151
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Lobato-Márquez D, Díaz-Orejas R, García-Del Portillo F. Toxin-antitoxins and bacterial virulence. FEMS Microbiol Rev 2016; 40:592-609. [PMID: 27476076 DOI: 10.1093/femsre/fuw022] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2016] [Indexed: 12/25/2022] Open
Abstract
Bacterial virulence relies on a delicate balance of signals interchanged between the invading microbe and the host. This communication has been extensively perceived as a battle involving harmful molecules produced by the pathogen and host defenses. In this review, we focus on a largely unexplored element of this dialogue, as are toxin-antitoxin (TA) systems of the pathogen. TA systems are reported to respond to stresses that are also found in the host and, as a consequence, could modulate the physiology of the intruder microbe. This view is consistent with recent studies that demonstrate a contribution of distinct TA systems to virulence since their absence alters the course of the infection. TA loci are stress response modules that, therefore, could readjust pathogen metabolism to favor the generation of slow-growing or quiescent cells 'before' host defenses irreversibly block essential pathogen activities. Some toxins of these TA modules have been proposed as potential weapons used by the pathogen to act on host targets. We discuss all these aspects based on studies that support some TA modules as important regulators in the pathogen-host interface.
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Affiliation(s)
- Damián Lobato-Márquez
- Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Darwin 3, 28049 Madrid, Spain Centro de Investigaciones Biológicas-CSIC (CIB-CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Ramón Díaz-Orejas
- Centro de Investigaciones Biológicas-CSIC (CIB-CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Francisco García-Del Portillo
- Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
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152
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Brannon JR, Hadjifrangiskou M. The arsenal of pathogens and antivirulence therapeutic strategies for disarming them. Drug Des Devel Ther 2016; 10:1795-806. [PMID: 27313446 PMCID: PMC4890686 DOI: 10.2147/dddt.s98939] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Pathogens deploy an arsenal of virulence factors (VFs) to establish themselves within their infectious niche. The discovery of antimicrobial compounds and their development into therapeutics has made a monumental impact on human and microbial populations. Although humans have used antimicrobials for medicinal and agricultural purposes, microorganism populations have developed and shared resistance mechanisms to persevere in the face of classical antimicrobials. However, a positive substitute is antivirulence therapy; antivirulence therapeutics prevent or interrupt an infection by counteracting a pathogen's VFs. Their application can reduce the use of broad-spectrum antimicrobials and dampen the frequency with which resistant strains emerge. Here, we summarize the contribution of VFs to various acute and chronic infections. In correspondence with this, we provide an overview of the research and development of antivirulence strategies.
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Affiliation(s)
- John R Brannon
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Maria Hadjifrangiskou
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Urologic Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
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153
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Abstract
Escherichia coli is one of the world's best-characterized organisms, because it has been extensively studied for over a century. However, most of this work has focused on E. coli grown under laboratory conditions that do not faithfully simulate its natural environments. Therefore, the historical perspectives on E. coli physiology and life cycle are somewhat skewed toward experimental systems that feature E. coli growing logarithmically in a test tube. Typically a commensal bacterium, E. coli resides in the lower intestines of a slew of animals. Outside of the lower intestine, E. coli can adapt and survive in a very different set of environmental conditions. Biofilm formation allows E. coli to survive, and even thrive, in environments that do not support the growth of planktonic populations. E. coli can form biofilms virtually everywhere: in the bladder during a urinary tract infection, on in-dwelling medical devices, and outside of the host on plants and in the soil. The E. coli extracellular matrix (ECM), primarily composed of the protein polymer named curli and the polysaccharide cellulose, promotes adherence to organic and inorganic surfaces and resistance to desiccation, the host immune system, and other antimicrobials. The pathways that govern E. coli biofilm formation, cellulose production, and curli biogenesis will be discussed in this article, which concludes with insights into the future of E. coli biofilm research and potential therapies.
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154
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Sahlberg Bang C, Kruse R, Johansson K, Persson K. Carbon monoxide releasing molecule-2 (CORM-2) inhibits growth of multidrug-resistant uropathogenic Escherichia coli in biofilm and following host cell colonization. BMC Microbiol 2016; 16:64. [PMID: 27067266 PMCID: PMC4828782 DOI: 10.1186/s12866-016-0678-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 03/29/2016] [Indexed: 12/24/2022] Open
Abstract
Background Increased resistance to antimicrobial agents is a characteristic of many bacteria growing in biofilms on for example indwelling urinary catheters or in intracellular bacterial reservoirs. Biofilm-related infections caused by multidrug-resistant bacteria, such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, are a major challenge. The aim of this study was to investigate if a carbon monoxide-releasing molecule (CORM-2) has antibacterial effects against ESBL-producing uropathogenic E. coli (UPEC) in the biofilm mode of growth and following colonization of host bladder epithelial cells. Results The effect of CORM-2 was examined on bacteria grown within an established biofilm (biofilm formed for 24 h on plastic surface) by a live/dead viability staining assay. CORM-2 (500 μM) exposure for 24 h killed approximately 60 % of the ESBL-producing UPEC isolate. A non-ESBL-producing UPEC isolate and the E. coli K-12 strain TG1 were also sensitive to CORM-2 exposure when grown in biofilms. The antibacterial effect of CORM-2 on planktonic bacteria was reduced and delayed in the stationary growth phase compared to the exponential growth phase. In human bladder epithelial cell colonization experiments, CORM-2 exposure for 4 h significantly reduced the bacterial counts of an ESBL-producing UPEC isolate. Conclusion This study shows that CORM-2 has antibacterial properties against multidrug-resistant UPEC under biofilm-like conditions and following host cell colonization, which motivate further studies of its therapeutic potential.
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Affiliation(s)
- Charlotte Sahlberg Bang
- Faculty of Medicine and Health, Örebro University, SE-701 82, Örebro, Sweden.,iRiSC - Inflammatory Responses and Infection Susceptibility Centre, Örebro University, SE-701 82, Örebro, Sweden
| | - Robert Kruse
- Faculty of Medicine and Health, Örebro University, SE-701 82, Örebro, Sweden.,iRiSC - Inflammatory Responses and Infection Susceptibility Centre, Örebro University, SE-701 82, Örebro, Sweden
| | - Kjell Johansson
- Faculty of Medicine and Health, Örebro University, SE-701 82, Örebro, Sweden
| | - Katarina Persson
- Faculty of Medicine and Health, Örebro University, SE-701 82, Örebro, Sweden. .,iRiSC - Inflammatory Responses and Infection Susceptibility Centre, Örebro University, SE-701 82, Örebro, Sweden.
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155
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Bacterial Etiologies and Antibiotic Susceptibility Pattern of Urinary Tract Infections at the Pediatric Ward of Dastgheib Hospital, Shiraz, Iran: A Three-Year Study (2009 - 2011). ARCHIVES OF CLINICAL INFECTIOUS DISEASES 2016. [DOI: 10.5812/archcid.28973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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156
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Balachandran AA, Wildman SS, Strutt M, Duckett J. Is chronic urinary infection a cause of overactive bladder? Eur J Obstet Gynecol Reprod Biol 2016; 201:108-12. [PMID: 27088624 DOI: 10.1016/j.ejogrb.2016.03.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/14/2016] [Accepted: 03/17/2016] [Indexed: 12/21/2022]
Abstract
Overactive bladder (OAB) is a diagnosis resulting from a combination of multiple underlying factors. Current traditional treatments are based on anticholinergic blockade which have marginal benefits and are associated with poor tolerability and continuation rates. There is mounting evidence that chronic low grade bacterial bladder colonisation may exacerbate OAB symptoms and may explain why the current treatment strategies are not always successful. However, standard diagnostic laboratory tests to identify the presence of such bacterial infection are unreliable. Newer technologies such as RNA sequencing and extended culture techniques, show that urine is not sterile and organisms that are found in urine may be responsible for OAB symptoms. This article aims to review the current evidence suggesting that micro-organisms in urine may be important in the aetiology of OAB or may exacerbate OAB symptoms.
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Affiliation(s)
- Aswini A Balachandran
- Department of Obstetrics and Gynaecology, Medway Maritime Hospital, Gillingham, Kent ME7 5NY, UK.
| | | | | | - Jonathan Duckett
- Department of Obstetrics and Gynaecology, Medway Maritime Hospital, Gillingham, Kent ME7 5NY, UK
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157
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Ting K, Aitken KJ, Penna F, Samiei AN, Sidler M, Jiang JX, Ibrahim F, Tolg C, Delgado-Olguin P, Rosenblum N, Bägli DJ. Uropathogenic E. coli (UPEC) Infection Induces Proliferation through Enhancer of Zeste Homologue 2 (EZH2). PLoS One 2016; 11:e0149118. [PMID: 26964089 PMCID: PMC4786126 DOI: 10.1371/journal.pone.0149118] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 01/27/2016] [Indexed: 01/13/2023] Open
Abstract
Host-pathogen interactions can induce epigenetic changes in the host directly, as well as indirectly through secreted factors. Previously, uropathogenic Escherichia coli (UPEC) was shown to increase DNA methyltransferase activity and expression, which was associated with methylation-dependent alterations in the urothelial expression of CDKN2A. Here, we showed that paracrine factors from infected cells alter expression of another epigenetic writer, EZH2, coordinate with proliferation. Urothelial cells were inoculated with UPEC, UPEC derivatives, or vehicle (mock infection) at low moi, washed, then maintained in media with Gentamycin. Urothelial conditioned media (CM) and extracellular vesicles (EV) were isolated after the inoculations and used to treat naïve urothelial cells. EZH2 increased with UPEC infection, inoculation-induced CM, and inoculation-induced EV vs. parallel stimulation derived from mock-inoculated urothelial cells. We found that infection also increased proliferation at one day post-infection, which was blocked by the EZH2 inhibitor UNC1999. Inhibition of demethylation at H3K27me3 had the opposite effect and augmented proliferation. CONCLUSION: Uropathogen-induced paracrine factors act epigenetically by altering expression of EZH2, which plays a key role in early host cell proliferative responses to infection.
