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Chen L, Li J, Xiao B. The role of sialidases in the pathogenesis of bacterial vaginosis and their use as a promising pharmacological target in bacterial vaginosis. Front Cell Infect Microbiol 2024; 14:1367233. [PMID: 38495652 PMCID: PMC10940449 DOI: 10.3389/fcimb.2024.1367233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 02/19/2024] [Indexed: 03/19/2024] Open
Abstract
Bacterial vaginosis (BV) is an infection of the genital tract characterized by disturbance of the normally Lactobacilli-dominated vaginal flora due to the overgrowth of Gardnerella and other anaerobic bacteria. Gardnerella vaginalis, an anaerobic pathogen and the major pathogen of BV, produces sialidases that cleave terminal sialic acid residues off of human glycans. By desialylation, sialidases not only alter the function of sialic acid-containing glycoconjugates but also play a vital role in the attachment, colonization and spread of many other vaginal pathogens. With known pathogenic effects, excellent performance of sialidase-based diagnostic tests, and promising therapeutic potentials of sialidase inhibitors, sialidases could be used as a biomarker of BV. This review explores the sources of sialidases and their role in vaginal dysbiosis, in aims to better understand their participation in the pathogenesis of BV and their value in the diagnosis and treatment of BV.
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Affiliation(s)
- Liuyan Chen
- Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, China
| | - Jiayue Li
- School of Medicine, University College Dublin, Dublin, Ireland
| | - Bingbing Xiao
- Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, China
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Ding X, Robbe-Masselot C, Fu X, Léonard R, Marsac B, Dauriat CJG, Lepissier A, Rytter H, Ramond E, Dupuis M, Euphrasie D, Dubail I, Schimmich C, Qin X, Parraga J, Leite-de-Moraes M, Ferroni A, Chassaing B, Sermet-Gaudelus I, Charbit A, Coureuil M, Jamet A. Airway environment drives the selection of quorum sensing mutants and promote Staphylococcus aureus chronic lifestyle. Nat Commun 2023; 14:8135. [PMID: 38065959 PMCID: PMC10709412 DOI: 10.1038/s41467-023-43863-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
Staphylococcus aureus is a predominant cause of chronic lung infections. While the airway environment is rich in highly sialylated mucins, the interaction of S. aureus with sialic acid is poorly characterized. Using S. aureus USA300 as well as clinical isolates, we demonstrate that quorum-sensing dysfunction, a hallmark of S. aureus adaptation, correlates with a greater ability to consume free sialic acid, providing a growth advantage in an air-liquid interface model and in vivo. Furthermore, RNA-seq experiment reveals that free sialic acid triggers transcriptional reprogramming promoting S. aureus chronic lifestyle. To support the clinical relevance of our results, we show the co-occurrence of S. aureus, sialidase-producing microbiota and free sialic acid in the airway of patients with cystic fibrosis. Our findings suggest a dual role for sialic acid in S. aureus airway infection, triggering virulence reprogramming and driving S. aureus adaptive strategies through the selection of quorum-sensing dysfunctional strains.
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Affiliation(s)
- Xiongqi Ding
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Catherine Robbe-Masselot
- Université Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Xiali Fu
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Renaud Léonard
- Université Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Benjamin Marsac
- Université Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Charlene J G Dauriat
- INSERM U1016, CNRS UMR8104, Université Paris Cité, Team «Mucosal Microbiota in Chronic Inflammatory Diseases», F75014, Paris, France
| | - Agathe Lepissier
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Héloïse Rytter
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Elodie Ramond
- Genoscope, UMR8030, Laboratory of Systems & Synthetic Biology (LISSB), Xenome team, F91057, Evry, France
| | - Marion Dupuis
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Daniel Euphrasie
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Iharilalao Dubail
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Cécile Schimmich
- Anses, Laboratory of Animal Health in Normandy, Physiopathology and epidemiology of equine diseases (PhEED), RD 675, F14430, Goustranville, France
| | - Xiaoquan Qin
- Université Paris Cité, Institut de physique du globe de Paris, CNRS, F75005, Paris, France
| | - Jessica Parraga
- Department of Clinical Microbiology, Necker-Enfants Malades Hospital, AP-HP Centre Université de Paris Cité, F75015, Paris, France
| | - Maria Leite-de-Moraes
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Agnes Ferroni
- Department of Clinical Microbiology, Necker-Enfants Malades Hospital, AP-HP Centre Université de Paris Cité, F75015, Paris, France
| | - Benoit Chassaing
- INSERM U1016, CNRS UMR8104, Université Paris Cité, Team «Mucosal Microbiota in Chronic Inflammatory Diseases», F75014, Paris, France
| | - Isabelle Sermet-Gaudelus
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Alain Charbit
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France
| | - Mathieu Coureuil
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France.
| | - Anne Jamet
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F75015, Paris, France.
- Department of Clinical Microbiology, Necker-Enfants Malades Hospital, AP-HP Centre Université de Paris Cité, F75015, Paris, France.
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Keil J, Rafn GR, Turan IM, Aljohani MA, Sahebjam-Atabaki R, Sun XL. Sialidase Inhibitors with Different Mechanisms. J Med Chem 2022; 65:13574-13593. [PMID: 36252951 PMCID: PMC9620260 DOI: 10.1021/acs.jmedchem.2c01258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Indexed: 11/28/2022]
Abstract
Sialidases, or neuraminidases, are enzymes that catalyze the hydrolysis of sialic acid (Sia)-containing molecules, mostly removal of the terminal Sia (desialylation). By desialylation, sialidase can modulate the functionality of the target compound and is thus often involved in biological pathways. Inhibition of sialidases with inhibitors is an important approach for understanding sialidase function and the underlying mechanisms and could serve as a therapeutic approach as well. Transition-state analogues, such as anti-influenza drugs oseltamivir and zanamivir, are major sialidase inhibitors. In addition, difluoro-sialic acids were developed as mechanism-based sialidase inhibitors. Further, fluorinated quinone methide-based suicide substrates were reported. Sialidase product analogue inhibitors were also explored. Finally, natural products have shown competitive inhibiton against viral, bacterial, and human sialidases. This Perspective describes sialidase inhibitors with different mechanisms and their activities and future potential, which include transition-state analogue inhibitors, mechanism-based inhibitors, suicide substrate inhibitors, product analogue inhibitors, and natural product inhibitors.
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Affiliation(s)
- Joseph
M. Keil
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Garrett R. Rafn
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Isaac M. Turan
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Majdi A. Aljohani
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Reza Sahebjam-Atabaki
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Xue-Long Sun
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
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Patel VC, Lee S, McPhail MJW, Da Silva K, Guilly S, Zamalloa A, Witherden E, Støy S, Manakkat Vijay GK, Pons N, Galleron N, Huang X, Gencer S, Coen M, Tranah TH, Wendon JA, Bruce KD, Le Chatelier E, Ehrlich SD, Edwards LA, Shoaie S, Shawcross DL. Rifaximin-α reduces gut-derived inflammation and mucin degradation in cirrhosis and encephalopathy: RIFSYS randomised controlled trial. J Hepatol 2022; 76:332-342. [PMID: 34571050 DOI: 10.1016/j.jhep.2021.09.010] [Citation(s) in RCA: 91] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 08/20/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Rifaximin-α is efficacious for the prevention of recurrent hepatic encephalopathy (HE), but its mechanism of action remains unclear. We postulated that rifaximin-α reduces gut microbiota-derived endotoxemia and systemic inflammation, a known driver of HE. METHODS In a placebo-controlled, double-blind, mechanistic study, 38 patients with cirrhosis and HE were randomised 1:1 to receive either rifaximin-α (550 mg BID) or placebo for 90 days. PRIMARY OUTCOME 50% reduction in neutrophil oxidative burst (OB) at 30 days. SECONDARY OUTCOMES changes in psychometric hepatic encephalopathy score (PHES) and neurocognitive functioning, shotgun metagenomic sequencing of saliva and faeces, plasma and faecal metabolic profiling, whole blood bacterial DNA quantification, neutrophil toll-like receptor (TLR)-2/4/9 expression and plasma/faecal cytokine analysis. RESULTS Patients were well-matched: median MELD (11 rifaximin-α vs. 10 placebo). Rifaximin-α did not lead to a 50% reduction in spontaneous neutrophil OB at 30 days compared to baseline (p = 0.48). However, HE grade normalised (p = 0.014) and PHES improved (p = 0.009) after 30 days on rifaximin-α. Rifaximin-α reduced circulating neutrophil TLR-4 expression on day 30 (p = 0.021) and plasma tumour necrosis factor-α (TNF-α) (p <0.001). Rifaximin-α suppressed oralisation of the gut, reducing levels of mucin-degrading sialidase-rich species, Streptococcus spp, Veillonella atypica and parvula, Akkermansia and Hungatella. Rifaximin-α promoted a TNF-α- and interleukin-17E-enriched intestinal microenvironment, augmenting antibacterial responses to invading pathobionts and promoting gut barrier repair. Those on rifaximin-α were less likely to develop infection (odds ratio 0.21; 95% CI 0.05-0.96). CONCLUSION Rifaximin-α led to resolution of overt and covert HE, reduced the likelihood of infection, reduced oralisation of the gut and attenuated systemic inflammation. Rifaximin-α plays a role in gut barrier repair, which could be the mechanism by which it ameliorates bacterial translocation and systemic endotoxemia in cirrhosis. CLINICAL TRIAL NUMBER ClinicalTrials.gov NCT02019784. LAY SUMMARY In this clinical trial, we examined the underlying mechanism of action of an antibiotic called rifaximin-α which has been shown to be an effective treatment for a complication of chronic liver disease which effects the brain (termed encephalopathy). We show that rifaximin-α suppresses gut bacteria that translocate from the mouth to the intestine and cause the intestinal wall to become leaky by breaking down the protective mucus barrier. This suppression resolves encephalopathy and reduces inflammation in the blood, preventing the development of infection.
