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Abstract
Neutrophils or polymorphonuclear neutrophils (PMNs) are an important component of innate host defense. These phagocytic leukocytes are recruited to infected tissues and kill invading microbes. There are several general characteristics of neutrophils that make them highly effective as antimicrobial cells. First, there is tremendous daily production and turnover of granulocytes in healthy adults-typically 1011 per day. The vast majority (~95%) of these cells are neutrophils. In addition, neutrophils are mobilized rapidly in response to chemotactic factors and are among the first leukocytes recruited to infected tissues. Most notably, neutrophils contain and/or produce an abundance of antimicrobial molecules. Many of these antimicrobial molecules are toxic to host cells and can destroy host tissues. Thus, neutrophil activation and turnover are highly regulated processes. To that end, aged neutrophils undergo apoptosis constitutively, a process that contains antimicrobial function and proinflammatory capacity. Importantly, apoptosis facilitates nonphlogistic turnover of neutrophils and removal by macrophages. This homeostatic process is altered by interaction with microbes and their products, as well as host proinflammatory molecules. Microbial pathogens can delay neutrophil apoptosis, accelerate apoptosis following phagocytosis, or cause neutrophil cytolysis. Here, we review these processes and provide perspective on recent studies that have potential to impact this paradigm.
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Affiliation(s)
- Scott D Kobayashi
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Mark T Quinn
- Department of Microbiology & Cell Biology, Montana State University, Bozeman, Montana, USA
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2
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Hampton MB, Dickerhof N. Inside the phagosome: A bacterial perspective. Immunol Rev 2023; 314:197-209. [PMID: 36625601 DOI: 10.1111/imr.13182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The neutrophil phagosome is one of the most hostile environments that bacteria must face and overcome if they are to succeed as pathogens. Targeting bacterial defense mechanisms should lead to new therapies that assist neutrophils to kill pathogens, but this has not yet come to fruition. One of the limiting factors in this effort has been our incomplete knowledge of the complex biochemistry that occurs within the rapidly changing environment of the phagosome. The same compartmentalization that protects host tissue also limits our ability to measure events within the phagosome. In this review, we highlight the limitations in our knowledge, and how the contribution of bacteria to the phagosomal environment is often ignored. There appears to be significant heterogeneity among phagosomes, and it is important to determine whether survivors have more efficient defenses or whether they are ingested into less threatening environments than other bacteria. As part of these efforts, we discuss how monitoring or recovering bacteria from phagosomes can provide insight into the conditions they have faced. We also encourage the use of unbiased screening approaches to identify bacterial genes that are essential for survival inside neutrophil phagosomes.
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Affiliation(s)
- Mark B Hampton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Nina Dickerhof
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
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3
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Intracellular Habitation of Staphylococcus aureus: Molecular Mechanisms and Prospects for Antimicrobial Therapy. Biomedicines 2022; 10:biomedicines10081804. [PMID: 36009351 PMCID: PMC9405036 DOI: 10.3390/biomedicines10081804] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections pose a global health threat, especially with the continuous development of antibiotic resistance. As an opportunistic pathogen, MRSA infections have a high mortality rate worldwide. Although classically described as an extracellular pathogen, many studies have shown over the past decades that MRSA also has an intracellular aspect to its infectious cycle, which has been observed in vitro in both non-professional as well as professional phagocytes. In vivo, MRSA has been shown to establish an intracellular niche in liver Kupffer cells upon bloodstream infection. The staphylococci have evolved various evasion strategies to survive the antimicrobial environment of phagolysosomes and use these compartments to hide from immune cells and antibiotics. Ultimately, the host cells get overwhelmed by replicating bacteria, leading to cell lysis and bacterial dissemination. In this review, we describe the different intracellular aspects of MRSA infection and briefly mention S. aureus evasion strategies. We discuss how this intracellular niche of bacteria may assist in antibiotic tolerance development, and lastly, we describe various new antibacterial strategies that target the intracellular bacterial niche.
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4
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Ginsenoside 20(S)-Rh2 promotes cellular pharmacokinetics and intracellular antibacterial activity of levofloxacin against Staphylococcus aureus through drug efflux inhibition and subcellular stabilization. Acta Pharmacol Sin 2021; 42:1930-1941. [PMID: 34462563 PMCID: PMC8564512 DOI: 10.1038/s41401-021-00751-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023] Open
Abstract
Intracellular Staphylococcus aureus (S. aureus) often causes clinical failure and relapse after antibiotic treatment. We previously found that 20(S)-ginsenoside Rh2 [20(S)-Rh2] enhanced the therapeutic effect of quinolones in a mouse model of peritonitis, which we attributed to the increased concentrations of quinolones within bacteria. In this study, we investigated the enhancing effect of 20(S)-Rh2 on levofloxacin (LVF) from a perspective of intracellular bacteria. In S. aureus 25923-infected mice, coadministration of LVF (1.5 mg/kg, i.v.) and 20(S)-Rh2 (25, 50 mg/kg, i.g.) markedly increased the survival rate, and decreased intracellular bacteria counts accompanied by increased accumulation of LVF in peritoneal macrophages. In addition, 20(S)-Rh2 (1, 5, 10 μM) dose-dependently increased the uptake and accumulation of LVF in peritoneal macrophages from infected mice without drug treatment. In a model of S. aureus 25923-infected THP-1 macrophages, we showed that 20(S)-Rh2 (1, 5, 10 μM) dose-dependently enhanced the intracellular antibacterial activity of LVF. At the cellular level, 20(S)-Rh2 increased the intracellular accumulation of LVF by inhibiting P-gp and BCRP. PK-PD modeling revealed that 20(S)-Rh2 altered the properties of the cell but not LVF. At the subcellular level, 20(S)-Rh2 did not increase the distribution of LVF in lysosomes but exhibited a stronger sensitizing effect in acidic environments. Molecular dynamics (MD) simulations showed that 20(S)-Rh2 improved the stability of the DNA gyrase-LVF complex in lysosome-like acidic conditions. In conclusion, 20(S)-Rh2 promotes the cellular pharmacokinetics and intracellular antibacterial activities of LVF against S. aureus through efflux transporter inhibition and subcellular stabilization, which is beneficial for infection treatment.
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5
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Further Insight into the Mechanism of Human PMN Lysis following Phagocytosis of Staphylococcus aureus. Microbiol Spectr 2021; 9:e0088821. [PMID: 34704790 PMCID: PMC8549732 DOI: 10.1128/spectrum.00888-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Staphylococcus aureus is an important human pathogen that can cause a variety of diseases ranging from mild superficial skin infections to life-threatening conditions like necrotizing pneumonia, endocarditis, and septicemia. Polymorphonuclear leukocytes (PMNs; neutrophils in particular herein) are essential for host defense against S. aureus infections, and the microbe is phagocytosed readily. Most ingested bacteria are killed, but some S. aureus strains—such as the epidemic USA300 strain—have an enhanced ability to cause PMN lysis after phagocytosis. Although progress has been made, the mechanism for lysis after phagocytosis of S. aureus remains incompletely determined. Here, we tested the hypothesis that disruption of phagosome integrity and escape of S. aureus from the PMN phagosome into the cytoplasm precedes PMN lysis. We used USA300 wild-type and isogenic deletion strains to evaluate and/or verify the role of selected S. aureus molecules in this cytolytic process. Compared to the wild-type USA300 strain, Δagr, Δhla, ΔlukGH, and Δpsm strains each caused significantly less lysis of human PMNs 3 h and/or 6 h after phagocytosis, consistent with previous studies. Most notably, confocal microscopy coupled with selective permeabilization assays demonstrated that phagosome membrane integrity is largely maintained prior to PMN lysis after S. aureus phagocytosis. We conclude that PMN lysis does not require escape of S. aureus from the phagosome to the cytoplasm and that these are independent phenomena. The findings are consistent with the ability of S. aureus (via selected molecules) to trigger lysis of human PMNs by an undetermined signaling mechanism. IMPORTANCES. aureus strain USA300 has the ability to cause rapid lysis of human neutrophils after phagocytosis. Although this phenomenon likely contributes to the success of USA300 as a human pathogen, our knowledge of the mechanism remains incomplete. Here, we used a selective permeabilization assay coupled with confocal microscopy to demonstrate that USA300 is contained within human neutrophil phagosomes until the point of host cell lysis. Thus, consistent with a process in macrophages, S. aureus fails to escape into the neutrophil cytoplasm prior to cytolysis.
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Rungelrath V, DeLeo FR. Staphylococcus aureus, Antibiotic Resistance, and the Interaction with Human Neutrophils. Antioxid Redox Signal 2021; 34:452-470. [PMID: 32460514 PMCID: PMC8020508 DOI: 10.1089/ars.2020.8127] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Significance:Staphylococcus aureus is among the leading causes of bacterial infections worldwide. The high burden of S. aureus among human and animal hosts, which includes asymptomatic carriage and infection, is coupled with a notorious ability of the microbe to become resistant to antibiotics. Notably, S. aureus has the ability to produce molecules that promote evasion of host defense, including the ability to avoid killing by neutrophils. Recent Advances: Significant progress has been made to better understand S. aureus-host interactions. These discoveries include elucidation of the role played by numerous S. aureus virulence molecules during infection. Based on putative functions, a number of these virulence molecules, including S. aureus alpha-hemolysin and protein A, have been identified as therapeutic targets. Although it has not been possible to develop a vaccine that can prevent S. aureus infections, monoclonal antibodies specific for S. aureus virulence molecules have the potential to moderate the severity of disease. Critical Issues: Therapeutic options for treatment of methicillin-resistant S. aureus (MRSA) are limited, and the microbe typically develops resistance to new antibiotics. New prophylactics and/or therapeutics are needed. Future Directions: Research that promotes an enhanced understanding of S. aureus-host interaction is an important step toward developing new therapeutic approaches directed to moderate disease severity and facilitate treatment of infection. This research effort includes studies that enhance our view of the interaction of S. aureus with human neutrophils. Antioxid. Redox Signal. 34, 452-470.
