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Asadi A, Razavi S, Talebi M, Gholami M. A review on anti-adhesion therapies of bacterial diseases. Infection 2018; 47:13-23. [PMID: 30276540 DOI: 10.1007/s15010-018-1222-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/14/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Infections caused by bacteria are a foremost cause of morbidity and mortality in the world. The common strategy of treating bacterial infections is by local or systemic administration of antimicrobial agents. Currently, the increasing antibiotic resistance is a serious and global problem. Since the most important agent for infection is bacteria attaching to host cells, hence, new techniques and attractive approaches that interfere with the ability of the bacteria to adhere to tissues of the host or detach them from the tissues at the early stages of infection are good therapeutic strategies. METHODS All available national and international databanks were searched using the search keywords. Here, we review various approaches to anti-adhesion therapy, including use of receptor and adhesion analogs, dietary constituents, sublethal concentrations of antibiotics, and adhesion-based vaccines. RESULTS Altogether, the findings suggest that interference with bacterial adhesion serves as a new means to fight infectious diseases. CONCLUSION Anti-adhesion-based therapies can be effective in prevention and treatment of bacterial infections, but further work is needed to elucidate underlying mechanisms.
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Affiliation(s)
- Arezoo Asadi
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Shabnam Razavi
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Malihe Talebi
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Gholami
- Department of Microbiology and Virology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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Katzenmeyer KN, Szott LM, Bryers JD. Artificial opsonin enhances bacterial phagocytosis, oxidative burst and chemokine production by human neutrophils. Pathog Dis 2018; 75:3934653. [PMID: 28859309 DOI: 10.1093/femspd/ftx075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 07/04/2017] [Indexed: 12/23/2022] Open
Abstract
Here, we describe the application of an 'artificial opsonin' to stimulate the innate immune response against Gram-positive bacteria. The artificial opsonin comprises a poly(L-lysine)-graft-poly(ethylene glycol) backbone displaying multiple copies of vancomycin and human IgG-Fc. The vancomycin targets bacteria by recognizing d-Ala-d-Ala-terminated peptides present in the bacterial cell wall. The human IgG-Fc antibody fragments serve as phagocyte recognition moieties that recognize the Fcγ cell surface receptors expressed by professional human phagocytes. Staphylococcus epidermidis RP62A, a biofilm-forming, methicillin-resistant strain, was utilized to investigate the effects of opsonization on phagocytosis, oxidative burst and IL-8 chemokine production by human neutrophils. Results show that opsonization of S. epidermidis RP62A with the artificial opsonin resulted in an ∼2-fold increase in neutrophil phagocytosis. Analysis of the cell supernatant found a 2- to 3-fold increase in neutrophil IL-8 secretion. The neutrophil oxidative burst was investigated using the oxidation-sensitive fluorophore dihydrorhodamine-123. Bacterial opsonization resulted in a 20% increase in fluorescence intensity, indicating a significant increase in the production of reactive oxygen species by the neutrophils. These studies suggest that artificial opsonins may be a novel immunostimulation therapeutic strategy to control infections caused by Gram-positive bacteria, particularly those that are known to be immune evasive and/or antibiotic resistant.
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Affiliation(s)
- Kristy N Katzenmeyer
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
| | - Luisa M Szott
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
| | - James D Bryers
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
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Arciola CR, Speziale P, Montanaro L. Perspectives on DNA Vaccines. Targeting Staphylococcal Adhesins to Prevent Implant Infections. Int J Artif Organs 2018; 32:635-41. [DOI: 10.1177/039139880903200913] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
DNA vaccines consist of a plasmid DNA genetically engineered to produce one or more proteins able to elicit protective immune responses against virulence factors of infectious pathogens. Once introduced into the cells of the host, a DNA vaccine induces a high production of antigens by the endogenous presence of the peptide codifying gene; improves antigen processing and presentation; may be able to simultaneously co-express multiple antigenic molecules; and, lastly, switches on both humoral and cellular immune responses. In this mini-review, we underscore the advantageous characteristics of DNA vaccines compared with traditional ones and provide summaries of some of the more recent studies on them, mainly focusing the possibility of their use in targeting the staphylococcal adhesins that play a key role in the first adhesive phase of implant infections.