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Affiliation(s)
- Vishal C Patel
- Institute of Liver Studies, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK; Institute of Liver Studies, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK; The Roger Williams Institute of Hepatology (Foundation for Liver Research), 111 Coldharbour Lane, London, SE5 9NT, UK
| | - Sunjae Lee
- Centre for Host-Microbiome Interactions, Dental Institute, King's College London, UK; Science for Life Laboratory, KTH - Royal Institute of Technology, 171 21, Stockholm, Sweden; School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Republic of Korea
| | - Mark J W McPhail
- Institute of Liver Studies, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK; Institute of Liver Studies, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK; Imperial College London, Biomolecular Medicine, Division of Computational and Systems Medicine, Department of Surgery and Cancer, London, UK
| | - Kevin Da Silva
- University Paris-Saclay, INRAE, MetaGenoPolis, Jouy-en-Josas, 78350, France
| | - Susie Guilly
- University Paris-Saclay, INRAE, MetaGenoPolis, Jouy-en-Josas, 78350, France
| | - Ane Zamalloa
- Institute of Liver Studies, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Elizabeth Witherden
- Centre for Host-Microbiome Interactions, Dental Institute, King's College London, UK
| | - Sidsel Støy
- Aarhus University Hospital, Department of Hepatology and Gastroenterology, Aarhus, Denmark
| | - Godhev Kumar Manakkat Vijay
- Institute of Liver Studies, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Nicolas Pons
- University Paris-Saclay, INRAE, MetaGenoPolis, Jouy-en-Josas, 78350, France
| | - Nathalie Galleron
- University Paris-Saclay, INRAE, MetaGenoPolis, Jouy-en-Josas, 78350, France
| | - Xaiohong Huang
- Institute of Liver Studies, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Selin Gencer
- Imperial College London, Biomolecular Medicine, Division of Computational and Systems Medicine, Department of Surgery and Cancer, London, UK
| | - Muireann Coen
- Imperial College London, Biomolecular Medicine, Division of Computational and Systems Medicine, Department of Surgery and Cancer, London, UK
| | - Thomas Henry Tranah
- Institute of Liver Studies, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK; Institute of Liver Studies, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Julia Alexis Wendon
- Institute of Liver Studies, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK; Institute of Liver Studies, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Kenneth D Bruce
- King's College London, Institute of Pharmaceutical Science, 5th Floor Franklin-Wilkins Building, London, UK
| | | | | | - Lindsey Ann Edwards
- Institute of Liver Studies, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Saeed Shoaie
- Centre for Host-Microbiome Interactions, Dental Institute, King's College London, UK; Science for Life Laboratory, KTH - Royal Institute of Technology, 171 21, Stockholm, Sweden
| | - Debbie Lindsay Shawcross
- Institute of Liver Studies, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK; Institute of Liver Studies, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK.
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Lipničanová S, Chmelová D, Ondrejovič M, Frecer V, Miertuš S. Diversity of sialidases found in the human body - A review. Int J Biol Macromol 2020; 148:857-868. [PMID: 31945439 DOI: 10.1016/j.ijbiomac.2020.01.123] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/10/2020] [Accepted: 01/11/2020] [Indexed: 12/31/2022]
Abstract
Sialidases are enzymes essential for numerous organisms including humans. Hydrolytic sialidases (EC 3.2.1.18), trans-sialidases and anhydrosialidases (intramolecular trans-sialidases, EC 4.2.2.15) are glycoside hydrolase enzymes that cleave the glycosidic linkage and release sialic acid residues from sialyl substrates. The paper summarizes diverse sialidases present in the human body and their potential impact on development of antiviral compounds - inhibitors of viral neuraminidases. It includes a brief overview of catalytic mechanisms of action of sialidases and describes the origin of sialidases in the human body. This is followed by description of the structure and function of sialidase families with a special focus on the GH33 and GH34 families. Various effects of sialidases on human body are also briefly described. Modulation of sialidase activity may be considered a useful tool for effective treatment of various diseases. In some cases, it is desired to completely suppress the activity of sialidases by suitable inhibitors. Specific sialidase inhibitors are useful for the treatment of influenza, epilepsy, Alzheimer's disease, diabetes, different types of cancer, or heart defects. Challenges and future directions are shortly depicted in the final part of the paper.
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Affiliation(s)
- Sabina Lipničanová
- Department of Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia
| | - Daniela Chmelová
- Department of Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia.
| | - Miroslav Ondrejovič
- Department of Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia.
| | - Vladimír Frecer
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-83232 Bratislava, Slovakia; ICARST n.o., Jamnického 19, SK-84101, Bratislava, Slovakia.
| | - Stanislav Miertuš
- Department of Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia; ICARST n.o., Jamnického 19, SK-84101, Bratislava, Slovakia.
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Bacterial sialoglycosidases in Virulence and Pathogenesis. Pathogens 2019; 8:pathogens8010039. [PMID: 30909660 PMCID: PMC6471121 DOI: 10.3390/pathogens8010039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 12/12/2022] Open
Abstract
Human oral microbiome and dysbiotic infections have been recently evidently identified. One of the major reasons for such dysbiosis is impairment of the immune system. Periodontitis is a chronic inflammatory disease affecting the tissues that surround and support the teeth. In the United States., approximately 65 million people are affected by this condition. Its occurrence is also associated with many important systemic diseases such as cardiovascular disease, rheumatoid arthritis, and Alzheimer’s disease. Among the most important etiologies of periodontitis is Porphyromonas gingivalis, a keystone bacterial pathogen. Keystone pathogens can orchestrate inflammatory disease by remodeling a normally benign microbiota causing imbalance between normal and pathogenic microbiota (dysbiosis). The important characteristics of P. gingivalis causing dysbiosis are its virulence factors which cause effective subversion of host defenses to its advantage allowing other pathogens to grow. Some of the mechanisms involved in these processes are still not well-understood. However, various microbial strategies target host sialoglycoproteins for immune dysregulation. In addition, the enzymes that break down sialoglycoproteins and sialoglycans are the “sialoglycoproteases”, resulting in exposed terminal sialic acid. This process could lead to pathogen-toll like receptor (TLR) interactions mediated through sialic acid receptor ligand mechanisms. Assessing the function of P. gingivalis sialoglycoproteases, could pave the way to designing carbohydrate analogues and sialic acid mimetics to serve as drug targets.
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Role of Neuraminidase-Producing Bacteria in Exposing Cryptic Carbohydrate Receptors for Streptococcus gordonii Adherence. Infect Immun 2018; 86:IAI.00068-18. [PMID: 29661931 DOI: 10.1128/iai.00068-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 04/13/2018] [Indexed: 12/11/2022] Open
Abstract
Streptococcus gordonii is an early colonizer of the oral cavity. Although a variety of S. gordonii adherence mechanisms have been described, current dogma is that the major receptor for S. gordonii is sialic acid. However, as many bacterial species in the oral cavity produce neuraminidase that can cleave terminal sialic acid, it is unclear whether S. gordonii relies on sialic acid for adherence to oral surfaces or if this species has developed alternative binding strategies. Previous studies have examined adherence to immobilized glycoconjugates and identified binding to additional glycans, but no prior studies have defined the contribution of these different glycan structures in adherence to oral epithelial cells. We determined that the majority of S. gordonii strains tested did not rely on sialic acid for efficient adherence. In fact, adherence of some strains was significantly increased following neuraminidase treatment. Further investigation of representative strains that do not rely on sialic acid for adherence revealed binding not only to sialic acid via the serine-rich repeat protein GspB but also to β-1,4-linked galactose. Adherence to this carbohydrate occurs via an unknown adhesin distinct from those utilized by Streptococcus oralis and Streptococcus pneumoniae Demonstrating the potential biological relevance of binding to this cryptic receptor, we established that S. oralis increases S. gordonii adherence in a neuraminidase-dependent manner. These data suggest that S. gordonii has evolved to simultaneously utilize both terminal and cryptic receptors in response to the production of neuraminidase by other species in the oral environment.
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Positive- and Negative-Control Pathways by Blood Components for Intermedilysin Production in Streptococcus intermedius. Infect Immun 2017; 85:IAI.00379-17. [PMID: 28607101 DOI: 10.1128/iai.00379-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 06/08/2017] [Indexed: 11/20/2022] Open
Abstract
Streptococcus intermedius is an opportunistic bacterial pathogen secreting a human-specific cytolysin called intermedilysin (ILY) as a major pathogenic factor. This bacterium can degrade glycans into monosaccharides using two glycosidases, multisubstrate glycosidase A (MsgA) and neuraminidase (NanA). Here, we detected a stronger hemolytic activity mediated by ILY when S. intermedius PC574 was cultured in fetal bovine serum (FBS) than when it was grown in the standard culture medium. FBS-cultured cells also showed higher MsgA and NanA activity, although overproduction of ILY in FBS was undetectable in mutants nanA-null and msgA-null. Addition of purified MsgA and NanA to the FBS resulted in a release of 2.8 mM galactose and 4.3 mM N-acetylneuraminic acid; these sugar concentrations were sufficient to upregulate the expression of ILY, MsgA, and NanA. Conversely, when strain PC574 was cultured in human plasma, no similar increase in hemolytic activity was observed. Moreover, addition of human plasma to the culture in FBS appeared to inhibit the stimulatory effect of FBS on ILY, MsgA, and NanA, although there were individual differences among the plasma samples. We confirmed that human plasma contains immunoglobulins that can neutralize ILY, MsgA, and NanA activities. In addition, human plasma had a neutralizing effect on cytotoxicity of S. intermedius toward HepG2 cells in FBS, and a higher concentration of human plasma was necessary to reduce the cytotoxicity of an ILY-high-producing strain than an ILY-low-producing strain. Overall, our data show that blood contains factors that stimulate and inhibit ILY expression and activity, which may affect pathogenicity of S. intermedius.
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Streptococcus oralis Neuraminidase Modulates Adherence to Multiple Carbohydrates on Platelets. Infect Immun 2017; 85:IAI.00774-16. [PMID: 27993975 DOI: 10.1128/iai.00774-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/15/2016] [Indexed: 11/20/2022] Open
Abstract
Adherence to host surfaces is often mediated by bacterial binding to surface carbohydrates. Although it is widely appreciated that some bacterial species express glycosidases, previous studies have not considered whether bacteria bind to multiple carbohydrates within host glycans as they are modified by bacterial glycosidases. Streptococcus oralis is a leading cause of subacute infective endocarditis. Binding to platelets is a critical step in disease; however, the mechanisms utilized by S. oralis remain largely undefined. Studies revealed that S. oralis, like Streptococcus gordonii and Streptococcus sanguinis, binds platelets via terminal sialic acid. However, unlike those organisms, S. oralis produces a neuraminidase, NanA, which cleaves terminal sialic acid. Further studies revealed that following NanA-dependent removal of terminal sialic acid, S. oralis bound exposed β-1,4-linked galactose. Adherence to both these carbohydrates required Fap1, the S. oralis member of the serine-rich repeat protein (SRRP) family of adhesins. Mutation of a conserved residue required for sialic acid binding by other SRRPs significantly reduced platelet binding, supporting the hypothesis that Fap1 binds this carbohydrate. The mechanism by which Fap1 contributes to β-1,4-linked galactose binding remains to be defined; however, binding may occur via additional domains of unknown function within the nonrepeat region, one of which shares some similarity with a carbohydrate binding module. This study is the first demonstration that an SRRP is required to bind β-1,4-linked galactose and the first time that one of these adhesins has been shown to be required for binding of multiple glycan receptors.