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Affiliation(s)
- Kenneth Ting
- Faculty of Arts and Sciences, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Karen J. Aitken
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
- Urology Division, Department of Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
- * E-mail:
| | - Frank Penna
- Urology Division, Department of Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Alaleh Najdi Samiei
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Martin Sidler
- Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
- Urology Division, Department of Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jia-Xin Jiang
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Fadi Ibrahim
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Cornelia Tolg
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul Delgado-Olguin
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
- Physiology and Experimental Medicine, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Norman Rosenblum
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
- Nephrology Division, Department of Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Darius J. Bägli
- Faculty of Arts and Sciences, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Developmental and Stem Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
- Urology Division, Department of Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
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158
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Strengths and Limitations of Model Systems for the Study of Urinary Tract Infections and Related Pathologies. Microbiol Mol Biol Rev 2016; 80:351-67. [PMID: 26935136 DOI: 10.1128/mmbr.00067-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Urinary tract infections (UTIs) are some of the most common bacterial infections worldwide and are a source of substantial morbidity among otherwise healthy women. UTIs can be caused by a variety of microbes, but the predominant etiologic agent of these infections is uropathogenic Escherichia coli (UPEC). An especially troubling feature of UPEC-associated UTIs is their high rate of recurrence. This problem is compounded by the drastic increase in the global incidence of antibiotic-resistant UPEC strains over the past 15 years. The need for more-effective treatments for UTIs is driving research aimed at bettering our understanding of the virulence mechanisms and host-pathogen interactions that occur during the course of these infections. Surrogate models of human infection, including cell culture systems and the use of murine, porcine, avian, teleost (zebrafish), and nematode hosts, are being employed to define host and bacterial factors that modulate the pathogenesis of UTIs. These model systems are revealing how UPEC strains can avoid or overcome host defenses and acquire scarce nutrients while also providing insight into the virulence mechanisms used by UPEC within compromised individuals, such as catheterized patients. Here, we summarize our current understanding of UTI pathogenesis while also giving an overview of the model systems used to study the initiation, persistence, and recurrence of UTIs and life-threatening sequelae like urosepsis. Although we focus on UPEC, the experimental systems described here can also provide valuable insight into the disease processes associated with other bacterial pathogens both within the urinary tract and elsewhere within the host.
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159
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Oprea AE, Pandel LM, Dumitrescu AM, Andronescu E, Grumezescu V, Chifiriuc MC, Mogoantă L, Bălşeanu TA, Mogoşanu GD, Socol G, Grumezescu AM, Iordache F, Maniu H, Chirea M, Holban AM. Bioactive ZnO Coatings Deposited by MAPLE-An Appropriate Strategy to Produce Efficient Anti-Biofilm Surfaces. Molecules 2016; 21:molecules21020220. [PMID: 26891290 PMCID: PMC6273712 DOI: 10.3390/molecules21020220] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 02/03/2016] [Accepted: 02/05/2016] [Indexed: 11/16/2022] Open
Abstract
Deposition of bioactive coatings composed of zinc oxide, cyclodextrin and cefepime (ZnO/CD/Cfp) was performed by the Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The obtained nanostructures were characterized by X-ray diffraction, IR microscopy and scanning electron microscopy. The efficient release of cefepime was correlated with an increased anti-biofilm activity of ZnO/CD/Cfp composites. In vitro and in vivo tests have revealed a good biocompatibility of ZnO/CD/Cfp coatings, which recommend them as competitive candidates for the development of antimicrobial surfaces with biomedical applications. The release of the fourth generation cephalosporin Cfp in a biologically active form from the ZnO matrix could help preventing the bacterial adhesion and the subsequent colonization and biofilm development on various surfaces, and thus decreasing the risk of biofilm-related infections.
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Affiliation(s)
- Alexandra Elena Oprea
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest,1-7 Polizu Street, Bucharest 011061, Romania.
| | - Loredana Mihaela Pandel
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest,1-7 Polizu Street, Bucharest 011061, Romania.
| | - Ana Maria Dumitrescu
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest,1-7 Polizu Street, Bucharest 011061, Romania.
| | - Ecaterina Andronescu
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest,1-7 Polizu Street, Bucharest 011061, Romania.
| | - Valentina Grumezescu
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest,1-7 Polizu Street, Bucharest 011061, Romania.
- Lasers Department, National Institute for Lasers, Plasma & Materials, P. O. Box MG-36, Magurele 769231, Romania.
| | - Mariana Carmen Chifiriuc
- Microbiology Immunology Department, Faculty of Biology, University of Bucharest, 1-3 Portocalelor Lane, Sector 5, Bucharest 77206, Romania.
- Research Institute of the University of Bucharest, ICUB, Splaiul Independentei 91-95, Bucharest 010271, Romania.
| | - Laurenţiu Mogoantă
- Research Center for Microscopic Morphology and Immunology, University of Medicine and Pharmacy of Craiova, Petru Rares Street, No. 2, Craiova 200349, Romania.
| | - Tudor-Adrian Bălşeanu
- Research Center for Clinical and Experimental Medicine, University of Medicine and Pharmacy of Craiova, Petru Rares Street, No. 2, Craiova 200349, Romania.
| | - George Dan Mogoşanu
- Department of Pharmacognosy & Phytotherapy, Faculty of Pharmacy, University of Medicine and Pharmacy of Craiova, Petru Rares Street, No. 2, Craiova 200349, Romania.
| | - Gabriel Socol
- Lasers Department, National Institute for Lasers, Plasma & Materials, P. O. Box MG-36, Magurele 769231, Romania.
| | - Alexandru Mihai Grumezescu
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest,1-7 Polizu Street, Bucharest 011061, Romania.
| | - Florin Iordache
- Flow Cytometry and Cell Therapy Laboratory, Institute of Cellular Biology and Pathology "NicolaeSimionescu" (ICBP), Bucharest 050568, Romania.
| | - Horia Maniu
- Flow Cytometry and Cell Therapy Laboratory, Institute of Cellular Biology and Pathology "NicolaeSimionescu" (ICBP), Bucharest 050568, Romania.
| | - Mariana Chirea
- Department of Electrical & Electronics Engineering, IDEALAB, Koç University, Rumeli Feneri Yolu, Sariyer, Istanbul 34450, Turkey.
| | - Alina Maria Holban
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest,1-7 Polizu Street, Bucharest 011061, Romania.
- Microbiology Immunology Department, Faculty of Biology, University of Bucharest, 1-3 Portocalelor Lane, Sector 5, Bucharest 77206, Romania.
- Research Institute of the University of Bucharest, ICUB, Splaiul Independentei 91-95, Bucharest 010271, Romania.
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160
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Histone Deacetylase 6 Regulates Bladder Architecture and Host Susceptibility to Uropathogenic Escherichia coli. Pathogens 2016; 5:pathogens5010020. [PMID: 26907353 PMCID: PMC4810141 DOI: 10.3390/pathogens5010020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/05/2016] [Indexed: 01/05/2023] Open
Abstract
Histone deacetylase 6 (HDAC6) is a non-canonical, mostly cytosolic histone deacetylase that has a variety of interacting partners and substrates. Previous work using cell-culture based assays coupled with pharmacological inhibitors and gene-silencing approaches indicated that HDAC6 promotes the actin- and microtubule-dependent invasion of host cells by uropathogenic Escherichia coli (UPEC). These facultative intracellular pathogens are the major cause of urinary tract infections. Here, we examined the involvement of HDAC6 in bladder colonization by UPEC using HDAC6 knockout mice. Though UPEC was unable to invade HDAC6(-/-) cells in culture, the bacteria had an enhanced ability to colonize the bladders of mice that lacked HDAC6. This effect was transient, and by six hours post-inoculation bacterial titers in the HDAC6(-/-) mice were reduced to levels seen in wild type control animals. Subsequent analyses revealed that the mutant mice had greater bladder volume capacity and fluid retention, along with much higher levels of acetylated a-tubulin. In addition, infiltrating neutrophils recovered from the HDAC6(-/-) bladder harbored significantly more viable bacteria than their wild type counterparts. Cumulatively, these changes may negate any inhibitory effects that the lack of HDAC6 has on UPEC entry into individual host cells, and suggest roles for HDAC6 in other urological disorders such as urinary retention.
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161
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Jarvis C, Han Z, Kalas V, Klein R, Pinkner JS, Ford B, Binkley J, Cusumano CK, Cusumano Z, Mydock-McGrane L, Hultgren SJ, Janetka JW. Antivirulence Isoquinolone Mannosides: Optimization of the Biaryl Aglycone for FimH Lectin Binding Affinity and Efficacy in the Treatment of Chronic UTI. ChemMedChem 2016; 11:367-73. [PMID: 26812660 DOI: 10.1002/cmdc.201600006] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Indexed: 12/26/2022]
Abstract
Uropathogenic E. coli (UPEC) employ the mannose-binding adhesin FimH to colonize the bladder epithelium during urinary tract infection (UTI). Previously reported FimH antagonists exhibit good potency and efficacy, but low bioavailability and a short half-life in vivo. In a rational design strategy, we obtained an X-ray structure of lead mannosides and then designed mannosides with improved drug-like properties. We show that cyclizing the carboxamide onto the biphenyl B-ring aglycone of biphenyl mannosides into a fused heterocyclic ring, generates new biaryl mannosides such as isoquinolone 22 (2-methyl-4-(1-oxo-1,2-dihydroisoquinolin-7-yl)phenyl α-d-mannopyranoside) with enhanced potency and in vivo efficacy resulting from increased oral bioavailability. N-Substitution of the isoquinolone aglycone with various functionalities produced a new potent subseries of FimH antagonists. All analogues of the subseries have higher FimH binding affinity than unsubstituted lead 22, as determined by thermal shift differential scanning fluorimetry assay. Mannosides with pyridyl substitution on the isoquinolone group inhibit bacteria-mediated hemagglutination and prevent biofilm formation by UPEC with single-digit nanomolar potency, which is unprecedented for any FimH antagonists or any other antivirulence compounds reported to date.
