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Gao S, Jin W, Quan Y, Li Y, Shen Y, Yuan S, Yi L, Wang Y, Wang Y. Bacterial capsules: Occurrence, mechanism, and function. NPJ Biofilms Microbiomes 2024; 10:21. [PMID: 38480745 PMCID: PMC10937973 DOI: 10.1038/s41522-024-00497-6] [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: 09/15/2023] [Accepted: 03/05/2024] [Indexed: 03/17/2024] Open
Abstract
In environments characterized by extended multi-stress conditions, pathogens develop a variety of immune escape mechanisms to enhance their ability to infect the host. The capsules, polymers that bacteria secrete near their cell wall, participates in numerous bacterial life processes and plays a crucial role in resisting host immune attacks and adapting to their niche. Here, we discuss the relationship between capsules and bacterial virulence, summarizing the molecular mechanisms of capsular regulation and pathogenesis to provide new insights into the research on the pathogenesis of pathogenic bacteria.
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Affiliation(s)
- Shuji Gao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Wenjie Jin
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yingying Quan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yue Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yamin Shen
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Shuo Yuan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Li Yi
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
- College of Life Science, Luoyang Normal University, Luoyang, 471934, China
| | - Yuxin Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
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Jiang JH, Cameron DR, Nethercott C, Aires-de-Sousa M, Peleg AY. Virulence attributes of successful methicillin-resistant Staphylococcus aureus lineages. Clin Microbiol Rev 2023; 36:e0014822. [PMID: 37982596 PMCID: PMC10732075 DOI: 10.1128/cmr.00148-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe and often fatal infections. MRSA epidemics have occurred in waves, whereby a previously successful lineage has been replaced by a more fit and better adapted lineage. Selection pressures in both hospital and community settings are not uniform across the globe, which has resulted in geographically distinct epidemiology. This review focuses on the mechanisms that trigger the establishment and maintenance of current, dominant MRSA lineages across the globe. While the important role of antibiotic resistance will be mentioned throughout, factors which influence the capacity of S. aureus to colonize and cause disease within a host will be the primary focus of this review. We show that while MRSA possesses a diverse arsenal of toxins including alpha-toxin, the success of a lineage involves more than just producing toxins that damage the host. Success is often attributed to the acquisition or loss of genetic elements involved in colonization and niche adaptation such as the arginine catabolic mobile element, as well as the activity of regulatory systems, and shift metabolism accordingly (e.g., the accessory genome regulator, agr). Understanding exactly how specific MRSA clones cause prolonged epidemics may reveal targets for therapies, whereby both core (e.g., the alpha toxin) and acquired virulence factors (e.g., the Panton-Valentine leukocidin) may be nullified using anti-virulence strategies.
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Affiliation(s)
- Jhih-Hang Jiang
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - David R. Cameron
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Cara Nethercott
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Marta Aires-de-Sousa
- Laboratory of Molecular Genetics, Institutode Tecnologia Químicae Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
- Escola Superior de Saúde da Cruz Vermelha Portuguesa-Lisboa (ESSCVP-Lisboa), Lisbon, Portugal
| | - Anton Y. Peleg
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Melbourne, Victoria, Australia
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Cheung GYC, Bae JS, Otto M. Pathogenicity and virulence of Staphylococcus aureus. Virulence 2021; 12:547-569. [PMID: 33522395 PMCID: PMC7872022 DOI: 10.1080/21505594.2021.1878688] [Citation(s) in RCA: 414] [Impact Index Per Article: 138.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus is one of the most frequent worldwide causes of morbidity and mortality due to an infectious agent. This pathogen can cause a wide variety of diseases, ranging from moderately severe skin infections to fatal pneumonia and sepsis. Treatment of S. aureus infections is complicated by antibiotic resistance and a working vaccine is not available. There has been ongoing and increasing interest in the extraordinarily high number of toxins and other virulence determinants that S. aureus produces and how they impact disease. In this review, we will give an overview of how S. aureus initiates and maintains infection and discuss the main determinants involved. A more in-depth understanding of the function and contribution of S. aureus virulence determinants to S. aureus infection will enable us to develop anti-virulence strategies to counteract the lack of an anti-S. aureus vaccine and the ever-increasing shortage of working antibiotics against this important pathogen.
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Affiliation(s)
- Gordon Y. C. Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Justin S. Bae
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
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Abstract
Polysaccharides are often the most abundant antigens found on the extracellular surfaces of bacterial cells. These polysaccharides play key roles in interactions with the outside world, and for many bacterial pathogens, they represent what is presented to the human immune system. As a result, many vaccines have been or currently are being developed against carbohydrate antigens. In this review, we explore the diversity of capsular polysaccharides (CPS) in Salmonella and other selected bacterial species and explain the classification and function of CPS as vaccine antigens. Despite many vaccines being developed using carbohydrate antigens, the low immunogenicity and the diversity of infecting strains and serovars present an antigen formulation challenge to manufacturers. Vaccines tend to focus on common serovars or have changing formulations over time, reflecting the trends in human infection, which can be costly and time-consuming. We summarize the approaches to generate carbohydrate-based vaccines for Salmonella, describe vaccines that are in development and emphasize the need for an effective vaccine against non-typhoidal Salmonella strains.
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Visansirikul S, Kolodziej SA, Demchenko AV. Staphylococcus aureuscapsular polysaccharides: a structural and synthetic perspective. Org Biomol Chem 2020; 18:783-798. [DOI: 10.1039/c9ob02546d] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This review surveys known structures of staphylococcal polysaccharides and summarizes all synthetic efforts to obtain these sequences.
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Affiliation(s)
- Satsawat Visansirikul
- Department of Chemistry and Biochemistry
- University of Missouri – St Louis
- One University Boulevard
- St Louis
- USA
| | | | - Alexei V. Demchenko
- Department of Chemistry and Biochemistry
- University of Missouri – St Louis
- One University Boulevard
- St Louis
- USA
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Keinhörster D, George SE, Weidenmaier C, Wolz C. Function and regulation of Staphylococcus aureus wall teichoic acids and capsular polysaccharides. Int J Med Microbiol 2019; 309:151333. [DOI: 10.1016/j.ijmm.2019.151333] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 07/09/2019] [Accepted: 07/17/2019] [Indexed: 01/05/2023] Open
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Development of a molecular serotyping scheme and a multiplexed luminex-based array for Providencia. J Microbiol Methods 2018; 153:14-23. [DOI: 10.1016/j.mimet.2018.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/11/2018] [Accepted: 08/15/2018] [Indexed: 11/20/2022]
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Li T, Huang M, Song Z, Zhang H, Chen C. Biological characteristics and conjugated antigens of ClfA A-FnBPA and CP5 in Staphylococcus aureus. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 2018; 82:48-54. [PMID: 29382968 PMCID: PMC5764038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 02/27/2017] [Indexed: 06/07/2023]
Abstract
To obtain immunogenic conjugate antigens, adipic acid dihydrazide (ADH), as a bridge, and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimidehydrochloride (EDAC), as a coupling agent, were used to conjugate the purified fusion protein, clumping factor A-fibronectin binding protein ClfA A-FnBPA, and type 5 capsular polysaccharide (CP5). The conjugates were mixed with an adjuvant, and mice were immunized 3 times and challenged with Staphylococcus aureus 1 week later. Antibody titers were determined by indirect enzyme-linked immunosorbent assay (ELISA). At 14 days after the first immunization, antibodies against the purified protein and conjugate were detected; after 28 days, antibody levels increased; and a week after the third immunization, antibody levels continued to increase. However, the conjugate antibody titers were higher than those of the purified protein during the study, and no IgG antibodies against purified CP5 were detected during the entire experiment. The protection rate increased to 90% in the conjugate group, indicating that the conjugate imparts a relatively higher protective efficacy than the purified protein and purified CP5.
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Affiliation(s)
| | | | | | | | - Chuangfu Chen
- Address all correspondence to Dr. Chuangfu Chen; telephone: +86-0993-2058002; fax: +86-0993-2058002; e-mail:
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Gogoi-Tiwari J, Williams V, Waryah CB, Costantino P, Al-Salami H, Mathavan S, Wells K, Tiwari HK, Hegde N, Isloor S, Al-Sallami H, Mukkur T. Mammary Gland Pathology Subsequent to Acute Infection with Strong versus Weak Biofilm Forming Staphylococcus aureus Bovine Mastitis Isolates: A Pilot Study Using Non-Invasive Mouse Mastitis Model. PLoS One 2017; 12:e0170668. [PMID: 28129375 PMCID: PMC5271311 DOI: 10.1371/journal.pone.0170668] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/09/2017] [Indexed: 12/30/2022] Open
Abstract
Background Biofilm formation by Staphylococcus aureus is an important virulence attribute because of its potential to induce persistent antibiotic resistance, retard phagocytosis and either attenuate or promote inflammation, depending upon the disease syndrome, in vivo. This study was undertaken to evaluate the potential significance of strength of biofilm formation by clinical bovine mastitis-associated S. aureus in mammary tissue damage by using a mouse mastitis model. Methods Two S. aureus strains of the same capsular phenotype with different biofilm forming strengths were used to non-invasively infect mammary glands of lactating mice. Biofilm forming potential of these strains were determined by tissue culture plate method, ica typing and virulence gene profile per detection by PCR. Delivery of the infectious dose of S. aureus was directly through the teat lactiferous duct without invasive scraping of the teat surface. Both bacteriological and histological methods were used for analysis of mammary gland pathology of mice post-infection. Results Histopathological analysis of the infected mammary glands revealed that mice inoculated with the strong biofilm forming S. aureus strain produced marked acute mastitic lesions, showing profuse infiltration predominantly with neutrophils, with evidence of necrosis in the affected mammary glands. In contrast, the damage was significantly less severe in mammary glands of mice infected with the weak biofilm-forming S. aureus strain. Although both IL-1β and TNF-α inflammatory biomarkers were produced in infected mice, level of TNF-α produced was significantly higher (p<0.05) in mice inoculated with strong biofilm forming S. aureus than the weak biofilm forming strain. Conclusion This finding suggests an important role of TNF-α in mammary gland pathology post-infection with strong biofilm-forming S. aureus in the acute mouse mastitis model, and offers an opportunity for the development of novel strategies for reduction of mammary tissue damage, with or without use of antimicrobials and/or anti-inflammatory compounds for the treatment of bovine mastitis.