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Affiliation(s)
- Viktoria Rungelrath
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
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7
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Ha KP, Clarke RS, Kim GL, Brittan JL, Rowley JE, Mavridou DAI, Parker D, Clarke TB, Nobbs AH, Edwards AM. Staphylococcal DNA Repair Is Required for Infection. mBio 2020; 11:e02288-20. [PMID: 33203752 PMCID: PMC7683395 DOI: 10.1128/mbio.02288-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 10/14/2020] [Indexed: 01/07/2023] Open
Abstract
To cause infection, Staphylococcus aureus must withstand damage caused by host immune defenses. However, the mechanisms by which staphylococcal DNA is damaged and repaired during infection are poorly understood. Using a panel of transposon mutants, we identified the rexBA operon as being important for the survival of Staphylococcus aureus in whole human blood. Mutants lacking rexB were also attenuated for virulence in murine models of both systemic and skin infections. We then demonstrated that RexAB is a member of the AddAB family of helicase/nuclease complexes responsible for initiating the repair of DNA double-strand breaks. Using a fluorescent reporter system, we were able to show that neutrophils cause staphylococcal DNA double-strand breaks through reactive oxygen species (ROS) generated by the respiratory burst, which are repaired by RexAB, leading to the induction of the mutagenic SOS response. We found that RexAB homologues in Enterococcus faecalis and Streptococcus gordonii also promoted the survival of these pathogens in human blood, suggesting that DNA double-strand break repair is required for Gram-positive bacteria to survive in host tissues. Together, these data demonstrate that DNA is a target of host immune cells, leading to double-strand breaks, and that the repair of this damage by an AddAB-family enzyme enables the survival of Gram-positive pathogens during infection.IMPORTANCE To cause infection, bacteria must survive attack by the host immune system. For many bacteria, including the major human pathogen Staphylococcus aureus, the greatest threat is posed by neutrophils. These immune cells ingest the invading organisms and try to kill them with a cocktail of chemicals that includes reactive oxygen species (ROS). The ability of S. aureus to survive this attack is crucial for the progression of infection. However, it was not clear how the ROS damaged S. aureus and how the bacterium repaired this damage. In this work, we show that ROS cause breaks in the staphylococcal DNA, which must be repaired by a two-protein complex known as RexAB; otherwise, the bacterium is killed, and it cannot sustain infection. This provides information on the type of damage that neutrophils cause S. aureus and the mechanism by which this damage is repaired, enabling infection.
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Affiliation(s)
- Kam Pou Ha
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Rebecca S Clarke
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Gyu-Lee Kim
- Department of Pathology, Immunology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Jane L Brittan
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Jessica E Rowley
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Despoina A I Mavridou
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - Dane Parker
- Department of Pathology, Immunology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Thomas B Clarke
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Angela H Nobbs
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
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8
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Watkins KE, Unnikrishnan M. Evasion of host defenses by intracellular Staphylococcus aureus. ADVANCES IN APPLIED MICROBIOLOGY 2020; 112:105-141. [PMID: 32762866 DOI: 10.1016/bs.aambs.2020.05.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Staphylococcus aureus is one of the leading causes of hospital and community-acquired infections worldwide. The increasing occurrence of antibiotic resistant strains and the high rates of recurrent staphylococcal infections have placed several treatment challenges on healthcare systems. In recent years, it has become evident that S. aureus is a facultative intracellular pathogen, able to invade and survive in a range of cell types. The ability to survive intracellularly provides this pathogen with yet another way to evade antibiotics and immune responses during infection. Intracellular S. aureus have been strongly linked to several recurrent infections, including severe bone infections and septicemias. S. aureus is armed with an array of virulence factors as well as an intricate network of regulators that enable it to survive, replicate and escape from a number of immune and nonimmune host cells. It is able to successfully manipulate host cell pathways and use it as a niche to multiply, disseminate, as well as persist during an infection. This bacterium is also known to adapt to the intracellular environment by forming small colony variants, which are metabolically inactive. In this review we will discuss the clinical evidence, the molecular pathways involved in S. aureus intracellular persistence, and new treatment strategies for targeting intracellular S. aureus.
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9
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Multi-functionalized nanocarriers targeting bacterial reservoirs to overcome challenges of multi drug-resistance. ACTA ACUST UNITED AC 2020; 28:319-332. [PMID: 32193748 DOI: 10.1007/s40199-020-00337-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/11/2020] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Infectious diseases associated with intracellular bacteria such as Staphylococcus aureus, Salmonella typhimurium and Mycobacterium tuberculosis are important public health concern. Emergence of multi and extensively drug-resistant bacterial strains have made it even more obstinate to offset such infections. Bacteria residing within intracellular compartments provide additional barriers to effective treatment. METHOD Information provided in this review has been collected by accessing various electronic databases including Google scholar, Web of science, Scopus, and Nature index. Search was performed using keywords nanoparticles, intracellular targeting, multidrug resistance, Staphylococcus aureus; Salmonella typhimurium; Mycobacterium tuberculosis. Information gathered was categorized into three major sections as 'Intracellular targeting of Staphylococcus aureus, Intracellular targeting of Salmonella typhimurium and Intracellular targeting of Mycobacterium tuberculosis' using variety of nanocarrier systems. RESULTS Conventional management for infectious diseases typically comprises of long-term treatment with a combination of antibiotics, which may lead to side effects and decreased patient compliance. A wide range of multi-functionalized nanocarrier systems have been studied for delivery of drugs within cellular compartments where bacteria including Staphylococcus aureus, Salmonella typhimurium and Mycobacterium tuberculosis reside. Such carrier systems along with targeted delivery have been utilized for sustained and controlled delivery of drugs. These strategies have been found useful in overcoming the drawbacks of conventional treatments including multi-drug resistance. CONCLUSION Development of multi-functional nanocargoes encapsulating antibiotics that are proficient in targeting and releasing drug into infected reservoirs seems to be a promising strategy to circumvent the challenge of multidrug resistance. Graphical abstract.
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10
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Moldovan A, Fraunholz MJ. In or out: Phagosomal escape of Staphylococcus aureus. Cell Microbiol 2019; 21:e12997. [PMID: 30576050 DOI: 10.1111/cmi.12997] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/29/2018] [Accepted: 12/17/2018] [Indexed: 12/29/2022]
Abstract
Staphylococcus aureus is internalised by host cells in vivo, and recent research results suggest that the bacteria use this intracellularity to persist in the host and form a reservoir for recurrent infections. However, in different cells types, the pathogen resorts to alternative strategies to survive phagocytosis and the antimicrobial mechanisms of host cells. In non-professional phagocytes, S. aureus either escapes the endosome followed by cytoplasmic replication or replicates within autophagosomes. Professional phagocytes possess a limited capacity to kill S. aureus and hence the bacteria, well equipped with immune evasive mechanisms, replicate within the cells, eventually lyse out of the cells and thus persist in a continuous cycle of phagocytosis, host cell death, and bacterial release.
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Affiliation(s)
- Adriana Moldovan
- Chair of Microbiology, University of Würzburg, Würzburg, Germany
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11
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Pollitt EJG, Szkuta PT, Burns N, Foster SJ. Staphylococcus aureus infection dynamics. PLoS Pathog 2018; 14:e1007112. [PMID: 29902272 PMCID: PMC6019756 DOI: 10.1371/journal.ppat.1007112] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/26/2018] [Accepted: 05/21/2018] [Indexed: 01/22/2023] Open
Abstract
Staphylococcus aureus is a human commensal that can also cause systemic infections. This transition requires evasion of the immune response and the ability to exploit different niches within the host. However, the disease mechanisms and the dominant immune mediators against infection are poorly understood. Previously it has been shown that the infecting S. aureus population goes through a population bottleneck, from which very few bacteria escape to establish the abscesses that are characteristic of many infections. Here we examine the host factors underlying the population bottleneck and subsequent clonal expansion in S. aureus infection models, to identify underpinning principles of infection. The bottleneck is a common feature between models and is independent of S. aureus strain. Interestingly, the high doses of S. aureus required for the widely used "survival" model results in a reduced population bottleneck, suggesting that host defences have been simply overloaded. This brings into question the applicability of the survival model. Depletion of immune mediators revealed key breakpoints and the dynamics of systemic infection. Loss of macrophages, including the liver Kupffer cells, led to increased sensitivity to infection as expected but also loss of the population bottleneck and the spread to other organs still occurred. Conversely, neutrophil depletion led to greater susceptibility to disease but with a concomitant maintenance of the bottleneck and lack of systemic spread. We also used a novel microscopy approach to examine abscess architecture and distribution within organs. From these observations we developed a conceptual model for S. aureus disease from initial infection to mature abscess. This work highlights the need to understand the complexities of the infectious process to be able to assign functions for host and bacterial components, and why S. aureus disease requires a seemingly high infectious dose and how interventions such as a vaccine may be more rationally developed.
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Affiliation(s)
- Eric J. G. Pollitt
- Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, Western Bank, Sheffield, United Kingdom
| | - Piotr T. Szkuta
- Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, Western Bank, Sheffield, United Kingdom
| | - Nicola Burns
- Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, Western Bank, Sheffield, United Kingdom
| | - Simon J. Foster
- Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, Western Bank, Sheffield, United Kingdom
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12
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Hussain S, Joo J, Kang J, Kim B, Braun GB, She ZG, Kim D, Mann AP, Mölder T, Teesalu T, Carnazza S, Guglielmino S, Sailor MJ, Ruoslahti E. Antibiotic-loaded nanoparticles targeted to the site of infection enhance antibacterial efficacy. Nat Biomed Eng 2018; 2:95-103. [PMID: 29955439 DOI: 10.1038/s41551-017-0187-5] [Citation(s) in RCA: 226] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Bacterial resistance to antibiotics has made it necessary to resort to antibiotics that have considerable toxicities. Here, we show that the cyclic 9-amino acid peptide CARGGLKSC (CARG), identified via phage display on Staphylococcus aureus (S. aureus) bacteria and through in vivo screening in mice with S. aureus-induced lung infections, increases the antibacterial activity of CARG-conjugated vancomycin-loaded nanoparticles in S. aureus-infected tissues and reduces the needed overall systemic dose, minimizing side effects. CARG binds specifically to S. aureus bacteria but not Pseudomonas bacteria in vitro, selectively accumulates in S. aureus-infected lungs and skin of mice but not in non-infected tissue and Pseudomonas-infected tissue, and significantly enhances the accumulation of intravenously injected vancomycin-loaded porous silicon nanoparticles bearing the peptide in S. aureus-infected mouse lung tissue. The targeted nanoparticles more effectively suppress staphylococcal infections in vivo relative to equivalent doses of untargeted vancomycin nanoparticles or of free vancomycin. The therapeutic delivery of antibiotic-carrying nanoparticles bearing peptides targeting infected tissue may help combat difficult-to-treat infections.
