund, Lund University, Lund, Sweden
- Singapore Immunology Network (SIgN), Biomedical Sciences Institutes, Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
- * E-mail:
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Zav'yalov V, Zavialov A, Zav'yalova G, Korpela T. Adhesive organelles of Gram-negative pathogens assembled with the classical chaperone/usher machinery: structure and function from a clinical standpoint. FEMS Microbiol Rev 2009; 34:317-78. [PMID: 20070375 DOI: 10.1111/j.1574-6976.2009.00201.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
This review summarizes current knowledge on the structure, function, assembly and biomedical applications of the superfamily of adhesive fimbrial organelles exposed on the surface of Gram-negative pathogens with the classical chaperone/usher machinery. High-resolution three-dimensional (3D) structure studies of the minifibers assembling with the FGL (having a long F1-G1 loop) and FGS (having a short F1-G1 loop) chaperones show that they exploit the same principle of donor-strand complementation for polymerization of subunits. The 3D structure of adhesive subunits bound to host-cell receptors and the final architecture of adhesive fimbrial organelles reveal two functional families of the organelles, respectively, possessing polyadhesive and monoadhesive binding. The FGL and FGS chaperone-assembled polyadhesins are encoded exclusively by the gene clusters of the γ3- and κ-monophyletic groups, respectively, while gene clusters belonging to the γ1-, γ2-, γ4-, and π-fimbrial clades exclusively encode FGS chaperone-assembled monoadhesins. Novel approaches are suggested for a rational design of antimicrobials inhibiting the organelle assembly or inhibiting their binding to host-cell receptors. Vaccines are currently under development based on the recombinant subunits of adhesins.
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Graham LL, Ceri H, Costerton JW. Lectin-like Proteins from Uroepithelial Cells which InhibitIn VitroAdherence of Three Urethral Bacterial Isolates to Uroepithelial Cells. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2009. [DOI: 10.3109/08910609209141293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- L. L. Graham
- Department of Biology, University of Calgary Calgary, Alberta, T2N 1N4, Canada
| | - H. Ceri
- Department of Biology, University of Calgary Calgary, Alberta, T2N 1N4, Canada
| | - J. W. Costerton
- Department of Biology, University of Calgary Calgary, Alberta, T2N 1N4, Canada
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25
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Jacobson SH. P-fimbriated Escherichia coli in adults with renal scarring and pyelonephritis. ACTA MEDICA SCANDINAVICA. SUPPLEMENTUM 2009; 713:1-64. [PMID: 2880464 DOI: 10.1111/j.0954-6820.1986.tb13963.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The commonest organism in urinary tract infections (UTI) is Escherichia coli. Pyelonephritogenic E.coli strains possess P-fimbriae which firmly attach to uroepithelial cells by recognition of a carbohydrate structure, alpha-D-Galp-(1-4)-beta-D-Galp, which is confined within all glycosphingolipids related to the human P-blood group antigens. Several investigators have studied virulence properties of E.coli and host resistance in relation to UTI. Uroepithelial cells from children and women with recurrent UTI have an increased capacity to bind E.coli. In contrast to previous studies the present one deals with patients with renal scarring, who constitute the major risk group among patients with UTI. P-fimbriae mediated binding to uroepithelial cells was studied and the risk of recurrent UTI in patients with renal scarring was determined. Ninety per cent of the E.coli isolates from female patients with acute non-obstructive pyelonephritis in this study possess P-fimbriae (I). The fecal E.coli colonies obtained from these patients were P-fimbriated in 55% compared to 11% of the fecal E.coli colonies from healthy controls. The P-blood group distribution in 56 female patients with renal scarring and a history of febrile UTI was the same as in a control group of 39 healthy subjects (II). A history of recurrent and/or early infections did not increase the percentage of the P1 blood group phenotype. Forty-nine female patients with renal scarring were prospectively investigated for the incidence of symptomatic UTI in relation to fecal colonization with P-fimbriated E.coli (III). Fifty-three per cent of the patients had altogether 65 episodes of symptomatic UTI during the three-year follow-up (0.036 infections per month). Eight patients (16%) had nine attacks of acute pyelonephritis and 4/5 of the tested E.coli strains from these patients were P-fimbriated. No relationship was demonstrated between the presence of P-fimbriated E.coli in the fecal flora and the development of subsequent acute pyelonephritis. The binding of P-fimbriated E.coli to uroepithelial cells from 19 female patients with renal scarring was studied with the fluorescence-activated cell sorting (FACS) analysis (IV). The uroepithelial cells from the patients with renal scarring exhibited a significantly higher binding capacity (p less than 0.01) than uroepithelial cells from healthy controls. Furthermore, uroepithelial cells from the patients with renal scarring and kidney insufficiency had a higher availability of P-fimbriae receptors on their uroepithelial cells than cells obtained from patients with renal scarring and normal renal function (r = -0.75, p less than 0.001) (V).(ABSTRACT TRUNCATED AT 400 WORDS)
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26
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Vandewalle A, Chassin C. [Renal collecting duct cells act as modulators of the innate immune response during ascending pyelonephritis]. Med Sci (Paris) 2009; 25:224-6. [PMID: 19361380 DOI: 10.1051/medsci/2009253224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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27
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Mestecky J, Russell MW. Specific antibody activity, glycan heterogeneity and polyreactivity contribute to the protective activity of S-IgA at mucosal surfaces. Immunol Lett 2009; 124:57-62. [PMID: 19524784 PMCID: PMC2697127 DOI: 10.1016/j.imlet.2009.03.013] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 03/26/2009] [Indexed: 01/19/2023]
Abstract
An explanation of the principles and mechanisms involved in peaceful co-existence between animals and the huge, diverse, and ever-changing microbiota that resides on their mucosal surfaces represents a challenging puzzle that is fundamental in everyday survival. In addition to mechanical barriers and a variety of innate defense factors, mucosal immunoglobulins (Igs) provide protection by two complementary mechanisms: specific antibody activity and innate, Ig glycan-mediated binding, both of which serve to contain the mucosal microbiota in its physiological niche. Thus, the interaction of bacterial ligands with IgA glycans constitutes a discrete mechanism that is independent of antibody specificity and operates primarily in the intestinal tract. This mucosal site is by far the most heavily colonized with an enormously diverse bacterial population, as well as the most abundant production site for antibodies, predominantly of the IgA isotype, in the entire immune system. In embodying both adaptive and innate immune mechanisms within a single molecule, S-IgA maintains comprehensive protection of mucosal surfaces with economy of structure and function.