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Affiliation(s)
- Jully Gogoi-Tiwari
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Selesih, Aizawl, Mizoram, India
| | - Vincent Williams
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Charlene Babra Waryah
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- Department of Medicine and Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Paul Costantino
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Hani Al-Salami
- School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Sangeetha Mathavan
- School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Kelsi Wells
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Harish Kumar Tiwari
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
| | | | - Shrikrishna Isloor
- Veterinary College, Karnataka Veterinary, Animal and Fisheries Sciences University, Bangalore, India
| | | | - Trilochan Mukkur
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- * E-mail:
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10
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Surface Glycopolymers Are Crucial for In Vitro Anti-Wall Teichoic Acid IgG-Mediated Complement Activation and Opsonophagocytosis of Staphylococcus aureus. Infect Immun 2015; 83:4247-55. [PMID: 26283333 DOI: 10.1128/iai.00767-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/10/2015] [Indexed: 01/07/2023] Open
Abstract
The cell envelopes of many Gram-positive bacteria contain wall teichoic acids (WTAs). Staphylococcus aureus WTAs are composed of ribitol phosphate (RboP) or glycerol phosphate (GroP) backbones substituted with D-alanine and N-acetyl-D-glucosamine (GlcNAc) or N-acetyl-D-galactosamine (GalNAc). Two WTA glycosyltransferases, TarM and TarS, are responsible for modifying the RboP WTA with α-GlcNAc and β-GlcNAc, respectively. We recently reported that purified human serum anti-WTA IgG specifically recognizes β-GlcNAc of the staphylococcal RboP WTA and then facilitates complement C3 deposition and opsonophagocytosis of S. aureus laboratory strains. This prompted us to examine whether anti-WTA IgG can induce C3 deposition on a diverse set of clinical S. aureus isolates. To this end, we compared anti-WTA IgG-mediated C3 deposition and opsonophagocytosis abilities using 13 different staphylococcal strains. Of note, the majority of S. aureus strains tested was recognized by anti-WTA IgG, resulting in C3 deposition and opsonophagocytosis. A minority of strains was not recognized by anti-WTA IgG, which correlated with either extensive capsule production or an alteration in the WTA glycosylation pattern. Our results demonstrate that the presence of WTAs with TarS-mediated glycosylation with β-GlcNAc in clinically isolated S. aureus strains is an important factor for induction of anti-WTA IgG-mediated C3 deposition and opsonophagocytosis.
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11
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Gogoi-Tiwari J, Babra Waryah C, Sunagar R, Veeresh HB, Nuthanalakshmi V, Preethirani PL, Sharada R, Isloor S, Bhat A, Al-Salami H, Hegde NR, Mukkur TK. Typing ofStaphylococcus aureusisolated from bovine mastitis cases in Australia and India. Aust Vet J 2015. [DOI: 10.1111/avj.12349] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- J Gogoi-Tiwari
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin University; Perth Western Australia Australia
| | - C Babra Waryah
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin University; Perth Western Australia Australia
| | - R Sunagar
- Ella Foundation; Genome Valley, Shameerpet Mandal Hyderabad India
| | - HB Veeresh
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - V Nuthanalakshmi
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - PL Preethirani
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - R Sharada
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - S Isloor
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - A Bhat
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - H Al-Salami
- School of Pharmacy, Faculty of Health Sciences; Curtin University; Perth Western Australia Australia
| | - NR Hegde
- Ella Foundation; Genome Valley, Shameerpet Mandal Hyderabad India
| | - TK Mukkur
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin University; Perth Western Australia Australia
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12
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Weidenmaier C, Lee JC. Structure and Function of Surface Polysaccharides of Staphylococcus aureus. Curr Top Microbiol Immunol 2015; 409:57-93. [PMID: 26728067 DOI: 10.1007/82_2015_5018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The major surface polysaccharides of Staphylococcus aureus include the capsular polysaccharide (CP), cell wall teichoic acid (WTA), and polysaccharide intercellular adhesin/poly-β(1-6)-N-acetylglucosamine (PIA/PNAG). These glycopolymers are important components of the staphylococcal cell envelope, but none of them is essential to S. aureus viability and growth in vitro. The overall biosynthetic pathways of CP, WTA, and PIA/PNAG have been elucidated, and the functions of most of the biosynthetic enzymes have been demonstrated. Because S. aureus CP and WTA (but not PIA/PNAG) utilize a common cell membrane lipid carrier (undecaprenyl-phosphate) that is shared by the peptidoglycan biosynthesis pathway, there is evidence that these processes are highly integrated and temporally regulated. Regulatory elements that control glycopolymer biosynthesis have been described, but the cross talk that orchestrates the biosynthetic pathways of these three polysaccharides remains largely elusive. CP, WTA, and PIA/PNAG each play distinct roles in S. aureus colonization and the pathogenesis of staphylococcal infection. However, they each promote bacterial evasion of the host immune defences, and WTA is being explored as a target for antimicrobial therapeutics. All the three glycopolymers are viable targets for immunotherapy, and each (conjugated to a carrier protein) is under evaluation for inclusion in a multivalent S. aureus vaccine. Future research findings that increase our understanding of these surface polysaccharides, how the bacterial cell regulates their expression, and their biological functions will likely reveal new approaches to controlling this important bacterial pathogen.
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Affiliation(s)
- Christopher Weidenmaier
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen and German Center for Infection Research, Tübingen, Germany
| | - Jean C Lee
- Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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13
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Chan YGY, Kim HK, Schneewind O, Missiakas D. The capsular polysaccharide of Staphylococcus aureus is attached to peptidoglycan by the LytR-CpsA-Psr (LCP) family of enzymes. J Biol Chem 2014; 289:15680-90. [PMID: 24753256 DOI: 10.1074/jbc.m114.567669] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Envelope biogenesis in bacteria involves synthesis of intermediates that are tethered to the lipid carrier undecaprenol-phosphate. LytR-CpsA-Psr (LCP) enzymes have been proposed to catalyze the transfer of undecaprenol-linked intermediates onto the C6-hydroxyl of MurNAc in peptidoglycan, thereby promoting attachment of wall teichoic acid (WTA) in bacilli and staphylococci and capsular polysaccharides (CPS) in streptococci. S. aureus encodes three lcp enzymes, and a variant lacking all three genes (Δlcp) releases WTA from the bacterial envelope and displays a growth defect. Here, we report that the type 5 capsular polysaccharide (CP5) of Staphylococcus aureus Newman is covalently attached to the glycan strands of peptidoglycan. Cell wall attachment of CP5 is abrogated in the Δlcp variant, a defect that is best complemented via expression of lcpC in trans. CP5 synthesis and peptidoglycan attachment are not impaired in the tagO mutant, suggesting that CP5 synthesis does not involve the GlcNAc-ManNAc linkage unit of WTA and may instead utilize another Wzy-type ligase to assemble undecaprenyl-phosphate intermediates. Thus, LCP enzymes of S. aureus are promiscuous enzymes that attach secondary cell wall polymers with discrete linkage units to peptidoglycan.
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Affiliation(s)
- Yvonne Gar-Yun Chan
- From the Department of Microbiology, University of Chicago, Chicago, Illinois 60637 and
| | - Hwan Keun Kim
- From the Department of Microbiology, University of Chicago, Chicago, Illinois 60637 and
| | - Olaf Schneewind
- From the Department of Microbiology, University of Chicago, Chicago, Illinois 60637 and the Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Argonne, Illinois 60439
| | - Dominique Missiakas
- From the Department of Microbiology, University of Chicago, Chicago, Illinois 60637 and the Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Argonne, Illinois 60439
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Development of an experimentally induced Streptococcus uberis subclinical mastitis in goats. Vet Microbiol 2011; 154:376-83. [PMID: 21924846 DOI: 10.1016/j.vetmic.2011.07.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 07/23/2011] [Accepted: 07/26/2011] [Indexed: 11/22/2022]
Abstract
Streptococcus uberis is a major environmental mastitis-causing pathogen. The infections are predominantly subclinical and are frequently undetected and untreated for extended periods of time. More information about the pathogenesis of S. uberis mastitis would be useful. To our knowledge, no experimental studies into the mastitis pathogenesis caused by S. uberis have been described in lactating goats. The aim of this study was to reproduce an experimentally induced S. uberis subclinical mastitis in lactating goats aimed to evaluate the inflammatory response, dynamics of infection and the pathological findings within the first hours of intramammary inoculation with S. uberis. Six Saanen goats in mid-lactation were inoculated with 1.7 × 10(8)cfu of S. uberis. Bacterial growth peaked in milk from challenged right mammary halves (RMH) at 4h PI. Shedding of viable bacteria showed a marked decrease at 20 h PI. Mean somatic cell counts in milk from the RMH peaked at 20 h PI. Inoculation with S. uberis was followed by a decrease in the mean total number of leukocytes. Signs and systemic symptoms were not evoked by intramammary inoculation. S. uberis could be isolated in tissue from all RMH. Histological examination of specimens of the RMH and lymph nodes of the goats showed an increased inflammatory response throughout the experiment. The histological findings correlated with the immunohistochemical detection of S. uberis in RMH. In conclusion, the experimental inoculation of S. uberis in lactating goats is capable of eliciting an inflammatory response and causing pathological changes, resulting in a subclinical mastitis. This investigation shows that goat might to represent a valuable model for the study of the mastitis pathogenesis caused by S. uberis.