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Affiliation(s)
- Cassie Jarvis
- Washington University School of Medicine, Department of Biochemistry and Molecular Biophysics, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Zhenfu Han
- Washington University School of Medicine, Department of Biochemistry and Molecular Biophysics, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Vasilios Kalas
- Washington University School of Medicine, Department of Molecular Microbiology, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Roger Klein
- Washington University School of Medicine, Department of Molecular Microbiology, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Jerome S Pinkner
- Washington University School of Medicine, Department of Molecular Microbiology, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Bradley Ford
- Washington University School of Medicine, Department of Molecular Microbiology, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Jana Binkley
- Washington University School of Medicine, Department of Molecular Microbiology, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Corinne K Cusumano
- Washington University School of Medicine, Department of Molecular Microbiology, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Zachary Cusumano
- Fimbrion Therapeutics Inc., 4041 Forest Park Ave., St. Louis, MO, 63108, USA
| | | | - Scott J Hultgren
- Washington University School of Medicine, Department of Molecular Microbiology, 660 S. Euclid Ave., St. Louis, MO, 63110, USA. .,Washington University School of Medicine, Center for Women's Infectious Disease Research (cWIDR), 660 S. Euclid Ave., St. Louis, MO, 63110, USA.
| | - James W Janetka
- Washington University School of Medicine, Department of Biochemistry and Molecular Biophysics, 660 S. Euclid Ave., St. Louis, MO, 63110, USA. .,Washington University School of Medicine, Center for Women's Infectious Disease Research (cWIDR), 660 S. Euclid Ave., St. Louis, MO, 63110, USA.
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162
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Uropathogenic Escherichia coli Metabolite-Dependent Quiescence and Persistence May Explain Antibiotic Tolerance during Urinary Tract Infection. mSphere 2016; 1:mSphere00055-15. [PMID: 27303698 PMCID: PMC4863606 DOI: 10.1128/msphere.00055-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/04/2015] [Indexed: 12/16/2022] Open
Abstract
In the present study, it is shown that although Escherichia coli CFT073, a human uropathogenic (UPEC) strain, grows in liquid glucose M9 minimal medium, it fails to grow on glucose M9 minimal medium agar plates seeded with ≤10(6) CFU. The cells on glucose plates appear to be in a "quiescent" state that can be prevented by various combinations of lysine, methionine, and tyrosine. Moreover, the quiescent state is characteristic of ~80% of E. coli phylogenetic group B2 multilocus sequence type 73 strains, as well as 22.5% of randomly selected UPEC strains isolated from community-acquired urinary tract infections in Denmark. In addition, E. coli CFT073 quiescence is not limited to glucose but occurs on agar plates containing a number of other sugars and acetate as sole carbon sources. It is also shown that a number of E. coli CFT073 mini-Tn5 metabolic mutants (gnd, gdhA, pykF, sdhA, and zwf) are nonquiescent on glucose M9 minimal agar plates and that quiescence requires a complete oxidative tricarboxylic acid (TCA) cycle. In addition, evidence is presented that, although E. coli CFT073 quiescence and persistence in the presence of ampicillin are alike in that both require a complete oxidative TCA cycle and each can be prevented by amino acids, E. coli CFT073 quiescence occurs in the presence or absence of a functional rpoS gene, whereas maximal persistence requires a nonfunctional rpoS. Our results suggest that interventions targeting specific central metabolic pathways may mitigate UPEC infections by interfering with quiescence and persistence. IMPORTANCE Recurrent urinary tract infections (UTIs) affect 10 to 40% of women. In up to 77% of those cases, the recurrent infections are caused by the same uropathogenic E. coli (UPEC) strain that caused the initial infection. Upon infection of urothelial transitional cells in the bladder, UPEC appear to enter a nongrowing quiescent intracellular state that is thought to serve as a reservoir responsible for recurrent UTIs. Here, we report that many UPEC strains enter a quiescent state when ≤10(6) CFU are seeded on glucose M9 minimal medium agar plates and show that mutations in several genes involved in central carbon metabolism prevent quiescence, as well as persistence, possibly identifying metabolic pathways involved in UPEC quiescence and persistence in vivo.
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163
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Avalos Vizcarra I, Hosseini V, Kollmannsberger P, Meier S, Weber SS, Arnoldini M, Ackermann M, Vogel V. How type 1 fimbriae help Escherichia coli to evade extracellular antibiotics. Sci Rep 2016; 6:18109. [PMID: 26728082 PMCID: PMC4700443 DOI: 10.1038/srep18109] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 11/04/2015] [Indexed: 01/06/2023] Open
Abstract
To survive antibiotics, bacteria use two different strategies: counteracting antibiotic effects by expression of resistance genes or evading their effects e.g. by persisting inside host cells. Since bacterial adhesins provide access to the shielded, intracellular niche and the adhesin type 1 fimbriae increases bacterial survival chances inside macrophages, we asked if fimbriae also influenced survival by antibiotic evasion. Combined gentamicin survival assays, flow cytometry, single cell microscopy and kinetic modeling of dose response curves showed that type 1 fimbriae increased the adhesion and internalization by macrophages. This was caused by strongly decreased off-rates and affected the number of intracellular bacteria but not the macrophage viability and morphology. Fimbriae thus promote antibiotic evasion which is particularly relevant in the context of chronic infections.
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Affiliation(s)
- Ima Avalos Vizcarra
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zürich, 8093 Zürich, Switzerland
| | - Vahid Hosseini
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zürich, 8093 Zürich, Switzerland
| | - Philip Kollmannsberger
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zürich, 8093 Zürich, Switzerland
| | - Stefanie Meier
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zürich, 8093 Zürich, Switzerland
| | - Stefan S Weber
- Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Markus Arnoldini
- Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland.,Department of Environmental Microbiology, Eawag, 8600 Dübendorf, Switzerland
| | - Martin Ackermann
- Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland.,Department of Environmental Microbiology, Eawag, 8600 Dübendorf, Switzerland
| | - Viola Vogel
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zürich, 8093 Zürich, Switzerland
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164
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Kell DB, Kenny LC. A Dormant Microbial Component in the Development of Preeclampsia. Front Med (Lausanne) 2016; 3:60. [PMID: 27965958 PMCID: PMC5126693 DOI: 10.3389/fmed.2016.00060] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 11/04/2016] [Indexed: 12/12/2022] Open
Abstract
Preeclampsia (PE) is a complex, multisystem disorder that remains a leading cause of morbidity and mortality in pregnancy. Four main classes of dysregulation accompany PE and are widely considered to contribute to its severity. These are abnormal trophoblast invasion of the placenta, anti-angiogenic responses, oxidative stress, and inflammation. What is lacking, however, is an explanation of how these themselves are caused. We here develop the unifying idea, and the considerable evidence for it, that the originating cause of PE (and of the four classes of dysregulation) is, in fact, microbial infection, that most such microbes are dormant and hence resist detection by conventional (replication-dependent) microbiology, and that by occasional resuscitation and growth it is they that are responsible for all the observable sequelae, including the continuing, chronic inflammation. In particular, bacterial products such as lipopolysaccharide (LPS), also known as endotoxin, are well known as highly inflammagenic and stimulate an innate (and possibly trained) immune response that exacerbates the inflammation further. The known need of microbes for free iron can explain the iron dysregulation that accompanies PE. We describe the main routes of infection (gut, oral, and urinary tract infection) and the regularly observed presence of microbes in placental and other tissues in PE. Every known proteomic biomarker of "preeclampsia" that we assessed has, in fact, also been shown to be raised in response to infection. An infectious component to PE fulfills the Bradford Hill criteria for ascribing a disease to an environmental cause and suggests a number of treatments, some of which have, in fact, been shown to be successful. PE was classically referred to as endotoxemia or toxemia of pregnancy, and it is ironic that it seems that LPS and other microbial endotoxins really are involved. Overall, the recognition of an infectious component in the etiology of PE mirrors that for ulcers and other diseases that were previously considered to lack one.
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Affiliation(s)
- Douglas B. Kell
- School of Chemistry, The University of Manchester, Manchester, UK
- The Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
- Centre for Synthetic Biology of Fine and Speciality Chemicals, The University of Manchester, Manchester, UK
- *Correspondence: Douglas B. Kell,
| | - Louise C. Kenny
- The Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland
- Department of Obstetrics and Gynecology, University College Cork, Cork, Ireland
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165
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Vumma R, Bang CS, Kruse R, Johansson K, Persson K. Antibacterial effects of nitric oxide on uropathogenic Escherichia coli during bladder epithelial cell colonization--a comparison with nitrofurantoin. J Antibiot (Tokyo) 2015; 69:183-6. [PMID: 26531685 DOI: 10.1038/ja.2015.112] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 09/30/2015] [Accepted: 10/08/2015] [Indexed: 02/05/2023]
Affiliation(s)
- Ravi Vumma
- School of Health and Medical Sciences, Örebro University, Örebro, Sweden
| | - Charlotte Sahlberg Bang
- School of Health and Medical Sciences, Örebro University, Örebro, Sweden.,iRiSC-Inflammatory Responses and Infection Susceptibility Centre, Örebro University, Örebro, Sweden
| | - Robert Kruse
- School of Health and Medical Sciences, Örebro University, Örebro, Sweden.,iRiSC-Inflammatory Responses and Infection Susceptibility Centre, Örebro University, Örebro, Sweden
| | - Kjell Johansson
- School of Health and Medical Sciences, Örebro University, Örebro, Sweden
| | - Katarina Persson
- School of Health and Medical Sciences, Örebro University, Örebro, Sweden.,iRiSC-Inflammatory Responses and Infection Susceptibility Centre, Örebro University, Örebro, Sweden
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166
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167
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Pichl CM, Feilhauer S, Schwaigerlehner RM, Gabor F, Wirth M, Neutsch L. Glycan-mediated uptake in urothelial primary cells: Perspectives for improved intravesical drug delivery in urinary tract infections. Int J Pharm 2015; 495:710-8. [DOI: 10.1016/j.ijpharm.2015.09.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/08/2015] [Accepted: 09/11/2015] [Indexed: 10/23/2022]
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168
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Chahales P, Thanassi DG. Structure, Function, and Assembly of Adhesive Organelles by Uropathogenic Bacteria. Microbiol Spectr 2015; 3:10.1128/microbiolspec.UTI-0018-2013. [PMID: 26542038 PMCID: PMC4638162 DOI: 10.1128/microbiolspec.uti-0018-2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Indexed: 01/02/2023] Open
Abstract
Bacteria assemble a wide range of adhesive proteins, termed adhesins, to mediate binding to receptors and colonization of surfaces. For pathogenic bacteria, adhesins are critical for early stages of infection, allowing the bacteria to initiate contact with host cells, colonize different tissues, and establish a foothold within the host. The adhesins expressed by a pathogen are also critical for bacterial-bacterial interactions and the formation of bacterial communities, including biofilms. The ability to adhere to host tissues is particularly important for bacteria that colonize sites such as the urinary tract, where the flow of urine functions to maintain sterility by washing away non-adherent pathogens. Adhesins vary from monomeric proteins that are directly anchored to the bacterial surface to polymeric, hair-like fibers that extend out from the cell surface. These latter fibers are termed pili or fimbriae, and were among the first identified virulence factors of uropathogenic Escherichia coli. Studies since then have identified a range of both pilus and non-pilus adhesins that contribute to bacterial colonization of the urinary tract, and have revealed molecular details of the structures, assembly pathways, and functions of these adhesive organelles. In this review, we describe the different types of adhesins expressed by both Gram-negative and Gram-positive uropathogens, what is known about their structures, how they are assembled on the bacterial surface, and the functions of specific adhesins in the pathogenesis of urinary tract infections.