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Affiliation(s)
- Sazid Hussain
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Jinmyoung Joo
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA.,Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jinyoung Kang
- Department of Nanoengineering, University of California, San Diego, La Jolla, CA, USA
| | - Byungji Kim
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA, USA
| | - Gary B Braun
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.,STEMCELL Technologies Inc., Vancouver, Canada
| | - Zhi-Gang She
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.,Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Dokyoung Kim
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Aman P Mann
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Tarmo Mölder
- Laboratory of Cancer Biology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Tambet Teesalu
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.,Laboratory of Cancer Biology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.,Center for Nanomedicine, and Department of Cell, Molecular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Santina Carnazza
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali- ChiBioFarAm, Università di Messina, Messina, Italy
| | - Salvatore Guglielmino
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali- ChiBioFarAm, Università di Messina, Messina, Italy
| | - Michael J Sailor
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA.,Department of Nanoengineering, University of California, San Diego, La Jolla, CA, USA.,Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA, USA
| | - Erkki Ruoslahti
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA. .,Center for Nanomedicine, and Department of Cell, Molecular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA.
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13
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Buvelot H, Posfay-Barbe KM, Linder P, Schrenzel J, Krause KH. Staphylococcus aureus, phagocyte NADPH oxidase and chronic granulomatous disease. FEMS Microbiol Rev 2017; 41:139-157. [PMID: 27965320 DOI: 10.1093/femsre/fuw042] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2016] [Indexed: 11/14/2022] Open
Abstract
Dysfunction of phagocytes is a relevant risk factor for staphylococcal infection. The most common hereditary phagocyte dysfunction is chronic granulomatous disease (CGD), characterized by impaired generation of reactive oxygen species (ROS) due to loss of function mutations within the phagocyte NADPH oxidase NOX2. Phagocytes ROS generation is fundamental to eliminate pathogens and to regulate the inflammatory response to infection. CGD is characterized by recurrent and severe bacterial and fungal infections, with Staphylococcus aureus as the most frequent pathogen, and skin and lung abscesses as the most common clinical entities. Staphylococcus aureus infection may occur in virtually any human host, presumably because of the many virulence factors of the bacterium. However, in the presence of functional NOX2, staphylococcal infections remain rare and are mainly linked to breaches of the skin barrier. In contrast, in patients with CGD, S. aureus readily survives and frequently causes clinically apparent disease. Astonishingly, little is known why S. aureus, which possesses a wide range of antioxidant enzymes (e.g. catalase, SOD), is particularly sensitive to control through NOX2. In this review, we will evaluate the discovery of CGD and our present knowledge of the role of NOX2 in S. aureus infection.
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Affiliation(s)
- Helene Buvelot
- Division of General Internal Medicine, Geneva University Hospitals, CH-1211 Geneva 4, Switzerland
| | - Klara M Posfay-Barbe
- Paediatric Infectious Diseases Unit, Department of Paediatrics, University Hospitals of Geneva, 1205 Geneva and Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland
| | - Patrick Linder
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland
| | - Jacques Schrenzel
- Divisions of Infectious Diseases and Laboratory Medicine, Geneva University Hospitals, CH-1211 Geneva 4, Switzerland
| | - Karl-Heinz Krause
- Divisions of Infectious Diseases and Laboratory Medicine, Geneva University Hospitals, CH-1211 Geneva 4, Switzerland.,Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland
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14
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Ryu JC, Kim MJ, Kwon Y, Oh JH, Yoon SS, Shin SJ, Yoon JH, Ryu JH. Neutrophil pyroptosis mediates pathology of P. aeruginosa lung infection in the absence of the NADPH oxidase NOX2. Mucosal Immunol 2017; 10:757-774. [PMID: 27554297 DOI: 10.1038/mi.2016.73] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 07/21/2016] [Indexed: 02/04/2023]
Abstract
Nod-like receptor family, CARD domain-containing 4 (NLRC4) inflammasome activation is required for efficient clearance of intracellular pathogens through caspsase-1-dependent pyroptosis in macrophages. Although neutrophils have a critical role in protection from Pseudomonas aeruginosa infection, the mechanisms regulating inflammasome-mediated pyroptosis in neutrophils and its physiological role are largely unknown. We sought to determine the specific mechanisms regulating neutrophil pyroptosis in P. aeruginosa strain PAO1 (PAO1) lung infection and to identify the pathological role of this process. Nox2-/- models with reduced neutrophil antibacterial activity exhibited increased neutrophil pyroptosis, which was mediated by flagellin, a pathogenic PAO1 component. We also demonstrate that PAO1-induced pyroptosis depended on NLRC4 and Toll-like receptor 5 (TLR5) in neutrophils generated from Nlrc4-/- or Tlr5-/- mice. Our study reveals previously unknown mechanisms and physiological role of neutrophil pyroptosis during P. aeruginosa lung infection. Furthermore, our findings regarding neutrophil pyroptosis in the context of neutrophil dysfunction may explain the causes of acute and/or chronic infectious diseases discovered in immune-compromised patients.
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Affiliation(s)
- J-C Ryu
- Research Center for Natural Human Defense System, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - M-J Kim
- Research Center for Natural Human Defense System, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Y Kwon
- Research Center for Natural Human Defense System, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - J-H Oh
- Research Center for Natural Human Defense System, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - S S Yoon
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.,Department of Microbiology and Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, Korea
| | - S J Shin
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.,Department of Microbiology and Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, Korea
| | - J-H Yoon
- Research Center for Natural Human Defense System, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.,Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea.,The Airway Mucus Institute, Yonsei University College of Medicine, Seoul, Korea
| | - J-H Ryu
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.,Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea
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15
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Mariathasan S, Tan MW. Antibody-Antibiotic Conjugates: A Novel Therapeutic Platform against Bacterial Infections. Trends Mol Med 2017; 23:135-149. [PMID: 28126271 DOI: 10.1016/j.molmed.2016.12.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/15/2016] [Accepted: 12/16/2016] [Indexed: 11/26/2022]
Abstract
Antibodies are potent components of the immune repertoire and have been successfully exploited to treat bacterial infections. Recently an antibody-antibiotic conjugate (AAC) that combines key attributes of an antibody and antibiotic has been shown to be efficacious against Staphylococcus aureus infection. An AAC has three components: an antibiotic payload to kill bacteria, an antibody to target delivery of the payload to bacteria, and a linker attaching the payload to the antibody. With increasing understanding of the biology and pathophysiology of S. aureus, this article highlights how this knowledge has led to the design principles of an efficacious AAC, and discusses how the AAC platform could be translationally applied to treat other perilous infectious diseases.
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Affiliation(s)
- Sanjeev Mariathasan
- Department of Late-Stage Oncology Biomarkers Development, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Man-Wah Tan
- Department of Infectious Diseases, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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16
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Abstract
Staphylococcus aureus is a leading cause of human infections worldwide. The pathogen produces numerous molecules that can interfere with recognition and binding by host innate immune cells, an initial step required for the ingestion and subsequent destruction of microbes by phagocytes. To better understand the interaction of this pathogen with human immune cells, we compared the association of S. aureus and S. epidermidis with leukocytes in human blood. We found that a significantly greater proportion of B cells associated with S. epidermidis relative to S. aureus. Complement components and complement receptors were important for the binding of B cells with S. epidermidis. Experiments using staphylococci inactivated by ultraviolet radiation and S. aureus isogenic deletion mutants indicated that S. aureus secretes molecules regulated by the SaeR/S two-component system that interfere with the ability of human B cells to bind this bacterium. We hypothesize that the relative inability of B cells to bind S. aureus contributes to the microbe’s success as a human pathogen.
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17
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Oyama T, Miyazaki M, Yoshimura M, Takata T, Ohjimi H, Jimi S. Biofilm-Forming Methicillin-Resistant Staphylococcus aureus Survive in Kupffer Cells and Exhibit High Virulence in Mice. Toxins (Basel) 2016; 8:toxins8070198. [PMID: 27376326 PMCID: PMC4963831 DOI: 10.3390/toxins8070198] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/15/2016] [Accepted: 06/24/2016] [Indexed: 11/26/2022] Open
Abstract
Although Staphylococcus aureus is part of the normal body flora, heavy usage of antibiotics has resulted in the emergence of methicillin-resistant strains (MRSA). MRSA can form biofilms and cause indwelling foreign body infections, bacteremia, soft tissue infections, endocarditis, and osteomyelitis. Using an in vitro assay, we screened 173 clinical blood isolates of MRSA and selected 20 high-biofilm formers (H-BF) and low-biofilm formers (L-BF). These were intravenously administered to mice and the general condition of mice, the distribution of bacteria, and biofilm in the liver, lung, spleen, and kidney were investigated. MRSA count was the highest in the liver, especially within Kupffer cells, which were positive for acid polysaccharides that are associated with intracellular biofilm. After 24 h, the general condition of the mice worsened significantly in the H-BF group. In the liver, bacterial deposition and aggregation and the biofilm-forming spot number were all significantly greater for H-BF group than for L-BF. CFU analysis revealed that bacteria in the H-BF group survived for long periods in the liver. These results indicate that the biofilm-forming ability of MRSA is a crucial factor for intracellular persistence, which could lead to chronic infections.
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Affiliation(s)
- Takuto Oyama
- Department of Plastic, Reconstructive and Aesthetic Surgery, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
| | - Motoyasu Miyazaki
- Department of Pharmacy, Fukuoka University Chikushi Hospital, Chikusino 818-8502, Japan.
| | - Michinobu Yoshimura
- Department of Medical Oncology, Hematology, and Infectious Diseases, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
| | - Tohru Takata
- Department of Medical Oncology, Hematology, and Infectious Diseases, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
| | - Hiroyuki Ohjimi
- Department of Plastic, Reconstructive and Aesthetic Surgery, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
| | - Shiro Jimi
- Central Laboratory for Pathology and Morphology, Department of Pathology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
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18
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19
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McGuinness WA, Kobayashi SD, DeLeo FR. Evasion of Neutrophil Killing by Staphylococcus aureus. Pathogens 2016; 5:E32. [PMID: 26999220 PMCID: PMC4810153 DOI: 10.3390/pathogens5010032] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 01/08/2023] Open
Abstract
Staphylococcus aureus causes many types of infections, ranging from self-resolving skin infections to severe or fatal pneumonia. Human innate immune cells, called polymorphonuclear leukocytes (PMNs or neutrophils), are essential for defense against S. aureus infections. Neutrophils are the most prominent cell type of the innate immune system and are capable of producing non-specific antimicrobial molecules that are effective at eliminating bacteria. Although significant progress has been made over the past few decades, our knowledge of S. aureus-host innate immune system interactions is incomplete. Most notably, S. aureus has the capacity to produce numerous molecules that are directed to protect the bacterium from neutrophils. Here we review in brief the role played by neutrophils in defense against S. aureus infection, and correspondingly, highlight selected S. aureus molecules that target key neutrophil functions.