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King JD, Kocíncová D, Westman EL, Lam JS. Review: Lipopolysaccharide biosynthesis in Pseudomonas aeruginosa. Innate Immun 2009; 15:261-312. [PMID: 19710102 DOI: 10.1177/1753425909106436] [Citation(s) in RCA: 225] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Pseudomonas aeruginosa causes serious nosocomial infections, and an important virulence factor produced by this organism is lipopolysaccharide (LPS). This review summarizes knowledge about biosynthesis of all three structural domains of LPS - lipid A, core oligosaccharide, and O polysaccharides. In addition, based on similarities with other bacterial species, this review proposes new hypothetical pathways for unstudied steps in the biosynthesis of P. aeruginosa LPS. Lipid A biosynthesis is discussed in relation to Escherichia coli and Salmonella, and the biosyntheses of core sugar precursors and core oligosaccharide are summarised. Pseudomonas aeruginosa attaches a Common Polysaccharide Antigen and O-Specific Antigen polysaccharides to lipid A-core. Both forms of O polysaccharide are discussed with respect to their independent synthesis mechanisms. Recent advances in understanding O-polysaccharide biosynthesis since the last major review on this subject, published nearly a decade ago, are highlighted. Since P. aeruginosa O polysaccharides contain unusual sugars, sugar-nucleotide biosynthesis pathways are reviewed in detail. Knowledge derived from detailed studies in the O5, O6 and O11 serotypes is applied to predict biosynthesis pathways of sugars in poorly-studied serotypes, especially O1, O4, and O13/O14. Although further work is required, a full understanding of LPS biosynthesis in P. aeruginosa is almost within reach.
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Affiliation(s)
- Jerry D King
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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McNally DJ, Schoenhofen IC, Mulrooney EF, Whitfield DM, Vinogradov E, Lam JS, Logan SM, Brisson JR. Identification of labile UDP-ketosugars in Helicobacter pylori, Campylobacter jejuni and Pseudomonas aeruginosa: key metabolites used to make glycan virulence factors. Chembiochem 2007; 7:1865-8. [PMID: 17031886 DOI: 10.1002/cbic.200600298] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- David J McNally
- National Research Council of Canada-Institute for Biological Sciences, Ottawa ON, K1A 0R6, Canada.
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17
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Lindsay JA, Holden MTG. Understanding the rise of the superbug: investigation of the evolution and genomic variation of Staphylococcus aureus. Funct Integr Genomics 2006; 6:186-201. [PMID: 16453141 DOI: 10.1007/s10142-005-0019-7] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Accepted: 11/01/2005] [Indexed: 12/22/2022]
Abstract
The bacterium Staphylococcus aureus is a common cause of human infection, and it is becoming increasingly virulent and resistant to antibiotics. Our understanding of the evolution of this species has been greatly enhanced by the recent sequencing of the genomes of seven strains of S. aureus. Comparative genomic analysis allows us to identify variation in the chromosomes and understand the mechanisms by which this versatile bacterium has accumulated diversity within its genome structure.
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Affiliation(s)
- Jodi A Lindsay
- Department of Cellular and Molecular Medicine, St. George's, University of London, Cranmer Terrace, London, SW17 0RE, UK
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18
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Watts A, Ke D, Wang Q, Pillay A, Nicholson-Weller A, Lee JC. Staphylococcus aureus strains that express serotype 5 or serotype 8 capsular polysaccharides differ in virulence. Infect Immun 2005; 73:3502-11. [PMID: 15908379 PMCID: PMC1111869 DOI: 10.1128/iai.73.6.3502-3511.2005] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 01/05/2005] [Accepted: 01/25/2005] [Indexed: 11/20/2022] Open
Abstract
Most isolates of Staphylococcus aureus produce a serotype 5 (CP5) or 8 (CP8) capsular polysaccharide. To investigate whether CP5 and CP8 differ in their biological properties, we created isogenic mutants of S. aureus Reynolds that expressed CP5, CP8, or no capsule. Biochemical analyses of CP5 and CP8 purified from the isogenic S. aureus strains were consistent with published structures. The degree of O acetylation of each polysaccharide was similar, but CP5 showed a greater degree of N acetylation. Mice challenged with the CP5(+) strain showed a significantly higher bacteremia level than mice challenged with the CP8(+) strain. Similarly, the CP5(+) strain survived preferentially in the bloodstream and kidneys of infected mice challenged with a mixed inoculum containing both strains. The enhanced virulence of the CP5(+) strain in vivo correlated with its greater resistance to in vitro killing in whole mouse blood. Likewise, in vitro opsonophagocytic killing assays with human neutrophils and sera revealed greater survival of the Reynolds (CP5) strain, even though the kinetics of opsonization by C3b and iC3b was similar for both the CP5(+) and CP8(+) strains. Electron micrographs demonstrated C3 molecules on the cell wall beneath the capsule layer for both serotype 5 and 8 strains. Purified CP5 and CP8 stimulated a modest oxidative burst in human neutrophils but failed to activate the alternative complement pathway. These results indicate that CP5 and CP8 differ in a number of biological properties, and these differences likely contribute to the relative virulence of serotype 5 and 8 S. aureus in vivo.
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Affiliation(s)
- Andrew Watts
- Channing Laboratory, 181 Longwood Avenue, Boston, MA 02115, USA
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19
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Mulrooney EF, Poon KKH, McNally DJ, Brisson JR, Lam JS. Biosynthesis of UDP-N-acetyl-L-fucosamine, a precursor to the biosynthesis of lipopolysaccharide in Pseudomonas aeruginosa serotype O11. J Biol Chem 2005; 280:19535-42. [PMID: 15778500 DOI: 10.1074/jbc.m500612200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
UDP-N-acetyl-L-fucosamine is a precursor to l-fucosamine in the lipopolysaccharide of Pseudomonas aeruginosa serotype O11 and the capsule of Staphylococcus aureus type 5. We have demonstrated previously the involvement of three enzymes, WbjB, WbjC, and WbjD, in the biosynthesis of UDP-2-acetamido-2,6-dideoxy-L-galactose or UDP-N-acetyl-L-fucosamine (UDP-l-FucNAc). An intermediate compound from the coupled-reaction of WbjB-WbjC with the initial substrate UDP-2-acetamido-2-deoxy-alpha-D-glucose or UDP-N-acetyl-D-glucosamine (UDP-GlcNAc) was purified, and the structure was determined by NMR spectroscopy to be UDP-2-acetamido-2,6-dideoxy-L-talose (UDP-L-PneNAc). WbjD could then convert this intermediate into a new product with the same mass, consistent with a C-2 epimerization reaction. Those results led us to propose a pathway for the biosynthesis of UDP-L-FucNAc; however, the exact enzymatic activity of each of these proteins has not been defined. Here, we describe a fast protein liquid chromatography (FPLC)-based anion-exchange procedure, which allowed the separation and purification of the products of C-2 epimerization due to WbjD. Also, the application of a cryogenically cooled probe in NMR spectrometry offers the greatest sensitivity for determining the structures of minute quantities of materials, allowing the identification of the final product of the pathway. Our results showed that WbjB is bifunctional, catalyzing firstly C-4, C-6 dehydration and secondly C-5 epimerization in the reaction with the substrate UDP-D-GlcNAc, producing two intermediates. WbjC is also bifunctional, catalyzing C-3 epimerization of the second intermediate followed by reduction at C-4. The FPLC-based procedure provided good resolution of the final product of WbjD reaction from its epimer/substrate UDP-l-PneNAc, and the use of the cryogenically cooled probe in NMR revealed unequivocally that the final product is UDP-L-FucNAc.
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Affiliation(s)
- Erin F Mulrooney
- Department of Microbiology, University of Guelph, Ontario, Canada
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20
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Krarup A, Sørensen UBS, Matsushita M, Jensenius JC, Thiel S. Effect of capsulation of opportunistic pathogenic bacteria on binding of the pattern recognition molecules mannan-binding lectin, L-ficolin, and H-ficolin. Infect Immun 2005; 73:1052-60. [PMID: 15664949 PMCID: PMC547010 DOI: 10.1128/iai.73.2.1052-1060.2005] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2004] [Revised: 08/17/2004] [Accepted: 09/21/2004] [Indexed: 11/20/2022] Open
Abstract
Mannan-binding lectin (MBL), L-ficolin, and H-ficolin are pattern recognition molecules of the innate immune system. We investigated their ability to bind to different serotypes and noncapsulated variants of two gram-positive bacterial species, Streptococcus pneumoniae and Staphylococcus aureus. MBL did not bind to capsulated S. aureus or capsulated S. pneumoniae but did bind to a noncapsulated S. aureus variant (Wood). L-ficolin bound to some capsulated S. aureus serotypes (serotypes 1, 8, 9, 11, and 12) and capsulated S. pneumoniae serotypes (11A, 11D, and 11F) but not to noncapsulated strains. H-ficolin did not bind to any of the S. pneumoniae and S. aureus serotypes included in this study but did bind to one strain of Aerococcus viridans. The concentrations of the three proteins in 97 plasma samples were estimated. The median concentrations were 0.8 mug per ml for MBL, 3.3 mug per ml for L-ficolin, and 18.4 mug per ml for H-ficolin.