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Affiliation(s)
- Peter Chahales
- Center for Infectious Diseases and Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794
| | - David G Thanassi
- Center for Infectious Diseases and Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794
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169
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Wu N, He L, Cui P, Wang W, Yuan Y, Liu S, Xu T, Zhang S, Wu J, Zhang W, Zhang Y. Ranking of persister genes in the same Escherichia coli genetic background demonstrates varying importance of individual persister genes in tolerance to different antibiotics. Front Microbiol 2015; 6:1003. [PMID: 26483762 PMCID: PMC4588708 DOI: 10.3389/fmicb.2015.01003] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/07/2015] [Indexed: 12/31/2022] Open
Abstract
Despite the identification of many genes and pathways involved in the persistence phenomenon of bacteria, the relative importance of these genes in a single organism remains unclear. Here, using Escherichia coli as a model, we generated mutants of 21 known candidate persister genes and compared the relative importance of these mutants in persistence to various antibiotics (ampicillin, gentamicin, norfloxacin, and trimethoprim) at different times. We found that oxyR, dnaK, sucB, relA, rpoS, clpB, mqsR, and recA were prominent persister genes involved in persistence to multiple antibiotics. These genes map to the following pathways: antioxidative defense pathway (oxyR), global regulators (dnaK, clpB, and rpoS), energy production (sucB), stringent response (relA), toxin-antitoxin (TA) module (mqsR), and SOS response (recA). Among the TA modules, the ranking order was mqsR, lon, relE, tisAB, hipA, and dinJ. Intriguingly, rpoS deletion caused a defect in persistence to gentamicin but increased persistence to ampicillin and norfloxacin. Mutants demonstrated dramatic differences in persistence to different antibiotics at different time points: some mutants (oxyR, dnaK, phoU, lon, recA, mqsR, and tisAB) displayed defect in persistence from early time points, while other mutants (relE, smpB, glpD, umuD, and tnaA) showed defect only at later time points. These results indicate that varying hierarchy and importance of persister genes exist and that persister genes can be divided into those involved in shallow persistence and those involved in deep persistence. Our findings suggest that the persistence phenomenon is a dynamic process with different persister genes playing roles of variable significance at different times. These findings have implications for improved understanding of persistence phenomenon and developing new drugs targeting persisters for more effective cure of persistent infections.
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Affiliation(s)
- Nan Wu
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Lei He
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Peng Cui
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Wenjie Wang
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Youhua Yuan
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Shuang Liu
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Tao Xu
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Shanshan Zhang
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Jing Wu
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Wenhong Zhang
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China
| | - Ying Zhang
- Key Lab of Molecular Virology, Institute of Medical Microbiology, Department of Infectious Diseases, Huashan Hospital, Fudan University Shanghai, China ; Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University Baltimore, MD, USA
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170
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Gandee L, Hsieh JT, Sperandio V, Moreira CG, Lai CH, Zimmern PE. The efficacy of immediate versus delayed antibiotic administration on bacterial growth and biofilm production of selected strains of uropathogenic Escherichia coli and Pseudomonas aeruginosa. Int Braz J Urol 2015; 41:67-77. [PMID: 25928511 PMCID: PMC4752058 DOI: 10.1590/s1677-5538.ibju.2015.01.10] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 06/01/2014] [Indexed: 12/02/2022] Open
Abstract
Purpose The treatment of urinary tract infections (UTI) with antibiotics is commonly used, but recurrence and antibiotic resistance have been growing and concerning clinicians. We studied whether the rapid onset of a protective biofilm may be responsible for the lack of effectiveness of antibiotics against selected bacteria. Materials and Methods Two established uropathogenic Escherichia coli strains, UTI89 and CFT073, and two Pseudomonas aeruginosa strains, PA01 and Boston-41501, were studied to establish a reliable biofilm formation process. Bacterial growth (BG) was determined by optical density at 600 nm (OD 600) using a spectrophotometer, while biofilm formation (BF) using crystal violet staining was measured at OD 550. Next, these bacterial strains were treated with clinically relevant antibiotics, ciprofloxacin HCl (200 ng/mL and 2 μg/mL), nitrofurantoin (20 μg/mL and 40 μg/mL) and ampicillin (50 μg/mL) at time points of 0 (T0) or after 6 hours of culture (T6). All measurements, including controls (bacteria -1% DMSO), were done in triplicates and repeated three times for consistency. Results The tested antibiotics effectively inhibited both BG and BF when administered at T0 for UPEC strains, but not when the antibiotic administration started 6 hours later. For Pseudomonas strains, only Ciprofloxacin was able to significantly inhibit bacterial growth at T0 but only at the higher concentration of 2 μg/mL for T6. Conclusion When established UPEC and Pseudomonas bacteria were allowed to culture for 6 hours before initialization of treatment, the therapeutic effect of selected antibiotics was greatly suppressed when compared to immediate treatment, probably as a result of the protective nature of the biofilm.
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Affiliation(s)
- Leah Gandee
- UT Southwestern Medical Center, Dallas, Texas, USA
| | | | | | | | - Chih-Ho Lai
- UT Southwestern Medical Center, Dallas, Texas, USA
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171
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Stærk K, Khandige S, Kolmos HJ, Møller-Jensen J, Andersen TE. Uropathogenic Escherichia coli Express Type 1 Fimbriae Only in Surface Adherent Populations Under Physiological Growth Conditions. J Infect Dis 2015; 213:386-94. [PMID: 26290608 DOI: 10.1093/infdis/jiv422] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 08/10/2015] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Most uropathogenic Escherichia coli (UPEC) strains harbor genes encoding adhesive type 1 fimbria (T1F). T1F is a key factor for successful establishment of urinary tract infection. However, UPEC strains typically do not express T1F in the bladder urine, and little is understood about its induction in vivo. METHODS A flow chamber infection model was used to grow UPEC under conditions simulating distinct infection niches in the bladder. Type 1 fimbriation on isolated UPEC was subsequently determined by yeast cell agglutination and immunofluorescence microscopy, and the results were correlated with the ability to adhere to and invade cultured human bladder cells. RESULTS Although inactive during planktonic growth in urine, T1F expression occurs when UPEC settles on and infects bladder epithelial cells or colonizes catheters. As a result, UPEC in these sessile populations enhances bladder cell adhesion and invasion potential. Only T1F-negative UPEC are subsequently released to the urine, thus limiting T1F expression to surface-associated UPEC alone. CONCLUSIONS Our results demonstrate that T1F expression is strictly regulated under physiological growth conditions with increased expression during surface growth adaptation and infection of uroepithelial cells. This leads to separation of UPEC into low-expression planktonic populations and high-expression sessile populations.
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Affiliation(s)
- Kristian Stærk
- Research Unit of Clinical Microbiology Odense University Hospital, Denmark
| | - Surabhi Khandige
- Department of Biochemistry and Molecular Biology, University of Southern Denmark
| | - Hans Jørn Kolmos
- Research Unit of Clinical Microbiology Odense University Hospital, Denmark
| | - Jakob Møller-Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark
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172
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Schumacher MA, Balani P, Min J, Chinnam NB, Hansen S, Vulić M, Lewis K, Brennan RG. HipBA-promoter structures reveal the basis of heritable multidrug tolerance. Nature 2015. [PMID: 26222023 DOI: 10.1038/nature14662] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Multidrug tolerance is largely responsible for chronic infections and caused by a small population of dormant cells called persisters. Selection for survival in the presence of antibiotics produced the first genetic link to multidrug tolerance: a mutant in the Escherichia coli hipA locus. HipA encodes a serine-protein kinase, the multidrug tolerance activity of which is neutralized by binding to the transcriptional regulator HipB and hipBA promoter. The physiological role of HipA in multidrug tolerance, however, has been unclear. Here we show that wild-type HipA contributes to persister formation and that high-persister hipA mutants cause multidrug tolerance in urinary tract infections. Perplexingly, high-persister mutations map to the N-subdomain-1 of HipA far from its active site. Structures of higher-order HipA-HipB-promoter complexes reveal HipA forms dimers in these assemblies via N-subdomain-1 interactions that occlude their active sites. High-persistence mutations, therefore, diminish HipA-HipA dimerization, thereby unleashing HipA to effect multidrug tolerance. Thus, our studies reveal the mechanistic basis of heritable, clinically relevant antibiotic tolerance.