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Affiliation(s)
- Jiri Mestecky
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35295-2170, USA.
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28
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Ragnarsdóttir B, Fischer H, Godaly G, Grönberg-Hernandez J, Gustafsson M, Karpman D, Lundstedt AC, Lutay N, Rämisch S, Svensson ML, Wullt B, Yadav M, Svanborg C. TLR- and CXCR1-dependent innate immunity: insights into the genetics of urinary tract infections. Eur J Clin Invest 2008; 38 Suppl 2:12-20. [PMID: 18826477 DOI: 10.1111/j.1365-2362.2008.02004.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The susceptibility to urinary tract infection (UTI) is controlled by the innate immune response and Toll like receptors (TLRs) are the sentinels of this response. If productive, TLR4 signalling may initiate the symptomatic disease process. In the absence of TLR4 signalling the infected host instead develops an asymptomatic carrier state. The activation of mucosal TLR4 is also influenced by the properties of the infecting strain, and pathogens use their virulence factors to trigger 'pathogen-specific' TLR4 responses in the urinary tract but do not respond to the asymptomatic carrier strains in patients with asymptomatic bacteriuria (ABU). The TLR4 dependence has been demonstrated in mice and the relevance of low TLR4 function for protection for human disease was recently confirmed in children with asymptomatic bacteriuria, who expressed less TLR4 than age matched controls. Functional chemokines and functional chemokine receptors are crucial for neutrophil recruitment, and for the neutrophil dependent bacterial clearance. Interleukin (IL)-8 receptor deficient mice develop acute septic infections and chronic tissue damage, due to aberrant neutrophil function. This mechanism is relevant for human UTI as pyelonephritis prone children express low levels of the human CXCL8 (Il-8) receptor, CXC chemokine receptor 1 (CXCR1) and often have heterozygous CXCR1 polymorphisms. This review illustrates how intimately the innate response and the susceptibility to UTI are linked and sophisticated recognition mechanisms that rely on microbial virulence and on host TLR4 and CXCR1 signalling.
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Affiliation(s)
- B Ragnarsdóttir
- Department of Microbiology, Immunology & Glycobiology (MIG), Institute of Laboratory Medicine, Lund University, Lund, Sweden
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Edén CS, Hagberg L, Hanson LA, Korhonen T, Leffler H, Olling S. Adhesion of Escherichia coli in urinary tract infection. CIBA FOUNDATION SYMPOSIUM 2008; 80:161-87. [PMID: 6114819 DOI: 10.1002/9780470720639.ch11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In individuals prone to urinary tract infections the intestine is colonized by E. Coli strains that possess a combination of properties determining virulence. Such an E. coli strain may colonize the vaginal and periurethral area and ascend the urinary tract. The ability to attach to the mucosal surface is thought to be essential for E. coli to colonize and to remain in the urinary tract. Most E. coli from patients with urinary tract infection show one or both of two adherence properties. One may depend on the recognition by type 1 fimbriae of mannose-containing residues in the urinary slime. It is measured as mannose-sensitive haemagglutination and is found on most E. coli strains. The second adherence property is detected as attachment to human urinary tract epithelial cells and as mannose-resistant agglutination of human erythrocytes. This may depend on the recognition of globo-series glycolipids in the epithelial cell surface. Possession of this adherence factor is strongly related to virulence. Most strains from patients with acute pyelonephritis and cystitis have this property but it is rare in strains from patients with asymptomatic bacteriuria and strains from normal faeces. Local antibodies may interfere with bacterial attachment, thus possibly preventing the colonization that precedes urinary tract infection or modifying an established infection. Vaginal antibodies are known to coat E. coli from the stools. Antibodies in the urine of patients with acute pyelonephritis inhibit attachment of the infecting strain to uroepithelial cells. Antibodies directed against several bacterial surface structures, for example O antigen and fimbriae, are likely to inhibit attachment by steric hindrance or agglutination. The role of antibodies in adhesion-mediating structure such as fimbriae in susceptibility to and the outcome of human urinary tract infection remains to be investigated.