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Davis JCC, Lewis ZT, Krishnan S, Bernstein RM, Moore SE, Prentice AM, Mills DA, Lebrilla CB, Zivkovic AM. Growth and Morbidity of Gambian Infants are Influenced by Maternal Milk Oligosaccharides and Infant Gut Microbiota. Sci Rep 2017; 7:40466. [PMID: 28079170 PMCID: PMC5227965 DOI: 10.1038/srep40466] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 12/06/2016] [Indexed: 12/25/2022] Open
Abstract
Human milk oligosaccharides (HMOs) play an important role in the health of an infant as substrate for beneficial gut bacteria. Little is known about the effects of HMO composition and its changes on the morbidity and growth outcomes of infants living in areas with high infection rates. Mother's HMO composition and infant gut microbiota from 33 Gambian mother/infant pairs at 4, 16, and 20 weeks postpartum were analyzed for relationships between HMOs, microbiota, and infant morbidity and growth. The data indicate that lacto-N-fucopentaose I was associated with decreased infant morbidity, and 3'-sialyllactose was found to be a good indicator of infant weight-for-age. Because HMOs, gut microbiota, and infant health are interrelated, the relationship between infant health and their microbiome were analyzed. While bifidobacteria were the dominant genus in the infant gut overall, Dialister and Prevotella were negatively correlated with morbidity, and Bacteroides was increased in infants with abnormal calprotectin. Mothers nursing in the wet season (July to October) produced significantly less oligosaccharides compared to those nursing in the dry season (November to June). These results suggest that specific types and structures of HMOs are sensitive to environmental conditions, protective of morbidity, predictive of growth, and correlated with specific microbiota.
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Affiliation(s)
- Jasmine C. C. Davis
- Department of Chemistry, University of California, Davis, CA 95616, United States
- Foods for Health Institute, University of California, Davis, CA 95616, United States
| | - Zachery T. Lewis
- Foods for Health Institute, University of California, Davis, CA 95616, United States
- Department of Food Science and Technology, University of California, Davis, CA 95616, United States
| | - Sridevi Krishnan
- Department of Nutrition, University of California, Davis, CA 95616, United States
| | - Robin M. Bernstein
- Department of Anthropology, University of Colorado, Boulder, CO 80309, United States
- Health and Society Program, Institute of Behavioral Science, University of Colorado, Boulder, CO 80309, United States
| | - Sophie E. Moore
- Medical Research Council (MRC) Human Nutrition Research, Cambridge, UK
- MRC Unit, The Gambia and MRC International Nutrition Group, London School of Hygiene & Tropical Medicine, London, UK
| | - Andrew M. Prentice
- MRC Unit, The Gambia and MRC International Nutrition Group, London School of Hygiene & Tropical Medicine, London, UK
| | - David A. Mills
- Foods for Health Institute, University of California, Davis, CA 95616, United States
- Department of Food Science and Technology, University of California, Davis, CA 95616, United States
- Department of Viticulture and Enology, University of California, Davis, CA 95616, United States
| | - Carlito B. Lebrilla
- Department of Chemistry, University of California, Davis, CA 95616, United States
- Foods for Health Institute, University of California, Davis, CA 95616, United States
| | - Angela M. Zivkovic
- Foods for Health Institute, University of California, Davis, CA 95616, United States
- Department of Nutrition, University of California, Davis, CA 95616, United States
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11
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Neuraminidase (sialidase) from Aeromonas sp. strain 40/02 – isolation and partial purification. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-0990-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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12
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Woods K, Beighton D, Klein JL. Identification of the ‘Streptococcus anginosus group’ by matrix-assisted laser desorption ionization – time-of-flight mass spectrometry. J Med Microbiol 2014; 63:1143-1147. [DOI: 10.1099/jmm.0.076653-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) provides rapid, accurate and cost-effective identification of a range of bacteria and is rapidly changing the face of routine diagnostic microbiology. However, certain groups of bacteria, for example streptococci (in particular viridans or non-haemolytic streptococci), are less reliably identified by this method. We studied the performance of MALDI-TOF MS for identification of the ‘Streptococcus anginosus group’ (SAG) to species level. In total, 116 stored bacteraemia isolates identified by conventional methods as belonging to the SAG were analysed by MALDI-TOF MS. Partial 16S rRNA gene sequencing, supplemented with sialidase activity testing, was performed on all isolates to provide ‘gold standard’ identification against which to compare MALDI-TOF MS performance. Overall, 100 % of isolates were correctly identified to the genus level and 93.1 % to the species level by MALDI-TOF MS. However, only 77.6 % were correctly identified to the genus level and 59.5 % to the species level by a MALDI-TOF MS direct transfer method alone. Use of a rapid in situ extraction method significantly improved identification rates when compared with the direct transfer method (P<0.001). We recommend routine use of this method to reduce the number of time-consuming full extractions required for identification of this group of bacteria by MALDI-TOF MS in the routine diagnostic laboratory. Only 22 % (1/9) of Streptococcus intermedius isolates were reliably identified by MALDI-TOF MS to the species level, even after full extraction. MALDI-TOF MS reliably identifies S. anginosus and Streptococcus constellatus to the species level but does not reliably identify S. intermedius.
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Affiliation(s)
- Katherine Woods
- Directorate of Infection, Guys & St Thomas Hospitals NHS Foundation Trust, 5th Floor North Wing, St Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, UK
| | - David Beighton
- Department of Oral Biology, Leeds Dental Institute, University of Leeds, Clarendon Way, Leeds LS2 9LU, UK
- Department of Microbiology, KCL Dental Institute, Floor 17, Guys Tower, London SE1 9RT, UK
| | - John L. Klein
- Directorate of Infection, Guys & St Thomas Hospitals NHS Foundation Trust, 5th Floor North Wing, St Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, UK
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13
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Compans RW, Oldstone MBA. Secondary bacterial infections in influenza virus infection pathogenesis. Curr Top Microbiol Immunol 2014; 385:327-56. [PMID: 25027822 PMCID: PMC7122299 DOI: 10.1007/82_2014_394] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Influenza is often complicated by bacterial pathogens that colonize the nasopharynx and invade the middle ear and/or lung epithelium. Incidence and pathogenicity of influenza-bacterial coinfections are multifactorial processes that involve various pathogenic virulence factors and host responses with distinct site- and strain-specific differences. Animal models and kinetic models have improved our understanding of how influenza viruses interact with their bacterial co-pathogens and the accompanying immune responses. Data from these models indicate that considerable alterations in epithelial surfaces and aberrant immune responses lead to severe inflammation, a key driver of bacterial acquisition and infection severity following influenza. However, further experimental and analytical studies are essential to determining the full mechanistic spectrum of different viral and bacterial strains and species and to finding new ways to prevent and treat influenza-associated bacterial coinfections. Here, we review recent advances regarding transmission and disease potential of influenza-associated bacterial infections and discuss the current gaps in knowledge.
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Affiliation(s)
- Richard W. Compans
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia USA
| | - Michael B. A. Oldstone
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California USA
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14
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Louwen R, Staals RHJ, Endtz HP, van Baarlen P, van der Oost J. The role of CRISPR-Cas systems in virulence of pathogenic bacteria. Microbiol Mol Biol Rev 2014; 78:74-88. [PMID: 24600041 PMCID: PMC3957734 DOI: 10.1128/mmbr.00039-13] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) genes are present in many bacterial and archaeal genomes. Since the discovery of the typical CRISPR loci in the 1980s, well before their physiological role was revealed, their variable sequences have been used as a complementary typing tool in diagnostic, epidemiologic, and evolutionary analyses of prokaryotic strains. The discovery that CRISPR spacers are often identical to sequence fragments of mobile genetic elements was a major breakthrough that eventually led to the elucidation of CRISPR-Cas as an adaptive immunity system. Key elements of this unique prokaryotic defense system are small CRISPR RNAs that guide nucleases to complementary target nucleic acids of invading viruses and plasmids, generally followed by the degradation of the invader. In addition, several recent studies have pointed at direct links of CRISPR-Cas to regulation of a range of stress-related phenomena. An interesting example concerns a pathogenic bacterium that possesses a CRISPR-associated ribonucleoprotein complex that may play a dual role in defense and/or virulence. In this review, we describe recently reported cases of potential involvement of CRISPR-Cas systems in bacterial stress responses in general and bacterial virulence in particular.
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15
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Sukeno A, Nagamune H, Whiley RA, Jafar SI, Aduse-Opoku J, Ohkura K, Maeda T, Hirota K, Miyake Y, Kourai H. Intermedilysin Is Essential for the Invasion of Hepatoma HepG2 Cells byStreptococcus intermedius. Microbiol Immunol 2013; 49:681-94. [PMID: 16034212 DOI: 10.1111/j.1348-0421.2005.tb03647.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Streptococcus intermedius causes endogenous infections leading to abscesses. This species produces intermedilysin (ILY), a human-specific cytolysin. Because of the significant correlation between higher ILY production levels by S. intermedius and deep-seated abscesses, we constructed ily knockout mutant UNS38 B3 and complementation strain UNS38 B3R1 in order to investigate the role of ILY in deep-seated infections. Strain UNS38 reduced the viability of human liver cell line HepG2 at infection but not of rat liver cell line BRL3A. Isogenic mutant strain UNS38 B3 was not cytotoxic in either cell line. Quantification of S. intermedius revealed that in infected HepG2 cells UNS38 but not UNS38 B3 increased intracellularly concomitantly with increasing cell damage. This difference between UNS38 and UNS38 B3 was not observed with UNS38 B3R1. Invasion and proliferation in BRL3A cells was not observed. Masking UNS38 or UNS38 B3R1 with ILY antibody drastically decreased adherence and invasion of HepG2. Moreover, coating strain UNS38 B3 with ILY partially restored adherence to HepG2 but without subsequent bacterial growth. At 1 day post-infection, many intact UNS38 were detected in the damaged phagosomes of HepG2 with bacterial proliferation observed in the cytoplasm of dead HepG2 after an additional 2 day incubation. These results indicate that surface-bound ILY on S. intermedius is an important factor for invasion of human cells by this bacterium and that secretion of ILY within host cells is essential for subsequent host cell death. These data strongly implicate ILY as an important factor in the pathogenesis of abscesses in vivo by this streptococcus.
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Affiliation(s)
- Akiko Sukeno
- Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Japan
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16
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Okayama H, Nagata E, Ito HO, Oho T, Inoue M. Experimental Abscess Formation Caused by Human Dental Plaque. Microbiol Immunol 2013; 49:399-405. [PMID: 15905601 DOI: 10.1111/j.1348-0421.2005.tb03742.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human dental plaque consists of a wide variety of microorganisms, some of which are believed to cause systemic infections, including abscesses, at various sites in the body. To confirm this hypothesis experimentally, we examined the abscess-forming ability of native dental plaque in mice, the microbial features of the infectious locus produced by the plaque, and the anti-phagocytic property of microbial isolates. Aliquots of a suspension of supragingival dental plaque containing 6 x 10(6) colony-forming unit of bacteria were injected subcutaneously into the dorsa of mice. Abscess formation was induced in 76 of 85 mice using ten different plaque samples. Thirteen microorganisms were isolated from pus samples aspirated from abscess lesions. The microbial composition of pus, examined in 17 of 76 abscesses, was very simple compared to that of the plaque sample that had induced the abscess. The majority of the isolates belonged to the Streptococcus anginosus group, normally a minor component of plaque samples. S. anginosus was the most frequently detected organism and the most prevalent in seven abscesses, and Streptococcus intermedius and Streptococcus constellatus were predominant in one and three abscess samples, respectively. Each isolate of S. anginosus group produced abscesses in mice, and heat-treated supragingival dental plaque influenced the abscess-forming ability of S. anginosus isolate. These isolates possessed a high antiphagocytic capacity against human polymorphonuclear leukocytes. Our results suggest that human supragingival dental plaque itself is a source of the infectious pathogens that cause abscess formation.