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Affiliation(s)
- Maria A Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - Pooja Balani
- Antimicrobial Discovery Center, Northeastern University, Department of Biology, Boston, Massachusetts 02115, USA
| | - Jungki Min
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - Naga Babu Chinnam
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - Sonja Hansen
- Antimicrobial Discovery Center, Northeastern University, Department of Biology, Boston, Massachusetts 02115, USA
| | - Marin Vulić
- Antimicrobial Discovery Center, Northeastern University, Department of Biology, Boston, Massachusetts 02115, USA
| | - Kim Lewis
- Antimicrobial Discovery Center, Northeastern University, Department of Biology, Boston, Massachusetts 02115, USA
| | - Richard G Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
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173
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Efficacy of Fluoroquinolone/Probiotic Combination Therapy for Recurrent Urinary Tract Infection in Children: A Retrospective Analysis. Clin Ther 2015; 37:2143-7. [PMID: 26233470 DOI: 10.1016/j.clinthera.2015.06.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 06/22/2015] [Accepted: 06/29/2015] [Indexed: 02/03/2023]
Abstract
PURPOSE Children with normal urinary tract anatomy and function and highly recurrent urinary tract infection (rUTI) may have a lack of alternatives when antibiotic prophylaxis and "watchful waiting" approaches fail. This retrospective review reports the outcomes in children who received a fluoroquinolone/probiotic combination in an attempt to quantify a reduction in rUTI that was perceived by both clinicians and patients' families. METHODS Data from all children with rUTIs previously managed with a fluoroquinolone/probiotic combination at the Pediatric Infectious Diseases Clinic at Duke University Medical Center (Durham, North Carolina) were identified and analyzed. FINDINGS Data from 10 children were eligible for inclusion. Compared with before therapy initiation, total UTI episodes were significantly fewer after therapy initiation (57 vs 4; P = 0.0001). Seven (70%) were free of rUTIs during the follow-up period. Of the 8 patients with known compliance, 7 (88%) were free of rUTIs. IMPLICATIONS Given the chronic nature of these patients' symptoms, the significant decrease in UTI after the initiation of therapy, and the increase in the interval without an infection and/or its symptoms, this treatment regimen has the potential to improve overall quality of life, decrease antibiotic courses, and decrease health care costs in children with rUTI. These results will be validated with a larger cohort of patients in a prospective, randomized trial.
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174
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Intracellular Bacterial Communities: A Potential Etiology for Chronic Lower Urinary Tract Symptoms. Urology 2015; 86:425-31. [PMID: 26189137 DOI: 10.1016/j.urology.2015.04.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 03/25/2015] [Accepted: 04/02/2015] [Indexed: 11/22/2022]
Abstract
Patients with persistent lower urinary tract symptoms and negative urine cultures are often difficult to treat. Infection may go undetected in these patients because the concentrations of bacteria in their urine are beneath the threshold of standard urine culture techniques. Empiric treatment may result in temporary relief, followed by recurrent symptoms. Occult and recurrent urinary tract infection may be due to both invasion of the bladder wall by uropathogenic Escherichia coli and the formation of biofilm-like intracellular bacterial communities. This review examines emerging evidence for a role of intracellular bacterial communities in human infection.
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175
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Imidazolium salts as small-molecule urinary bladder exfoliants in a murine model. Antimicrob Agents Chemother 2015; 59:5494-502. [PMID: 26124168 DOI: 10.1128/aac.00881-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 06/19/2015] [Indexed: 01/19/2023] Open
Abstract
We present a novel family of small-molecule urinary bladder exfoliants that are expected to be of great value in preclinical studies of urologic conditions and have improved potential for translation compared with prior agents. There is broad urologic interest in the therapeutic potential of such exfoliating agents. The primary agent used in preclinical models, the cationic peptide protamine sulfate (PS), has limited translational potential due to concerns including systemic adverse reactions and bladder tissue injury. Intravesical application of a safe, systemically nontoxic exfoliant would have potential utility in the eradication of Escherichia coli and other uropathogens that reside in the bladder epithelium following cystitis, as well as in chronic bladder pain and bladder cancer. Here, we introduce a family of imidazolium salts with potent and focused exfoliating activity on the bladder epithelium. Synthesis and purification were straightforward and scalable, and the compounds exhibited prolonged stability in lyophilized form. Most members of the compound family were cytotoxic to cultured uroepithelial cells, with >10-fold differences in potency across the series. Upon topical (intravesical) administration of selected compounds to the murine bladder, complete epithelial exfoliation was achieved with physiologically relevant imidazolium concentrations and brief contact times. The exfoliative activity of these compounds was markedly improved in comparison to PS, as assessed by microscopy, immunofluorescence, and immunoblotting for uroplakins. Bladder uroepithelium regenerated within days to yield a histologically normal appearance, and no toxicity was observed. Finally, the chemical scaffold offers an opportunity for inclusion of antimicrobials or conjugation with chemotherapeutic or other moieties.
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176
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Delley M, Bruttin A, Richard M, Affolter M, Rezzonico E, Brück WM. In vitroactivity of commercial probioticLactobacillusstrains against uropathogenicEscherichia coli. FEMS Microbiol Lett 2015; 362:fnv096. [DOI: 10.1093/femsle/fnv096] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2015] [Indexed: 12/28/2022] Open
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Pathogenesis of human diffusely adhering Escherichia coli expressing Afa/Dr adhesins (Afa/Dr DAEC): current insights and future challenges. Clin Microbiol Rev 2015; 27:823-69. [PMID: 25278576 DOI: 10.1128/cmr.00036-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The pathogenicity and clinical pertinence of diffusely adhering Escherichia coli expressing the Afa/Dr adhesins (Afa/Dr DAEC) in urinary tract infections (UTIs) and pregnancy complications are well established. In contrast, the implication of intestinal Afa/Dr DAEC in diarrhea is still under debate. These strains are age dependently involved in diarrhea in children, are apparently not involved in diarrhea in adults, and can also be asymptomatic intestinal microbiota strains in children and adult. This comprehensive review analyzes the epidemiology and diagnosis and highlights recent progress which has improved the understanding of Afa/Dr DAEC pathogenesis. Here, I summarize the roles of Afa/Dr DAEC virulence factors, including Afa/Dr adhesins, flagella, Sat toxin, and pks island products, in the development of specific mechanisms of pathogenicity. In intestinal epithelial polarized cells, the Afa/Dr adhesins trigger cell membrane receptor clustering and activation of the linked cell signaling pathways, promote structural and functional cell lesions and injuries in intestinal barrier, induce proinflammatory responses, create angiogenesis, instigate epithelial-mesenchymal transition-like events, and lead to pks-dependent DNA damage. UTI-associated Afa/Dr DAEC strains, following adhesin-membrane receptor cell interactions and activation of associated lipid raft-dependent cell signaling pathways, internalize in a microtubule-dependent manner within urinary tract epithelial cells, develop a particular intracellular lifestyle, and trigger a toxin-dependent cell detachment. In response to Afa/Dr DAEC infection, the host epithelial cells generate antibacterial defense responses. Finally, I discuss a hypothetical role of intestinal Afa/Dr DAEC strains that can act as "silent pathogens" with the capacity to emerge as "pathobionts" for the development of inflammatory bowel disease and intestinal carcinogenesis.
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178
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Hibbing ME, Conover MS, Hultgren SJ. The unexplored relationship between urinary tract infections and the autonomic nervous system. Auton Neurosci 2015; 200:29-34. [PMID: 26108548 DOI: 10.1016/j.autneu.2015.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 05/14/2015] [Accepted: 06/02/2015] [Indexed: 11/30/2022]
Abstract
Urinary tract infections (UTIs), the majority of which are caused by uropathogenic E. coli (UPEC), are extremely common infections that preferentially effect women. Additional complicating factors, such as catheterization, diabetes, and spinal cord injuries can increase the frequency and severity of UTIs. The rise of antimicrobial resistant uropathogens and the ability of this disease to chronically recur make the development of alternative preventative and therapeutic modalities a priority. The major symptoms of UTIs, urgency, frequency, and dysuria, are readouts of the autonomic nervous system (ANS) and the majority of the factors that lead to complicated UTIs have been shown to impact ANS function. This review summarizes the decades' long efforts to understand the molecular mechanisms of the interactions between UPEC and the host, with a particular focus on the recent findings revealing the molecular, bacteriological, immunological and epidemiological complexity of pathogenesis. Additionally, we describe the progress that has been made in: i) generating vaccines and anti-virulence compounds that prevent and/or treat UTI by blocking bacterial adherence to urinary tract tissue and; and ii) elucidating the mechanism by which anti-inflammatories are able to alleviate symptoms and improve disease prognosis. Finally, the potential relationships between the ANS and UTI are considered throughout. While these relationships have not been experimentally explored, the known interactions between numerous UTI characteristics (symptoms, complicating factors, and inflammation) and ANS function suggest that UTIs are directly impacting ANS stimulation and that ANS (dys)function may alter UTI prognosis.
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Affiliation(s)
- Michael E Hibbing
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine in St. Louis, St. Louis, MO 63110-1010, United States; Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO 63110-1010, United States.
| | - Matt S Conover
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine in St. Louis, St. Louis, MO 63110-1010, United States; Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO 63110-1010, United States
| | - Scott J Hultgren
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine in St. Louis, St. Louis, MO 63110-1010, United States; Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO 63110-1010, United States.
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179
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Complete Genome Sequence of Uropathogenic Escherichia coli Strain CI5. GENOME ANNOUNCEMENTS 2015; 3:3/3/e00558-15. [PMID: 26021932 PMCID: PMC4447917 DOI: 10.1128/genomea.00558-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Escherichia coli represents the primary etiological agent responsible for urinary tract infections, one of the most common infections in humans. We report here the complete genome sequence of uropathogenic Escherichia coli strain CI5, a clinical pyelonephritis isolate used for studying pathogenesis.