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30
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Bergsten G, Wullt B, Schembri MA, Leijonhufvud I, Svanborg C. Do type 1 fimbriae promote inflammation in the human urinary tract? Cell Microbiol 2007; 9:1766-81. [PMID: 17359236 DOI: 10.1111/j.1462-5822.2007.00912.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Type 1 fimbriae have been implicated as virulence factors in animal models of urinary tract infection (UTI), but the function in human disease remains unclear. This study used a human challenge model to examine if type 1 fimbriae trigger inflammation in the urinary tract. The asymptomatic bacteriuria strain Escherichia coli 83972, which fails to express type 1 fimbriae, due to a 4.25 kb fimB-fimD deletion, was reconstituted with a functional fim gene cluster and fimbrial expression was monitored through a gfp reporter. Each patient was inoculated with the fim+ or fim- variants on separate occasions, and the host response to type 1 fimbriae was quantified by intraindividual comparisons of the responses to the fim+ or fim- isogens, using cytokines and neutrophils as end-points. Type 1 fimbriae did not promote inflammation and adherence was poor, as examined on exfoliated cells in urine. This was unexpected, as type 1 fimbriae enhanced the inflammatory response to the same strain in the murine urinary tract and as P fimbrial expression by E. coli 83972 enhances adherence and inflammation in challenged patients. We conclude that type 1 fimbriae do not contribute to the mucosal inflammatory response in the human urinary tract.
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Affiliation(s)
- Göran Bergsten
- Department of Microbiology, Immunology, and Glycobiology, Lund University, Lund, Sweden
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31
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Lee YM, Dodson KW, Hultgren SJ. Adaptor function of PapF depends on donor strand exchange in P-pilus biogenesis of Escherichia coli. J Bacteriol 2007; 189:5276-83. [PMID: 17496084 PMCID: PMC1951870 DOI: 10.1128/jb.01648-06] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
P-pilus biogenesis occurs via the highly conserved chaperone-usher pathway and involves the strict coordination of multiple subunit proteins. All nonadhesin structural P-pilus subunits possess the same topology, consisting of two domains: an incomplete immunoglobulin-like fold (pilin body) and an N-terminal extension. Pilus subunits form interactions with one another through donor strand exchange, occurring at the usher, in which the N-terminal extension of an incoming subunit completes the pilin body of the preceding subunit, allowing the incorporation of the subunit into the pilus fiber. In this study, pilus subunits in which the N-terminal extension was either deleted or swapped with that of another subunit were used to examine the role of each domain of PapF in functions involving donor strand exchange and hierarchical assembly. We found that the N-terminal extension of PapF is required to adapt the PapG adhesin to the tip of the fiber. The pilin body of PapF is required to efficiently initiate assembly of the remainder of the pilus, with the assistance of the N-terminal extension. Thus, distinct functions were assigned to each region of the PapF subunit. In conclusion, all pilin subunits possess the same overall architectural topology; however, each N-terminal extension and pilin body has specific functions in pilus biogenesis.
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Affiliation(s)
- Yvonne M Lee
- Department of Molecular Microbiology, Washington University School of Medicine, 660 South Euclid Ave., Campus Box 8230, St. Louis, MO 63110, USA
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Bidhendi SM, Sattari M, Pourbakhsh SA, Mobarez A, Vandyousefi J, Khaki P, Heidari MH, Kazemnejad A. Blocking adherence of uropathogenic Escherichia coli isolate to HEP-2 cells and bladder of mice in the presence of antibody against p-fimbriae. Biologicals 2007; 35:99-105. [PMID: 16879977 DOI: 10.1016/j.biologicals.2006.03.012] [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: 12/08/2005] [Revised: 03/21/2006] [Accepted: 03/26/2006] [Indexed: 11/17/2022] Open
Abstract
Presence of fimbriae on Escherichia coli isolated from the urine of patients with urinary tract infection was related to the ability of the bacteria to attach to human uroepithelial cells. One of the 50 isolates that expresses high MRHA p-fimbriae, selected and antibody against p-fimbriae from it, showed blocking of attachment of bacteria to HEP-2 cell in 1:1024 titer. Also, 1:512 titer of this antiserum to blocking of attachment in bladder tissue of mice is significant.
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Abstract
Urinary tract infections (UTIs) remain a significant clinical problem, despite antibiotic treatment and surgical correction of reflux and malformations. Here we propose that novel molecular tools may be applied to modernize and individualize the diagnosis and therapy of UTI. Determinants of bacterial virulence and host resistance are relatively well understood at the molecular level, and technology for their detection is within reach.