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Affiliation(s)
- Hidehito Okayama
- Department of Preventive Dentistry, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Japan
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17
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Corcuera MT, Gómez-Lus ML, Gómez-Aguado F, Maestre JR, Ramos MDC, Alonso MJ, Prieto J. Morphological plasticity of Streptococcus oralis isolates for biofilm production, invasiveness, and architectural patterns. Arch Oral Biol 2013; 58:1584-93. [PMID: 24112723 DOI: 10.1016/j.archoralbio.2013.07.011] [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: 12/03/2012] [Revised: 06/03/2013] [Accepted: 07/23/2013] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Streptococcus oralis is an early coloniser of the oral cavity that contributes to dental plaque formation. Many different genotypes can coexist in the same individual and cause opportunistic infections such as bacterial endocarditis. However, little is known about virulence factors involved in those processes. The aim was to analyze the evolving growth of S. oralis colony/biofilm to find out potentially pathogenic features. DESIGN Thirty-three S. oralis isolates were analyzed for: (1) biofilm production, by spectrophotometric microtiter plate assay; (2) colonial internal architecture, by histological methods and light and electron microscopy; (3) agar invasion, by a new colony-biofilm assay. RESULTS S. oralis colonies showed two different growth patterns: (1) fast growth rate without invasion or minimally invasive; (2) slow growth rate, but high invasion ability. 12.1% of strains were biofilm non-producers and 24.2% not invasive, compared to 51.5% biofilm high-producers and 39.4% very invasive. Both phenotypic characteristics tended to be mutually exclusive. However, a limited number of strains (15%) co-expressed these features at the highest level. CONCLUSIONS Morphological plasticity of S. oralis highlighted in this study may have important ecological and clinical implications. Coexistence of strains with different growth patterns could produce a synergic effect in the formation and development of subgingival dental plaque. Moreover, invasiveness might regulate dissemination and colonisation mechanisms. Simultaneous co-expression of high-invasive and high-biofilm phenotypes gives a fitness advantage during colonisation and may confer higher pathogenic potential.
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18
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Dige I, Schlafer S, Nyvad B. Difference in initial dental biofilm accumulation between night and day. Acta Odontol Scand 2012; 70:441-7. [PMID: 22126594 DOI: 10.3109/00016357.2011.634833] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE The study of initial microbial colonization on dental surfaces is a field of intensive research because of the aetiological role of biofilms in oral diseases. Most previous studies of de novo accumulation and composition of dental biofilms in vivo do not differentiate between biofilms formed during day and night. This study hypothesized that there is a diurnal variation in the rate of accumulation of bacteria on solid surfaces in the oral cavity. MATERIALS AND METHODS In situ biofilm from healthy individuals was collected for 12 h during day and night, respectively, subjected to fluorescent in situ hybridization and visualized using confocal laser scanning microscopy. RESULTS Analysis of the biofilms using stereological methods and digital image analysis revealed a consistent statistically significant difference between both the total number of bacteria and the biovolume in the two 12-h groups (p = 0.012), with the highest accumulation of bacteria during daytime (a factor of 8.8 and 6.1 higher, respectively). Hybridization with probes specific for streptococci and Actinomyces naeslundii indicated a higher proportion of streptococci in biofilms grown during daytime as compared to night-time. No differences could be observed for A. naeslundii. The degree of microbial coverage and the bacterial composition varied considerably between different individuals. CONCLUSION The data provide firm evidence that initial biofilm formation decreases during the night, which may reflect differences in the availability of salivary nutrients. This finding is of significant importance when studying population dynamics during experimental dental biofilm formation.
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Affiliation(s)
- Irene Dige
- Department of Dental Pathology, Operative Dentistry and Endodontics, School of Dentistry, Aarhus Faculty of Health Sciences, Aarhus University, Denmark.
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19
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Nishikawa T, Shimizu K, Tanaka T, Kuroda K, Takayama T, Yamamoto T, Hanada N, Hamada Y. Bacterial neuraminidase rescues influenza virus replication from inhibition by a neuraminidase inhibitor. PLoS One 2012; 7:e45371. [PMID: 23028967 PMCID: PMC3445474 DOI: 10.1371/journal.pone.0045371] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 08/15/2012] [Indexed: 12/27/2022] Open
Abstract
Influenza virus neuraminidase (NA) cleaves terminal sialic acid residues on oligosaccharide chains that are receptors for virus binding, thus playing an important role in the release of virions from infected cells to promote the spread of cell-to-cell infection. In addition, NA plays a role at the initial stage of viral infection in the respiratory tract by degrading hemagglutination inhibitors in body fluid which competitively inhibit receptor binding of the virus. Current first line anti-influenza drugs are viral NA-specific inhibitors, which do not inhibit bacterial neuraminidases. Since neuraminidase producing bacteria have been isolated from oral and upper respiratory commensal bacterial flora, we posited that bacterial neuraminidases could decrease the antiviral effectiveness of NA inhibitor drugs in respiratory organs when viral NA is inhibited. Using in vitro models of infection, we aimed to clarify the effects of bacterial neuraminidases on influenza virus infection in the presence of the NA inhibitor drug zanamivir. We found that zanamivir reduced progeny virus yield to less than 2% of that in its absence, however the yield was restored almost entirely by the exogenous addition of bacterial neuraminidase from Streptococcus pneumoniae. Furthermore, cell-to-cell infection was severely inhibited by zanamivir but restored by the addition of bacterial neuraminidase. Next we examined the effects of bacterial neuraminidase on hemagglutination inhibition and infectivity neutralization activities of human saliva in the presence of zanamivir. We found that the drug enhanced both inhibitory activities of saliva, while the addition of bacterial neuraminidase diminished this enhancement. Altogether, our results showed that bacterial neuraminidases functioned as the predominant NA when viral NA was inhibited to promote the spread of infection and to inactivate the neutralization activity of saliva. We propose that neuraminidase from bacterial flora in patients may reduce the efficacy of NA inhibitor drugs during influenza virus infection. (295 words).
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Affiliation(s)
- Tomoko Nishikawa
- SRBD Project, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- Division and Department of Obstetrics and Gynecology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- Department of Oral & Maxillofacial Surgery, Tsurumi University School of Dental Medicine, Turumi-ku, Yokohama, Japan
| | - Kazufumi Shimizu
- SRBD Project, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- Division and Department of Obstetrics and Gynecology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- * E-mail:
| | - Torahiko Tanaka
- SRBD Project, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- Division of Biochemistry, Department of Biomedical Sciences, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Kazumichi Kuroda
- SRBD Project, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- Division of Microbiology, Department of Pathology and Microbiology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Tadatoshi Takayama
- SRBD Project, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- Division of Digestive Surgery, Department of Surgery, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Tatsuo Yamamoto
- SRBD Project, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- Division and Department of Obstetrics and Gynecology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Nobuhiro Hanada
- SRBD Project, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
- Department of Translational Research, Tsurumi University School of Dental Medicine, Turumi-ku, Yokohama, Japan
| | - Yoshiki Hamada
- Department of Oral & Maxillofacial Surgery, Tsurumi University School of Dental Medicine, Turumi-ku, Yokohama, Japan
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20
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Two gene clusters coordinate galactose and lactose metabolism in Streptococcus gordonii. Appl Environ Microbiol 2012; 78:5597-605. [PMID: 22660715 DOI: 10.1128/aem.01393-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus gordonii is an early colonizer of the human oral cavity and an abundant constituent of oral biofilms. Two tandemly arranged gene clusters, designated lac and gal, were identified in the S. gordonii DL1 genome, which encode genes of the tagatose pathway (lacABCD) and sugar phosphotransferase system (PTS) enzyme II permeases. Genes encoding a predicted phospho-β-galactosidase (LacG), a DeoR family transcriptional regulator (LacR), and a transcriptional antiterminator (LacT) were also present in the clusters. Growth and PTS assays supported that the permease designated EII(Lac) transports lactose and galactose, whereas EII(Gal) transports galactose. The expression of the gene for EII(Gal) was markedly upregulated in cells growing on galactose. Using promoter-cat fusions, a role for LacR in the regulation of the expressions of both gene clusters was demonstrated, and the gal cluster was also shown to be sensitive to repression by CcpA. The deletion of lacT caused an inability to grow on lactose, apparently because of its role in the regulation of the expression of the genes for EII(Lac), but had little effect on galactose utilization. S. gordonii maintained a selective advantage over Streptococcus mutans in a mixed-species competition assay, associated with its possession of a high-affinity galactose PTS, although S. mutans could persist better at low pHs. Collectively, these results support the concept that the galactose and lactose systems of S. gordonii are subject to complex regulation and that a high-affinity galactose PTS may be advantageous when S. gordonii is competing against the caries pathogen S. mutans in oral biofilms.
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Lewis AL, Lewis WG. Host sialoglycans and bacterial sialidases: a mucosal perspective. Cell Microbiol 2012; 14:1174-82. [PMID: 22519819 DOI: 10.1111/j.1462-5822.2012.01807.x] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/09/2012] [Accepted: 04/17/2012] [Indexed: 12/20/2022]
Abstract
Sialic acids are nine-carbon-backbone sugars that occupy outermost positions on vertebrate cells and secreted sialoglycoproteins. These negatively charged hydrophilic carbohydrates have a variety of biological, biophysical and immunological functions. Mucosal surfaces and secretions of the mouth, airway, gut and vagina are especially sialoglycan-rich. Given their prominent positions and important functions, a variety of microbial strategies have targeted host sialic acids for adherence, mimicry and/or degradation. Here we review the roles of bacterial sialidases (neuraminidases) during colonization and pathogenesis of mammalian mucosal surfaces. Evidence is presented to support the myriad roles of mucosal sialoglycans in protecting the host from bacterial infection. In opposition, many bacteria hydrolyse sialic acids during associations with the gastrointestinal, oral, respiratory and reproductive tracts. Sialidases promote bacterial survival in mucosal niche environments in several ways, including: (i) nutritional benefits of sialic acid catabolism, (ii) unmasking of cryptic host ligands used for adherence, (iii) participation in biofilm formation and (iv) modulation of immune function. Bacterial sialidases are among the best-studied enzymes involved in pathogenesis and may also drive commensal and/or symbiotic host associations. Future studies should continue to define host substrates of bacterial sialidases and the mechanisms of their pathologic, commensal and symbiotic interactions with the mammalian host.
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Affiliation(s)
- Amanda L Lewis
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
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22
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Löfling J, Vimberg V, Battig P, Henriques-Normark B. Cellular interactions by LPxTG-anchored pneumococcal adhesins and their streptococcal homologues. Cell Microbiol 2010; 13:186-97. [PMID: 21199258 DOI: 10.1111/j.1462-5822.2010.01560.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In this review we focus on three important families of LPxTG-anchored adhesins in the human pathogen Streptococcus pneumoniae, but also their homologues in related streptococci. We discuss the contribution of these streptococcal adhesins to host tropism, pathogenesis and their interactions with different host cell types. The first surface structures discussed are the heteropolymeric pili that have been found in important streptococcal pathogens such as S. pneumoniae, S. pyogenes, S. agalactiae and E. faecalis/faecium. Major and minor pilus subunit proteins are covalently joined and finally attached to the cell wall through the action of specific sortases. The role of pili and individual pilin subunits in adhesion and pathogenesis and their structure and assembly in different streptococcal species are being covered. Furthermore, we address recent findings regarding a family of large glycosylated serine-rich repeat (SRR) proteins that act as fibrillar adhesins for which homologues have been found in several streptococcal species including pneumococci. In the pneumococcal genome both pili and its giant SRR protein are encoded by accessory genes present in particular clonal lineages for which epidemiological information is available. Finally, we briefly discuss the role played by the pneumococcal neuraminidase NanA in adhesion and pathogenesis.