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Affiliation(s)
- Anders Krarup
- Department of Medical Microbiology and Immunology, The Bartholin Building, University of Aarhus, DK-8000 Aarhus C, Denmark
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21
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Chia JS, Lin YL, Lien HT, Chen JY. Platelet aggregation induced by serotype polysaccharides from Streptococcus mutans. Infect Immun 2004; 72:2605-17. [PMID: 15102769 PMCID: PMC387875 DOI: 10.1128/iai.72.5.2605-2617.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelet aggregation plays an important role in the pathogenesis of infective endocarditis induced by viridans streptococci or staphylococci. Aggregation induced in vitro involves direct binding of bacteria to platelets through multiple surface components. Using platelet aggregometry, we demonstrated in this study that two Streptococcus mutans laboratory strains, GS-5 and Xc, and two clinical isolates could aggregate platelets in an irreversible manner in rabbit platelet-rich plasma preparations. The aggregation was partially inhibited by prostaglandin I(2) (PGI(2)) in a dose-dependent manner. Whole bacteria and heated bacterial cell wall extracts were able to induce aggregation. Cell wall polysaccharides extracted from the wild-type Xc strain, containing serotype-specific polysaccharides which are composed of rhamnose-glucose polymers (RGPs), could induce platelet aggregation in the presence of plasma. Aggregation induced by the serotype-specific RGP-deficient mutant Xc24R was reduced by 50% compared to the wild-type strain Xc. In addition, cell wall polysaccharides extracted from Xc24R failed to induce platelet aggregation. The Xc strain, but not the Xc24R mutant, could induce platelet aggregation when preincubated with plasma. Both Xc and Xc24R failed to induce platelets to aggregate in plasma depleted of immunoglobulin G (IgG), but aggregation was restored by replenishment of anti-serotype c IgG. Analysis by flow cytometry showed that S. mutans RGPs could bind directly to rabbit and human platelets. Furthermore, cell wall polysaccharides extracted from the Xc, but not the Xc24R, strain could induce pseudopod formation of both rabbit and human platelets in the absence of plasma. Distinct from the aggregation of rabbit platelets, bacterium-triggered aggregation of human platelets required a prolonged lag phase and could be blocked completely by PGI(2). RGPs also trigger aggregation of human platelets in a donor-dependent manner, either as a transient and reversible or a complete and irreversible response. These results indicated that serotype-specific RGPs, a soluble product of S. mutans, could directly bind to and activate platelets from both rabbit and human. In the presence of plasma containing IgG specific to RGPs, RGPs could trigger aggregation of both human and rabbit platelets, but the degree of aggregation in human platelets depends on the donors.
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Affiliation(s)
- Jean-San Chia
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China.
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22
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Maira-Litran T, Kropec A, Goldmann D, Pier GB. Biologic properties and vaccine potential of the staphylococcal poly-N-acetyl glucosamine surface polysaccharide. Vaccine 2004; 22:872-9. [PMID: 15040940 DOI: 10.1016/j.vaccine.2003.11.033] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Staphylococci have become the most common causes of nosocomial bacterial infections, and this fact, along with increasing problems associated with antimicrobial resistance, spurs the need for finding immunotherapeutic alternatives to prevent and possibly treat these infections. Most virulent, clinical isolates of both coagulase-negative staphylococci (CoNS) and Staphylococcus aureus carry the ica locus which encodes proteins that synthesize a polymer of beta-1-6 linked N-acetyl glucosamine residues (PNAG). Animal studies have shown purified PNAG can elicit protective immunity against both CoNS and S. aureus, suggesting its potential as a broadly protective vaccine for many clinically important strains of staphylococci.
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Affiliation(s)
- Tomas Maira-Litran
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, 181 Longwood Avenue, Boston, MA 02115, USA.
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23
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Robbins JB, Schneerson R, Horwith G, Naso R, Fattom A. Staphylococcus aureus types 5 and 8 capsular polysaccharide-protein conjugate vaccines. Am Heart J 2004; 147:593-8. [PMID: 15077073 DOI: 10.1016/j.ahj.2004.01.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Staphylococcus aureus, the first or second most common pathogen isolated from patients, is capsulated; there are at least 12 capsular types, and types 5 and 8 comprise approximately 85% of blood. Types 5 and 8, composed of a trisaccharide repeat unit including a mannose uronic acid and 2 fucoses, are non-immunogenic. As protein conjugates, they induce opsonophagocytic antibodies that confer type-specific active and passive protection in mice. METHODS A phase II study of patients with end-stage renal disease showed that these conjugates induced approximately one third of the immunoglobulin G antibody of healthy individuals. Increasing the dose to 100 microg of polysaccharide induced levels similar to that in healthy individuals injected with 25 microg. RESULTS In a double-blinded randomized and controlled study of patients undergoing renal dialysis, the conjugates induced statistically significant protection against bacteremia for as long as 10 months after immunization. The estimated protective level was 80 microg Ab/mL. At re-injection approximately 2 years later, 83 of 83 recipients responded with protective levels. CONCLUSIONS Conjugate vaccine-induced antibodies to the types 5 and 8 capsular polysaccharide antibodies of S aureus prevent bacteremia caused by this pathogen. The extent and duration of conjugate-induced immunity can be extended by re-immunization approximately 1 year later. Studies of patients undergoing cardiovascular surgery who would be immunized with the staphylococcus conjugates when they are immunologically intact are planned.
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Affiliation(s)
- John B Robbins
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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24
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Abstract
Serotype 5 and 8 capsular polysaccharides predominate among clinical isolates of Staphylococcus aureus. The results of experiments in animal models of infection have revealed that staphylococcal capsules are important in the pathogenesis of S. aureus infections. The capsule enhances staphylococcal virulence by impeding phagocytosis, resulting in bacterial persistence in the bloodstream of infected hosts. S. aureus capsules also promote abscess formation in rats. Although the capsule has been shown to modulate S. aureus adherence to endothelial surfaces in vitro, animal studies suggest that it also promotes bacterial colonization and persistence on mucosal surfaces. S. aureus capsular antigens are surface associated, limited in antigenic specificity, and highly conserved among clinical isolates. With the emergence of vancomycin-resistant S. aureus in the United States in 2002, new strategies are needed to combat staphylococcal infections. Purified serotype 5 and 8 capsular polysaccharides offer promise as target antigens for a vaccine to prevent staphylococcal infections, although the inclusion of other antigens is likely to be essential in the development of an effective S. aureus vaccine. The genetics and mechanisms of capsule biosynthesis are complex, and much work remains to enhance our understanding of capsule biosynthesis and its regulation.
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Affiliation(s)
- Katherine O'Riordan
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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25
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Bender MH, Cartee RT, Yother J. Positive correlation between tyrosine phosphorylation of CpsD and capsular polysaccharide production in Streptococcus pneumoniae. J Bacteriol 2003; 185:6057-66. [PMID: 14526017 PMCID: PMC225014 DOI: 10.1128/jb.185.20.6057-6066.2003] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CpsA, CpsB, CpsC, and CpsD are part of a tyrosine phosphorylation regulatory system involved in modulation of capsule synthesis in Streptococcus pneumoniae and many other gram-positive and gram-negative bacteria. Using an immunoblotting technique, we observed distinct laddering patterns of S. pneumoniae capsular polysaccharides of various serotypes and found that transfer of the polymer from the membrane to the cell wall was independent of size. Deletion of cps2A, cps2B, cps2C, or cps2D in the serotype 2 strain D39 did not affect the ability to transfer capsule to the cell wall. Deletion of cps2C or cps2D, which encode two domains of an autophosphorylating tyrosine kinase, resulted in the production of only short-chain polymers. The function of Cps2A is unknown, and the polymer laddering pattern of the cps2A deletion mutants appeared similar to that of the parent, although the total amount of capsule was decreased. Loss of Cps2B, a tyrosine phosphatase and a kinase inhibitor, resulted in an increase in capsule amount and a normal ladder pattern. However, Cps2B mutants exhibited reduced virulence following intravenous inoculation of mice and were unable to colonize the nasopharynx, suggesting a diminished capacity to sense or respond to these environments. In D39 and its isogenic mutants, the amounts of capsule and tyrosine-phosphorylated Cps2D (Cps2D approximately P) correlated directly. In contrast, restoration of type 2 capsule production followed by deletion of cps2B in Rx1, a laboratory passaged D39 derivative containing multiple uncharacterized mutations, resulted in decreased capsule amounts but no alteration in Cps2D approximately P levels. Thus, a factor outside the capsule locus, which is either missing or defective in the Rx1 background, is important in the control of capsule synthesis.