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Affiliation(s)
- Will A McGuinness
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, MT 59840, USA.
| | - Scott D Kobayashi
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, MT 59840, USA.
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, MT 59840, USA.
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20
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Lehar SM, Pillow T, Xu M, Staben L, Kajihara KK, Vandlen R, DePalatis L, Raab H, Hazenbos WL, Morisaki JH, Kim J, Park S, Darwish M, Lee BC, Hernandez H, Loyet KM, Lupardus P, Fong R, Yan D, Chalouni C, Luis E, Khalfin Y, Plise E, Cheong J, Lyssikatos JP, Strandh M, Koefoed K, Andersen PS, Flygare JA, Wah Tan M, Brown EJ, Mariathasan S. Novel antibody-antibiotic conjugate eliminates intracellular S. aureus. Nature 2015. [PMID: 26536114 DOI: 10.1038/nature16057.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Staphylococcus aureus is considered to be an extracellular pathogen. However, survival of S. aureus within host cells may provide a reservoir relatively protected from antibiotics, thus enabling long-term colonization of the host and explaining clinical failures and relapses after antibiotic therapy. Here we confirm that intracellular reservoirs of S. aureus in mice comprise a virulent subset of bacteria that can establish infection even in the presence of vancomycin, and we introduce a novel therapeutic that effectively kills intracellular S. aureus. This antibody-antibiotic conjugate consists of an anti-S. aureus antibody conjugated to a highly efficacious antibiotic that is activated only after it is released in the proteolytic environment of the phagolysosome. The antibody-antibiotic conjugate is superior to vancomycin for treatment of bacteraemia and provides direct evidence that intracellular S. aureus represents an important component of invasive infections.
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Affiliation(s)
- Sophie M Lehar
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Thomas Pillow
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Min Xu
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Leanna Staben
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Kimberly K Kajihara
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Richard Vandlen
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Laura DePalatis
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Helga Raab
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Wouter L Hazenbos
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - J Hiroshi Morisaki
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Janice Kim
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Summer Park
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Martine Darwish
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Byoung-Chul Lee
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Hilda Hernandez
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Kelly M Loyet
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Patrick Lupardus
- Structural Biology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Rina Fong
- Structural Biology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Donghong Yan
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Cecile Chalouni
- Pathology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Elizabeth Luis
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Yana Khalfin
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Emile Plise
- Drug metabolism and Pharmacokinetics Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Jonathan Cheong
- Drug metabolism and Pharmacokinetics Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Joseph P Lyssikatos
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Magnus Strandh
- Symphogen A/S, Pederstrupvej 93, DK-2750 Ballerup, Denmark
| | - Klaus Koefoed
- Symphogen A/S, Pederstrupvej 93, DK-2750 Ballerup, Denmark
| | | | - John A Flygare
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Man Wah Tan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Eric J Brown
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Sanjeev Mariathasan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
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21
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Dastgheyb SS, Otto M. Staphylococcal adaptation to diverse physiologic niches: an overview of transcriptomic and phenotypic changes in different biological environments. Future Microbiol 2015; 10:1981-95. [PMID: 26584249 DOI: 10.2217/fmb.15.116] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Host niches can differ strongly regarding, for example, oxygen tension, pH or nutrient availability. Staphylococcus aureus and other staphylococci are common colonizers of human epithelia as well as important human pathogens. The phenotypes that they show in different host environments, and the corresponding bacterial transcriptomes and proteomes, are currently under intense investigation. In this review, we examine the available literature describing staphylococcal phenotypes, such as expression of virulence factors, gross morphologic characteristics and growth patterns, in various physiological environments. Going forward, these studies will help researchers and clinicians to form an enhanced and more detailed picture of the interactions existing between the host and staphylococci as some of its most frequent colonizers and invaders.
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Affiliation(s)
- Sana S Dastgheyb
- Pathogen Molecular Genetics Section, Laborartory of Bacteriology, National Institute of Allergy & Infectious Diseases, The National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laborartory of Bacteriology, National Institute of Allergy & Infectious Diseases, The National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
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22
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Lehar SM, Pillow T, Xu M, Staben L, Kajihara KK, Vandlen R, DePalatis L, Raab H, Hazenbos WL, Morisaki JH, Kim J, Park S, Darwish M, Lee BC, Hernandez H, Loyet KM, Lupardus P, Fong R, Yan D, Chalouni C, Luis E, Khalfin Y, Plise E, Cheong J, Lyssikatos JP, Strandh M, Koefoed K, Andersen PS, Flygare JA, Wah Tan M, Brown EJ, Mariathasan S. Novel antibody-antibiotic conjugate eliminates intracellular S. aureus. Nature 2015; 527:323-8. [PMID: 26536114 DOI: 10.1038/nature16057] [Citation(s) in RCA: 541] [Impact Index Per Article: 60.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 10/06/2015] [Indexed: 11/09/2022]
Abstract
Staphylococcus aureus is considered to be an extracellular pathogen. However, survival of S. aureus within host cells may provide a reservoir relatively protected from antibiotics, thus enabling long-term colonization of the host and explaining clinical failures and relapses after antibiotic therapy. Here we confirm that intracellular reservoirs of S. aureus in mice comprise a virulent subset of bacteria that can establish infection even in the presence of vancomycin, and we introduce a novel therapeutic that effectively kills intracellular S. aureus. This antibody-antibiotic conjugate consists of an anti-S. aureus antibody conjugated to a highly efficacious antibiotic that is activated only after it is released in the proteolytic environment of the phagolysosome. The antibody-antibiotic conjugate is superior to vancomycin for treatment of bacteraemia and provides direct evidence that intracellular S. aureus represents an important component of invasive infections.
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Affiliation(s)
- Sophie M Lehar
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Thomas Pillow
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Min Xu
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Leanna Staben
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Kimberly K Kajihara
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Richard Vandlen
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Laura DePalatis
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Helga Raab
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Wouter L Hazenbos
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - J Hiroshi Morisaki
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Janice Kim
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Summer Park
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Martine Darwish
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Byoung-Chul Lee
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Hilda Hernandez
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Kelly M Loyet
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Patrick Lupardus
- Structural Biology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Rina Fong
- Structural Biology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Donghong Yan
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Cecile Chalouni
- Pathology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Elizabeth Luis
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Yana Khalfin
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Emile Plise
- Drug metabolism and Pharmacokinetics Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Jonathan Cheong
- Drug metabolism and Pharmacokinetics Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Joseph P Lyssikatos
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Magnus Strandh
- Symphogen A/S, Pederstrupvej 93, DK-2750 Ballerup, Denmark
| | - Klaus Koefoed
- Symphogen A/S, Pederstrupvej 93, DK-2750 Ballerup, Denmark
| | | | - John A Flygare
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Man Wah Tan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Eric J Brown
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Sanjeev Mariathasan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
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23
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Abstract
PURPOSE OF REVIEW Methicillin-resistant strains of the important human pathogen Staphylococcus aureus pose a significant public health threat in the community, as they are easily transmitted, especially prone to cause invasive disease, and infect otherwise healthy individuals. The mechanistic basis for the ability of these organisms to evade the innate immune responses remains incompletely defined. RECENT FINDINGS The success of pathogens such as S. aureus rests, in part, on their capacity to overcome neutrophil-mediated host defense to establish infection and cause human disease. S. aureus has the potential to thwart effective neutrophil chemotaxis, and phagocytosis, and succeeds in evading killing by neutrophils. Furthermore, S. aureus surviving within neutrophils promotes neutrophil cytolysis, with release of host-derived molecules that promote local inflammation. Here, we provide a brief overview of our understanding of the mechanisms by which S. aureus - including methicillin-resistant S. aureus - avoids neutrophil-mediated host defense and causes disease. SUMMARY Understanding the molecular mechanisms by which S. aureus avoids neutrophil-mediated responses and initiates signaling cascades that culminate in neutrophil lysis will provide insights prerequisite to the development of novel targets for treating staphylococcal infections.
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Dey S, Bishayi B. Killing of Staphylococcus aureus in murine macrophages by chloroquine used alone and in combination with ciprofloxacin or azithromycin. J Inflamm Res 2015; 8:29-47. [PMID: 25653549 PMCID: PMC4309780 DOI: 10.2147/jir.s76045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This study aimed to determine any alteration in the killing of Staphylococcus aureus in murine peritoneal macrophages when chloroquine (CQ) is used alone compared with when it is used in combination with ciprofloxacin (CIP) or azithromycin (AZM). The study also aimed to find out the implication of reactive oxygen species (ROS) production and cytokine release in the intracellular killing of S. aureus in macrophages. We present here data obtained with a model of S. aureus-infected mouse peritoneal macrophages in which the intracellular growth of the bacteria and the influence of antibiotics was monitored for 30, 60, and 90 minutes in the presence or absence of CQ along with the production of ROS and alteration in levels of antioxidant enzymes and cytokines. It was observed that S. aureus-triggered cytokine response was regulated when macrophages were co-cultured with CQ and AZM as compared with CQ stimulation only. It can be suggested that action of AZM in mediating bacterial killing is enhanced by the presence of CQ, indicating enhanced uptake of AZM during early infection that may be essential for bacteria killing by AZM. Reduction of oxidative stress burden on the S. aureus-infected macrophages may pave the way for better killing of internalized S. aureus by CQ plus ciprofloxacin (CIP) or CQ plus AZM. Based on these observations, one may speculate that in an inflammatory milieu, CQ loaded with AZM elicits a stronger proinflammatory response by increasing the intracellular uptake of AZM or CIP, thus enabling the immune system to mount a more robust and prolonged response against intracellular pathogens.