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Affiliation(s)
- J Löfling
- Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
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Abstract
Dental biofilms produce acids from carbohydrates that result in caries. According to the extended caries ecological hypothesis, the caries process consists of 3 reversible stages. The microflora on clinically sound enamel surfaces contains mainly non-mutans streptococci and Actinomyces, in which acidification is mild and infrequent. This is compatible with equilibrium of the demineralization/remineralization balance or shifts the mineral balance toward net mineral gain (dynamic stability stage). When sugar is supplied frequently, acidification becomes moderate and frequent. This may enhance the acidogenicity and acidurance of the non-mutans bacteria adaptively. In addition, more aciduric strains, such as ‘low-pH’ non-mutans streptococci, may increase selectively. These microbial acid-induced adaptation and selection processes may, over time, shift the demineralization/remineralization balance toward net mineral loss, leading to initiation/progression of dental caries (acidogenic stage). Under severe and prolonged acidic conditions, more aciduric bacteria become dominant through acid-induced selection by temporary acid-impairment and acid-inhibition of growth (aciduric stage). At this stage, mutans streptococci and lactobacilli as well as aciduric strains of non-mutans streptococci, Actinomyces, bifidobacteria, and yeasts may become dominant. Many acidogenic and aciduric bacteria are involved in caries. Environmental acidification is the main determinant of the phenotypic and genotypic changes that occur in the microflora during caries.
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Affiliation(s)
- N. Takahashi
- Division of Oral Ecology and Biochemistry, Department of Oral Biology, Tohoku University Graduate School of Dentistry, 4–1 Seiryo-machi, Aoba-ku, Sendai, 980–8575, Japan
| | - B. Nyvad
- School of Dentistry, Faculty of Health Sciences, University of Aarhus, Denmark
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24
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Douglas CWI. Possible Pathogenic Mechanisms of Oral Streptococci. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2009. [DOI: 10.3109/08910609409141351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- C. W. I. Douglas
- Department of Oral Pathology, School of Clinical Dentistry, Claremont Crescent, Sheffield, S10 2TA, UK
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Wickström C, Herzberg MC, Beighton D, Svensäter G. Proteolytic degradation of human salivary MUC5B by dental biofilms. MICROBIOLOGY-SGM 2009; 155:2866-2872. [PMID: 19556293 DOI: 10.1099/mic.0.030536-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The degradation of complex substrates, like salivary mucins, requires an arsenal of glycosidases and proteases to sequentially degrade the oligosaccharides and polypeptide backbone. The mucin MUC5B is a complex oligomeric glycoprotein, heterogeneous in molecular mass (14-40 x 10(6) Da), with a diverse repertoire of oligosaccharides, differing in composition and charge. The aim of this study was to investigate whether proteolytic degradation of the mucin polypeptide backbone could be identified and if cooperation of dental biofilm bacteria was required. Cooperative bacteria-mediated proteolysis of MUC5B was determined by comparing individual species and mixed consortia of strains isolated from supragingival plaque, and freshly harvested supragingival plaque. Proteolytic activity was analysed using fluorescent labelled substrate and by visualizing mucin degradation by SDS-PAGE. Dental plaque degraded the polypeptide backbone of the salivary MUC5B mucin. The mucin was also degraded by a specific consortium of isolated species from supragingival plaque, although individual species and other consortia did not. Certain bacteria in supragingival dental plaque therefore cooperate as a consortium to proteolyse human salivary MUC5B and hydrolyse glycosides.
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Affiliation(s)
- Claes Wickström
- Department of Oral Biology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Mark C Herzberg
- Mucosal and Vaccine Research Center, Minneapolis VA Medical Center, Minneapolis, MN 55417, USA.,Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - David Beighton
- Infection Research Group, Dental Institute, King's College, London, UK
| | - Gunnel Svensäter
- Department of Oral Biology, Faculty of Odontology, Malmö University, Malmö, Sweden
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Wickström C, Hamilton IR, Svensäter G. Differential metabolic activity by dental plaque bacteria in association with two preparations of MUC5B mucins in solution and in biofilms. Microbiology (Reading) 2009; 155:53-60. [DOI: 10.1099/mic.0.022111-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Salivary mucin, MUC5B, is an oligomeric glycoprotein, heterogeneous in size and with a diverse repertoire of oligosaccharides, which differ in composition and charge. Since complex salivary glycoproteins are considered to be the major source of nutrients for the oral supragingival microbiota, the major aim of the current study was to determine whether different preparations of non-denatured MUC5B could be isolated exhibiting different biological properties in relation to the microflora associated with the surfaces of the oral cavity. Two preparations, solMUC5B and gelMUC5B, were isolated by density-gradient centrifugation and were shown to have different buoyant densities, carbohydrate content and surface-adsorbing characteristics. To ascertain differences in biological activity, the two mucin preparations, both in solution and adsorbed to a model surface, were incubated with freshly isolated dental plaque and assayed for metabolic (dehydrogenase) activity with the fluoresecent substrate CTC (5-cyano-2,3-ditolyl tetrazolium chloride). The plaque bacteria exhibited higher metabolism with the solMUC5B preparation in solution, with 79.4 % active plaque cells compared to the controls without mucin (9.6 %), while gelMUC5B showed 48.2 % active cells with the same plaque population. In contrast, the same mucins adhered to a surface elicited a significantly lower metabolic response, with surface-associated plaque cells showing only 12.1 % active cells with solMUC5B and 29.2 % with gelMUC5B. These results suggested that the metabolism by the plaque cells adsorbed to surface-associated mucins was downregulated compared to the same cells suspended in mucin solution. This was confirmed in an experiment where active dispersed plaque/solMUC5B suspensions were shown to lose significant metabolic activity (e.g. 74.9 to 19.3 %) when allowed to interact with gelMUC5B adsorbed to a surface. Clearly, the solMUC5B and gelMUC5B preparations exhibited different biological activity when assayed with freshly plaque bacteria in suspension and in a biofilm.
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Affiliation(s)
- Claes Wickström
- Department of Oral Biology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Ian R. Hamilton
- Department of Oral Biology, Faculty of Dentistry, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Gunnel Svensäter
- Department of Oral Biology, Faculty of Odontology, Malmö University, Malmö, Sweden
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27
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Do T, Henssge U, Gilbert SC, Clark D, Beighton D. Evidence for recombination between a sialidase (nanH) of Actinomyces naeslundii and Actinomyces oris, previously named 'Actinomyces naeslundii genospecies 1 and 2'. FEMS Microbiol Lett 2008; 288:156-62. [PMID: 18823396 PMCID: PMC2667307 DOI: 10.1111/j.1574-6968.2008.01336.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 07/31/2008] [Indexed: 11/30/2022] Open
Abstract
Actinomyces spp., predominant members of human oral biofilms, may use extracellular sialidase to promote adhesion, deglycosylate immunoglobulins and liberation of nutrients. Partial nanH gene sequences (1,077 bp) from Actinomyces oris (n=74), Actinomyces naeslundii (n=30), Actinomyces viscosus (n=1) and Actinomyces johnsonii (n=2) which included the active-site region and the bacterial neuraminidase repeats (BNRs) were compared. The sequences were aligned and each species formed a distinct cluster with five isolates having intermediate positions. These five isolates (two A. oris and three A. naeslundii) exhibited interspecies recombination. The nonsynonymous/synonymous ratio was <1 for both A. oris and A. naeslundii indicating that nanH in both species is under stabilizing selective pressure; nonsynonymous mutations are not selected. However, for A. oris significant negative values in tests for neutral selection suggested the rate of mutation in A. oris was greater than in A. naeslundii but with selection against nonsynonymous mutations. This was supported by the observation that the frequency of polymorphic sites in A. oris, which were monomorphic in A. naeslundii was significantly greater than the frequency of polymorphic sites in A. naeslundii which were monomorphic in A. oris (chi(2)=7.011; P=0.00081). The higher proportions of A. oris in the oral biofilm might be explained by the higher mutation rate facilitating an increased ability to respond successfully to environmental stress.
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Affiliation(s)
- Thuy Do
- King's College, School of Medicine and Dentistry, London, UK
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28
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Wickström C, Svensäter G. Salivary gel-forming mucin MUC5B – a nutrient for dental plaque bacteria. ACTA ACUST UNITED AC 2008; 23:177-82. [DOI: 10.1111/j.1399-302x.2007.00407.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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29
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Liu D, Yumoto H, Hirota K, Murakami K, Takahashi K, Hirao K, Matsuo T, Ohkura K, Nagamune H, Miyake Y. Histone-like DNA binding protein of Streptococcus intermedius induces the expression of pro-inflammatory cytokines in human monocytes via activation of ERK1/2 and JNK pathways. Cell Microbiol 2007; 10:262-76. [PMID: 17883418 DOI: 10.1111/j.1462-5822.2007.01040.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Streptococcus intermedius is a commensal associated with serious, deep-seated purulent infections in major organs, such as the brain and liver. Histone-like DNA binding protein (HLP) is an accessory architectural protein in a variety of bacterial cellular processes. In this study, we investigated the mechanisms of pro-inflammatory cytokine inductions in THP-1 cells by stimulation with recombinant HLP of S. intermedius (rSi-HLP). rSi-HLP stimulation-induced production of pro-inflammatory cytokines (IL-8, IL-1 beta and TNF-alpha) occurred in a time- and dose-dependent manner. In contrast with the heat-stable activity of DNA binding, the induction activity of rSi-HLP was heat-unstable. In subsequent studies, rSi-HLP acted cooperatively with lipoteichoic acid, the synthetic Toll-like receptor 2 agonist, Pam3CSK4, and the cytosolic nucleotide binding oligomerization domain 2 receptor agonist, muramyldipeptide. Furthermore, Western blot and blocking assays with specific inhibitors showed that rSi-HLP stimulation induced the activation of cell signal transduction pathways, extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). In addition to its physiological role in bacterial growth through DNA binding, these results indicate that Si-HLP can trigger a cascade of events that induce pro-inflammatory responses via ERK1/2 and JNK signal pathways, and suggest that bacterial HLP may contribute to the activation of host innate immunity during bacterial infection.