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Affiliation(s)
- Matthew H Bender
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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26
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Kneidinger B, O'Riordan K, Li J, Brisson JR, Lee JC, Lam JS. Three highly conserved proteins catalyze the conversion of UDP-N-acetyl-D-glucosamine to precursors for the biosynthesis of O antigen in Pseudomonas aeruginosa O11 and capsule in Staphylococcus aureus type 5. Implications for the UDP-N-acetyl-L-fucosamine biosynthetic pathway. J Biol Chem 2003; 278:3615-27. [PMID: 12464616 DOI: 10.1074/jbc.m203867200] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N-Acetyl-l-fucosamine is a constituent of surface polysaccharide structures of Pseudomonas aeruginosa and Staphylococcus aureus. The three P. aeruginosa enzymes WbjB, WbjC, and WbjD, as well as the S. aureus homologs Cap5E, Cap5F, and Cap5G, involved in the biosynthesis of N-acetyl-l-fucosamine have been overexpressed and purified to near homogeneity. Capillary electrophoresis (CE), mass spectroscopy (MS), and nuclear magnetic resonance spectroscopy have been used to elucidate the biosynthesis pathway, which proceeds in five reaction steps. WbjB/Cap5E catalyzed 4,6-dehydration of UDP-N-acetyl-d-glucosamine and 3- and 5-epimerization to yield a mixture of three keto-deoxy-sugars. The third intermediate compound was subsequently reduced at C-4 to UDP-2-acetamido-2,6-dideoxy-l-talose by WbjC/Cap5F. Incubation of UDP-2-acetamido-2,6-dideoxy-l-talose (UDP-TalNAc) with WbjD/Cap5G resulted in a new peak separable by CE that demonstrated identical mass and fragmentation patterns by CE-MS/MS to UDP-TalNAc. These results are consistent with WbjD/Cap5G-mediated 2-epimerization of UDP-TalNAc to UDP-FucNAc. A nonpolar gene knockout of wbjB, the first of the genes associated with this pathway, was constructed in P. aeruginosa serotype O11 strain PA103. The corresponding mutant produced rough lipopolysaccharide devoid of B-band O antigen. This lipopolysaccharide deficiency could be complemented with P. aeruginosa wbjB or with the S. aureus homolog cap5E. Insertional inactivation of either the cap5G or cap5F genes abolished capsule polysaccharide production in the S. aureus strain Newman. Providing the appropriate gene in trans, thereby complementing these mutants, fully restored the capsular polysaccharide phenotype.
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Affiliation(s)
- Bernd Kneidinger
- Canadian Bacterial Diseases Network, Department of Microbiology, University of Guelph, Ontario N1G 2W1, Canada
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27
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Ryding U, Espersen F, Söderquist B, Christensson B. Evaluation of seven different enzyme-linked immunosorbent assays for serodiagnosis of Staphylococcus aureus bacteremia. Diagn Microbiol Infect Dis 2002; 42:9-15. [PMID: 11821165 DOI: 10.1016/s0732-8893(01)00311-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Serologic assays for Staphylococcus aureus antibodies were evaluated regarding their ability to differentiate between uncomplicated and complicated S. aureus bacteremia, between S. aureus and non-S. aureus bacteremia, and between S. aureus and non-S. aureus endocarditis. METHODS Enzyme-linked immunosorbent assays (ELISAs) were performed to measure Ig G antibodies against seven S. aureus antigens (peptidoglycan, teichoic acid, S. aureus ultrasonicate, whole S. aureus cells, alpha-toxin, lipase and capsular polysaccharide) in 129 patients with S. aureus bacteremia (including 51 with endocarditis), 78 patients with non-S. aureus bacteremia (including 27 with endocarditis) and 100 febrile non-bacteremic controls. RESULTS Whole-cell ELISA was the most sensitive assay. The specificity of all assays was low. Two different combinations of ELISAs for whole cells, teichoic acid,alpha-toxin, lipase and capsular polysaccharide did distinguish between S. aureus and non-S. aureus endocarditis, but not between uncomplicated and complicated S. aureus bacteremia.
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Affiliation(s)
- U Ryding
- Department of Infectious Diseases, Ostersund Hospital, Ostersund, Sweden.
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28
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Creuzenet C, Lam JS. Topological and functional characterization of WbpM, an inner membrane UDP-GlcNAc C6 dehydratase essential for lipopolysaccharide biosynthesis in Pseudomonas aeruginosa. Mol Microbiol 2001; 41:1295-310. [PMID: 11580835 DOI: 10.1046/j.1365-2958.2001.02589.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
WbpM is essential for the biosynthesis of B-band lipopolysaccharide (LPS) in many serotypes of Pseudomonas aeruginosa. Homologues that can functionally complement a wbpM null mutant and that are also necessary for virulence have been identified in numerous pathogenic bacteria. WbpM and most of its homologues are large membrane proteins, which has long hampered the elucidation of their biochemical function. This paper describes the detailed characterization of WbpM using both in vivo and in vitro approaches. LacZ and PhoA fusion experiments showed that WbpM was anchored to the inner membrane via four N-terminal transmembrane domains, whereas the C-terminal catalytic domain resided in the cytoplasm. Although the membrane domains did not have any catalytic activity, complementation experiments suggested that they were important for the polymerization of high-molecular-weight B-band LPS. The biochemical characterization of a soluble truncated form of WbpM, His-S262, showed that WbpM was a C6 dehydratase specific for UDP-GlcNAc. It exhibited unusual low temperature (25-30 degrees C) and high pH (pH 10) optima. Although WbpM possessed an altered catalytic triad composed of SMK as opposed to SYK commonly found in other dehydratases, its catalysis was very efficient, with a kcat of 168 min(-1) and a kcat/Km of 58 mM(-1) min(-1). These unusual physico-kinetic properties suggested a potentially different mechanism of C6 dehydration for WbpM and its large homologues. His-S262 is now a precious tool for further structure-function studies.
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Affiliation(s)
- C Creuzenet
- Department of Microbiology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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29
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Stedman NL, Brown TP, Brooks RL, Bounous DI. Heterophil function and resistance to staphylococcal challenge in broiler chickens naturally infected with avian leukosis virus subgroup J. Vet Pathol 2001; 38:519-27. [PMID: 11572559 DOI: 10.1354/vp.38-5-519] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Avian leukosis virus subgroup J has a high tropism for myeloid lineage cells and frequently induces neoplastic transformation of myelocytes. The impact of congenital avian leukosis virus subgroup J infection on the function of circulating heterophils and susceptibility to staphylococcal infection was investigated. Six-week-old broiler chickens negative for exogenous avian leukosis viruses or congenitally infected with avian leukosis virus subgroup J were inoculated intravenously with 10(6) colony-forming units of Staphylococcus aureus, and pre- and postinoculation heterophil function was assessed. All chickens developed a leukocytosis with heterophilia after inoculation, but total leukocyte and heterophil counts were significantly higher in leukosis-negative chickens than in virus-infected chickens. Tenosynovitis was more severe in leukosis-negative chickens, and 2/10 (20%) of the virus-infected chickens had no histologic evidence of tenosynovitis. Osteomyelitis in the tibiotarsus or tarsometatarsus developed in 5/10 (50%) of the chickens in each group. S. aureus was recovered from the hock joint of 6/10 (60%) of the chickens in each group. Heterophils from all chickens exhibited similar phagocytic ability pre- and postinoculation. Heterophils from virus-infected chickens exhibited less bactericidal ability preinoculation than did heterophils from leukosis-negative chickens. However, postinoculation bactericidal ability was similar in both groups. Avian leukosis virus subgroup J provirus was present in heterophils isolated from congenitally infected chickens. Heterophils isolated from broiler chickens congenitally infected with avian leukosis virus subgroup J exhibit no significant functional deficits, and infected and uninfected chickens exhibit similar susceptibility to staphylococcal infection.
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Affiliation(s)
- N L Stedman
- Department of Veterinary Pathology, College of Veterinary Medicine, University of Georgia, Athens, 30602, USA
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30
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Tzianabos AO, Wang JY, Lee JC. Structural rationale for the modulation of abscess formation by Staphylococcus aureus capsular polysaccharides. Proc Natl Acad Sci U S A 2001; 98:9365-70. [PMID: 11470905 PMCID: PMC55426 DOI: 10.1073/pnas.161175598] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus aureus is a medically important bacterial pathogen that is a common cause of superficial and deep-seated abscesses in humans. Most S. aureus isolates produce either a serotype 5 or 8 capsular polysaccharide (CP) that has been shown to enhance bacterial virulence. We investigated the role of S. aureus CPs in modulating abscess formation in an experimental animal model of intraabdominal infection. Structural studies of CP8 revealed that it has a zwitterionic charge motif conferred by the negatively charged carboxyl group of N-acetylmannosaminuronic acid and free amino groups available on partially N-acetylated fucosamine residues. We report that purified CP5 and CP8 facilitated intraabdominal abscess formation in animals when given i.p. with a sterile cecal contents adjuvant. Chemical modifications that neutralized the positively or negatively charged groups on CP8 abrogated its ability to provoke abscesses. Rats prophylactically treated with CP8 s.c. were protected against abscess formation induced by homologous or heterologous zwitterionic polysaccharides. Likewise, treatment with CP8 protected against challenge with viable S. aureus strains PS80 (a capsule type 8 strain) or COL (a methicillin-resistant capsule type 5 strain). Purified CP8 was a potent activator of rat and human CD4(+) T cells in vitro. When transferred to naive rats, these activated T cells modulated the development of intraabdominal abscess formation. These results provide a structure/function rationale for abscess formation by S. aureus and expand the sphere of encapsulated organisms that interact directly with T cells to regulate this host response to bacterial infection.
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Affiliation(s)
- A O Tzianabos
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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31
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Tollersrud T, Zernichow L, Andersen SR, Kenny K, Lund A. Staphylococcus aureus capsular polysaccharide type 5 conjugate and whole cell vaccines stimulate antibody responses in cattle. Vaccine 2001; 19:3896-903. [PMID: 11427263 DOI: 10.1016/s0264-410x(01)00124-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Dairy heifers were immunized subcutaneously with one of four different vaccines which contained preparations of Staphylococcus aureus capsular polysaccharide type 5 (CP5) and a mineral oil adjuvant, or received a placebo containing saline and adjuvant. The vaccine containing a CP5-human serum albumin conjugate (CP5-HSA) and the vaccine with formaldehyde inactivated whole cells expressing CP5, both elicited strong anti-CP5 antibody responses. After two injections three weeks apart and a third injection 10 months later, the mean level and duration of the anti-CP5 antibody response was significantly higher in the whole cell group. No differences were found between the two groups with regard to the relative proportion of IgG subclasses, and the antibody responses to the polysaccharide were composed of both the IgG1 and IgG2. Vaccines containing only free CP5 or CP5 mixed with HSA produced weak and transient humoral immune responses. Only animals vaccinated with the whole cell vaccine or the conjugate vaccine showed responses to CP5 in a lymphocyte proliferation assay conducted one year after the third vaccination. This study indicates that CP5 expressed on the surface of formaldehyde inactivated whole cells, emulsified in an oil adjuvant, gives a strong and long lasting immune response in cattle. The use of conjugation technology, although effective, might not be necessary in order to achieve an immune response against S. aureus CP5 in cattle.