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Affiliation(s)
- G Godaly
- Institute of Laboratory Medicine, Department of Microbiology, Immunology and Glycobiology, Lund University, Lund, Sweden
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Lane MC, Mobley HLT. Role of P-fimbrial-mediated adherence in pyelonephritis and persistence of uropathogenic Escherichia coli (UPEC) in the mammalian kidney. Kidney Int 2007; 72:19-25. [PMID: 17396114 DOI: 10.1038/sj.ki.5002230] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
P fimbria, a mannose-resistant adhesin of uropathogenic Escherichia coli (UPEC), has been shown to be associated with acute pyelonephritis. The pap gene cluster encodes the proteins required for P-fimbrial biogenesis, including papG, which encodes the tip adhesin. The three most studied PapG molecular variants, which are shown to bind distinct isoreceptors, are PapGI, -II, and -III. PapGII preferentially binds globoside, or GbO4, a glycolipid isoreceptor of the human kidney. Studies using different animal models of ascending urinary tract infection (UTI) have demonstrated a variable role for P fimbriae, and specifically PapGII-mediated adherence, in renal colonization. The disparities in the results obtained from those studies are likely to be attributed to the differences in animal models and UPEC strains utilized. One explanation that is discussed in detail is the contribution of multiple fimbriae of UPEC that potentially mediate adherence to the mammalian kidney. Overall, P fimbriae appear to play some role in mediating adherence to uroepithelial cells in vivo and establishing an inflammatory response during renal colonization, thus contributing to kidney damage during acute pyelonephritis. To verify that P fimbriae contribute to the pathogenesis of UPEC during ascending UTI (and in particular acute pyelonephritis), future studies should be conducted to satisfy fully all three tenets of the molecular Koch's postulates, including complementation of a mutated allele.
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Affiliation(s)
- M C Lane
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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35
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Sakallioglu O, Sakallioglu AE. The effect of ABO-Rh blood group determinants on urinary tract infections. Int Urol Nephrol 2007; 39:577-9. [PMID: 17268901 DOI: 10.1007/s11255-006-0075-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Accepted: 03/21/2006] [Indexed: 11/28/2022]
Abstract
BACKGROUND Blood group antigens are a group of carbohydrate determinants found on erythrocytes, phagocytes, lymphocytes and certain epithelial tissues including urothelium. There are several publications that defines enhanced bacterial adhesions due to genetic markers such as blood group types. METHODS The ABO-Rh blood group distribution of patients with UTI and Escherichia coli(+) urine culture were compared with ABO-Rh blood group distribution of our country. RESULTS The distribution of blood groups was as follows; 36.6% A Rh+, 4.9% A Rh-, 12.2% B Rh+, 2.4% B Rh-, 31.7% O Rh+, 2.4% O Rh-, 4.9% AB Rh+, respectively; and none with AB Rh- blood group. There was a significant correlation between our study group and ABO-Rh phenotypes distribution of Turkish population. CONCLUSIONS The concordance of UTI with blood group ARh+ may be due to the most seen of ARh+ phenotype in the investigated population. We suggest that before defining the relationships on genetical markers, it would be more reliable to correlate them with their local distributions in the population.
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Affiliation(s)
- Onur Sakallioglu
- Pediatric Nephrology Unit, Gulhane Military Medicine Academy, Etlik, Ankara, Turkey.
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36
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Godaly G, Otto G, Burdick MD, Strieter RM, Svanborg C. Fimbrial lectins influence the chemokine repertoire in the urinary tract mucosa. Kidney Int 2007; 71:778-86. [PMID: 17228365 DOI: 10.1038/sj.ki.5002076] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The defense against mucosal infections relies on chemokines that recruit inflammatory cells to the mucosa. This study examined if the chemokine response to uro-pathogenic Escherichia coli is influenced by fimbrial expression. The CXC (CXCL1, CXCL5, CXCL8, CXCL9, CXCL10) and CC chemokines (CCL2, CCL3, CCL5) were quantified after in vitro infection of uro-epithelial cells with a fimbriated E. coli pyelonephritis isolate, or with P or type 1 fimbriated transformants of an avirulent E. coli K-12 strain. The response profile was shown to vary with the fimbrial type. Type 1 fimbriated E. coli elicited mainly CXCL1 and CXCL8, whereas P fimbriated E. coli stimulated CCL2 and CCL5 and class II were more potent chemokine inducers than class III P fimbriae. Chemokines were also quantified in urine samples from 73 patients with febrile urinary tract infection, and analyzed as a function of disease severity and fimbrial expression by the strain infecting each patient. A complex CXC and CC chemokine response was detected in patient urine, with a significant influence of the fimbrial type. The results show that virulence factors like fimbriae may modify the mucosal chemokine response. This mechanism may allow the host to adjust the inflammatory cell infiltrate to fit the infecting strain.
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Affiliation(s)
- G Godaly
- Department of MIG, Division of Laboratory Medicine, Lund University, Lund, Sweden.
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37
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Fischer H, Ellström P, Ekström K, Gustafsson L, Gustafsson M, Svanborg C. Ceramide as a TLR4 agonist; a putative signalling intermediate between sphingolipid receptors for microbial ligands and TLR4. Cell Microbiol 2007; 9:1239-51. [PMID: 17223929 DOI: 10.1111/j.1462-5822.2006.00867.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Mucosal Toll-like receptors (TLRs) respond to pathogens, but remain inert to the indigenous flora, suggesting that the TLRs can receive pathogen-specific signals. For example, TLR4 signalling is activated in CD14-negative epithelial cells by P-fimbriated, uropathogenic Escherichia coli, but not by lipopolysaccharide. The fimbriae use glycosphingolipids as recognition receptors and there is release of ceramide, which is the membrane-anchoring domain of the receptors. In this study, ceramide was identified as a TLR4 agonist and as a putative signalling intermediate between the glycosphingolipid recognition receptors and TLR4. Exogenous ceramide activated a TLR4-dependent epithelial cell response, as shown by exposing stably transfected TLR4-positive or -negative human embryonal kidney cells to C2 and C6 ceramide. A similar, TLR4-dependent response occurred after deliberate release of endogenous long-chained ceramide with sphingomyelinase. Microbial ligands with glycosphingolipid specificity (P fimbriae or the B subunit of Shiga toxin) were shown to increase the levels of ceramide and to trigger a TLR4-dependent response in epithelial cells. The results show that ceramide activates TLR4 signalling and suggest that this mechanism might allow pathogens to elicit mucosal TLR4 responses by perturbing sphingolipid receptors for virulence ligands like P fimbriae.