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Affiliation(s)
- Somrita Dey
- Department of Physiology, Immunology laboratory, University of Calcutta, University Colleges of Science and Technology, Calcutta, India
| | - Biswadev Bishayi
- Department of Physiology, Immunology laboratory, University of Calcutta, University Colleges of Science and Technology, Calcutta, India
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25
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I n Vitro Anti-inflammatory and Immunomodulatory Effects of Ciprofloxacin or Azithromycin in Staphylococcus aureus-Stimulated Murine Macrophages are Beneficial in the Presence of Cytochalasin D. Inflammation 2014; 38:1050-69. [DOI: 10.1007/s10753-014-0070-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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26
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The neutrophil NLRC4 inflammasome selectively promotes IL-1β maturation without pyroptosis during acute Salmonella challenge. Cell Rep 2014; 8:570-82. [PMID: 25043180 DOI: 10.1016/j.celrep.2014.06.028] [Citation(s) in RCA: 303] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 06/01/2014] [Accepted: 06/18/2014] [Indexed: 12/19/2022] Open
Abstract
The macrophage NLRC4 inflammasome drives potent innate immune responses against Salmonella by eliciting caspase-1-dependent proinflammatory cytokine production (e.g., interleukin-1β [IL-1β]) and pyroptotic cell death. However, the potential contribution of other cell types to inflammasome-mediated host defense against Salmonella was unclear. Here, we demonstrate that neutrophils, typically viewed as cellular targets of IL-1β, themselves activate the NLRC4 inflammasome during acute Salmonella infection and are a major cell compartment for IL-1β production during acute peritoneal challenge in vivo. Importantly, unlike macrophages, neutrophils do not undergo pyroptosis upon NLRC4 inflammasome activation. The resistance of neutrophils to pyroptotic death is unique among inflammasome-signaling cells so far described and allows neutrophils to sustain IL-1β production at a site of infection without compromising the crucial inflammasome-independent antimicrobial effector functions that would be lost if neutrophils rapidly lysed upon caspase-1 activation. Inflammasome pathway modification in neutrophils thus maximizes host proinflammatory and antimicrobial responses during pathogen challenge.
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27
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Bishayi B, Bandyopadhyay D, Majhi A, Adhikary R. Possible Role of Toll-like Receptor-2 in the Intracellular Survival ofStaphylococcus aureusin Murine Peritoneal Macrophages: Involvement of Cytokines and Anti-Oxidant Enzymes. Scand J Immunol 2014; 80:127-43. [PMID: 24846691 DOI: 10.1111/sji.12195] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 05/13/2014] [Indexed: 11/29/2022]
Affiliation(s)
- B. Bishayi
- Department of Physiology, Immunology Laboratory; University of Calcutta; University Colleges of Science and Technology; Calcutta West Bengal India
| | - D. Bandyopadhyay
- Department of Physiology, Oxidative Stress and Free Radical Biology Laboratory; University of Calcutta; University Colleges of Science and Technology; Calcutta West Bengal India
| | - A. Majhi
- Department of Physiology, Immunology Laboratory; University of Calcutta; University Colleges of Science and Technology; Calcutta West Bengal India
| | - R. Adhikary
- Department of Physiology, Immunology Laboratory; University of Calcutta; University Colleges of Science and Technology; Calcutta West Bengal India
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28
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Intravitreal injection of the chimeric phage endolysin Ply187 protects mice from Staphylococcus aureus endophthalmitis. Antimicrob Agents Chemother 2014; 58:4621-9. [PMID: 24890598 DOI: 10.1128/aac.00126-14] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The treatment of endophthalmitis is becoming very challenging due to the emergence of multidrug-resistant bacteria. Hence, the development of novel therapeutic alternatives for ocular use is essential. Here, we evaluated the therapeutic potential of Ply187AN-KSH3b, a chimeric phage endolysin derived from the Ply187 prophage, in a mouse model of Staphylococcus aureus endophthalmitis. Our data showed that the chimeric Ply187 endolysin exhibited strong antimicrobial activity against both methicillin-sensitive S. aureus and methicillin-resistant S. aureus (MRSA) strains, as evidenced by MIC determinations, reductions in turbidity, and disruption of biofilms. Moreover, exposure of S. aureus to Ply187 for up to 10 generations did not lead to resistance development. The intravitreal injection of chimeric Ply187 (at 6 or 12 h postinfection) significantly improved the outcome of endophthalmitis, preserved retinal structural integrity, and maintained visual function as assessed by electroretinogram analysis. Furthermore, phage lysin treatment significantly reduced the bacterial burden and the levels of inflammatory cytokines and neutrophil infiltration in the eyes. These results indicate that the intravitreal administration of a phage lytic enzyme attenuates the development of bacterial endophthalmitis in mice. To the best of our knowledge, this is the first study demonstrating the therapeutic use of phage-based antimicrobials in ocular infections.
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Greenlee-Wacker MC, Rigby KM, Kobayashi SD, Porter AR, DeLeo FR, Nauseef WM. Phagocytosis of Staphylococcus aureus by human neutrophils prevents macrophage efferocytosis and induces programmed necrosis. THE JOURNAL OF IMMUNOLOGY 2014; 192:4709-17. [PMID: 24729616 DOI: 10.4049/jimmunol.1302692] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) pose a significant threat to human health. Polymorphonuclear leukocytes (PMN) are the first responders during staphylococcal infection, but 15-50% of the initial ingested inoculum survives within the PMN phagosome and likely contributes directly or indirectly to disease pathogenesis. We hypothesize that surviving intracellular CA-MRSA undermine effective phagocyte-mediated defense by causing a decrease in macrophage uptake of PMN containing viable S. aureus and by promoting PMN lysis. In support of this hypothesis, PMN harboring viable CA-MRSA strain USA300 (PMN-SA) upregulated the "don't eat me" signal CD47, remained bound to the surface, and were inefficiently ingested by macrophages. In addition, coculture with PMN-SA altered the macrophage phenotype. Compared to macrophages fed USA300 alone, macrophages challenged with PMN-SA produced more IL-8 and less IL-1 receptor antagonist, TNF-α, activated caspase-1, and IL-1β. Although they exhibited some features of apoptosis within 3 h following ingestion of S. aureus, including phosphatidylserine exposure and mitochondrial membrane depolarization, PMN-SA had sustained levels of proliferating cell nuclear Ag expression, absence of caspase activation, and underwent lysis within 6 h following phagocytosis. PMN lysis was dependent on receptor-interacting protein 1, suggesting that PMN-SA underwent programmed necrosis or necroptosis. These data are the first demonstration, to our knowledge, that bacteria can promote sustained expression of proliferating cell nuclear Ag and that human PMN undergo necroptosis. Together, these findings demonstrate that S. aureus surviving within PMN undermine the innate immune response and may provide insight into the pathogenesis of S. aureus disease.
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Affiliation(s)
- Mallary C Greenlee-Wacker
- Inflammation Program, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Veterans Administration Medical Center, Iowa City, IA 52240
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Lu T, Porter AR, Kennedy AD, Kobayashi SD, DeLeo FR. Phagocytosis and killing of Staphylococcus aureus by human neutrophils. J Innate Immun 2014; 6:639-49. [PMID: 24713863 DOI: 10.1159/000360478] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 02/10/2014] [Indexed: 11/19/2022] Open
Abstract
Neutrophils are essential for host defense against Staphylococcus aureus infections. Although significant progress has been made, our understanding of neutrophil interactions with S. aureus remains incomplete. To provide a more comprehensive view of this process, we investigated phagocytosis and killing of S. aureus by human neutrophils using varied assay conditions in vitro. A greater percentage of bacteria were internalized by adherent neutrophils compared to those in suspension, and, unexpectedly, uptake of S. aureus by adherent neutrophils occurred efficiently in the absence of opsonins. An antibody specific for S. aureus promoted uptake of unopsonized bacteria in suspension, but had little or no capacity to enhance phagocytosis of S. aureus opsonized with normal human serum or by adherent neutrophils. Collectively, these results indicate that assay conditions can have a significant influence on the phagocytosis and killing of S. aureus by neutrophils. More importantly, the results suggest a vaccine approach directed to enhance opsonophagocytosis alone is not sufficient to promote increased killing of S. aureus by human neutrophils. With the emergence and reemergence of antibiotic-resistant microorganisms, establishing parameters that are optimal for studying neutrophil-S. aureus interactions will pave the way towards developing immune-directed strategies for anti-staphylococcal therapies.
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Affiliation(s)
- Thea Lu
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Mont., USA
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McVicker G, Prajsnar TK, Williams A, Wagner NL, Boots M, Renshaw SA, Foster SJ. Clonal expansion during Staphylococcus aureus infection dynamics reveals the effect of antibiotic intervention. PLoS Pathog 2014; 10:e1003959. [PMID: 24586163 PMCID: PMC3937288 DOI: 10.1371/journal.ppat.1003959] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 01/14/2014] [Indexed: 11/19/2022] Open
Abstract
To slow the inexorable rise of antibiotic resistance we must understand how drugs impact on pathogenesis and influence the selection of resistant clones. Staphylococcus aureus is an important human pathogen with populations of antibiotic-resistant bacteria in hospitals and the community. Host phagocytes play a crucial role in controlling S. aureus infection, which can lead to a population "bottleneck" whereby clonal expansion of a small fraction of the initial inoculum founds a systemic infection. Such population dynamics may have important consequences on the effect of antibiotic intervention. Low doses of antibiotics have been shown to affect in vitro growth and the generation of resistant mutants over the long term, however whether this has any in vivo relevance is unknown. In this work, the population dynamics of S. aureus pathogenesis were studied in vivo using antibiotic-resistant strains constructed in an isogenic background, coupled with systemic models of infection in both the mouse and zebrafish embryo. Murine experiments revealed unexpected and complex bacterial population kinetics arising from clonal expansion during infection in particular organs. We subsequently elucidated the effect of antibiotic intervention within the host using mixed inocula of resistant and sensitive bacteria. Sub-curative tetracycline doses support the preferential expansion of resistant microorganisms, importantly unrelated to effects on growth rate or de novo resistance acquisition. This novel phenomenon is generic, occurring with methicillin-resistant S. aureus (MRSA) in the presence of β-lactams and with the unrelated human pathogen Pseudomonas aeruginosa. The selection of resistant clones at low antibiotic levels can result in a rapid increase in their prevalence under conditions that would previously not be thought to favor them. Our results have key implications for the design of effective treatment regimes to limit the spread of antimicrobial resistance, where inappropriate usage leading to resistance may reduce the efficacy of life-saving drugs.