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Affiliation(s)
- T Tollersrud
- Department of Immunoprophylaxis, National Veterinary Institute, PB 8156, 0033 Oslo Dep., Norway.
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Jiang SM, Wang L, Reeves PR. Molecular characterization of Streptococcus pneumoniae type 4, 6B, 8, and 18C capsular polysaccharide gene clusters. Infect Immun 2001; 69:1244-55. [PMID: 11179285 PMCID: PMC98014 DOI: 10.1128/iai.69.3.1244-1255.2001] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Capsular polysaccharide (CPS) is a major virulence factor in Streptococcus pneumoniae. CPS gene clusters of S. pneumoniae types 4, 6B, 8, and 18C were sequenced and compared with those of CPS types 1, 2, 14, 19F, 19A, 23F, and 33F. All have the same four genes at the 5' end, encoding proteins thought to be involved in regulation and export. Sequences of these genes can be divided into two classes, and evidence of recombination between them was observed. Next is the gene encoding the transferase for the first step in the synthesis of CPS. The predicted amino acid sequences of these first sugar transferases have multiple transmembrane segments, a feature lacking in other transferases. Sugar pathway genes are located at the 3' end of the gene cluster. Comparison of the four dTDP-L-rhamnose pathway genes (rml genes) of CPS types 1, 2, 6B, 18C, 19F, 19A, and 23F shows that they have the same gene order and are highly conserved. There is a gradient in the nature of the variation of rml genes, the average pairwise difference for those close to the central region being higher than that for those close to the end of the gene cluster and, again, recombination sites can be observed in these genes. This is similar to the situation we observed for rml genes of O-antigen gene clusters of Salmonella enterica. Our data indicate that the conserved first four genes at the 5' ends and the relatively conserved rml genes at the 3' ends of the CPS gene clusters were sites for recombination events involved in forming new forms of CPS. We have also identified wzx and wzy genes for all sequenced CPS gene clusters by use of motifs.
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Affiliation(s)
- S M Jiang
- Department of Microbiology, The University of Sydney, Sydney, New South Wales 2006, Australia
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Creuzenet C, Schur MJ, Li J, Wakarchuk WW, Lam JS. FlaA1, a new bifunctional UDP-GlcNAc C6 Dehydratase/ C4 reductase from Helicobacter pylori. J Biol Chem 2000; 275:34873-80. [PMID: 10954725 DOI: 10.1074/jbc.m006369200] [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: 11/06/2022] Open
Abstract
FlaA1 is a small soluble protein of unknown function in Helicobacter pylori. It has homologues that are essential for the virulence of numerous medically relevant bacteria. FlaA1 was overexpressed as a histidine-tagged protein and purified to homogeneity by nickel chelation and cation exchange chromatography. Spectrophotometric assays, capillary electrophoresis, and mass spectrometry analyses showed that FlaA1 is a novel bifunctional C(6) dehydratase/C(4) reductase specific for UDP-GlcNAc. It converts UDP-GlcNAc into a UDP-4-keto-6-methyl-GlcNAc intermediate, which is stereospecifically reduced into UDP-QuiNAc. Substrate conversions as high as 80% were obtained at equilibrium. The K(m) and V(max) for UDP-GlcNAc were 159 microm and 65 pmol/min, respectively. No exogenous cofactor was required to obtain full activity of FlaA1. Additional NADH was only used with poor efficiency for the reduction step. The biochemical characterization of FlaA1 is important for the elucidation of biosynthetic pathways that lead to the formation of 2,6-deoxysugars in medically relevant bacteria. It establishes unambiguously the first step of the pathway and provides the means of preparing the substrate UDP-QuiNAc, which is necessary for the study of downstream enzymes.
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Affiliation(s)
- C Creuzenet
- University of Guelph, Department of Microbiology, Guelph, Ontario N1G 2W1, Canada
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34
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Mckenney D, Pouliot K, Wang Y, Murthy V, Ulrich M, Döring G, Lee JC, Goldmann DA, Pier GB. Vaccine potential of poly-1-6 beta-D-N-succinylglucosamine, an immunoprotective surface polysaccharide of Staphylococcus aureus and Staphylococcus epidermidis. J Biotechnol 2000; 83:37-44. [PMID: 11000458 DOI: 10.1016/s0168-1656(00)00296-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Staphylococcus aureus and S. epidermidis are among the most common causes of nosocomial infection, and S. aureus is also of major concern to human health due to its occurrence in community-acquired infections. These staphylococcal species are also major pathogens for domesticated animals. We have previously identified poly-N-succinyl beta-1-6 glucosamine (PNSG) as the chemical form of the S. epidermidis capsular polysaccharide/adhesin (PS/A) which mediates adherence of coagulase-negative staphylococci (CoNS) to biomaterials, serves as the capsule for strains of CoNS that express PS/A, and is a target for protective antibodies. We have recently found that PNSG is made by S. aureus as well, where it is an environmentally regulated, in vivo-expressed surface polysaccharide and similarly serves as a target for protective immunity. Only a minority of fresh human clinical isolates of S. aureus elaborate PNSG in vitro but most could be induced to do so under specific in vitro growth conditions. However, by immunofluorescence microscopy, S. aureus cells in infected human sputa and lung elaborated PNSG. The ica genes, previously shown to encode proteins in CoNS that synthesize PNSG, were found by PCR in all S. aureus strains examined, and immunogenic and protective PNSG could be isolated from S. aureus. Active and passive immunization of mice with PNSG protected them against metastatic kidney infections after intravenous inoculation with eight phenotypically PNSG-negative S. aureus. Isolates recovered from kidneys expressed PNSG, but expression was lost with in vitro culture. Strong antibody responses to PNSG were elicited in S. aureus infected mice, and a PNSG-capsule was observed by electron microscopy on isolates directly plated from infected kidneys. PNSG represents a previously unidentified surface polysaccharide of S. aureus that is elaborated during human and animal infection and is a prominent target for protective antibodies.
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Affiliation(s)
- D Mckenney
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115-5804, USA
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35
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Tollersrud T, Kenny K, Reitz AJ, Lee JC. Genetic and serologic evaluation of capsule production by bovine mammary isolates of Staphylococcus aureus and other Staphylococcus spp. from Europe and the United States. J Clin Microbiol 2000; 38:2998-3003. [PMID: 10921967 PMCID: PMC87170 DOI: 10.1128/jcm.38.8.2998-3003.2000] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bovine mastitis caused by Staphylococcus aureus is responsible for major economic losses to the dairy industry, and more-effective therapeutic or preventive approaches are sorely needed. The predominance of staphylococcal capsular polysaccharide types 5 and 8 among human isolates from many sources is well documented, but there seems to be a greater variation in the distribution of capsular serotypes among isolates from cows. A total of 636 isolates of S. aureus from cases of bovine mastitis in Sweden, Denmark, Finland, Iceland, Ireland, and the United States were investigated for production of capsular polysaccharide types 5 and 8. Approximately half of all the European isolates tested were of serotype 8, although variation among countries and among isolates of clinical and subclinical origin was observed. Sweden had the highest frequency (87%) of serotypeable isolates, and Finland had the lowest (48%). Capsule types 5 and 8 accounted for only 42% of the U.S. isolates tested. A few isolates showed weak reactivity with CP5 antiserum in a colony blot assay, and an enzyme-linked immunosorbent assay inhibition method confirmed that the levels of capsule produced by these strains were <10% of those produced by control strains. Fifty isolates that failed to react with capsular antisera all possessed the genes for production of capsular polysaccharide type 5 or 8. These results underscore the variability in capsule production by bovine isolates of S. aureus from different geographic regions. This information is important for the rational design of a capsule-based vaccine to prevent S. aureus bovine mastitis.
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Affiliation(s)
- T Tollersrud
- Section of Immunoprophylaxis, National Veterinary Institute, Oslo, Norway.
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36
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Snodgrass JL, Mohamed N, Ross JM, Sau S, Lee CY, Smeltzer MS. Functional analysis of the Staphylococcus aureus collagen adhesin B domain. Infect Immun 1999; 67:3952-9. [PMID: 10417161 PMCID: PMC96678 DOI: 10.1128/iai.67.8.3952-3959.1999] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Staphylococcus aureus collagen adhesin (CNA) occurs in at least four forms that differ in the number (one, two, three, or four) of B domains. The B domains contain 187 amino acids and are located between the domains that anchor CNA to the cell envelope and the ligand-binding A domain. To determine whether a B domain is required for functional expression of CNA, we cloned the 2B cna gene from S. aureus strain Phillips and then eliminated both B domains by overlapping PCR. The absence of a B domain did not affect processing of the collagen adhesin to the cell surface or the ability to bind collagen. Based on our recent demonstration that the capsule can mask CNA on the surface of S. aureus cells (A. F. Gillaspy et al., Infect. Immun. 66:3170-3178, 1998), we also investigated the possibility that multiple B domains can extend the ligand-binding A domain outward from the cell surface and thereby overcome the inhibitory effect of the capsule. Specifically, we cloned the naturally occurring 4B CNA variant from S. aureus UAMS-639 and, by successive elimination of B domains, generated 1, 2, and 3B variants that are isogenic with respect to the 4B clone. After introducing each variant into microencapsulated and heavily encapsulated strains of S. aureus and growing cells under conditions known to affect capsule production (e.g., growth on Columbia agar), we correlated capsule production with exposure of CNA on the cell surface and the ability to bind collagen. Under no circumstance was the masking effect of the capsule reduced by the presence of multiple B domains. These results indicate that the B domains do not extend the ligand-binding A domain outward in a fashion that can overcome the inhibition of collagen binding associated with capsule production.