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Affiliation(s)
- Hans Fischer
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Sölvegatan 23, S-22362 Lund, Sweden
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Abstract
Urinary tract infection (UTI) is a common clinical syndrome in women. Most UTIs are caused by Escherichia coli. UTI has become a productive and accessible model system for studying the molecular details of how bacteria interact with mucosal surfaces and the nature of the host response. Important advances in the past year include the discovery of new virulence determinants; better understanding the pathogenic role of the ubiquitous motility organelle, the flagellum; and defining aspects of coordinate regulation of virulence determinants in the pathogenesis of UTI.
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Affiliation(s)
- Ann E Stapleton
- Department of Medicine, Division of Infectious Diseases, 1959 NE Pacific, Box 356523, University of Washington, Seattle, WA 98195, USA.
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Wright KJ, Hultgren SJ. Sticky fibers and uropathogenesis: bacterial adhesins in the urinary tract. Future Microbiol 2006; 1:75-87. [PMID: 17661687 DOI: 10.2217/17460913.1.1.75] [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: 11/21/2022] Open
Abstract
Adhesins mediate the introduction of bacteria to the host in the sometimes life-long relationship of uropathogenic Esherichia coli (UPEC) and the human urinary tract. As a class of extracellular proteins, adhesins enable bacteria to adhere to and, in some cases, invade host tissue; adhesins render UPEC virulent and permit host colonization. Adhesin receptor interactions at the host interface determine tissue tropism and disease progression in that niche, with each adhesin preferring unique sites within the urinary tract. This review focuses on known adhesins implicated in uropathogenesis, the structural basis of tissue tropism, postinvasion intracellular replication, current therapeutic design strategies, and newly discovered fimbrial gene clusters that may play a role in urinary tract infections.
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Affiliation(s)
- Kelly J Wright
- Washington University School of Medicine, Department of Molecular Microbiology, Washington University School of Medicine, MO 63110, USA.
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40
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Balagué C, Khan AA, Fernandez L, Redolfi AL, Aquili V, Voltattorni P, Hofer C, Ebner G, Dueñas S, Cerniglia CE. Occurrence of non-O157 shiga toxin-producing Escherichia coli in ready-to-eat food from supermarkets in Argentina. Food Microbiol 2006; 23:307-13. [PMID: 16943019 DOI: 10.1016/j.fm.2005.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Revised: 03/15/2005] [Accepted: 03/15/2005] [Indexed: 10/25/2022]
Abstract
Between June 2000 and December 2001, 500 food samples were collected from supermarkets and shops selling ready-to-eat food in Rosario, Argentina, and examined for Escherichia coli. Forty-nine E. coli isolates from food samples were further characterized for virulence genes by multiplex polymerase chain reaction (PCR) targeting the stx1, stx2, stx2e, eaeA, CNF1, CNF2, Einv, LTI, STI, and STII genes in four groups. Out of 49 E. coli isolates screened by multiplex PCR, only 10 possessed Shiga toxin genes, stx1 and stx2 genes and none possessed the other genes. The Shiga toxin positive E. coli strains (STEC) were isolated from soft, cottage cheeses, chicken with sauce and vegetables mayonase. These E. coli isolates were serogrouped and belonged to O18 (two strains), O8, O57w, O79, O44, and O128; three strains were untypeable. Pulsed-field gel electrophoresis (PFGE) with XbaI generated a unique profile for each, having 10-15 bands ranging from 50 to 500 kb, except that strain ARG 20 generated small bands and was partly degraded. These strains are potential foodborne pathogens and their presence in ready-to-eat food illustrates the need to keep a careful watch for the source of pathogens and then develop methods to control them.
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Affiliation(s)
- Claudia Balagué
- Faculty of Biochemical and Pharmaceutical Sciences, National University of Rosario, Argentina
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41
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Svensson M, Platt FM, Svanborg C. Glycolipid receptor depletion as an approach to specific antimicrobial therapy. FEMS Microbiol Lett 2006; 258:1-8. [PMID: 16630247 DOI: 10.1111/j.1574-6968.2006.00175.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Mucosal pathogens recognize glycoconjugate receptors at the site of infection, and attachment is an essential first step in disease pathogenesis. Inhibition of attachment may prevent disease, and several approaches have been explored. This review discusses the prevention of bacterial attachment and disease by agents that modify the glycosylation of cell surface glycoconjugates. Glycosylation inhibitors were tested in the urinary tract infection model, where P-fimbriated Escherichia coli rely on glycosphingolipid receptors for attachment and tissue attack. N-butyldeoxynojirimycin blocked the expression of glucosylceramide-derived glycosphingolipids and attachment was reduced. Bacterial persistence in the kidneys was impaired and the inflammatory response was abrogated. N-butyldeoxynojirimycin was inactive against strains which failed to engage these receptors, including type 1 fimbriated or nonadhesive strains. In vivo attachment has been successfully prevented by soluble receptor analogues, but there is little clinical experience of such inhibitors. Large-scale synthesis of complex carbohydrates, which could be used as attachment inhibitors, remains a technical challenge. Antibodies to bacterial lectins involved in attachment may be efficient inhibitors, and fimbrial vaccines have been developed. Glycosylation inhibitors have been shown to be safe and efficient in patients with lipid storage disease and might therefore be tested in urinary tract infection. This approach differs from current therapies, including antibiotics, in that it targets the pathogens which recognize these receptors.