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Affiliation(s)
- Gareth McVicker
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, United Kingdom
| | - Tomasz K. Prajsnar
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, United Kingdom
- MRC Centre for Developmental and Biomedical Genetics, University of Sheffield, Western Bank, Sheffield, United Kingdom
| | - Alexander Williams
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, United Kingdom
- MRC Centre for Developmental and Biomedical Genetics, University of Sheffield, Western Bank, Sheffield, United Kingdom
| | - Nelly L. Wagner
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, United Kingdom
- Department of Infection and Immunity, University of Sheffield, Western Bank, Sheffield, United Kingdom
| | - Michael Boots
- Biosciences, University of Exeter, Cornwall Campus, Penryn, United Kingdom
| | - Stephen A. Renshaw
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, United Kingdom
- MRC Centre for Developmental and Biomedical Genetics, University of Sheffield, Western Bank, Sheffield, United Kingdom
- Department of Infection and Immunity, University of Sheffield, Western Bank, Sheffield, United Kingdom
| | - Simon J. Foster
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, United Kingdom
- * E-mail:
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Abstract
Staphylococcus epidermidis is the most frequently encountered member of the coagulase-negative staphylococci on human epithelial surfaces. It has emerged as an important nosocomial pathogen, especially in infections of indwelling medical devices. The mechanisms that S. epidermidis uses to survive during infection are in general of a passive nature, reflecting their possible origin in the commensal life of this bacterium. Most importantly, S. epidermidis excels in forming biofilms, sticky agglomerations that inhibit major host defense mechanisms. Furthermore, S. epidermidis produces a series of protective surface polymers and exoenzymes. Moreover, S. epidermidis has the capacity to secrete strongly cytolytic members of the phenol-soluble modulin (PSM) family, but PSMs in S. epidermidis overall appear to participate primarily in biofilm development. Finally, there is evidence for a virulence gene reservoir function of S. epidermidis, as it appears to have transferred important immune evasion and antibiotic resistance factors to Staphylococcus aureus. Conversely, S. epidermidis also has a beneficial role in balancing the microflora on human epithelial surfaces by controlling outgrowth of harmful bacteria such as in particular S. aureus. Recent research yielded detailed insight into key S. epidermidis virulence determinants and their regulation, in particular as far as biofilm formation is concerned, but we still have a serious lack of understanding of the in vivo relevance of many pathogenesis mechanisms and the factors that govern the commensal life of S. epidermidis.
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Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
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Abstract
Staphylococcus aureus is a prominent cause of human infections worldwide and is notorious for its ability to acquire resistance to antibiotics. Methicillin-resistant S. aureus (MRSA), in particular, is endemic in hospitals and is the most frequent cause of community-associated bacterial infections in the United States. Inasmuch as treatment options for severe MRSA infections are limited, there is need for a vaccine that protects against such infections. However, recent efforts to generate a staphylococcal vaccine have met with little success in human clinical trials. These failures are somewhat puzzling, since the vaccine antigens tested promote opsonophagocytosis in vitro and confer protection in animal infection models. One possibility is that the pathogen inhibits (and/or fails to elicit) the development of protective immunity in humans. Indeed, S. aureus produces numerous molecules that can potentially promote immune evasion, including protein A (SpA), an immunoglobulin (Ig)-binding protein present on the bacterial surface and freely secreted into the extracellular environment. SpA binds the Fc region of antibody and the Fab regions of the B-cell receptor, processes that are known to block opsonophagocytosis and cause B-cell death in vitro. In a recent study, Falugi et al. [F. Falugi, H. K. Kim, D. M. Missiakas, and O. Schneewind, mBio 4(5):e00575-13, 2013] showed that vaccination with spa mutant S. aureus strains lacking antibody Fc- and/or Fab-binding capacity protects against subsequent challenge with the USA300 epidemic strain. The findings provide strong support for the idea that SpA promotes S. aureus immune evasion in vivo and form the foundation for a new approach in our efforts to develop a vaccine that prevents severe S. aureus infections.
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Hamza T, Dietz M, Pham D, Clovis N, Danley S, Li B, Li B. Intra-cellular Staphylococcus aureus alone causes infection in vivo. Eur Cell Mater 2013; 25:341-50; discussion 350. [PMID: 23832687 PMCID: PMC3830899 DOI: 10.22203/ecm.v025a24] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Chronic and recurrent bone infections occur frequently but have not been explained. Staphylococcus aureus (S. aureus) is often found among chronic and recurrent infections and may be responsible for such infections. One possible reason is that S. aureus can internalize and survive within host cells and by doing so, S. aureus can evade both host defense mechanisms and most conventional antibiotic treatments. In this study, we hypothesized that intra-cellular S. aureus could induce infections in vivo. Osteoblasts were infected with S. aureus and, after eliminating extra-cellular S. aureus, inoculated into an open fracture rat model. Bacterial cultures and radiographic observations at post-operative day 21 confirmed local bone infections in animals inoculated with intra-cellular S. aureus within osteoblasts alone. We present direct in vivo evidence that intra-cellular S. aureus could be sufficient to induce bone infection in animals; we found that intra-cellular S. aureus inoculation of as low as 102 colony forming units could induce severe bone infections. Our data may suggest that intra-cellular S. aureus can "hide" in host cells during symptom-free periods and, under certain conditions, they may escape and lead to infection recurrence. Intra-cellular S. aureus therefore could play an important role in the pathogenesis of S. aureus infections, especially those chronic and recurrent infections in which disease episodes may be separated by weeks, months, or even years.
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Affiliation(s)
- Therwa Hamza
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506,Department of Basic Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV 26506
| | - Matthew Dietz
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506
| | - Danh Pham
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506
| | - Nina Clovis
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506
| | - Suzanne Danley
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506
| | - Bingyun Li
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506,Department of Basic Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV 26506,WVNano Initiative, Morgantown, WV 26506,Mary Babb Randolph Cancer Center, Morgantown, WV 26506,Correspondence to: Bingyun Li, PhD, Associate Professor, Director, Nanomedicine Laboratory, Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506-9196, USA, Tel: 1-304-293-1075, Fax: 1-304-293-7070,
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Lu T, Kobayashi SD, Quinn MT, Deleo FR. A NET Outcome. Front Immunol 2012; 3:365. [PMID: 23227026 PMCID: PMC3514450 DOI: 10.3389/fimmu.2012.00365] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 11/16/2012] [Indexed: 01/11/2023] Open
Abstract
Neutrophils constitute a critical part of innate immunity and are well known for their ability to phagocytose and kill invading microorganisms. The microbicidal processes employed by neutrophils are highly effective at killing most ingested bacteria and fungi. However, an alternative non-phagocytic antimicrobial mechanism of neutrophils has been proposed whereby microorganisms are eliminated by neutrophil extracellular traps (NETs). NETs are comprised of DNA, histones, and antimicrobial proteins extruded by neutrophils during NETosis, a cell death pathway reported to be distinct from apoptosis, phagocytosis-induced cell death, and necrosis. Although multiple laboratories have reported NETs using various stimuli in vitro, the molecular mechanisms involved in this process have yet to be definitively elucidated, and many questions regarding the formation and putative role or function of NETs in innate host defense remain unanswered. It is with these questions in mind that we provide some reflection and perspective on NETs and NETosis.
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Affiliation(s)
- Thea Lu
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health Hamilton, MT, USA
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Prajsnar TK, Hamilton R, Garcia-Lara J, McVicker G, Williams A, Boots M, Foster SJ, Renshaw SA. A privileged intraphagocyte niche is responsible for disseminated infection of Staphylococcus aureus in a zebrafish model. Cell Microbiol 2012; 14:1600-19. [PMID: 22694745 PMCID: PMC3470706 DOI: 10.1111/j.1462-5822.2012.01826.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 01/30/2023]
Abstract
The innate immune system is the primary defence against the versatile pathogen, Staphylococcus aureus. How this organism is able to avoid immune killing and cause infections is poorly understood. Using an established larval zebrafish infection model, we have shown that overwhelming infection is due to subversion of phagocytes by staphylococci, allowing bacteria to evade killing and found foci of disease. Larval zebrafish coinfected with two S. aureus strains carrying different fluorescent reporter gene fusions (but otherwise isogenic) had bacterial lesions, at the time of host death, containing predominantly one strain. Quantitative data using two marked strains revealed that the strain ratios, during overwhelming infection, were often skewed towards the extremes, with one strain predominating. Infection with passaged bacterial clones revealed the phenomenon not to bedue to adventitious mutations acquired by the pathogen. After infection of the host, all bacteria are internalized by phagocytes and the skewing of population ratios is absolutely dependent on the presence of phagocytes. Mathematical modelling of pathogen population dynamics revealed the data patterns are consistent with the hypothesis that a small number of infected phagocytes serve as an intracellular reservoir for S. aureus, which upon release leads to disseminated infection. Strategies to specifically alter neutrophil/macrophage numbers were used to map the potential subpopulation of phagocytes acting as a pathogen reservoir, revealing neutrophils as the likely ‘niche’. Subsequently in a murine sepsis model, S. aureus abscesses in kidneys were also found to be predominantly clonal, therefore likely founded by an individual cell, suggesting a potential mechanism analogous to the zebrafish model with few protected niches. These findings add credence to the argument that S. aureus control regimes should recognize both the intracellular as well as extracellular facets of the S. aureus life cycle.
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Affiliation(s)
- Tomasz K Prajsnar
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, UK
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Kim HK, Thammavongsa V, Schneewind O, Missiakas D. Recurrent infections and immune evasion strategies of Staphylococcus aureus. Curr Opin Microbiol 2012; 15:92-9. [PMID: 22088393 PMCID: PMC3538788 DOI: 10.1016/j.mib.2011.10.012] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 10/21/2011] [Accepted: 10/21/2011] [Indexed: 12/15/2022]
Abstract
Staphylococcus aureus causes purulent skin and soft tissue infections (SSTIs) that frequently reoccur. Staphylococal SSTIs can lead to invasive disease and sepsis, which are among the most significant causes of infectious disease mortality in both developed and developing countries. Human or animal infections with S. aureus do not elicit protective immunity against staphylococcal diseases. Here we review what is known about the immune evasive strategies of S. aureus that enable the pathogen's escape from protective immune responses. Three secreted products are discussed in detail, staphylococcal protein A (SpA), staphylococcal binder of immunoglobulin (Sbi) and adenosine synthase A (AdsA). By forming a complex with V(H)3-type IgM on the surface of B cells, SpA functions as a superantigen to modulate antibody responses to staphylococcal infection. SpA also captures pathogen-specific antibodies by binding their Fcγ portion. The latter activity of SpA is shared by Sbi, which also associates with complement factors 3d and factor H to promote the depletion of complement. AdsA synthesizes the immune signaling molecule adenosine, thereby dampening innate and adaptive immune responses during infection. We discuss strategies how the three secreted products of staphylococci may be exploited for the development of vaccines and therapeutics.