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Affiliation(s)
- Carla Renata Arciola
- Research Unit on Implant Infections, Rizzoli Orthopedic Institute, Bologna - Italy
- Experimental Pathology Department, University of Bologna, Bologna - Italy
| | - Pietro Speziale
- Department of Biochemistry, University of Pavia, Pavia - Italy
| | - Lucio Montanaro
- Research Unit on Implant Infections, Rizzoli Orthopedic Institute, Bologna - Italy
- Experimental Pathology Department, University of Bologna, Bologna - Italy
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Innovative Solutions to Sticky Situations: Antiadhesive Strategies for Treating Bacterial Infections. Microbiol Spectr 2017; 4. [PMID: 27227305 DOI: 10.1128/microbiolspec.vmbf-0023-2015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial adherence to host tissue is an essential process in pathogenesis, necessary for invasion and colonization and often required for the efficient delivery of toxins and other bacterial effectors. As existing treatment options for common bacterial infections dwindle, we find ourselves rapidly approaching a tipping point in our confrontation with antibiotic-resistant strains and in desperate need of new treatment options. Bacterial strains defective in adherence are typically avirulent and unable to cause infection in animal models. The importance of this initial binding event in the pathogenic cascade highlights its potential as a novel therapeutic target. This article seeks to highlight a variety of strategies being employed to treat and prevent infection by targeting the mechanisms of bacterial adhesion. Advancements in this area include the development of novel antivirulence therapies using small molecules, vaccines, and peptides to target a variety of bacterial infections. These therapies target bacterial adhesion through a number of mechanisms, including inhibition of pathogen receptor biogenesis, competition-based strategies with receptor and adhesin analogs, and the inhibition of binding through neutralizing antibodies. While this article is not an exhaustive description of every advancement in the field, we hope it will highlight several promising examples of the therapeutic potential of antiadhesive strategies.
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Haghighat S, Siadat SD, Rezayat Sorkhabadi SM, Akhavan Sepahi A, Sadat SM, Yazdi MH, Mahdavi M. Recombinant PBP2a as a vaccine candidate against methicillin-resistant Staphylococcus aureus : Immunogenicity and protectivity. Microb Pathog 2017; 108:32-39. [DOI: 10.1016/j.micpath.2017.04.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/17/2017] [Accepted: 04/26/2017] [Indexed: 11/28/2022]
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Haghighat S, Siadat SD, Sorkhabadi SMR, Sepahi AA, Mahdavi M. Cloning, expression and purification of autolysin from methicillin-resistant Staphylococcus aureus: potency and challenge study in Balb/c mice. Mol Immunol 2016; 82:10-18. [PMID: 28006655 DOI: 10.1016/j.molimm.2016.12.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/09/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022]
Abstract
Staphylococcus aureus (MRSA) is an opportunistic pathogen which causes a variety of clinical diseases and leads to high rates of morbidity and mortality. Development of an effective vaccine appears to be a useful strategy to control the infection. Here, the internal region of atl was cloned into the pET24a plasmid and expressed in E. coli BL21 (DE3). Cloning of atl was confirmed by colony-PCR, enzymatic digestion and sequencing. Protein expressed in E coli, BL21 DE3 and was confirmed with SDS-PAGE and western blot analysis. Subsequently, BALB/c mice were injected subcutaneously three times with 20μg of the recombinant autolysin. After Bleeding, autolysin-specific total IgG antibodies and isotypes were evaluated using ELISA. Opsonophagocytic killing assay was performed and experimental challenge was done by intraperitoneal injection with sub lethal doses of MRSA in mice and also survival rate was regularly monitored. Results showed that vaccinated mice could exhibit higher levels of autolysin-specific antibodies (P<0.0001) with a predominant IgG1 response versus control group. Results from in vitro experiments indicated that S. aureus opsonized with immunized-mice sera displayed significantly increased phagocytic uptake and effective intracellular killing versus non-immunized mice. The number of viable bacteria in the kidney of immunized mice showed 1000 times less than the control mice; additionally, an increased survival rate was found after immunization with the candidate vaccine versus control group. Results from this study demonstrated that the autolysin is a valuable target for the development of immunotherapeutic strategies against S. aureus and candidate vaccines.