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Affiliation(s)
- Majlis Svensson
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, University of Lund, Lund, Sweden
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42
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Fischer H, Yamamoto M, Akira S, Beutler B, Svanborg C. Mechanism of pathogen-specific TLR4 activation in the mucosa: fimbriae, recognition receptors and adaptor protein selection. Eur J Immunol 2006; 36:267-77. [PMID: 16385628 DOI: 10.1002/eji.200535149] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The mucosal host defence discriminates pathogens from commensals, and prevents infection while allowing the normal flora to persist. Paradoxically, Toll-like receptors (TLR) control the mucosal defence against pathogens, even though the TLR recognise conserved molecules like LPS, which are shared between pathogens and commensals. This study proposes a mechanism of pathogen-specific mucosal TLR4 activation, involving adhesive ligands and their host cell receptors. TLR4 signalling was activated in CD14-negative, LPS-unresponsive epithelial cells by P fimbriated, uropathogenic Escherichia coli but not by a mutant lacking fimbriae. Epithelial TLR4 signalling in vivo involved the glycosphingolipid receptors for P fimbriae and the adaptor proteins Toll/IL-1R (TIR) domain-containing adaptor inducing IFN-beta (TRIF)/TRIF-related adaptor molecule (TRAM), but myeloid differentiation protein 88 (MyD88)/TIR domain-containing adaptor protein were not required for the epithelial response. Substituting the P fimbriae with type 1 fimbriae changed TLR4 signalling from the TRIF to the MyD88 adaptor pathway. In addition, the adaptor proteins and the fimbrial type were found to influence bacterial clearance. Trif(-/-) and Tram(-/-) mice remained infected with P fimbriated E. coli but cleared the type 1 fimbriated strain, while Myd88(-/-) mice became carriers of both the P and the type 1 fimbriated bacteria. Thus, TLR4 may be engaged specifically by pathogens, when the proper cell surface receptors are engaged by virulence ligands.
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Affiliation(s)
- Hans Fischer
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, S-22362 Lund, Sweden.
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Svanborg C, Bergsten G, Fischer H, Godaly G, Gustafsson M, Karpman D, Lundstedt AC, Ragnarsdottir B, Svensson M, Wullt B. Uropathogenic Escherichia coli as a model of host-parasite interaction. Curr Opin Microbiol 2006; 9:33-9. [PMID: 16406777 DOI: 10.1016/j.mib.2005.12.012] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2005] [Accepted: 12/22/2005] [Indexed: 11/16/2022]
Abstract
Resistance to mucosal infection varies greatly in the population, but the molecular basis of disease susceptibility is often unknown. Studies of host-pathogen infections are helpful to identify virulence factors, which characterise disease isolates, and successful defence strategies of hosts that resist infection. In the urinary tract infection (UTI) model, we have identified crucial steps in the pathogen-activated innate host response, and studied the genetic control of these activation steps. Furthermore, genetic variation in the innate host-response defence is investigated as a basis of disease susceptibility. The Toll-like receptor 4 (TLR4) controls initial mucosal response to uropathogenic Escherichia coli (UPEC). Bacterial TLR4 activation in epithelial cells leads to chemokine secretion and neutrophil recruitment and TLR4 mutant mice develop an asymptomatic carrier state. The chemokine receptor CXCR1 determines the efficiency of neutrophil migration and activation, and thus of bacterial clearance. CXCR1 mutant mice become bacteremic and develop renal scars and studies in UTI prone children have detected low CXCR1 expression, suggesting that CXCR1 is also essential for human disease susceptibility.
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Affiliation(s)
- Catharina Svanborg
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
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Bergsten G, Wullt B, Svanborg C. Escherichia coli, fimbriae, bacterial persistence and host response induction in the human urinary tract. Int J Med Microbiol 2005; 295:487-502. [PMID: 16238023 DOI: 10.1016/j.ijmm.2005.07.008] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Urinary tract infections (UTI) are among the most common bacterial infections in humans. Symptomatic UTIs may be acute, recurrent or chronic but the most frequent form of UTI is asymptomatic bacteruria (ABU). In ABU, the mucosa remains inert, despite the presence of large bacterial numbers in urine. The difference in disease severity reflects the virulence of the infecting strain and the propensity of the host to respond to infection. It is essential to understand the molecular basis of disease diversity and the molecular interactions between bacteria and host that determine asymptomatic carriage and the transition to disease. We discuss the initial interactions between bacteria and the mucosal surfaces in the human urinary tract, and the bacterial factors involved in the breach of mucosal inertia. Specifically, the contribution of P and type 1 fimbriae to bacterial establishment and host response induction are investigated. The results show that P fimbriae serve as independent virulence factors when expressed by an ABU strain, by promoting the establishment of bacteriuria and the innate host response, which is the cause of symptoms and tissue damage. P fimbriae thus fulfil the molecular Koch postulates as independent virulence factors in the human urinary tract. Type 1 fimbriae, in contrast, did not act as virulence factors in this model, and thus appear to serve a different function in man than in the murine model.