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Affiliation(s)
- Hwan Keun Kim
- Department of Microbiology, University of Chicago, 920 East 58 Street, Chicago, IL 60637
| | - Vilasack Thammavongsa
- Department of Microbiology, University of Chicago, 920 East 58 Street, Chicago, IL 60637
| | - Olaf Schneewind
- Department of Microbiology, University of Chicago, 920 East 58 Street, Chicago, IL 60637
| | - Dominique Missiakas
- Department of Microbiology, University of Chicago, 920 East 58 Street, Chicago, IL 60637
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38
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Cheng AG, DeDent AC, Schneewind O, Missiakas D. A play in four acts: Staphylococcus aureus abscess formation. Trends Microbiol 2011; 19:225-32. [PMID: 21353779 DOI: 10.1016/j.tim.2011.01.007] [Citation(s) in RCA: 193] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Revised: 01/05/2011] [Accepted: 01/25/2011] [Indexed: 01/16/2023]
Abstract
Staphylococcus aureus is an important human pathogen that causes skin and soft tissue abscesses. Abscess formation is not unique to staphylococcal infection and purulent discharge has been widely considered a physiological feature of healing and tissue repair. Here we present a different view, whereby S. aureus deploys specific virulence factors to promote abscess lesions that are distinctive for this pathogen. In support of this model, only live S. aureus is able to form abscesses, requiring genes that act at one or more of four discrete stages during the development of these infectious lesions. Protein A and coagulases are distinctive virulence attributes for S. aureus, and humoral immune responses specific for these polypeptides provide protection against abscess formation in animal models of staphylococcal disease.
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Affiliation(s)
- Alice G Cheng
- Department of Microbiology, University of Chicago, Chicago, Illinois 60637, USA
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Thwaites GE, Gant V. Are bloodstream leukocytes Trojan Horses for the metastasis of Staphylococcus aureus? Nat Rev Microbiol 2011; 9:215-22. [PMID: 21297670 DOI: 10.1038/nrmicro2508] [Citation(s) in RCA: 214] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Staphylococcus aureus bacteraemia remains very difficult to treat, and a large proportion of cases result in potentially lethal metastatic infection. Unpredictable and persistent bacteraemia in the face of highly active, usually bactericidal antibiotics is the strongest predictor of death or disseminated disease. Although S. aureus has conventionally been considered an extracellular pathogen, much evidence demonstrates that it can survive intracellularly. In this Opinion article, we propose that phagocytes, and specifically neutrophils, represent a privileged site for S. aureus in the bloodstream, offering protection from most antibiotics and providing a mechanism by which the bacterium can travel to and infect distant sites. Furthermore, we suggest how this can be experimentally confirmed and how it may prompt a change in the current paradigm of S. aureus bacteraemia and identify better treatment options for improved clinical outcomes.
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Affiliation(s)
- Guy E Thwaites
- Centre for Molecular Microbiology and Infection, Imperial College, Exhibition Road, South Kensington, London SW7 2AZ, UK.
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40
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Edwards AM, Massey RC. How does Staphylococcus aureus escape the bloodstream? Trends Microbiol 2011; 19:184-90. [PMID: 21227700 DOI: 10.1016/j.tim.2010.12.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 12/06/2010] [Accepted: 12/13/2010] [Indexed: 12/11/2022]
Abstract
Staphylococcus aureus is a major cause of bacteraemia, which frequently leads to infective endocarditis, osteomyelitis, septic arthritis and metastatic abscess formation. The development of these secondary infections is due to bacterial dissemination from the blood into surrounding tissues and is associated with significantly increased morbidity and mortality. Despite the importance of S. aureus extravasation in disease progression, there is relatively little understanding of the molecular mechanisms by which this pathogen crosses the endothelial barrier and establishes new sites of infection. Recent work has identified a number of putative routes by which S. aureus can escape the bloodstream. In this article we review these new developments and set them in the context of strategies used by other established pathogens to traverse cellular barriers.
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Affiliation(s)
- Andrew M Edwards
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
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Cheung GYC, Rigby K, Wang R, Queck SY, Braughton KR, Whitney AR, Teintze M, DeLeo FR, Otto M. Staphylococcus epidermidis strategies to avoid killing by human neutrophils. PLoS Pathog 2010; 6:e1001133. [PMID: 20949069 PMCID: PMC2951371 DOI: 10.1371/journal.ppat.1001133] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 09/06/2010] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus epidermidis is a leading nosocomial pathogen. In contrast to its more aggressive relative S. aureus, it causes chronic rather than acute infections. In highly virulent S. aureus, phenol-soluble modulins (PSMs) contribute significantly to immune evasion and aggressive virulence by their strong ability to lyse human neutrophils. Members of the PSM family are also produced by S. epidermidis, but their role in immune evasion is not known. Notably, strong cytolytic capacity of S. epidermidis PSMs would be at odds with the notion that S. epidermidis is a less aggressive pathogen than S. aureus, prompting us to examine the biological activities of S. epidermidis PSMs. Surprisingly, we found that S. epidermidis has the capacity to produce PSMδ, a potent leukocyte toxin, representing the first potent cytolysin to be identified in that pathogen. However, production of strongly cytolytic PSMs was low in S. epidermidis, explaining its low cytolytic potency. Interestingly, the different approaches of S. epidermidis and S. aureus to causing human disease are thus reflected by the adaptation of biological activities within one family of virulence determinants, the PSMs. Nevertheless, S. epidermidis has the capacity to evade neutrophil killing, a phenomenon we found is partly mediated by resistance mechanisms to antimicrobial peptides (AMPs), including the protease SepA, which degrades AMPs, and the AMP sensor/resistance regulator, Aps (GraRS). These findings establish a significant function of SepA and Aps in S. epidermidis immune evasion and explain in part why S. epidermidis may evade elimination by innate host defense despite the lack of cytolytic toxin expression. Our study shows that the strategy of S. epidermidis to evade elimination by human neutrophils is characterized by a passive defense approach and provides molecular evidence to support the notion that S. epidermidis is a less aggressive pathogen than S. aureus.
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Affiliation(s)
- Gordon Y. C. Cheung
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kevin Rigby
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana, United States of America
| | - Rong Wang
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana, United States of America
| | - Shu Y. Queck
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana, United States of America
| | - Kevin R. Braughton
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana, United States of America
| | - Adeline R. Whitney
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana, United States of America
| | - Martin Teintze
- Chemistry & Biochemistry Department, Montana State University, Bozeman, Montana, United States of America
| | - Frank R. DeLeo
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana, United States of America
| | - Michael Otto
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Harries MJ, Paus R. The pathogenesis of primary cicatricial alopecias. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2152-62. [PMID: 20889564 DOI: 10.2353/ajpath.2010.100454] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cicatricial (scarring) alopecia results from irreversible damage to epithelial stem cells located in the bulge region of the hair follicle, generally as a result of inflammatory mechanisms (eg, in the context of autoimmune disease). In primary cicactricial alopecia (PCA), the hair follicle itself is the key target of autoaggressive immunity. This group of permanent hair loss disorders can be classified into distinct subgroups, characterized by the predominant peri-follicular inflammatory cell type. In none of these PCA forms do we know exactly why hair follicles begin to attract such an infiltrate. Thus, it is not surprising that halting or even reversing this inflammation in PCA is often extremely difficult. However, increasing evidence suggests that healthy hair follicle epithelial stem cells enjoy relative protection from inflammatory assault by being located in an immunologically "privileged" niche. Because this protection may collapse in PCA, one key challenge in PCA research is to identify the specific signaling pathways that endanger, or restore, the relative immunoprotection of these stem cells. After a summary of pathobiological principles that underlie the development and clinical phenotype of PCA, we close by defining key open questions that need to be answered if more effective treatment modalities for this therapeutically very frustrating, but biologically fascinating, group of diseases are to be developed.
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43
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Pang YY, Schwartz J, Thoendel M, Ackermann LW, Horswill AR, Nauseef WM. agr-Dependent interactions of Staphylococcus aureus USA300 with human polymorphonuclear neutrophils. J Innate Immun 2010; 2:546-59. [PMID: 20829608 DOI: 10.1159/000319855] [Citation(s) in RCA: 175] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 08/03/2010] [Indexed: 01/25/2023] Open
Abstract
The emergence of serious infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has fueled interest in the contributions of specific staphylococcal virulence factors to clinical disease. To assess the contributions of agr-dependent factors to the fate of organisms in polymorphonuclear neutrophils (PMN), we examined the consequences for organism and host cells of feeding PMN with wild-type CA-MRSA (LAC) or CA-MRSA (LAC agr KO) at different multiplicities of infection (MOIs). Phagocytosed organisms rapidly increased the transcription of RNAIII in a time- and MOI-dependent fashion; extracellular USA300 (LAC) did not increase RNAIII expression despite having the capacity to respond to autoinducing peptide-enriched culture medium. HOCl-mediated damage and intracellular survival were the same in the wild-type and USA300 (LAC agr KO). PMN lysis by ingested USA300 (LAC) was time- and MOI-dependent and, at MOIs >1, required α-hemolysin (hla) as USA300 (LAC agr KO) and USA300 (LAC hla KO) promoted PMN lysis only at high MOIs. Taken together, these data demonstrate activation of the agr operon in human PMN with the subsequent production of α-hemolysin and PMN lysis. The extent to which these events in the phagosomes of human PMN contribute to the increased morbidity and mortality of infections with USA300 (LAC) merits further study.
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Affiliation(s)
- Yun Yun Pang
- Department of Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa 52241, USA
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Kobayashi SD, Braughton KR, Palazzolo-Ballance AM, Kennedy AD, Sampaio E, Kristosturyan E, Whitney AR, Sturdevant DE, Dorward DW, Holland SM, Kreiswirth BN, Musser JM, DeLeo FR. Rapid neutrophil destruction following phagocytosis of Staphylococcus aureus. J Innate Immun 2010; 2:560-75. [PMID: 20587998 DOI: 10.1159/000317134] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 04/13/2010] [Indexed: 01/01/2023] Open
Abstract
Mechanisms underlying the enhanced virulence phenotype of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are incompletely defined, but presumably include evasion of killing by human polymorphonuclear leukocytes (PMNs or neutrophils). To better understand this phenomenon, we investigated the basis of rapid PMN lysis after phagocytosis of USA300, a prominent CA-MRSA strain. Survival of USA300 clinical isolates after phagocytosis ultimately resulted in neutrophil lysis. PMNs containing ingested USA300 underwent morphological changes consistent with apoptosis, but lysed rapidly thereafter (within 6 h), whereas cells undergoing FAS-mediated apoptosis or phagocytosis-induced cell death remained intact. Phagosome membranes remained intact until the point of PMN destruction, suggesting lysis was not caused by escape of S. aureus from phagosomes or the cytolytic action of pore-forming toxins. Microarray analysis of the PMN transcriptome after phagocytosis of representative community-associated S. aureus and healthcare-associated MRSA strains revealed changes unique to community-associated S. aureus strains, such as upregulation of transcripts involved in regulation of calcium homeostasis. Collectively, the data suggest that neutrophil destruction after phagocytosis of USA300 is in part a form of programmed necrosis rather than direct lysis by S. aureus pore-forming toxins. We propose that the ability of CA-MRSA strains to induce programmed necrosis of neutrophils is a component of enhanced virulence.