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Affiliation(s)
- Setareh Haghighat
- Department of Microbiology, Faculty of Advanced Sciences and Technology, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran.
| | - Seyed Davar Siadat
- Department of Mycobacteriology & Pulmonary Research, Microbiology Research center, Pasteur Institute of Iran, Tehran, Iran.
| | - Seyed Mehdi Rezayat Sorkhabadi
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran
| | - Abbas Akhavan Sepahi
- Department of Microbiology, Faculty of Basic Sciences, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Mehdi Mahdavi
- Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
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Krachler AM, Orth K. Targeting the bacteria-host interface: strategies in anti-adhesion therapy. Virulence 2014; 4:284-94. [PMID: 23799663 PMCID: PMC3710331 DOI: 10.4161/viru.24606] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Bacterial infections are a major cause of morbidity and mortality worldwide and are increasingly problematic to treat due to the rise in antibiotic-resistant strains. It becomes more and more challenging to develop new antimicrobials that are able to withstand the ever-increasing repertoire of bacterial resistance mechanisms. This necessitates the development of alternative approaches to prevent and treat bacterial infections. One of the first steps during bacterial infection is adhesion of the pathogen to host cells. A pathogen’s ability to colonize and invade host tissues strictly depends on this process. Thus, interference with adhesion (anti-adhesion therapy) is an efficient way to prevent or treat bacterial infections. As a basis to present different strategies to interfere with pathogen adhesion, this review briefly introduces general concepts of bacterial attachment to host cells. We further discuss advantages and disadvantages of anti-adhesion treatments and issues that are in need of improvement so as to make anti-adhesion compounds a more broadly applicable alternative to conventional antimicrobials.
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Affiliation(s)
- Anne Marie Krachler
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
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Middleton JR. Staphylococcus aureusantigens and challenges in vaccine development. Expert Rev Vaccines 2014; 7:805-15. [DOI: 10.1586/14760584.7.6.805] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Brown AF, Leech JM, Rogers TR, McLoughlin RM. Staphylococcus aureus Colonization: Modulation of Host Immune Response and Impact on Human Vaccine Design. Front Immunol 2014; 4:507. [PMID: 24409186 PMCID: PMC3884195 DOI: 10.3389/fimmu.2013.00507] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 12/21/2013] [Indexed: 12/15/2022] Open
Abstract
In apparent contrast to its invasive potential Staphylococcus aureus colonizes the anterior nares of 20–80% of the human population. The relationship between host and microbe appears particularly individualized and colonization status seems somehow predetermined. After decolonization, persistent carriers often become re-colonized with their prior S. aureus strain, whereas non-carriers resist experimental colonization. Efforts to identify factors facilitating colonization have thus far largely focused on the microorganism rather than on the human host. The host responds to S. aureus nasal colonization via local expression of anti-microbial peptides, lipids, and cytokines. Interplay with the co-existing microbiota also influences colonization and immune regulation. Transient or persistent S. aureus colonization induces specific systemic immune responses. Humoral responses are the most studied of these and little is known of cellular responses induced by colonization. Intriguingly, colonized patients who develop bacteremia may have a lower S. aureus-attributable mortality than their non-colonized counterparts. This could imply a staphylococcal-specific immune “priming” or immunomodulation occurring as a consequence of colonization and impacting on the outcome of infection. This has yet to be fully explored. An effective vaccine remains elusive. Anti-S. aureus vaccine strategies may need to drive both humoral and cellular immune responses to confer efficient protection. Understanding the influence of colonization on adaptive response is essential to intelligent vaccine design, and may determine the efficacy of vaccine-mediated immunity. Clinical trials should consider colonization status and the resulting impact of this on individual patient responses. We urgently need an increased appreciation of colonization and its modulation of host immunity.