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Affiliation(s)
- Dali Liu
- Department of Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15, Kuramoto-cho, Tokushima 770-8504, Japan
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30
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King SJ, Whatmore AM, Dowson CG. NanA, a neuraminidase from Streptococcus pneumoniae, shows high levels of sequence diversity, at least in part through recombination with Streptococcus oralis. J Bacteriol 2005; 187:5376-86. [PMID: 16030232 PMCID: PMC1196044 DOI: 10.1128/jb.187.15.5376-5386.2005] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae, an important human pathogen, contains at least two genes, nanA and nanB, that express sialidase activity. NanA is a virulence determinant of pneumococci which is important in animal models of colonization and middle ear infections. The gene encoding NanA was detected in all 106 pneumococcal strains screened that represented 59 restriction profiles. Sequencing confirmed a high level of diversity, up to 17.2% at the nucleotide level and 14.8% at the amino acid level. NanA diversity is due to a number of mechanisms including insertions, point mutations, and recombination generating mosaic genes. The level of nucleotide divergence for each recombinant block is greater than 30% and much higher than the 20% identified within mosaic pbp genes, suggesting that a high selective pressure exists for these alterations. These data indicate that at least one of the four recombinant blocks identified originated from a Streptococcus oralis isolate, demonstrating for the first time that protein virulence determinants of pneumococci have, as identified previously for genes encoding penicillin binding proteins, evolved by recombination with oral streptococci. No amino acid alterations were identified within the aspartic boxes or predicted active site, suggesting that sequence variation may be important in evading the adaptive immune response. Furthermore, this suggests that nanA is an important target of the immune system in the interaction between the pneumococcus and host.
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Affiliation(s)
- Samantha J King
- 401A Johnson Pavilion, Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104-6076, USA.
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31
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Alam S, Brailsford SR, Adams S, Allison C, Sheehy E, Zoitopoulos L, Kidd EA, Beighton D. Genotypic heterogeneity of Streptococcus oralis and distinct aciduric subpopulations in human dental plaque. Appl Environ Microbiol 2000; 66:3330-6. [PMID: 10919787 PMCID: PMC92151 DOI: 10.1128/aem.66.8.3330-3336.2000] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genotypic heterogeneity of Streptococcus oralis isolated from the oral cavity was investigated using repetitive extragenic palindromic PCR. Unrelated subjects harbored unique genotypes, with numerous genotypes being isolated from an individual. S. oralis is the predominant aciduric bacterium isolated from noncarious tooth sites. Genotypic comparison of the aciduric populations isolated at pH 5.2 with those isolated from mitis-salivarius agar (MSA) (pH 7.0) indicated that the aciduric populations were genotypically distinct in the majority of subjects (chi(2) = 13.09; P = 0.0031). Neither the aciduric nor the MSA-isolated strains were stable, with no strains isolated at baseline being isolated 4 or 12 weeks later in the majority of subjects. The basis of this instability is unknown but is similar to that reported for Streptococcus mitis. Examination of S. oralis strains isolated from cohabiting couples demonstrated that in three of five couples, genotypically identical strains were isolated from both partners and this was confirmed by using Salmonella enteritidis repetitive element PCR and enterobacterial PCR typing. These data provide further evidence of the physiological and genotypic heterogeneity of non-mutans streptococci. The demonstration of distinct aciduric populations of S. oralis implies that the role of these and other non-mutans streptococci in the caries process requires reevaluation.
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Affiliation(s)
- S Alam
- Dental Caries Research Group, Guy's, King's, and St. Thomas' Dental Institute, London, England
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32
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Yeung MK. Molecular and genetic analyses of Actinomyces spp. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2000; 10:120-38. [PMID: 10759417 DOI: 10.1177/10454411990100020101] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Members of the genus Actinomyces are predominant primary colonizers of the oral cavity and play an important role in initiating plaque development. These bacteria have evolved unique mechanisms that favor colonization and persistence in this micro-environment. The expression of cell-surface fimbriae is correlated with the ability of these bacteria to adhere to specific receptors on the tooth and mucosal surfaces, and to interact with other plaque bacteria. The elaboration of sialidase is thought to enhance fimbriae-mediated adherence by unmasking the fimbrial receptors on mammalian cells. The presence of certain cell-associated or extracellular enzymes, including those involved in sucrose or urea metabolism, may provide the means for these bacteria to thrive under conditions when other growth nutrients are not available. Moreover, these enzyme activities may influence the distribution of other plaque bacteria and promote selection for Actinomyces spp. in certain ecological niches. The recent development of a genetic transfer system for Actinomyces spp. has allowed for studies the results of which demonstrate the existence of multiple genes involved in fimbriae synthesis and function, and facilitated the construction of allelic replacement mutants at each gene locus. Analyses of these mutants have revealed a direct correlation between the synthesis of assembled fimbriae and the observed adherence properties. Further genetic analysis of the various enzyme activities detected from strains of Actinomyces should allow for an assessment of the role of these components in microbial ecology, and their contribution to the overall success of Actinomyces spp. as a primary colonizer and a key player in oral health and disease.
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Affiliation(s)
- M K Yeung
- Department of Pediatric Dentistry, University of Texas Health Science Center at San Antonio, 78284, USA
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33
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Noyola DE, Clark B, O'Donnell FT, Atmar RL, Greer J, Demmler GJ. Comparison of a new neuraminidase detection assay with an enzyme immunoassay, immunofluorescence, and culture for rapid detection of influenza A and B viruses in nasal wash specimens. J Clin Microbiol 2000; 38:1161-5. [PMID: 10699013 PMCID: PMC86363 DOI: 10.1128/jcm.38.3.1161-1165.2000] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The performance of a new, rapid, easy-to-perform assay based on neuraminidase enzyme activity for detection of influenza virus types A and B was compared to detection by culture, indirect immunofluorescence, and enzyme immunoassay in 479 nasal wash specimens from children with respiratory infections. Compared to isolation of influenza virus by culture, the neuraminidase assay had a sensitivity of 70.1%, specificity of 92.4%, positive predictive value of 76.3%, and negative predictive value of 89.9%. There was a higher sensitivity for the detection of influenza A virus (76.4%) than for influenza B virus (40.9%). Indirect immunofluorescence showed a sensitivity of 59.8% and specificity of 97% compared to culture isolation for detection of influenza A and B viruses. Enzyme immunoassay showed a sensitivity of 89.7% and specificity of 98.1% for the detection of influenza A alone. The quality of the nasal wash specimen had a significant effect on the detection of influenza virus by all of the assays. A strong response of the neuraminidase assay was more likely to represent a culture-confirmed influenza infection. This new rapid neuraminidase assay was useful for the detection of influenza A and B viruses in nasal wash specimens.
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Affiliation(s)
- D E Noyola
- Departments of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.
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34
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Nagamune H, Whiley RA, Goto T, Inai Y, Maeda T, Hardie JM, Kourai H. Distribution of the intermedilysin gene among the anginosus group streptococci and correlation between intermedilysin production and deep-seated infection with Streptococcus intermedius. J Clin Microbiol 2000; 38:220-6. [PMID: 10618091 PMCID: PMC88699 DOI: 10.1128/jcm.38.1.220-226.2000] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The distribution of intermedilysin, a human-specific cytolysin, among the anginosus group streptococci and the correlation of toxin production and infection by Streptococcus intermedius were investigated. PCR and Southern hybridization specific for the intermedilysin gene revealed that the toxin gene exists only in S. intermedius and no homologue to the toxin gene is distributed in S. anginosus and S. constellatus. Thus, the intermedilysin gene is useful as a marker gene of S. intermedius. Moreover, a human-specific hemolysis assay and Western blotting with intermedilysin-specific antibodies clearly demonstrated that the intermedilysin production level in isolates from deep-seated infections, such as brain and liver abscesses, is higher (6.2- to 10.2-fold, respectively) than in strains from normal habitats, such as dental plaque, or from peripheral infection sites. However, other candidate virulence factors of S. intermedius, such as chondroitin sulfate depolymerase, hyaluronidase, and sialidase activities, did not show such a clear correlation between enzymatic activity and isolation sites or disease severity. From these results, intermedilysin is likely to be the pathogenic or triggering factor of significance in inducing deep-seated infections with S. intermedius.
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Affiliation(s)
- H Nagamune
- Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Tokushima 770-8506, Japan.
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35
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Byers HL, Tarelli E, Homer KA, Hambley H, Beighton D. Growth of Viridans streptococci on human serum alpha1-acid glycoprotein. J Dent Res 1999; 78:1370-80. [PMID: 10403465 DOI: 10.1177/00220345990780071201] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Viridans streptococci have emerged as major opportunistic pathogens. We suggest that for these bacteria to proliferate in vivo and cause disease, they must utilize host tissue components. We have therefore examined the ability of all recognized species of viridans streptococci to liberate and utilize the constituent sugars of the glycans of the extensively sialylated human serum alpha1-acid glycoprotein (AGP) as the sole source of carbohydrate to support in vitro growth. Analysis of residual glycans following bacterial growth was performed by high-pH anion exchange chromatography with pulsed amperometric detection and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Only those species which produced sialidase-namely, Streptococcus oralis, S. intermedius, and S. defectivus--grew on AGP. The extent of degradation of glycans was dependent on the particular glycosidases produced by the bacteria. S. defectivus produced only a sialidase which released the terminal N-acetylneuraminic acid residues of the glycans, and the liberated sugar was utilized. S. intermedius also produced beta-galactosidase and beta-N-acetylglucosaminidase, which removed galactose and N-acetylglucosamine from desialylated glycans, all of which again were utilized by the organism. S. oralis produced beta-galactosidase, beta-N-acetylglucosaminidase, and alpha-fucosidase and novel alpha- and beta-mannosidases which were apparent only from the analysis of the residual sugars of AGP. S. oralis cleaved all the sugars from AGP except for 22% of the N-acetylglucosamine. The residual N-acetylglucosamine residues remaining were those linked to the asparagine of the peptide backbone. All the monosaccharides released by S. oralis from AGP, with the exception of fucose, were utilized. Sialidase production may be a key factor for growth of these species of viridans streptococci on glycoproteins in vivo, since they are commonly associated with extra-oral diseases, with S. oralis emerging as an important pathogen.
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Affiliation(s)
- H L Byers
- Joint Microbiology Research Unit, Faculty of Clinical Dentistry, King's College School of Medicine and Dentistry, London, United Kingdom
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Prakobphol A, Tangemann K, Rosen SD, Hoover CI, Leffler H, Fisher SJ. Separate oligosaccharide determinants mediate interactions of the low-molecular-weight salivary mucin with neutrophils and bacteria. Biochemistry 1999; 38:6817-25. [PMID: 10346903 DOI: 10.1021/bi990145m] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The low-molecular-weight human salivary mucin (MG2) coats oral surfaces, where it is in a prime location for governing cell adhesion. Since oligosaccharides form many of the interactive facets on mucin molecules, we examined MG2 glycosylation as it relates to the molecule's adhesive functions. Our previous study of MG2 oligosaccharide structures showed that the termini predominantly carry T, sialyl-T, Lewisx (Lex), sialyl Lex (sLex), lactosamine, and sialyl lactosamine determinants [Prakobphol, A., et al. (1998) Biochemistry 37, 4916-4927]. In addition, we showed that sLex determinants confer L-selectin ligand activity to this molecule. Here we studied adhesive interactions between MG2 and cells that traffic in the oral cavity: neutrophils and bacteria. Under flow conditions, neutrophils tethered to MG2-coated surfaces at forces between 1.25 and 2 dyn/cm2, i.e., comparable to the shear stress generated at the tooth surface by salivary flow ( approximately 0.8 dyn/cm2). MG2 was also found in association with neutrophils isolated from the oral cavity, evidence that the cells interact with this mucin in vivo. Since MG2 serves as an adhesion receptor for bacteria, the MG2 saccharides that serve this function were also identified. Seven of 18 oral bacteria strains that were tested adhered to MG2. Importantly, six of these seven strains adhered via T antigen, sialyl-T antigen, and/or lactosamine sequences. No adherence to Lex and sLex epitopes was detected in all the strains that were tested. Together, these results suggest that distinct subsets of MG2 saccharides function as ligands for neutrophil L-selectin and receptors for bacterial adhesion, a finding with interesting implications for both oral health and mucin function.