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Affiliation(s)
- Scott D Kobayashi
- Laboratory of Human Bacterial Pathogenesis, Research Technologies Section, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA
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45
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Johnson JE, Cluff LE, Goshi K. STUDIES ON THE PATHOGENESIS OF STAPHYLOCOCCAL INFECTION : I. THE EFFECT OF REPEATED SKIN INFECTIONS. ACTA ACUST UNITED AC 2010; 113:235-48. [PMID: 19867186 PMCID: PMC2137353 DOI: 10.1084/jem.113.2.235] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The influence of repeated staphylococcal infection of rabbit skin upon the characteristics of the experimentally induced lesion was studied. It was found that the repeated infection was associated with the development of delayed hypersensitivity unaccompanied by the appearance of demonstrable serum antibody. The delayed hypersensitivity to the staphylococcus resulted in an increased infectivity of the organism in skin of the sensitized animal, characterized by intensification of the lesions seen with large bacterial inocula and the induction of abscesses with inocula incapable of producing any lesion in normal rabbit skin. Similarly, the severity of experimentally induced pyoarthrosis was greater in sensitized than in normal rabbits. Induction of delayed hypersensitivity by vaccination of rabbits with washed heat-killed staphylococci resulted in the same increased severity of the infection and an increase in infectivity of the microorganism. In contrast to the observations of cutaneous and joint infection, the sensitized animals appeared to be less susceptible to severe infection of the anterior chamber of the eye. The role of immunity and hypersensitivity in staphylococcal infection is discussed and the possibility that non-specific inflammation may influence staphylococcal infection in the same way as specific hypersensitivity is indicated. Studies to further elucidate this are presented in the following pages.
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Affiliation(s)
- J E Johnson
- Division of Allergy and Infectious Disease, Department of Medicine, The Johns Hopkins University School of Medicine and Hospital, Baltimore
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Goshi K, Cluff LE, Johnson JE. STUDIES ON THE PATHOGENESIS OF STAPHYLOCOCCAL INFECTION : III. THE EFFECT OF TISSUE NECROSIS AND ANTITOXIC IMMUNITY. ACTA ACUST UNITED AC 2010; 113:259-70. [PMID: 19867187 PMCID: PMC2137349 DOI: 10.1084/jem.113.2.259] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Necrosis of rabbit skin produced by thermal injury was found to result in a striking increase in local infectivity of staphylococci that were coagulase-positive and hemolytic, but no local increase in the infectivity of non-pathogenic staphylococci. Infection produced in necrotic burns extended beyond the area of burn and was characterized by hemorrhage, edema, and necrosis of contiguous normal skin. Such infections, however, never resulted in bacteriemia or metastatic abscesses, and there was no effect of the necrotic burn upon the infectivity of staphylococci injected into normal skin of the burned animal. Recovery of rabbits from severe burn infections was associated with the development of high titers of serum antibody to the alpha hemolysin or dermonecrotoxin of the staphylococcus. Thirty to 100 days after the initial burn infection, it was found that rabbits could no longer be infected in a necrotic burn, although infection induced in normal skin of these resistant animals was no different from that in normal rabbits. Immunity to infection by pathogenic staphylococci in necrotic burns could be induced by vaccination with potent alpha hemolysin toxoid, and this immunity was passively transferable with rabbit antiserum. No strain specificity was detected for this immunity in that immunization with toxoid prepared from bacteriophage type 52/42B/80/81 staphylococci protected animals against infection in a necrotic burn by other typable and non-typable staphylococci. Histopathological study of infected necrotic burns in normal rabbits showed extensive necrosis, hemorrhage, edema, and many masses of bacteria but leucocytic infiltration was observed only at the margin of the infection. In contrast, the infected necrotic burns in animals immunized with alpha hemolysin toxoid showed few bacteria and marked leucocytic infiltration throughout the burn. These experiments have, therefore, demonstrated a significant immunity to infection by pathogenic staphylococci in necrotic tissue but not in normal skin, associated with serum antibody to the alpha hemolysin or dermonecrotoxin of the bacteria. The implications of these findings are discussed.
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Affiliation(s)
- K Goshi
- Division of Allergy and Infectious Disease, Department of Medicine, The Johns Hopkins University School of Medicine and Hospital, Baltimore
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Abstract
Meticillin-resistant Staphylococcus aureus (MRSA) is endemic in hospitals worldwide, and causes substantial morbidity and mortality. Health-care-associated MRSA infections arise in individuals with predisposing risk factors, such as surgery or presence of an indwelling medical device. By contrast, many community-associated MRSA (CA-MRSA) infections arise in otherwise healthy individuals who do not have such risk factors. Additionally, CA-MRSA infections are epidemic in some countries. These features suggest that CA-MRSA strains are more virulent and transmissible than are traditional hospital-associated MRSA strains. The restricted treatment options for CA-MRSA infections compound the effect of enhanced virulence and transmission. Although progress has been made towards understanding emergence of CA-MRSA, virulence, and treatment of infections, our knowledge remains incomplete. Here we review the most up-to-date knowledge and provide a perspective for the future prophylaxis or new treatments for CA-MRSA infections.
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Affiliation(s)
- Frank R DeLeo
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA.
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Staphylococcal PknB as the first prokaryotic representative of the proline-directed kinases. PLoS One 2010; 5:e9057. [PMID: 20140229 PMCID: PMC2816222 DOI: 10.1371/journal.pone.0009057] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 01/18/2010] [Indexed: 01/25/2023] Open
Abstract
In eukaryotic cell types, virtually all cellular processes are under control of proline-directed kinases and especially MAP kinases. Serine/threonine kinases in general were originally considered as a eukaryote-specific enzyme family. However, recent studies have revealed that orthologues of eukaryotic serine/threonine kinases exist in bacteria. Moreover, various pathogenic species, such as Yersinia and Mycobacterium, require serine/threonine kinases for successful invasion of human host cells. The substrates targeted by bacterial serine/threonine kinases have remained largely unknown. Here we report that the serine/threonine kinase PknB from the important pathogen Staphylococcus aureus is released into the external milieu, which opens up the possibility that PknB does not only phosphorylate bacterial proteins but also proteins of the human host. To identify possible human targets of purified PknB, we studied in vitro phosphorylation of peptide microarrays and detected 68 possible human targets for phosphorylation. These results show that PknB is a proline-directed kinase with MAP kinase-like enzymatic activity. As the potential cellular targets for PknB are involved in apoptosis, immune responses, transport, and metabolism, PknB secretion may help the bacterium to evade intracellular killing and facilitate its growth. In apparent agreement with this notion, phosphorylation of the host-cell response coordinating transcription factor ATF-2 by PknB was confirmed by mass spectrometry. Taken together, our results identify PknB as the first prokaryotic representative of the proline-directed kinase/MAP kinase family of enzymes.
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Community-associated methicillin-resistant Staphylococcus aureus immune evasion and virulence. J Mol Med (Berl) 2010; 88:109-14. [PMID: 20049412 DOI: 10.1007/s00109-009-0573-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 11/17/2009] [Accepted: 12/02/2009] [Indexed: 12/31/2022]
Abstract
Staphylococcus aureus is a significant cause of human infections globally. Methicillin-resistant S. aureus (MRSA) emerged in the early 1960s and is now endemic in most healthcare facilities. Although healthcare-associated MRSA infections remain a major problem in most industrialized countries, those caused by community-associated MRSA (CA-MRSA) are now the most abundant cause of bacterial infections in the community in some parts of the world, such as the United States. The basis for the emergence and subsequent success of CA-MRSA is incompletely defined. However, the ability of the pathogen to cause disease in otherwise healthy individuals is likely attributed, in part, to its ability to circumvent killing by the innate immune system, which includes survival after phagocytosis by neutrophils. In this review, we discuss the role of neutrophils in host defense against S. aureus and highlight progress made toward understanding mechanisms of CA-MRSA virulence and pathogenesis.
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Li B, Jiang B, Dietz MJ, Smith ES, Clovis NB, Krishna Rao KM. Evaluation of local MCP-1 and IL-12 nanocoatings for infection prevention in open fractures. J Orthop Res 2010; 28:48-54. [PMID: 19588527 PMCID: PMC3886371 DOI: 10.1002/jor.20939] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The increasing incidence of bacterial infection and the appearance of Staphylococcus aureus (S. aureus) strains that are resistant to commonly used antibiotics has made it important to develop non-antibiotic approaches for infection prevention. The aim of this study was to develop local monocyte chemoattractant protein-1 (MCP-1) and interleukin-12 p70 (IL-12 p70) therapies to prevent S. aureus infection by enhancing the recruitment and activation of macrophages, which are believed to play an important role in infection prevention as the first line of defense against invading pathogens. Nanocoating systems for MCP-1 and IL-12 p70 deliveries were prepared, and their release characteristics desirable for infection prevention in open fractures were explored. Local MCP-1 therapy reduced S. aureus infection and influenced white blood cell populations, and local IL-12 p70 treatment had a more profound effect on preventing S. aureus infection. No synergistic relationship in decreasing S. aureus infection was observed when MCP-1 and IL-12 p70 treatments were combined. This reported new approach may reduce antibiotic use and antibiotic resistance.
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Affiliation(s)
- Bingyun Li
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506, USA,WVNano Initiative, Morgantown, WV 26506, USA,Department of Chemical Engineering, College of Engineering and Mineral Resources, West Virginia University, Morgantown, WV 26506, USA,Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Center for Disease Control and Prevention, Morgantown, WV 26505, USA,Correspondence to: Bingyun Li, PhD, Director, Biomaterials, Bioengineering & Nanotechnology Laboratory, Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506-9196, USA, Tel: 1-304-293-1075, Fax: 1-304-293-7070, , URL: http://www.hsc.wvu.edu/som/ortho/nanomedica-group/
| | - Bingbing Jiang
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506, USA
| | - Matthew J. Dietz
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506, USA
| | - E. Suzanne Smith
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506, USA
| | - Nina B. Clovis
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506, USA
| | - K. Murali Krishna Rao
- Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Center for Disease Control and Prevention, Morgantown, WV 26505, USA
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