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Affiliation(s)
- Göran Bergsten
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
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Torstensson E, KjÄll P, Richter-Dahlfors A. Imaging Techniques for the Study of Escherichia coli and Salmonella Infections. EcoSal Plus 2005; 1. [PMID: 26443519 DOI: 10.1128/ecosalplus.2.2.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Indexed: 06/05/2023]
Abstract
Infectious diseases are among the leading causes of mortality worldwide, and numerous bacterial species are included in the vast array of causative agents. This review describes microscopy-based techniques that can be used to study interactions between bacteria and infected host cells, bacterial gene expression in the infected animal, and bacteria-induced cell signaling in eukaryotic cells. As infectious model systems, urinary tract infections caused by uropathogenic Escherichia coli (UPEC) and a mouse model of typhoid fever caused by Salmonella enterica serovar Typhimurium are used. To study the interaction mechanism between bacteria and eukaryotic cells, one commonly uses cell lines, primary cells, and animal models. Within the host, bacteria can be located in various organs where they are exposed to different cell types, ranging from epithelial cells at the mucosal linings to phagocytic white blood cells. In each site, bacteria are exposed to specific sets of innate immune defense mechanisms, and to survive these threats, bacteria must rapidly adapt their gene expression profile to maximize their chance of survival in any situation. The rapid development of fluorescent reporter proteins and advances in microscopy-based techniques have provided new and promising approaches not only to locate bacteria in tissues, but also to analyze expression of virulence factors in individual bacteria and host cells during the progression of disease. These techniques enable, for the first time, studies of the complex microenvironments within infected organs and will reveal the alterations of bacterial physiology that occur during bacterial growth within a host.
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Affiliation(s)
- Elisabeth Torstensson
- Microbiology and Tumour Biology Center (MTC), Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Peter KjÄll
- Microbiology and Tumour Biology Center (MTC), Karolinska Institutet, 171 77 Stockholm, Sweden
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Akiba S, Yamamoto K, Kumagai H. Transglycosylation activity of the endo-beta-1,4-glucanase from Aspergillus niger IFO31125 and its application. J Biosci Bioeng 2005; 87:576-80. [PMID: 16232521 DOI: 10.1016/s1389-1723(99)80117-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/1998] [Accepted: 02/05/1999] [Indexed: 10/18/2022]
Abstract
Endo-beta-1,4-glucanase from Aspergillus niger was found to have an endo-type transglycosylation activity. The enzyme effectively transferred cellooligosaccharide residues to various 1-alkanols in the presence of cellopentaose as the oligosaccharide donor. By incubating the enzyme with 1-octanol and cellopentaose in the presence of acetonitrile, 1-octyl-cellotrioside was synthesized. The product was isolated by silica gel column chromatography and analyzed by mass spectrometry. p-NP-beta-Glc, p-NP-beta-Gal, p-NP-beta-GlcNAc, Ser, and Thr were also possible acceptors for the transglycosylation activity of the enzyme.
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Affiliation(s)
- S Akiba
- Biological Science Laboratories, Kao Corporation, 20 Higashi Fukashiba, Kamisu-machi, Kashima, Ibaraki 314-0103 Japan
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Abstract
Enterohaemorrhagic Escherichia coli has since the last 2 decades been known to cause severe and bloody diarrhoea as well as haemorrhagic colitis (HC) and haemorrhagic uraemic syndrome (HUS) especially among children. The importance of screening for EHEC among children and older patients with severe symptoms is apparent. Production of the verocytotoxins VT1 and VT2 are the main features of EHEC, and the VT types and mode of action during human infection is described. There are, however, other features adding to the pathogenicity. In this review we deal with the importance of properties such as fimbriae and adhesins as well as systems to meet the bacterial need for iron during infection. These factors are probably important for the establishment of EHEC in the gut and add to the bacterial virulence. It has now become evident that VT producing E. coli, irrespective of serogroup, might be human pathogens. We conclude that knowledge of the different possible virulence factors adds to the possibility of separating more virulent from less virulent isolates.
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Affiliation(s)
- Christina Welinder-Olsson
- Institute of Laboratory Medicine, Department of Clinical Bacteriology, Göteborg University, Göteborg, Sweden.