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Affiliation(s)
- A Prakobphol
- Department of Stomatology, University of California, San Francisco 94143, USA
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Prakobphol A, Thomsson KA, Hansson GC, Rosen SD, Singer MS, Phillips NJ, Medzihradszky KF, Burlingame AL, Leffler H, Fisher SJ. Human low-molecular-weight salivary mucin expresses the sialyl lewisx determinant and has L-selectin ligand activity. Biochemistry 1998; 37:4916-27. [PMID: 9538010 DOI: 10.1021/bi972612a] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Previously we showed that the low-molecular-weight mucin (MG2, encoded by MUC7), a major component of human submandibular/sublingual saliva, is a bacterial receptor that coats the tooth surface. Here we tested the hypothesis that the structure of its carbohydrate residues contains important information about its function. Purified MG2 (Mr 120 000) was digested with trypsin, and the resulting Mr 90 000 fragment, which carried primarily O-linked oligosaccharides, was subjected to reductive beta-elimination. The released oligosaccharides were characterized by using nuclear magnetic resonance spectroscopy and mass spectrometry. Of the 41 different structures we detected, the most prominent included NeuAcalpha2-->3Galbeta1-->3GalNAc-ol (sialyl-T antigen), Galbeta1-->4(Fucalpha1-->3)GlcNAcbeta1-->6(Galbeta1 -->3)GalNAc-ol [type 2 core with Lewisx (Lex) determinant], and NeuAcalpha2-->3Galbeta1-->4(Fucalpha1-->3)GlcNAcbet a1-->6(Galbeta1--> 3) GalNAc-ol [type 2 core with sialyl Lex (sLex) determinant]. We also detected di-, tri-, and pentasaccharides with one sulfate group. Lex, sLex, and related sulfated structures are ligands for selectins, adhesion molecules that mediate leukocyte trafficking. Therefore, we investigated whether MG2 was a selectin ligand. In an enzyme-linked immunosorbent assay, L-selectin chimeras interacted with immobilized MG2 in a Ca2+-dependent manner. L-Selectin chimeras also bound to MG2 immobilized on nitrocellulose. Together, these results suggest that the saccharides that MG2 carries could specify some of its important functions, which may include mediating leukocyte interactions in the oral cavity.
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Affiliation(s)
- A Prakobphol
- Department of Stomatology, University of California, San Francisco, San Francisco, California 94143, USA
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38
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Reinholdt J, Kilian M. Comparative analysis of immunoglobulin A1 protease activity among bacteria representing different genera, species, and strains. Infect Immun 1997; 65:4452-9. [PMID: 9353019 PMCID: PMC175640 DOI: 10.1128/iai.65.11.4452-4459.1997] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Immunoglobulin A1 (IgA1) proteases cleaving human IgA1 in the hinge region are produced constitutively by a number of pathogens, including Haemophilus influenzae, Neisseria meningitidis, Neisseria gonorrhoeae, and Streptococcus pneumoniae, as well as by some members of the resident oropharyngeal flora. Whereas IgA1 proteases have been shown to interfere with the functions of IgA antibodies in vitro, the exact role of these enzymes in the relationship of bacteria to a human host capable of responding with enzyme-neutralizing antibodies is not clear. Conceivably, the role of IgA1 proteases may depend on the quantity of IgA1 protease generated as well as on the balance between secreted and cell-associated forms of the enzyme. Therefore, we have compared levels of IgA1 protease activity in cultures of 38 bacterial strains representing different genera and species as well as strains of different pathogenic potential. Wide variation in activity generation rate was found overall and within some species. High activity was not an exclusive property of bacteria with documented pathogenicity. Almost all activity of H. influenzae, N. meningitidis, and N. gonorrhoeae strains was present in the supernatant. In contrast, large proportions of the activity in Streptococcus, Prevotella, and Capnocytophaga species was cell associated at early stationary phase, suggesting that the enzyme may play the role of a surface antigen. Partial release of cell-associated activity occurred during stationary phase. Within some taxa, the degree of activity variation correlated with degree of antigenic diversity of the enzyme as determined previously. This finding may indicate that the variation observed is of biological significance.
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Affiliation(s)
- J Reinholdt
- Department of Oral Biology, Royal Dental College, University of Aarhus, Aarhus C, Denmark.
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39
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Cisar JO, Takahashi Y, Ruhl S, Donkersloot JA, Sandberg AL. Specific inhibitors of bacterial adhesion: observations from the study of gram-positive bacteria that initiate biofilm formation on the tooth surface. Adv Dent Res 1997; 11:168-75. [PMID: 9524453 DOI: 10.1177/08959374970110010801] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Oral surfaces are bathed in secretory antibodies and other salivary macromolecules that are potential inhibitors of specific microbial adhesion. Indigenous Gram-positive bacteria that colonize teeth, including viridans streptococci and actinomyces, may avoid inhibition of adhesion by host secretory molecules through various strategies that involve the structural design and binding properties of bacterial adhesins and receptors. Further studies to define the interactions of these molecules within the host environment may suggest novel approaches for the control of oral biofilm formation.
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Affiliation(s)
- J O Cisar
- Laboratory of Microbial Ecology, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892, USA
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Nagamune H, Ohnishi C, Katsuura A, Fushitani K, Whiley RA, Tsuji A, Matsuda Y. Intermedilysin, a novel cytotoxin specific for human cells secreted by Streptococcus intermedius UNS46 isolated from a human liver abscess. Infect Immun 1996; 64:3093-100. [PMID: 8757839 PMCID: PMC174193 DOI: 10.1128/iai.64.8.3093-3100.1996] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A novel cytotoxin (intermedilysin) specific for human cells was identified as a cytolytic factor of Streptococcus intermedius UNS46 isolated from a human liver abscess. Intermedilysin caused human cell death with membrane blebs. Intermedilysin was purified from UNS46 culture medium by means of gel filtration and hydrophobic chromatography. The purified toxin was resolved into major and minor bands of 54 and 53 kDa, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These proteins reacted with an antibody against intermedilysin. Five internal peptide fragments of intermedilysin were sequenced and found to have 42 to 71% homology with the thiol-activated cytotoxin pneumolysin. However, the action of intermedilysin differed from that of thiol-activated cytotoxins, especially in terms of a lack of activation by dithiothreitol and resistance to treatments with N-ethylmaleimide and 5,5'-dithio-bis-(2-nitrobenzoic acid), although cholesterol inhibited the toxin activity. Intermedilysin was potently hemolytic on human erythrocytes but was 100-fold less effective on chimpanzee and cynomolgus monkey erythrocytes. Intermedilysin was not hemolytic in nine other animal species tested. Since human erythrocytes treated with trypsin were far less sensitive to intermedilysin than were the intact cells, a cell membrane protein(s) may participate in the intermedilysin action. These data demonstrated that intermedilysin is distinguishable from all known bacterial cytolysins.
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Affiliation(s)
- H Nagamune
- Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Japan
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Homer KA, Kelley S, Hawkes J, Beighton D, Grootveld MC. Metabolism of glycoprotein-derived sialic acid and N-acetylglucosamine by Streptococcus oralis. MICROBIOLOGY (READING, ENGLAND) 1996; 142 ( Pt 5):1221-1230. [PMID: 8704962 DOI: 10.1099/13500872-142-5-1221] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Nine strains of Streptococcus oralis, isolated from blood cultures of patients with infective endocarditis or from the oral cavity as part of the normal flora, were examined for their ability to elaborate sialidase (neuraminidase) and N-acetylglucosaminidase, enzymes which are involved in the degradation of glycoproteins. Both glycosidases were induced when bacteria were grown in a minimal medium supplemented with porcine gastric mucin, a model glycoprotein, and repressed when growth occurred in the presence of glucose. Cell-free extracts mucin-grown cultures expressed elevated levels of N-acetylneuraminate pyruvate-lyase (the first intracellular enzyme in the pathway of N-acetylneuraminate catabolism), N-acetylglucosamine (glcNAc)-6-phosphate deacetylase and glucosamine-6-phosphate deaminase (enzymes involved in the intracellular catabolism of GlcNAc 6-phosphate); activity of each of these intracellular enzymes was markedly repressed when bacteria were grown in media supplemented with alpha 1-acid glycoprotein, a major component of human plasma. Cells from these cultures expressed high levels of sialidase, N-acetylglucosaminidase, and the intracellular enzymes involved in the catabolism of N-acetyl-sugars released by action of these glycosidases. High-resolution 1H-NMR spectroscopy of spent culture supernatants revealed that sialic acid and GlcNAc residues of the molecularly mobile oligosaccharide side-chains of alpha 1-acid glycoprotein had been hydrolysed and the released sugars internalized by the bacteria. These data indicate that S. oralis has the ability to hydrolyse constituents of oligosaccharide side-chains of host-derived glycoproteins and to utilize simultaneously these released carbohydrates. The biochemical characteristics induced by the growth of S. oralis on glycoproteins may play a role in the survival and persistence of these bacteria at the infection site in vivo.
