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Thabit AK, Alghamdi AA, Alsaeed AK, Magbool NM, Alsowaida YS, Mahrous AJ, Alruwaili A, Albakistani ZK, Albangali BO, Alghumuy AM, Youssef SA, Alodayli RM, Almutairi MS. Linezolid-Associated Thrombocytopenia: Assessment of Risk Factors in Patients without Hemato-Oncologic Diseases. J Clin Med 2024; 13:2380. [PMID: 38673653 PMCID: PMC11050941 DOI: 10.3390/jcm13082380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Background: Linezolid is used for Gram-positive bacterial infections. Thrombocytopenia is one of its main adverse effects resulting from myelosuppression. Several studies have assessed risk factors that may increase the risk of this adverse effect. However, most studies included patients with hemato-oncologic diseases, which may confound such assessments. This study aimed to investigate risk factors for linezolid-associated thrombocytopenia in patients without hemato-oncologic diseases. Methods: This was a multicenter retrospective case-control study of adult patients treated with linezolid twice daily for ≥3 days. Patients with hemato-oncologic diseases, active dengue fever, active COVID-19, baseline platelet count <100 × 103/mm3, concurrent therapy with trimethoprim/sulfamethoxazole or valproic acid, and a recent platelet transfusion within 7 days were excluded. Thrombocytopenia was defined as a drop in platelet count below 100 × 103/mm3. Results: Out of 158 evaluated patients, 33 developed thrombocytopenia, indicating an incidence rate of 20.9%. Of all the risk factors assessed, creatinine clearance of <60 mL/min and bacteremia/infective endocarditis were significantly associated with linezolid-associated thrombocytopenia (adjusted odds ratios, 3.25 and 5.95; 95% CI 1.12-9.45 and 1.23-28.66; p = 0.031 and 0.026, respectively). End of therapy platelet counts were significantly lower in the cases than in the controls (79 vs. 243 × 103/mm3; p < 0.001). Similarly, the percentage of platelet count change was significantly different (-55.1% vs. -10.2%; p < 0.001). Conclusions: In our study, the incidence rate of linezolid-associated thrombocytopenia was 20.9%, and we found that patients with renal impairment and bacteremia may need close monitoring of platelet counts. Prospective studies are warranted to evaluate the potential need for renal dose adjustment.
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Affiliation(s)
- Abrar K. Thabit
- Pharmacy Practice Department, Faculty of Pharmacy, King Abdulaziz University, Jeddah 22254-2265, Saudi Arabia
| | - Arwa A. Alghamdi
- Faculty of Pharmacy, King Abdulaziz University, Jeddah 22254-2265, Saudi Arabia
| | - Afnan K. Alsaeed
- Faculty of Pharmacy, King Abdulaziz University, Jeddah 22254-2265, Saudi Arabia
| | - Nesereen M. Magbool
- Faculty of Pharmacy, King Abdulaziz University, Jeddah 22254-2265, Saudi Arabia
| | - Yazed S. Alsowaida
- Department of Clinical Pharmacy, College of Pharmacy, University of Ha’il, Hail 55473, Saudi Arabia
| | - Ahmad J. Mahrous
- Clinical Pharmacy Department, College of Pharmacy, Umm Al Qura University, Makkah 21955, Saudi Arabia
| | - Alya Alruwaili
- Department of Pharmaceutical Care, King Fahad Medical City, Riyadh 12231, Saudi Arabia
| | | | | | - Anas M. Alghumuy
- College of Pharmacy, Umm Al Qura University, Makkah 21955, Saudi Arabia
| | - Sara A. Youssef
- Department of Pharmaceutical Care, Saudi German Hospital, Hail 55481, Saudi Arabia
| | - Reem M. Alodayli
- Department of Pharmaceutical Care, Saudi German Hospital, Hail 55481, Saudi Arabia
| | - Masaad Saeed Almutairi
- Department of Pharmacy Practice, College of Pharmacy, Qassim University, Qassim 51452, Saudi Arabia;
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2
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Mariotti A, Ezzraimi AE, Camoin-Jau L. Effect of antiplatelet agents on Escherichia coli sepsis mechanisms: A review. Front Microbiol 2022; 13:1043334. [PMID: 36569083 PMCID: PMC9780297 DOI: 10.3389/fmicb.2022.1043334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/07/2022] [Indexed: 12/13/2022] Open
Abstract
Despite ever-increasing improvements in the prognosis of sepsis, this condition remains a frequent cause of hospitalization and mortality in Western countries. Sepsis exposes the patient to multiple complications, including thrombotic complications, due to the ability of circulating bacteria to activate platelets. One of the bacteria most frequently implicated in sepsis, Escherichia coli, a Gram-negative bacillus, has been described as being capable of inducing platelet activation during sepsis. However, to date, the mechanisms involved in this activation have not been clearly established, due to their multiple characteristics. Many signaling pathways are thought to be involved. At the same time, reports on the use of antiplatelet agents in sepsis to reduce platelet activation have been published, with variable results. To date, their use in sepsis remains controversial. The aim of this review is to summarize the currently available knowledge on the mechanisms of platelet activation secondary to Escherichia coli sepsis, as well as to provide an update on the effects of antiplatelet agents in these pathological circumstances.