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Affiliation(s)
- J L Snodgrass
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
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37
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McKenney D, Pouliot KL, Wang Y, Murthy V, Ulrich M, Döring G, Lee JC, Goldmann DA, Pier GB. Broadly protective vaccine for Staphylococcus aureus based on an in vivo-expressed antigen. Science 1999; 284:1523-7. [PMID: 10348739 DOI: 10.1126/science.284.5419.1523] [Citation(s) in RCA: 293] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Vaccines based on preferential expression of bacterial antigens during human infection have not been described. Staphylococcus aureus synthesized poly-N-succinyl beta-1-6 glucosamine (PNSG) as a surface polysaccharide during human and animal infection, but few strains expressed PNSG in vitro. All S. aureus strains examined carried genes for PNSG synthesis. Immunization protected mice against kidney infections and death from strains that produced little PNSG in vitro. Nonimmune infected animals made antibody to PNSG, but serial in vitro cultures of kidney isolates yielded mostly cells that did not produce PNSG. PNSG is a candidate for use in a vaccine to protect against S. aureus infection.
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Affiliation(s)
- D McKenney
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Department of Medicine, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
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38
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Ouyang S, Sau S, Lee CY. Promoter analysis of the cap8 operon, involved in type 8 capsular polysaccharide production in Staphylococcus aureus. J Bacteriol 1999; 181:2492-500. [PMID: 10198014 PMCID: PMC93676 DOI: 10.1128/jb.181.8.2492-2500.1999] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The production of type 8 capsular polysaccharide (CP8) in Staphylococcus aureus is regulated in response to a variety of environmental factors. The cap8 genes required for the CP8 production in strain Becker are transcribed as a single large transcript by a primary promoter located within a 0.45-kb region upstream of the first gene of the cap8 gene cluster. In this study, we analyzed the primary cap8 promoter region in detail. We determined the transcription initiation site of the primary transcript by primer extension and identified the potential promoter sequences. We found several inverted and direct repeats upstream of the promoter. Deletion analysis and site-directed mutagenesis showed that a 10-bp inverted repeat of one of the repeats was required for promoter activity. We showed that the distance but not the specific sequences between the inverted repeat and the promoter was critical to the promoter activity. However, insertion of a DNA sequence with two or four helix turns in this intervening region had a slight effect on promoter activity. To demonstrate the biological significance of the 10-bp inverted repeat, we constructed a strain with a mutation in the repeat in the S. aureus Becker chromosome and showed that the repeat affected CP8 production mostly at the transcriptional level. By gel mobility shift assay, we demonstrated that strain Becker produced at least one protein capable of specific binding to the 10-bp inverted repeat, indicating that the repeat serves as a positive regulatory protein binding site. In addition, reporter gene fusion analysis showed that the cap8 promoter activity was influenced by various growth media and affected most by yeast extract. Our results suggest that yeast extract may exert its profound inhibitory effect on cap8 gene expression through the 10-bp inverted repeat element.
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Affiliation(s)
- S Ouyang
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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39
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Wann ER, Dassy B, Fournier JM, Foster TJ. Genetic analysis of the cap5 locus of Staphylococcus aureus. FEMS Microbiol Lett 1999; 170:97-103. [PMID: 9919657 DOI: 10.1111/j.1574-6968.1999.tb13360.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Staphylococcus aureus expresses at least eight distinct serotypes of capsular polysaccharide (CP). Gene clusters involved in the expression of serotypes 1, 5 and 8 have been cloned and sequenced. In this report we describe the isolation and analysis of serotype 5 capsular polysaccharide-defective mutants. A naturally occurring cap mutation in the laboratory strains 8325-4 and RN4220 was mapped to the cap5E gene by genetic complementation. The cap5H-K genes were shown to be responsible for CP5 serotype specificity by transduction and complementation.
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Affiliation(s)
- E R Wann
- Moyne Institute of Preventive Medicine, Department of Microbiology, Trinity College, Dublin, Ireland
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40
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Fattom AI, Sarwar J, Basham L, Ennifar S, Naso R. Antigenic determinants of Staphylococcus aureus type 5 and type 8 capsular polysaccharide vaccines. Infect Immun 1998; 66:4588-92. [PMID: 9746554 PMCID: PMC108565 DOI: 10.1128/iai.66.10.4588-4592.1998] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial capsular polysaccharides (CP) are carbohydrate polymers comprised of repeating saccharide units. Several of these CP have side chains attached to their backbone structures. The side chains may include O-acetyl, phosphate, sialic acid, and other moieties. Those moieties represent the immunodominant epitopes and the most functional ones. The clinically significant Staphylococcus aureus type 5 CP (CP 5) and type 8 CP (CP 8) are comprised of a trisaccharide repeat unit with one O-acetyl group attached to each repeat unit. The immunogenicity of these CP and the functionality of antibodies to the backbone and the O-acetyl moieties were investigated. Immunization with the native CP conjugates (CP with 75% O-acetylation) elicited a high proportion of antibodies directed against the O-acetyl moiety. Nonetheless, all of the vaccinees produced antibodies to the backbone moieties as well. Conjugate vaccines made of de-O-acetylated CP elicited backbone antibodies only. Antibodies to both backbone and O-acetyl groups were found to be opsonic against S. aureus strains which varied in their O-acetyl content. Absorption studies with O-acetylated and de-O-acetylated CP showed that (i) native CP conjugates generated antibodies to both backbone and O-acetyl groups and (ii) O-acetylated isolates were opsonized by both populations of antibodies while the non-O-acetylated strains were predominantly opsonized by the backbone antibodies. These results suggest that S. aureus CP conjugate vaccines elicit multiple populations of antibodies with diverse specificities. Moreover, the antibodies of different specificities (backbone or O-acetyl) are all functional and efficient against the variations in bacterial CP that may occur among clinically significant S. aureus pathogenic isolates.
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Affiliation(s)
- A I Fattom
- W. W. Karakawa Microbial Pathogenesis Laboratory, Nabi, Rockville, MD 20852, USA.
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41
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Fox KF, Stewart GC, Fox A. Synthesis of microcapsule by Staphylococcus aureus is not responsive to environmental phosphate concentrations. Infect Immun 1998; 66:4004-7. [PMID: 9673297 PMCID: PMC108475 DOI: 10.1128/iai.66.8.4004-4007.1998] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The polysaccharide microcapsule of Staphylococcus aureus has been reported to be differentially expressed depending on growth conditions, with phosphate concentration being the critical environmental component. This study evaluated the effect of growth of a serotype 8 strain of S. aureus in phosphate-replete and phosphate-limiting media on microcapsule production. The presence of the cell wall polymers microcapsule and teichoic acid was measured by both gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. Production of microcapsule was unaffected by changes in the environmental phosphate concentration. There was, additionally, no evidence for a shift from teichoic acid to teichuronic acid synthesis.
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Affiliation(s)
- K F Fox
- Department of Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
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42
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Bhasin N, Albus A, Michon F, Livolsi PJ, Park JS, Lee JC. Identification of a gene essential for O-acetylation of the Staphylococcus aureus type 5 capsular polysaccharide. Mol Microbiol 1998; 27:9-21. [PMID: 9466251 DOI: 10.1046/j.1365-2958.1998.00646.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Staphylococcus aureus serotype 5 capsular polysaccharide (CP5) has a trisaccharide repeating unit of (-->4)-3-O-Ac-beta-D-ManNAcAp-(1-->4)-alpha-L-FucNAcp-(1-->3 )-beta-D-FucNAcp-(1-->). Tn918 mutagenesis of strain Reynolds yielded a mutant that produced wild-type levels of O-deacetylated CP5. The site and orientation of the single transposon insertion in mutant JL232 were determined by analysis of Southern blots and amplification of DNA flanking the transposon. DNA sequencing revealed that Tn918 was inserted within an open reading frame of 627 bp. The predicted amino acid sequence encodes a protein of approximately 26 kDa with homology to members of the NodL-LacA-CysE family of bacterial acetyltransferases. Southern blot analysis showed that genes similar to cap5H were present only in strains of S. aureus belonging to capsular serotypes 2, 4 and 5. In an in vitro assay, the parental strain was more resistant to opsonophagocytic killing than the mutant strain. In a mouse model of staphylococcal infection, the parental strain was able to seed the bloodstream from the peritoneal cavity and colonize the kidneys more efficiently than the O-deacetylated mutant. When cap5H was provided to the mutant in trans, it fully restored CP5 O-acetylation. The virulence of the complemented mutant strain closely approximated that of the parental strain.
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Affiliation(s)
- N Bhasin
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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43
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Kiser KB, Lee JC. Staphylococcus aureus cap5O and cap5P genes functionally complement mutations affecting enterobacterial common-antigen biosynthesis in Escherichia coli. J Bacteriol 1998; 180:403-6. [PMID: 9440531 PMCID: PMC106897 DOI: 10.1128/jb.180.2.403-406.1998] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The Staphylococcus aureus cap5P and cap5O genes of the type 5 capsule biosynthetic locus restore enterobacterial common-antigen expression to Escherichia coli mutants defective in rffE and rffD gene expression, respectively. Cap5P and Cap5O likely function as UDP-GlcNAc 2-epimerase and UDP-ManNAc dehydrogenase enzymes, respectively, in the synthesis of the capsule precursor UDP-ManNAcA.