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Affiliation(s)
- K A Homer
- Joint Microbiology Research Unit, King's College School of Medicine and Dentistry, Faculty of Clinical Dentistry, Caldecot Road, London SE5 9RW, UK
| | - S Kelley
- Joint Microbiology Research Unit, King's College School of Medicine and Dentistry, Faculty of Clinical Dentistry, Caldecot Road, London SE5 9RW, UK
| | - J Hawkes
- Department of Chemistry, King's College (Strand Campus), University of London, The Strand, London WC2R 2LS, UK
| | - D Beighton
- Joint Microbiology Research Unit, King's College School of Medicine and Dentistry, Faculty of Clinical Dentistry, Caldecot Road, London SE5 9RW, UK
| | - M C Grootveld
- Inflammation Research Group, The London Hospital Medical College, Ashfield Street, London E1 2AD, UK
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Oakey HJ, Harty DW, Knox KW. Enzyme production by lactobacilli and the potential link with infective endocarditis. THE JOURNAL OF APPLIED BACTERIOLOGY 1995; 78:142-8. [PMID: 7698950 DOI: 10.1111/j.1365-2672.1995.tb02834.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fifty-six strains of lactobacilli were examined for the production of glycosidases and proteases (arylamidases) that could be associated with the ability to grow in vivo and/or be a factor in the pathogenesis of endocarditis. The strains were from seven species, with an emphasis on Lactobacillus rhamnosus and Lact. paracasei subsp. paracasei, both of which have been associated with endocarditis and provided 12 of the 13 strains isolated from cases of the disease. Other species were Lact. acidophilus, Lact. plantarum, Lact. salivarius, Lact. fermentum and Lact. oris. Commonly expressed glycosidase activities were alpha-D-galactosidase and beta-N-acetyl-D-glucosaminidase followed by beta-D-glucosidase and alpha-L-fucosidase. The combined production of beta-N-acetyl-D-glucosaminidase and alpha-D-galactosidase was a feature of the endocarditis isolates. In contrast, beta-D-galactosidase was produced by very few of the strains within species implicated in endocarditis but most of the strains of Lact. salivarius, Lact. fermentum and Lact. oris. The most commonly produced arylamidases active against substrates employed for testing human blood clotting cascade were activated protein C(Ca)-like, activated factor X(Xa)-like and Hageman factor-like followed by kallikrein-like and chymotrypsin-like enzymes.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- H J Oakey
- Institute of Dental Research, Surry Hills, Sydney, NSW, Australia
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43
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Jansen HJ, van der Hoeven JS, van den Kieboom CW, Göertz JH, Camp PJ, Bakkeren JA. Degradation of immunoglobulin G by periodontal bacteria. ORAL MICROBIOLOGY AND IMMUNOLOGY 1994; 9:345-51. [PMID: 7870469 DOI: 10.1111/j.1399-302x.1994.tb00284.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Several subgingival microorganisms were tested for their ability to utilize human immunoglobulin G (IgG) as a substrate for growth. This was done using a protein-free chemically defined medium, supplemented with IgG. Stimulation of growth was observed for Capnocytophaga ochracea, Porphyromonas asaccharolytica, Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, Prevotella oralis, Lactobacillus catenaforme and Streptococcus intermedius. Immunoelectrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and a protein assay demonstrated that P. intermedia and P. endodontalis completely degraded the protein chains of IgG. Partial breakdown of IgG was observed for P. asaccharolytica and C. ochracea, whereas P. oralis cleaved the IgG heavy chain, yielding Fc and Fab fragments. All these bacteria utilized IgG as a substrate for growth. Binding studies using an enzyme-linked immunosorbent assay, revealed complete loss of in vitro antigen-antibody binding capacity after incubation of specific IgG with P. endodontalis and partial loss of binding with P. intermedia, P. gingivalis, C. ochracea or Fusobacterium nucleatum. Degradation or inactivation of IgG by oral bacteria is thought to be important in the causation of polymicrobial infections.
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Affiliation(s)
- H J Jansen
- Department of Periodontology and Preventive Dentistry, University of Nijmegen, the Netherlands
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Abstract
Although a wide range of bacterial species has been isolated from infected dental root canals it remains necessary to determine whether any particular group of such bacteria is associated with specific endodontic symptoms and clinical signs. In this study 30 root canals were examined microbiologically; of these, 14 were associated with pain, 20 with tenderness to percussion, 23 presented with wet root canals, seven with swelling, five with purulent exudate and four with a sinus. Clinical and microbiological correlation was observed particularly with regard to pain where anaerobes were isolated from 93% of painful canals and only from 53% of painfree canals. The former yielded means of 2.5 anaerobic species and 1.6 facultative species per canal, compared with 1.5 and 2.4 in painfree canals. Prevotella spp. were isolated from 64.2% of painful canals and 12.5% of painless canals (P < 0.01) similarly, peptostreptococci were isolated from 71.4% of painful and 31.3% of painless canals (P < 0.05). It was concluded that a significant association exists between pain and the presence of Prevotella and Peptostreptococcus spp. in dental root canals.
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Affiliation(s)
- B P Gomes
- Department of Restorative Dentistry, University Dental Hospital of Manchester, United Kingdom
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Rudney JD, Larson CJ. Use of restriction fragment polymorphism analysis of rRNA genes to assign species to unknown clinical isolates of oral viridans streptococci. J Clin Microbiol 1994; 32:437-43. [PMID: 7512095 PMCID: PMC263050 DOI: 10.1128/jcm.32.2.437-443.1994] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
This study evaluated restriction fragment length polymorphisms of rRNA genes (ribotyping) for genotypic identification of 53 oral isolates classified as "Streptococcus sanguis" by colony morphology. Isolates were from 8-h buccal plaque on lower first permanent molars of 20 subjects. DNA was digested with AatII and hybridized with digoxygenin-labeled cDNA of Escherichia coli 16S and 23S rRNA. Strains were ribotyped again with AlwNI or PvuII on the basis of the presence or absence of a 2,290-bp AatII band. Band patterns were compared with reference ribotypes for Streptococcus gordonii, Streptococcus sanguis, Streptococcus crista, Streptococcus oralis, Streptococcus mitis, and Streptococcus parasanguis strains. Forty-eight isolates could be assigned to a species (22 S. sanguis, 14 S. oralis, 12 S. gordonii). Multiple species were seen in 14 subjects; multiple strains of the same species occurred in 11 subjects. Our findings suggest that ribotyping can be used for genotypic identification of S. sanguis, S. oralis, and S. gordonii isolates.
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Affiliation(s)
- J D Rudney
- Department of Oral Science, School of Dentistry, University of Minnesota, Minneapolis 55455
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Yeung MK. Complete nucleotide sequence of the Actinomyces viscosus T14V sialidase gene: presence of a conserved repeating sequence among strains of Actinomyces spp. Infect Immun 1993; 61:109-16. [PMID: 8418033 PMCID: PMC302694 DOI: 10.1128/iai.61.1.109-116.1993] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The nucleotide sequence of the Actinomyces viscosus T14V sialidase gene (nanH) and flanking regions was determined. An open reading frame of 2,703 nucleotides that encodes a predominately hydrophobic protein of 901 amino acids (M(r), 92,871) was identified. The amino acid sequence at the amino terminus of the predicted protein exhibited properties characteristic of a typical leader peptide. Five 12-amino-acid units that shared between 33 and 67% sequence identity were noted within the central domain of the protein. Each unit contained the sequence Ser-X-Asp-X-Gly-X-Thr-Trp, which is conserved among other bacterial and trypanosoma sp. sialidases. Thus, the A. viscosus T14V nanH gene and the other prokaryotic and eukaryotic sialidase genes evolved from a common ancestor. Southern hybridization analyses under conditions of high stringency revealed the existence of DNA sequences homologous to A. viscosus T14V nanH in the genomes of 18 strains of five Actinomyces species that expressed various levels of sialidase activity. The data demonstrate that the sialidase genes from divergent groups of Actinomyces spp. are highly conserved.
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Affiliation(s)
- M K Yeung
- Department of Pediatric Dentistry, University of Texas Health Science Center, San Antonio 78284
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Beighton D, Radford JR, Naylor MN. Glycosidase activities in gingival crevicular fluid in subjects with adult periodontitis or gingivitis. Arch Oral Biol 1992; 37:343-8. [PMID: 1610303 DOI: 10.1016/0003-9969(92)90016-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Specific glycosidase activities were determined in samples of gingival crevicular fluid (GCF) collected from eight predetermined sites in two groups, each of 20 adult patients, with either gingivitis or periodontitis. The total activities (as units of enzyme activity per sample) of alpha-L-fucosidase, sialidase, beta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase and alpha-glucosidase were significantly greater in the periodontitis group. In contrast, the total beta-mannosidase and hexosaminidase A activities were significantly greater in the gingivitis group, while there was no significant difference in the total alpha-mannosidase activity between the groups. Only the specific activities (as units of enzyme activity per min per microliter of GCF) of beta-mannosidase and hexosaminidase A were significantly different between the groups being greater in the gingivitis group. When used to predict the clinical status of individual periodontal sites, the total enzyme activities had specificity and sensitivity values of 91.9 and 61.3%, respectively. Measurement of glycosidase activities might thus have a role in monitoring the efficacy of periodontal treatment or in predicting future periodontal disease but this will require further investigation.
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Affiliation(s)
- D Beighton
- Hunterian Dental Research Unit, London Hospital Medical College, Whitechapel, U.K
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Abstract
A genomic library of Actinomyces viscosus T14V DNA in lambda gt11 was screened for expression of neuraminidase activities. Four recombinant clones were detected that gave blue fluorescence upon incubation with a fluorogenic substrate, 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid. Of these, two were identical, and all of the neuraminidase-positive clones shared a common 3.4-kbp DNA region. Expression of the enzyme activities in Escherichia coli carrying the cloned DNA was independent of the lacZ promoter of the vector. Maxicell analysis revealed that the 3.4-kbp DNA insert directed synthesis of a protein with an apparent molecular mass of 100,000 Da. The protein from cell extracts of E. coli clones migrated as a single band that stained for enzyme activity after electrophoresis in a nondissociating polyacrylamide gel. Moreover, human erythrocytes incubated previously with cell lysates from neuraminidase-positive E. coli were hemagglutinated by Actinomyces spp. The enzyme expressed by E. coli was active on substrates containing alpha-2,3 and alpha-2,6 ketosidic linked sialyl residues. Similar substrate specificities were obtained for both the extracellular and cell-associated neuraminidases from A. viscosus T14V. The 3.4-kbp insert hybridized to DNA fragments in a Southern blot containing A. viscosus T14V chromosomal DNA that had been digested with various restriction endonucleases. Data from hybridization studies show that A. viscosus T14V contains a single copy of the neuraminidase gene.
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Affiliation(s)
- M K Yeung
- Department of Pediatric Dentistry, University of Texas Health Science Center, San Antonio 78284
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49
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Whiley RA, Fraser H, Hardie JM, Beighton D. Phenotypic differentiation of Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus strains within the "Streptococcus milleri group". J Clin Microbiol 1990; 28:1497-501. [PMID: 2380375 PMCID: PMC267976 DOI: 10.1128/jcm.28.7.1497-1501.1990] [Citation(s) in RCA: 193] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A biochemical scheme was developed by which strains of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus can reliably be distinguished from within the "Streptococcus milleri group." Strains identified as S. intermedius were differentiated by the ability to produce detectable levels of alpha-glucosidase, beta-galactosidase, beta-D-fucosidase, beta-N-acetylgalactosaminidase, beta-N-acetylglucosaminidase, and sialidase with 4-methylumbelliferyl-linked fluorogenic substrates in microdilution trays after 3 h of incubation at 37 degrees C, together with the production of hyaluronidase. Strains of S. constellatus and S. anginosus were differentiated by the production of alpha-glucosidase and hyaluronidase by the former and the production of beta-glucosidase by the latter. The majority of strains of the S. milleri group obtained from dental plaque were identified as S. intermedius, as were most strains isolated from abscesses of the brain and liver. Strains of S. constellatus and S. anginosus were from a wider variety of infections, both oral and nonoral, than were strains of S. intermedius, with the majority of strains from urogenital infections being identified as S. anginosus.
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Affiliation(s)
- R A Whiley
- Department of Oral Microbiology, London Hospital Medical College, Whitechapel, United Kingdom
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