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Howell AB, Reed JD, Krueger CG, Winterbottom R, Cunningham DG, Leahy M. A-type cranberry proanthocyanidins and uropathogenic bacterial anti-adhesion activity. PHYTOCHEMISTRY 2005; 66:2281-91. [PMID: 16055161 DOI: 10.1016/j.phytochem.2005.05.022] [Citation(s) in RCA: 332] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 04/06/2005] [Indexed: 05/03/2023]
Abstract
Clinical, epidemiological and mechanistic studies support the role of cranberry (Vaccinium macrocarpon Ait.) in maintaining urinary tract health. Cranberry proanthocyanidins contain A-type linkages and have been associated with preventing adhesion of P-fimbriated uropathogenic Escherichia coli to uroepithelial cells. It is not known if the presence of the A-type linkage is a prerequisite for anti-adhesion activity. Other commercial sources of proanthocyanidins with all B-type linkages have not previously been screened for this activity. The goals of this study were to compare the in vitro anti-adhesion activity of A-linked proanthocyanidins from cranberry juice cocktail with the anti-adhesion activities of B-linked proanthocyanidins from commercial grape and apple juices, green tea and dark chocolate, and determine if anti-adhesion activity is detectable in human urine following consumption of single servings of each commercial food product. Structural heterogeneity and presence of the A-type linkage in cranberry proanthocyanidins was confirmed utilizing MALDI-TOF/MS and DI/ESI MS, as was the presence of all B-type linkages in the proanthocyanidins from the other commercial products. The isolated A-type proanthocyanidins from cranberry juice cocktail elicited in vitro anti-adhesion activity at 60 microg/ml, the B-type proanthocyanidins from grape exhibited minor activity at 1200 microg/ml, while other B-type proanthocyanidins were not active. Anti-adhesion activity in human urine was detected following cranberry juice cocktail consumption, but not after consumption of the non-cranberry food products. Results suggest that presence of the A-type linkage in cranberry proanthocyanidins may enhance both in vitro and urinary bacterial anti-adhesion activities and aid in maintaining urinary tract health.
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Affiliation(s)
- Amy B Howell
- Marucci Center for Blueberry Cranberry Research, Rutgers University, Chatsworth, NJ 08019, USA.
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Svensson M, Irjala H, Alm P, Holmqvist B, Lundstedt AC, Svanborg C. Natural history of renal scarring in susceptible mIL-8Rh-/- mice. Kidney Int 2005; 67:103-10. [PMID: 15610233 DOI: 10.1111/j.1523-1755.2005.00060.x] [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: 11/29/2022]
Abstract
BACKGROUND Urinary tract infections (UTIs) cause end-stage renal disease (ESRD) but the molecular mechanisms have remained unclear. Recently, the interleukin (IL)-8 receptor was shown to control disease susceptibility in mice and low IL-8 receptor expression was observed in pyelonephritis-prone patients. METHODS Intravesical Escherichia coli infection was established in mIL-8Rh-/- or Balb/c control mice. Survival, bacterial persistence, and histology were used as measurements of disease severity. RESULTS Within 2 days, 19/30 mIL-8Rh-/- mice developed lethal infection with bacteremia. Surviving mice remained infected and developed progressive renal damage with pathologic neutrophil accumulation and abscess formation first under the pelvic epithelium and then throughout the tissue. Recruited immune effector cells were unable to remove the dying neutrophils and frustrated macrophages formed foam cell aggregates. As a result, there was successive destruction of the mucosal barrier, medulla and cortex and necrosis of the renal papilla. The mIL-8Rh+/+ mice all survived and infection was cleared within a few days without symptoms or tissue pathology. CONCLUSION mIL-8Rh-/- mice develop acute bacteremic pyelonephritis and renal scarring due to a dysfunctional neutrophil response. The tissue damage resembles human disease, and these mice offer a model system to study the molecular mechanisms of renal scarring.
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Affiliation(s)
- Majlis Svensson
- Institute of Laboratory Medicine, Department of Microbiology, Immunology and Glycobiology, University of Lund, Lund, Sweden
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Bouckaert J, Berglund J, Schembri M, De Genst E, Cools L, Wuhrer M, Hung CS, Pinkner J, Slättegård R, Zavialov A, Choudhury D, Langermann S, Hultgren SJ, Wyns L, Klemm P, Oscarson S, Knight SD, De Greve H. Receptor binding studies disclose a novel class of high-affinity inhibitors of the Escherichia coli FimH adhesin. Mol Microbiol 2005; 55:441-55. [PMID: 15659162 DOI: 10.1111/j.1365-2958.2004.04415.x] [Citation(s) in RCA: 329] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mannose-binding type 1 pili are important virulence factors for the establishment of Escherichia coli urinary tract infections (UTIs). These infections are initiated by adhesion of uropathogenic E. coli to uroplakin receptors in the uroepithelium via the FimH adhesin located at the tips of type 1 pili. Blocking of bacterial adhesion is able to prevent infection. Here, we provide for the first time binding data of the molecular events underlying type 1 fimbrial adherence, by crystallographic analyses of the FimH receptor binding domains from a uropathogenic and a K-12 strain, and affinity measurements with mannose, common mono- and disaccharides, and a series of alkyl and aryl mannosides. Our results illustrate that the lectin domain of the FimH adhesin is a stable and functional entity and that an exogenous butyl alpha-D-mannoside, bound in the crystal structures, exhibits a significantly better affinity for FimH (Kd = 0.15 microM) than mannose (Kd = 2.3 microM). Exploration of the binding affinities of alpha- d-mannosides with longer alkyl tails revealed affinities up to 5 nM. Aryl mannosides and fructose can also bind with high affinities to the FimH lectin domain, with a 100-fold improvement and 15-fold reduction in affinity, respectively, compared with mannose. Taken together, these relative FimH affinities correlate exceptionally well with the relative concentrations of the same glycans needed for the inhibition of adherence of type 1 piliated E. coli. We foresee that our findings will spark new ideas and initiatives for the development of UTI vaccines and anti-adhesive drugs to prevent anticipated and recurrent UTIs.
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Affiliation(s)
- Julie Bouckaert
- Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel and Vlaams Interuniversitair Instituut voor Biotechnologie, Building E, Pleinlaan 2, 1050 Brussels, Belgium
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