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Affiliation(s)
- K B Kiser
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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44
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Sau S, Bhasin N, Wann ER, Lee JC, Foster TJ, Lee CY. The Staphylococcus aureus allelic genetic loci for serotype 5 and 8 capsule expression contain the type-specific genes flanked by common genes. MICROBIOLOGY (READING, ENGLAND) 1997; 143 ( Pt 7):2395-2405. [PMID: 9245821 DOI: 10.1099/00221287-143-7-2395] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The nucleotide sequences of two gene clusters, cap5 and cap8, involved in the synthesis of Staphylococcus aureus type 5 and type 8 capsular polysaccharides (CPs), respectively were determined. Each gene cluster contained 16 ORFs, which were named cap5A through cap5P for type 5 CP and cap8A through cap8P for type 8 CP. The cap5 and cap8 loci were allelic and were mapped to the SmaI-G fragment in the standard SmaI map of Staph. aureus strain NCTC 8325. The predicted gene products of cap5A through cap5G and cap5L through cap5P are essentially identical to those of cap8A through cap8G and cap8L through cap8P, respectively, with very few amino acid substitutions. Four ORFs located in the central region of each locus are type-specific. A comparison of the predicted amino acid sequences of cap5 and cap8 with sequences found in the databases allowed tentative assignment of functions to 15 of the 16 ORFs. The majority of the capsule genes are likely to be involved in amino sugar synthesis; the remainder are likely to be involved in sugar transfer, capsule chain-length regulation, polymerization and transport.
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Affiliation(s)
- Subrata Sau
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Navneet Bhasin
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Elisabeth R Wann
- Microbiology Department, Moyne Institute, Trinity College, Dublin 2, Ireland
| | - Jean C Lee
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Timothy J Foster
- Microbiology Department, Moyne Institute, Trinity College, Dublin 2, Ireland
| | - Chia Y Lee
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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45
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Sau S, Sun J, Lee CY. Molecular characterization and transcriptional analysis of type 8 capsule genes in Staphylococcus aureus. J Bacteriol 1997; 179:1614-21. [PMID: 9045821 PMCID: PMC178874 DOI: 10.1128/jb.179.5.1614-1621.1997] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A 20.5-kb contiguous DNA fragment from Staphylococcus aureus Becker affecting type 8 capsule (CP8) biosynthesis was previously cloned. Sequencing analysis indicated that 16 open reading frames (ORFs) encoded within this fragment might be involved in CP8 synthesis. Using various plasmids containing DNA inserts derived from the 20.5-kb region, we showed by complementation of chemical mutants that 8 of the 16 ORFs were required for CP8 synthesis. To determine the involvement of the remaining eight ORFs, nonpolar gene-specific chromosomal mutations located in each of these ORFs were constructed. We found that three additional ORFs were also involved in the CP8 synthesis. Thus, 11 of the 16 ORFs were shown to affect CP8 synthesis. Complementation analyses of these 11 type 8 capsule (cap8) genes affecting CP8 production showed several promoters within the cap8 gene cluster. However, by Northern hybridization using either the entire cap8 gene cluster or the internal fragments of individual ORFs as probes, one 17-kb cap8-specific transcript was detected. Using xylE as the reporter gene, we found that the promoter at the beginning of the cap8 operon was much stronger than any of the internal promoters. These results suggest that the cap8 genes are transcribed mainly as a single large transcript. In addition, Southern hybridization analyses showed that cap8H, cap8I, cap8J, and cap8K, located in the central region of the cap8 gene cluster, were CP8 specific.
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Affiliation(s)
- S Sau
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City 66160, USA
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46
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Fattom AI, Sarwar J, Ortiz A, Naso R. A Staphylococcus aureus capsular polysaccharide (CP) vaccine and CP-specific antibodies protect mice against bacterial challenge. Infect Immun 1996; 64:1659-65. [PMID: 8613375 PMCID: PMC173976 DOI: 10.1128/iai.64.5.1659-1665.1996] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The efficacy of capsular polysaccharide (CP)-specific antibodies elicited by active immunization with vaccines composed of Staphylococcus aureus types 5 and 8 CP linked to Pseudomonas aeruginosa exoprotein A or with immune immunoglobulin G (I-IgG) obtained from vaccinated plasma donors was tested in lethal and sublethal bacterial mouse challenge models. A dose of 2 x 10(5) CFU of S. aureus type 5 CP per mouse administered intraperitoneally (i.p.) with 5% hog mucin was found to cause 80 to 100% mortality in BALB/c mice within 2 to 5 days. Mice passively immunized i.p. 24 h earlier or subcutaneously 48 h earlier with 0.5 ml of I-IgG showed significantly higher average survival rates than animals receiving standard IgG or saline (P < 0.01) following the bacterial challenge. Animals actively immunized with the monovalent type 5 CP-P. aeruginosa exoprotein A conjugate showed a survival rate of 73% compared with 13% in phosphate-buffered saline-immunized animals. The prechallenge geometric mean titer of type 5 CP antibodies in animals that died was significantly (P < 0.05) lower than that of animals which survived the challenge (95.7 versus 223.6 micrograms/ml, respectively). The IgG was further evaluated in mice challenged i.p. with a sublethal dose of 5 x 10(4) CFU per mouse. Serial blood counts were performed on surviving animals at 6, 12, 24, and 48 h. Surviving animals were sacrificed at 72 h, and bacterial counts were performed on their kidneys, livers, and peritoneal lavage fluids. Animals receiving I-IgG had lower bacterial counts in blood samples and lower bacterial densities in kidneys, livers, and peritoneal lavage samples than mice immunized with standard IgG (P < 0.05). These data suggest that S. aureus type 5 CP antibodies induced by active immunization or administered by passive immunization confer protection against S. aureus infections.
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Affiliation(s)
- A I Fattom
- W.W. Karakawa Microbial Pathogenesis Laboratory, NABI, Rockville, Maryland 20852, USA
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Sau S, Lee CY. Cloning of type 8 capsule genes and analysis of gene clusters for the production of different capsular polysaccharides in Staphylococcus aureus. J Bacteriol 1996; 178:2118-26. [PMID: 8606192 PMCID: PMC177913 DOI: 10.1128/jb.178.7.2118-2126.1996] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Eleven serotypes of capsular polysaccharide from Staphylococcus aureus have been reported. We have previously cloned a cluster of type 1 capsule (cap1) genes responsible for type 1 capsular polysaccharide biosynthesis in S. aureus M. To clone the type 8 capsule (cap8) genes, a plasmid library of type 8 strain Becker was screened with a labelled DNA fragment containing the cap1 genes under low-stringency conditions. One recombinant plasmid containing a 14-kb insert was chosen for further study and found to complement 14 of the 18 type 8 capsule-negative (Cap8-) mutants used in the study. Additional library screening, subcloning, and complementation experiments showed that all of the 18 Cap8- mutants were complemented by DNA fragments derived from a 20.5-kb contiguous region of the Becker chromosome. The mutants were mapped into six complementation groups, indicating that the cap8 genes are clustered. By Southern hybridization analyses under high-stringency conditions, we found that DNA fragments containing the cap8 gene cluster show extensive homology with all 17 strains tested, including type 1 strains. By further Southern analyses and cloning of the cap8-related homolog from strain M, we show that strain M carries an additional capsule gene cluster different from the cap1 gene cluster. In addition, by using DNA fragments containing different regions of the cap8 gene cluster as probes to hybridize DNA from different strains, we found that the central region of the cap8 gene cluster hybridizes only to DNAs from certain strains tested whereas the flanking regions hybridize to DNAs of all strains tested. Thus, the cap8 gene clusters and its closely related homologs are likely to have organizations similar to those of the encapsulation genes of other bacterial systems.
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Affiliation(s)
- S Sau
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, 66160, USA
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Naso R, Fattom A. Polysaccharide conjugate vaccines for the prevention of gram-positive bacterial infections. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 397:133-40. [PMID: 8718592 DOI: 10.1007/978-1-4899-1382-1_18] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- R Naso
- W. W. Karakawa Microbial Pathogenesis Laboratory, Univax Biologics, Inc., Rockville, Maryland 20852, USA
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Abstract
Previous studies have shown that 13 genes located in a 14.6-kb region of the chromosome of Staphylococcus aureus (Sa) M are required for type-1 capsular polysaccharide (CP1) biosynthesis. In this report, a total of 17 Sa strains producing different CP serotypes were analyzed by Southern hybridization using DNA probes from the cap1 coding region and the flanking sequences. The results showed that the sequence encoding cap1 genes was specific to CP1-producing strains. In addition, DNA regions of at least 18 kb flanking the cap1 genes were absent in most of the non-type-1 strains. These data suggest that the cap1 genes are associated with a chromosomally located discrete genetic element. One end of the element, referred to as the cap1 element, is located in a 1.7-kb fragment about 11.1 kb upstream from the first gene of the cap1 locus and the other end is located in a 0.8-kb region about 7.6 kb downstream from the last gene of the cap1 locus. Thus, the size of the cap1 element is between 33.3 and 35.8 kb.
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Affiliation(s)
- C Y Lee
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City 66160, USA
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Robbins JB, Schneerson R, Vann WF, Bryla DA, Fattom A. Prevention of systemic infections caused by group B streptococcus and Staphylococcus aureus by multivalent polysaccharide-protein conjugate vaccines. Ann N Y Acad Sci 1995; 754:68-82. [PMID: 7625682 DOI: 10.1111/j.1749-6632.1995.tb44439.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- J B Robbins
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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