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Affiliation(s)
- Aisling F Brown
- Host-Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute , Dublin , Ireland
| | - John M Leech
- Host-Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute , Dublin , Ireland
| | - Thomas R Rogers
- Sir Patrick Dun Laboratory, Department of Clinical Microbiology, Trinity College Dublin, St James's Hospital , Dublin , Ireland
| | - Rachel M McLoughlin
- Host-Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute , Dublin , Ireland
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Is there a future for a Staphylococcus aureus vaccine? Vaccine 2011; 30:2921-7. [PMID: 22115633 DOI: 10.1016/j.vaccine.2011.11.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 10/21/2011] [Accepted: 11/01/2011] [Indexed: 12/21/2022]
Abstract
Multiple attempts to develop a vaccine to prevent Staphylococcus aureus infections have failed. To date, all have been based upon the development of opsonic antibodies. New information suggests that cell mediated immunity may be critical for protection against S. aureus infections. The arm of the immune system that provides the protection contains the Th17/IL-17 axis. Th17 cells release IL-17, which are important for mobilization and activation of neutrophils. Naturally, antibodies aid the neutrophils in the uptake and killing of staphylococci, but immune globulin does not seem to be sufficient to afford protection. New approaches that focus on Th17/IL-17 may allow for the development of a successful S. aureus vaccine.
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Safety and immunogenicity of a novel Staphylococcus aureus vaccine: results from the first study of the vaccine dose range in humans. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:1868-74. [PMID: 20943877 DOI: 10.1128/cvi.00356-10] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Merck V710 is a novel vaccine containing the conserved Staphylococcus aureus iron surface determinant B shown to be protective in animal models. A phase I, multicenter, double-blind study of the dose range was conducted to assess the immunogenicity and safety of an adjuvanted liquid formulation of V710. A total of 124 adults (18 to 55 years of age) were randomized 1:1:1:1 to receive one 0.5-ml intramuscular injection of V710 (5 μg, 30 μg, or 90 μg) or saline placebo. A positive immune response was defined as at least a 2-fold increase in IsdB-specific IgG levels from baseline levels. Local and systemic adverse events were assessed for 5 and 14 days, respectively, following vaccination. Positive immune responses were detected in 12 (67%) of the 18 subjects in the groups receiving 30 and 90 μg V710 tested at day 10. At day 14, a significantly greater proportion of subjects manifested a positive immune response with higher geometric mean concentrations in the V710 30-μg (86%; geometric mean concentration of 116 μg/ml) and 90-μg (87%; geometric mean concentration of 131 μg/ml) dose groups than in the V710 5-μg (29%; geometric mean concentration of 51 μg/ml) or placebo (4%; geometric mean concentration of 23 μg/ml) groups. Immune responses were durable through day 84. Subjects <40 and ≥40 years of age had comparable immune responses. The most common adverse events were injection-site pain, nausea, fatigue, and headache, usually of mild intensity. No immediate reactions or serious adverse events were reported. In this first study of V710 in humans, a single 30-μg or 90-μg dose was more immunogenic than the 5-μg dose or placebo. Immune responses were evident by 10 to 14 days after vaccination in most responders.
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Abstract
Staphylococcal infections represent an enormous burden to the public health system in the US and worldwide. While traditionally restricted to the hospital setting, highly virulent strains have recently emerged that may cause severe, even fatal, disease in healthy adults outside healthcare settings. This situation, together with the increasing resistance to many antibacterials in a wide variety of staphylococcal strains, requires that vaccine development for staphylococcal diseases be re-evaluated. Finding a vaccine for staphylococci is not trivial, as protective immunity to staphylococcal infections does not appear to exist at a significant degree, which may be partly due to the fact that our immune system is in constant contact with staphylococcal antigens and many strains are commensal organisms on human epithelia. Furthermore, the most virulent species, Staphylococcus aureus, produces protein A, a powerful means to evade acquired host defense. While two high-profile vaccine preparations have failed clinical trials within the last few years, promising results from novel approaches based on the combination of systematically selected antigens have been reported. These combinatory vaccines target microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), a family of bacterial proteins that bind to human extracellular matrix components. In addition, polysaccharide and other nonprotein antigens may represent suitable vaccine targets on the staphylococcal cell surface.
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Affiliation(s)
- Michael Otto
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana 59840, USA.
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