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180
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Carey AJ, Tan CK, Ipe DS, Sullivan MJ, Cripps AW, Schembri MA, Ulett GC. Urinary tract infection of mice to model human disease: Practicalities, implications and limitations. Crit Rev Microbiol 2015; 42:780-99. [PMID: 26006172 DOI: 10.3109/1040841x.2015.1028885] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Urinary tract infections (UTIs) are among the most common bacterial infections in humans. Murine models of human UTI are vital experimental tools that have helped to elucidate UTI pathogenesis and advance knowledge of potential treatment and infection prevention strategies. Fundamentally, several variables are inherent in different murine models, and understanding the limitations of these variables provides an opportunity to understand how models may be best applied to research aimed at mimicking human disease. In this review, we discuss variables inherent in murine UTI model studies and how these affect model usage, data analysis and data interpretation. We examine recent studies that have elucidated UTI host-pathogen interactions from the perspective of gene expression, and review new studies of biofilm and UTI preventative approaches. We also consider potential standards for variables inherent in murine UTI models and discuss how these might expand the utility of models for mimicking human disease and uncovering new aspects of pathogenesis.
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Affiliation(s)
- Alison J Carey
- a Menzies Health Institute Queensland & School of Medical Sciences, Griffith University , Gold Coast , Australia
| | - Chee K Tan
- a Menzies Health Institute Queensland & School of Medical Sciences, Griffith University , Gold Coast , Australia
| | - Deepak S Ipe
- a Menzies Health Institute Queensland & School of Medical Sciences, Griffith University , Gold Coast , Australia
| | - Matthew J Sullivan
- a Menzies Health Institute Queensland & School of Medical Sciences, Griffith University , Gold Coast , Australia
| | - Allan W Cripps
- b Menzies Health Institute Queensland, Griffith University , Gold Coast , Australia , and
| | - Mark A Schembri
- c School of Chemistry and Molecular Biosciences, University of Queensland , Brisbane , Australia
| | - Glen C Ulett
- a Menzies Health Institute Queensland & School of Medical Sciences, Griffith University , Gold Coast , Australia
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181
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Niu H, Cui P, Shi W, Zhang S, Feng J, Wang Y, Sullivan D, Zhang W, Zhu B, Zhang Y. Identification of Anti-Persister Activity against Uropathogenic Escherichia coli from a Clinical Drug Library. Antibiotics (Basel) 2015; 4:179-87. [PMID: 27025620 PMCID: PMC4790332 DOI: 10.3390/antibiotics4020179] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 05/05/2015] [Accepted: 05/07/2015] [Indexed: 11/29/2022] Open
Abstract
Uropathogenic E. coli is a major cause of urinary tract infections (UTIs), but current antibiotics do not always effectively clear the persistent infection. To identify drugs that eliminate uropathogenic E. coli persisters, we screened a clinical drug library consisting of 1524 compounds using high throughput drug exposure assay in 96-well plates. Bacterial survival was assessed by growth on LB plates. We identified 14 drug candidates (tosufloxacin, colistin, sparfloxacin, moxifloxacin and gatifloxacin, enrofloxacin and sarafloxacin, octodrine, clofoctol, dibekacin, cephalosporin C, pazufloxacin, streptomycin and neomycin), which had high anti-persister activity. Among them, tosufloxacin and colistin had the highest anti-persister activity and could completely eradicate E. coli persisters in 3 days in vitro while the current UTI antibiotics failed to do so. Our findings may have implications for the development of a more effective treatment for UTIs.
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Affiliation(s)
- Hongxia Niu
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
- Lanzhou Center for Tuberculosis Research and Institute of Pathogenic Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China.
| | - Peng Cui
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
- Key Laboratory of Medical Molecular Virology, Department of Infectious Diseases, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China.
| | - Wanliang Shi
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Shuo Zhang
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Jie Feng
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Yong Wang
- Department of Clinical Microbiology Lab, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China.
| | - David Sullivan
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Wenhong Zhang
- Key Laboratory of Medical Molecular Virology, Department of Infectious Diseases, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China.
| | - Bingdong Zhu
- Lanzhou Center for Tuberculosis Research and Institute of Pathogenic Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China.
| | - Ying Zhang
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
- Key Laboratory of Medical Molecular Virology, Department of Infectious Diseases, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China.
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182
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Subinhibitory antibiotic therapy alters recurrent urinary tract infection pathogenesis through modulation of bacterial virulence and host immunity. mBio 2015; 6:mBio.00356-15. [PMID: 25827417 PMCID: PMC4453531 DOI: 10.1128/mbio.00356-15] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The capacity of subinhibitory levels of antibiotics to modulate bacterial virulence in vitro has recently been brought to light, raising concerns over the appropriateness of low-dose therapies, including antibiotic prophylaxis for recurrent urinary tract infection management. However, the mechanisms involved and their relevance in influencing pathogenesis have not been investigated. We characterized the ability of antibiotics to modulate virulence in the uropathogens Staphylococcus saprophyticus and Escherichia coli. Several antibiotics were able to induce the expression of adhesins critical to urothelial colonization, resulting in increased biofilm formation, colonization of murine bladders and kidneys, and promotion of intracellular niche formation. Mice receiving subinhibitory ciprofloxacin treatment were also more susceptible to severe infections and frequent recurrences. A ciprofloxacin prophylaxis model revealed this strategy to be ineffective in reducing recurrences and worsened infection by creating larger intracellular reservoirs at higher frequencies. Our study indicates that certain agents used for antibiotic prophylaxis have the potential to complicate infections. Antibiotics are the mainstay treatment for bacterial infections; however, evidence is emerging that argues these agents may have off-target effects if sublethal concentrations are present. Most studies have focused on changes occurring in vitro, leaving questions regarding the clinical relevance in vivo. We utilized a murine urinary tract infection model to explore the potential impact of low-dose antibiotics on pathogenesis. Using this model, we showed that subinhibitory antibiotics prime uropathogens for adherence and invasion of murine urothelial tissues. These changes in initial colonization promoted the establishment of chronic infection. Furthermore, treatment of chronically infected mice with subtherapeutic ciprofloxacin served to exacerbate infection. A part of these changes was thought to be due to suppression of mucosal immunity, as demonstrated through reductions in cytokine secretion and migration of leukocytes into the urinary tract. This work identifies novel risk factors associated with antibiotic therapy when dosing strategies fall below subtherapeutic levels.
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183
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Eravacycline (TP-434) is active in vitro against biofilms formed by uropathogenic Escherichia coli. Antimicrob Agents Chemother 2015; 59:2446-9. [PMID: 25624334 DOI: 10.1128/aac.04967-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eravacycline (formerly TP-434) was evaluated in vitro against pre-established biofilms formed by a uropathogenic Escherichia coli strain. Biofilms were eradicated by 0.5 μg/ml eravacycline, which was within 2-fold of the MIC for planktonic cells. In contrast, colistin and meropenem disrupted biofilms at 32 and 2 μg/ml, respectively, concentrations well above their respective MICs of 0.5 and 0.03 μg/ml. Gentamicin and levofloxacin eradicated biofilms at concentrations within 2-fold of their MICs.
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184
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Phenotypic heterogeneity enables uropathogenic Escherichia coli to evade killing by antibiotics and serum complement. Infect Immun 2015; 83:1056-67. [PMID: 25561706 DOI: 10.1128/iai.02725-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Uropathogenic strains of Escherichia coli (UPEC) are the major cause of bacteremic urinary tract infections. Survival in the bloodstream is associated with different mechanisms that help to resist serum complement-mediated killing. While the phenotypic heterogeneity of bacteria has been shown to influence antibiotic tolerance, the possibility that it makes cells refractory to killing by the immune system has not been experimentally tested. In the present study we sought to determine whether the heterogeneity of bacterial cultures is relevant to bacterial targeting by the serum complement system. We monitored cell divisions in the UPEC strain CFT073 with fluorescent reporter protein. Stationary-phase cells were incubated in active or heat-inactivated human serum in the presence or absence of different antibiotics (ampicillin, norfloxacin, and amikacin), and cell division and complement protein C3 binding were measured by flow cytometry and immunofluorescence microscopy. Heterogeneity in the doubling times of CFT073 cells in serum enabled three phenotypically different subpopulations to be distinguished, all of them being recognized by the C3 component of the complement system. The population of rapidly growing cells resists serum complement-mediated lysis. The dominant subpopulation of cells with intermediate growth rate is susceptible to serum. The third population, which does not resume growth upon dilution from stationary phase, is simultaneously protected from serum complement and antibiotics.
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185
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Vuotto C, Donelli G. Anaerobes in Biofilm-Based Healthcare-Associated Infections. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 830:97-112. [DOI: 10.1007/978-3-319-11038-7_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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186
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Reichhardt C, Fong JCN, Yildiz F, Cegelski L. Characterization of the Vibrio cholerae extracellular matrix: a top-down solid-state NMR approach. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1848:378-83. [PMID: 24911407 PMCID: PMC4406247 DOI: 10.1016/j.bbamem.2014.05.030] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 05/30/2014] [Accepted: 05/30/2014] [Indexed: 10/25/2022]
Abstract
Bacterial biofilms are communities of bacterial cells surrounded by a self-secreted extracellular matrix. Biofilm formation by Vibrio cholerae, the human pathogen responsible for cholera, contributes to its environmental survival and infectivity. Important genetic and molecular requirements have been identified for V. cholerae biofilm formation, yet a compositional accounting of these parts in the intact biofilm or extracellular matrix has not been described. As insoluble and non-crystalline assemblies, determinations of biofilm composition pose a challenge to conventional biochemical and biophysical analyses. The V. cholerae extracellular matrix composition is particularly complex with several proteins, complex polysaccharides, and other biomolecules having been identified as matrix parts. We developed a new top-down solid-state NMR approach to spectroscopically assign and quantify the carbon pools of the intact V. cholerae extracellular matrix using ¹³C CPMAS and ¹³C{(¹⁵N}, ¹⁵N{³¹P}, and ¹³C{³¹P}REDOR. General sugar, lipid, and amino acid pools were first profiled and then further annotated and quantified as specific carbon types, including carbonyls, amides, glycyl carbons, and anomerics. In addition, ¹⁵N profiling revealed a large amine pool relative to amide contributions, reflecting the prevalence of molecular modifications with free amine groups. Our top-down approach could be implemented immediately to examine the extracellular matrix from mutant strains that might alter polysaccharide production or lipid release beyond the cell surface; or to monitor changes that may accompany environmental variations and stressors such as altered nutrient composition, oxidative stress or antibiotics. More generally, our analysis has demonstrated that solid-state NMR is a valuable tool to characterize complex biofilm systems.
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Affiliation(s)
- Courtney Reichhardt
- Department of Chemistry, Stanford University, Mudd Building, Room 121, 333 Campus Drive, Stanford, CA 94305, USA.
| | - Jiunn C N Fong
- Department of Microbiology and Environmental Toxicology, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
| | - Fitnat Yildiz
- Department of Microbiology and Environmental Toxicology, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
| | - Lynette Cegelski
- Department of Chemistry, Stanford University, Mudd Building, Room 121, 333 Campus Drive, Stanford, CA 94305, USA.
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187
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Cecioni S, Imberty A, Vidal S. Glycomimetics versus Multivalent Glycoconjugates for the Design of High Affinity Lectin Ligands. Chem Rev 2014; 115:525-61. [DOI: 10.1021/cr500303t] [Citation(s) in RCA: 381] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Samy Cecioni
- CERMAV, Université Grenoble Alpes and CNRS, BP 53, F-38041 Grenoble Cedex 9, France
- Institut
de Chimie et Biochimie Moléculaires et Supramoléculaires,
Laboratoire de Chimie Organique 2 - Glycochimie, UMR 5246, Université Lyon 1 and CNRS, 43 Boulevard du 11 Novembre 1918, F-69622, Villeurbanne, France
| | - Anne Imberty
- CERMAV, Université Grenoble Alpes and CNRS, BP 53, F-38041 Grenoble Cedex 9, France
| | - Sébastien Vidal
- Institut
de Chimie et Biochimie Moléculaires et Supramoléculaires,
Laboratoire de Chimie Organique 2 - Glycochimie, UMR 5246, Université Lyon 1 and CNRS, 43 Boulevard du 11 Novembre 1918, F-69622, Villeurbanne, France
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188
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Impedimetric method for measuring ultra-low E. coli concentrations in human urine. Biosens Bioelectron 2014; 66:244-50. [PMID: 25437359 DOI: 10.1016/j.bios.2014.11.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 11/14/2014] [Accepted: 11/17/2014] [Indexed: 10/24/2022]
Abstract
In this study, we developed an interdigitated gold microelectrode-based impedance sensor to detect Escherichia coli (E. coli) in human urine samples for urinary tract infection (UTI) diagnosis. E. coli growth in human urine samples was successfully monitored during a 12-h culture, and the results showed that the maximum relative changes could be measured at 10Hz. An equivalent electrical circuit model was used for evaluating the variations in impedance characteristics of bacterial growth. The equivalent circuit analysis indicated that the change in impedance values at low frequencies was caused by double layer capacitance due to bacterial attachment and formation of biofilm on electrode surface in urine. A linear relationship between the impedance change and initial E. coli concentration was obtained with the coefficient of determination R(2)>0.90 at various growth times of 1, 3, 5, 7, 9 and 12h in urine. Thus our sensor is capable of detecting a wide range of E. coli concentration, 7×10(0) to 7×10(8) cells/ml, in urine samples with high sensitivity.
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189
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Navidinia M, Peerayeh SN, Fallah F, Bakhshi B, Sajadinia RS. Phylogenetic grouping and pathotypic comparison of urine and fecal Escherichia coli isolates from children with urinary tract infection. Braz J Microbiol 2014; 45:509-14. [PMID: 25242935 PMCID: PMC4166276 DOI: 10.1590/s1517-83822014000200019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 09/09/2013] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to investigate the phylogenetic background and to assess hlyD (involved in the secretion of haemolysin A) and intI1 (encoding a class 1 integrase) in Escherichia coli isolates derived from urinary and fecal specimens. A total of 200 E. coli isolates was collected from patients presenting with urinary tract infection (UTI) during September 2009 to September 2010 and screened for hlyD and intI1 genes by polymerase chain reaction (PCR). Phylogenetic analysis showed that E. coli is composed of four main phylogenetic groups (A, B1, B2 and D) and that uropathogenic E. coli (UPEC) isolates mainly belong to groups B2 (54%) and D (34%) whereas group A (44%) and D (26%) are predominant among commensal E. coli isolates. In this study, hlyD was present in 26% of UPEC and 2% of commensal E. coli isolates. However, hemolytic activity was detected for 42% of UPEC and 6% of commensal E. coli isolates (p < 0.05). intI1 gene was more frequently expressed in UPEC (24%) in comparison with commensal E. coli isolates (12%). Resistance to aztreonam, co-trimoxazole and cefpodoxime were frequently found among UPEC isolates whereas commensal E. coli isolates were commonly resistant to co-trimoxazole, nalidixic acid and cefotaxime. Concluding, a considerable difference between UPEC and commensal E. coli isolates was observed regarding their phylogenetic groups, presence of class 1 integron and hlyD gene, hemolysin activity and resistance pattern. The detection of class 1 integrons and hlyD gene was higher among UPEC compared with commensal E. coli isolates. These findings may contribute for a better understanding of the factors involved in the pathogenesis of UPEC.
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Affiliation(s)
- Masoumeh Navidinia
- Bacteriology Department Tarbiat Modarres University Tehran Iran Bacteriology Department, Tarbiat Modarres University, Tehran, Iran
| | - Shahin Najar Peerayeh
- Bacteriology Department Tarbiat Modarres University Tehran Iran Bacteriology Department, Tarbiat Modarres University, Tehran, Iran
| | - Fatemeh Fallah
- Pediatric Infection Research Center Mofid Childrens' Hospital Shahid Beheshti University of Medical Sciences Tehran Iran Pediatric Infection Research Center, Mofid Childrens' Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Bita Bakhshi
- Bacteriology Department Tarbiat Modarres University Tehran Iran Bacteriology Department, Tarbiat Modarres University, Tehran, Iran
| | - Raheleh Sadat Sajadinia
- Shahid Beheshti University of Medical Sciences Tehran Iran Shahid Beheshti University of Medical Sciences, Tehran, Iran
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190
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Robino L, Scavone P, Araujo L, Algorta G, Zunino P, Pírez MC, Vignoli R. Intracellular bacteria in the pathogenesis of Escherichia coli urinary tract infection in children. Clin Infect Dis 2014; 59:e158-64. [PMID: 25091303 DOI: 10.1093/cid/ciu634] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Uropathogenic Escherichia coli (UPEC) is the most common agent of urinary tract infection (UTI). The classic model of pathogenesis proposes the ascent of UPEC by the urethra and external adherence to the urothelium. Recently, the ability of UPEC to invade urothelial cells and to form intracellular bacterial communities (IBCs) has been described. METHODS The objective of the present study was to determine the presence of intracellular bacteria (IB) in children with UTI caused by E. coli and to characterize its virulence attributes and its relation with clinical outcomes. One hundred thirty-three children with E. coli UTI who attended a reference children's hospital between June and November 2012 were included. Urine samples were analyzed by optical and confocal microscopy looking for exfoliated urothelial cells with IB. Phylogenetic group and 24 virulence factors of UPEC were determined using multiplex polymerase chain reaction. Medical records were analyzed. RESULTS The presence of IB was detected in 49 of 133 (36.8%) samples by confocal microscopy, in 30 cases as IBC, and in 19 as isolated intracellular bacteria (IIB). Only 50% of these cases could be detected by light microscopy. Seventy-four medical records were analyzed, 34 with IBC/IIB, 40 without IB. Any virulence gene was associated with IBC/IIB. The presence of IBC/IIB was associated with recurrent UTI (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.3-9; P = .017), especially in children without urinary tract functional or morphological abnormalities (OR, 8.0; 95% CI, 2.3-27.4; P = .000). IBCs were associated with lower urinary tract syndrome (OR, 3.6; 95% CI, 1.1-11.8; P = .05) and absence of fever (P = .009). CONCLUSIONS IBCs/IIB could explain a high proportion of children with recurrent UTI.
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Affiliation(s)
- Luciana Robino
- Departamento de Bacteriología y Virología, Facultad de Medicina, Universidad de la República, Instituto de Higiene
| | - Paola Scavone
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable
| | - Lucia Araujo
- Departamento de Bacteriología y Virología, Facultad de Medicina, Universidad de la República, Instituto de Higiene
| | - Gabriela Algorta
- Departamento de Bacteriología y Virología, Facultad de Medicina, Universidad de la República, Instituto de Higiene Laboratorio Central, Centro Hospitalario Pereira Rossell
| | - Pablo Zunino
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable
| | - María Catalina Pírez
- Departamento de Pediatria, Centro Hospitalario Pereira Rossell, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Rafael Vignoli
- Departamento de Bacteriología y Virología, Facultad de Medicina, Universidad de la República, Instituto de Higiene
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191
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Shen XF, Ren LB, Teng Y, Zheng S, Yang XL, Guo XJ, Wang XY, Sha KH, Li N, Xu GY, Tian HW, Wang XY, Liu XK, Li J, Huang N. Luteolin decreases the attachment, invasion and cytotoxicity of UPEC in bladder epithelial cells and inhibits UPEC biofilm formation. Food Chem Toxicol 2014; 72:204-11. [PMID: 25051393 DOI: 10.1016/j.fct.2014.07.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 07/03/2014] [Accepted: 07/09/2014] [Indexed: 01/24/2023]
Abstract
Urinary tract infection (UTI), primarily caused by uropathogenic Escherichia coli (UPEC), is one of the most common infectious diseases worldwide. Emerging antibiotic resistance requires novel treatment strategies. Luteolin, a dietary polyphenolic flavonoid, has been confirmed as a potential antimicrobial agent. Here, we evaluated the sub-MICs of luteolin for potential properties to modulate the UPEC infection. We found that luteolin significantly decreased the attachment and invasion of UPEC J96 or CFT073 in human bladder epithelial cell lines T24. Meanwhile, obvious decreased expression of type 1 fimbriae adhesin fimH gene, lower bacterial surface hydrophobicity and swimming motility, were observed in luteolin-pretreated UPEC. Furthermore, luteolin could attenuate UPEC-induced cytotoxicity in T24 cells, which manifested as decreased activity of lactate dehydrogenase (LDH). Simultaneously, the inhibition of luteolin on UPEC-induced cytotoxicity was confirmed by ethidium bromide/acridine orange staining. Finally, the luteolin-pretreated UPEC showed a lower ability of biofilm formation. Collectively, these results indicated that luteolin decreased the attachment and invasion of UPEC in bladder epithelial cells, attenuated UPEC-induced cytotoxicity and biofilm formation via down-regulating the expression of adhesin fimH gene, reducing the bacterial surface hydrophobicity and motility.
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Affiliation(s)
- Xiao-fei Shen
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Lai-bin Ren
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Yan Teng
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Shuang Zheng
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Xiao-long Yang
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Xiao-juan Guo
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Xin-yuan Wang
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Kai-hui Sha
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Na Li
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Guang-ya Xu
- Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Han-wen Tian
- Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pharmacology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Xiao-ying Wang
- Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Xiao-kang Liu
- Department of Pharmacology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Jingyu Li
- Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China.
| | - Ning Huang
- Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China; Department of Pathophysiology, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041, China.
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192
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Moore KH, Malykhina AP. What is the role of covert infection in detrusor overactivity, and other LUTD? ICI-RS 2013. Neurourol Urodyn 2014; 33:606-10. [DOI: 10.1002/nau.22589] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 02/25/2014] [Indexed: 01/26/2023]
Affiliation(s)
- Kate H. Moore
- Pelvic Floor Unit; Department of Urogynaecology; University of New South Wales; Sydney NSW Australia
| | - Anna P. Malykhina
- Division of Urology; Department of Surgery; University of Pennsylvania; Philadelphia Pennsylvania
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193
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Cystitis: from urothelial cell biology to clinical applications. BIOMED RESEARCH INTERNATIONAL 2014; 2014:473536. [PMID: 24877098 PMCID: PMC4022113 DOI: 10.1155/2014/473536] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/15/2014] [Indexed: 12/23/2022]
Abstract
Cystitis is a urinary bladder disease with many causes and symptoms. The severity of cystitis ranges from mild lower abdominal discomfort to life-threatening haemorrhagic cystitis. The course of disease is often chronic or recurrent. Although cystitis represents huge economical and medical burden throughout the world and in many cases treatments are ineffective, the mechanisms of its origin and development as well as measures for effective treatment are still poorly understood. However, many studies have demonstrated that urothelial dysfunction plays a crucial role. In the present review we first discuss fundamental issues of urothelial cell biology, which is the core for comprehension of cystitis. Then we focus on many forms of cystitis, its current treatments, and advances in its research. Additionally we review haemorrhagic cystitis with one of the leading causative agents being chemotherapeutic drug cyclophosphamide and summarise its management strategies. At the end we describe an excellent and widely used animal model of cyclophosphamide induced cystitis, which gives researches the opportunity to get a better insight into the mechanisms involved and possibility to develop new therapy approaches.
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194
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Sycamore KF, Poorbaugh VR, Pullin SS, Ward CR. Comparison of urine and bladder or urethral mucosal biopsy culture obtained by transurethral cystoscopy in dogs with chronic lower urinary tract disease: 41 cases (2002 to 2011). J Small Anim Pract 2014; 55:364-8. [DOI: 10.1111/jsap.12225] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2014] [Indexed: 12/01/2022]
Affiliation(s)
- K. F. Sycamore
- Department of Small Animal Medicine and Surgery; University of Georgia; Athens GA 30602 USA
| | - V. R. Poorbaugh
- Department of Small Animal Medicine and Surgery; University of Georgia; Athens GA 30602 USA
| | - S. S. Pullin
- Department of Small Animal Medicine and Surgery; University of Georgia; Athens GA 30602 USA
| | - C. R. Ward
- Department of Small Animal Medicine and Surgery; University of Georgia; Athens GA 30602 USA
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195
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Blango MG, Ott EM, Erman A, Veranic P, Mulvey MA. Forced resurgence and targeting of intracellular uropathogenic Escherichia coli reservoirs. PLoS One 2014; 9:e93327. [PMID: 24667805 PMCID: PMC3965547 DOI: 10.1371/journal.pone.0093327] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/03/2014] [Indexed: 11/19/2022] Open
Abstract
Intracellular quiescent reservoirs of uropathogenic Escherichia coli (UPEC), which can seed the bladder mucosa during the acute phase of a urinary tract infection (UTI), are protected from antibiotic treatments and are extremely difficult to eliminate. These reservoirs are a potential source for recurrent UTIs that affect millions annually. Here, using murine infection models and the bladder cell exfoliant chitosan, we demonstrate that intracellular UPEC populations shift within the stratified layers of the urothelium during the course of a UTI. Following invasion of the terminally differentiated superficial layer of epithelial cells that line the bladder lumen, UPEC can multiply and disseminate, eventually establishing reservoirs within underlying immature host cells. If given access, UPEC can invade the superficial and immature bladder cells equally well. As infected immature host cells differentiate and migrate towards the apical surface of the bladder, UPEC can reinitiate growth and discharge into the bladder lumen. By inducing the exfoliation of the superficial layers of the urothelium, chitosan stimulates rapid regenerative processes and the reactivation and efflux of quiescent intracellular UPEC reservoirs. When combined with antibiotics, chitosan treatment significantly reduces bacterial loads within the bladder and may therefore be of therapeutic value to individuals with chronic, recurrent UTIs.
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Affiliation(s)
- Matthew G. Blango
- Division of Microbiology and Immunology, Pathology Department, University of Utah, Salt Lake City, Utah, United States of America
| | - Elizabeth M. Ott
- Division of Microbiology and Immunology, Pathology Department, University of Utah, Salt Lake City, Utah, United States of America
| | - Andreja Erman
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Ljublijana, Slovenia
| | - Peter Veranic
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Ljublijana, Slovenia
| | - Matthew A. Mulvey
- Division of Microbiology and Immunology, Pathology Department, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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196
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Hall MR, McGillicuddy E, Kaplan LJ. Biofilm: Basic Principles, Pathophysiology, and Implications for Clinicians. Surg Infect (Larchmt) 2014; 15:1-7. [DOI: 10.1089/sur.2012.129] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Michael R. Hall
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut
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197
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198
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Selective target inactivation rather than global metabolic dormancy causes antibiotic tolerance in uropathogens. Antimicrob Agents Chemother 2014; 58:2089-97. [PMID: 24449771 DOI: 10.1128/aac.02552-13] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Persister cells represent a multidrug-tolerant (MDT), physiologically distinct subpopulation of bacteria. The ability of these organisms to survive lethal antibiotic doses raises concern over their potential role in chronic disease, such as recurrent urinary tract infection (RUTI). Persistence is believed to be conveyed through global metabolic dormancy, which yields organisms unresponsive to external stimuli. However, recent studies have contested this stance. Here, various antibiotics that target different cellular processes were used to dissect the activity of transcription, translation, and peptidoglycan turnover in persister cells. Differential susceptibility patterns were found in type I and type II persisters, and responses differed between Staphylococcus saprophyticus and Escherichia coli uropathogens. Further, SOS-deficient strains were sensitized to ciprofloxacin, suggesting DNA gyrase activity in persisters and indicating the importance of active DNA repair systems for ciprofloxacin tolerance. These results indicate that global dormancy per se cannot sufficiently account for antibiotic tolerance. Rather, the activity of individual cellular processes dictates multidrug tolerance in an antibiotic-specific fashion. Furthermore, the susceptibility patterns of persisters depended on their mechanisms of onset, with subinhibitory antibiotic pretreatments selectively shutting down cognate targets and increasing the persister fraction against the same agent. Interestingly, antibiotics targeting transcription and translation enhanced persistence against multiple agents indirectly related to these processes. Conducting these assays with uropathogenic E. coli isolated from RUTI patients revealed an enriched persister fraction compared to organisms cleared with standard antibiotic therapy. This finding suggests that persister traits are either selected for during prolonged antibiotic treatment or initially contribute to therapy failure.
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199
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Lim JY, Pinkner JS, Cegelski L. Community behavior and amyloid-associated phenotypes among a panel of uropathogenic E. coli. Biochem Biophys Res Commun 2014; 443:345-50. [PMID: 24239885 PMCID: PMC3932320 DOI: 10.1016/j.bbrc.2013.11.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 11/04/2013] [Indexed: 11/15/2022]
Abstract
Uropathogenic Escherichia coli (UPEC) are the major causative agents of urinary tract infection and engage in a coordinated genetic and molecular cascade to colonize the urinary tract. Disrupting the assembly and/or function of virulence factors and bacterial biofilms has emerged as an attractive target for the development of new therapeutic strategies to prevent and treat urinary tract infection, particularly in the era of increasing antibiotic resistance among human pathogens. UPEC vary widely in their genetic and molecular phenotypes and more data are needed to understand the features that distinguish isolates as more or less virulent and as more robust biofilm formers or poor biofilm formers. Curli are extracellular functional amyloid fibers produced by E. coli that contribute to pathogenesis and influence the host response during urinary tract infection (UTI). We have examined the production of curli and curli-associated phenotypes including biofilm formation among a specific panel of human clinical UPEC that has been studied extensively in the mouse model of UTI. Motility, curli production, and curli-associated biofilm formation attached to plastic were the most prevalent behaviors, shared by most clinical isolates. We discuss these results in the context on the previously reported behavior and phenotypes of these isolates in the murine cystitis model in vivo.
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Affiliation(s)
- Ji Youn Lim
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States
| | - Jerome S Pinkner
- Department of Molecular Microbiology, Washington University, St. Louis, MO 63110, United States
| | - Lynette Cegelski
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States.
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200
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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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