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Affiliation(s)
- Antoine Mariotti
- Aix Marseille Univ., IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France,IHU Méditerranée Infection, Marseille, France,Haematology Laboratory, Hôpital de la Timone, APHM, Marseille, France
| | - Amina Ezzeroug Ezzraimi
- Aix Marseille Univ., IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France,IHU Méditerranée Infection, Marseille, France
| | - Laurence Camoin-Jau
- Aix Marseille Univ., IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France,IHU Méditerranée Infection, Marseille, France,Haematology Laboratory, Hôpital de la Timone, APHM, Marseille, France,*Correspondence: Laurence Camoin-Jau,
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3
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Staphylococcus aureus increases platelet reactivity in patients with infective endocarditis. Sci Rep 2022; 12:12933. [PMID: 35902612 PMCID: PMC9334290 DOI: 10.1038/s41598-022-16681-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/13/2022] [Indexed: 01/30/2023] Open
Abstract
Thromboembolism is frequent in infective endocarditis (IE). However, the optimal antithrombotic regimen in IE is unknown. Staphylococcus aureus (SA) is the leading cause of IE. First studies emphasize increased platelet reactivity by SA. In this pilot study, we hypothesized that platelet reactivity is increased in patients with SA− IE, which could be abrogated by antiplatelet medication. We conducted a prospective, observatory, single-center cohort study in 114 patients with IE, with four cohorts: (1) SA coagulase positive IE without aspirin (ASA) medication, (2) coagulase negative IE without ASA, (3) SA coagulase positive IE with ASA, (4) coagulase negative IE with ASA. Platelet function was measured by Multiplate electrode aggregometry, blood clotting by ROTEM thromboelastometry. Bleeding events were assessed according to TIMI classification. In ASA-naïve patients, aggregation with ADP was increased with coag. pos. IE (coagulase negative: 39.47 ± 4.13 AUC vs. coagulase positive: 59.46 ± 8.19 AUC, p = 0.0219). This was abrogated with ASA medication (coagulase negative: 42.4 ± 4.67 AUC vs. coagulase positive: 45.11 ± 6.063 AUC p = 0.7824). Aspirin did not increase bleeding in SA positive patients. However, in SA negative patients with aspirin, red blood cell transfusions were enhanced. SA coagulase positive IE is associated with increased platelet reactivity. This could be abrogated by aspirin without increased bleeding risk. The results of this pilot study suggest that ASA might be beneficial in SA coagulase positive IE. This needs to be confirmed in clinical trials.
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4
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Davenport P, Fan HH, Nolton E, Feldman HA, Lorenz V, Canas J, Acosta-Zaldívar M, Yakah W, Arthur C, Martin C, Stowell S, Koehler J, Mager D, Sola-Visner M. Platelet transfusions in a murine model of neonatal polymicrobial sepsis: Divergent effects on inflammation and mortality. Transfusion 2022; 62:1177-1187. [PMID: 35522536 DOI: 10.1111/trf.16895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 03/11/2022] [Accepted: 03/18/2022] [Indexed: 12/19/2022]
Abstract
BACKGROUND Platelet transfusions (PTxs) are often given to septic preterm neonates at high platelet count thresholds in an attempt to reduce bleeding risk. However, the largest randomized controlled trial (RCT) of neonatal transfusion thresholds found higher mortality and/or major bleeding in infants transfused at higher thresholds. Using a murine model, we investigated the effects of adult PTx on neonatal sepsis-induced mortality, systemic inflammation, and platelet consumption. STUDY DESIGN AND METHODS Polymicrobial sepsis was induced via intraperitoneal injection of cecal slurry preparations (CS1, 2, 3) into P10 pups. Two hours after infection, pups were transfused with washed adult Green Flourescent Protein (GFP+) platelets or control. Weights, platelet counts, and GFP% were measured before 4 and 24 h post-infection. At 24 h, blood was collected for quantification of plasma cytokines. RESULTS The CS batches varied in 24 h mortality (11%, 73%, and 30% in CS1, 2, and 3, respectively), due to differences in bacterial composition. PTx had differential effects on sepsis-induced mortality and systemic inflammatory cytokines, increasing both in mice infected with CS1 (low mortality) and decreasing both in mice infected with CS2 and 3. In a mathematical model of platelet kinetics, the consumption of transfused adult platelets was higher than that of endogenous neonatal platelets, regardless of CS batch. DISCUSSION Our findings support the hypothesis that transfused adult platelets are consumed faster than endogenous neonatal platelets in sepsis and demonstrate that PTx can enhance or attenuate neonatal inflammation and mortality in a model of murine polymicrobial sepsis, depending on the composition of the inoculum and/or the severity of sepsis.
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Affiliation(s)
- Patricia Davenport
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Hsuan-Hao Fan
- Department of Pharmaceutical Sciences, University of Buffalo, State University of New York, Buffalo, New York, USA
| | - Emily Nolton
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Henry A Feldman
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.,Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Viola Lorenz
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Jorge Canas
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | | | - William Yakah
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.,Division of Neonatology, Beth Israel Medical Center, Boston, Massachusetts, USA
| | - Connie Arthur
- Division of Transfusion Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
| | - Camilia Martin
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.,Division of Neonatology, Beth Israel Medical Center, Boston, Massachusetts, USA
| | - Sean Stowell
- Division of Transfusion Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
| | - Julia Koehler
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.,Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Donald Mager
- Department of Pharmaceutical Sciences, University of Buffalo, State University of New York, Buffalo, New York, USA
| | - Martha Sola-Visner
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
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5
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Di Bella S, Luzzati R, Principe L, Zerbato V, Meroni E, Giuffrè M, Crocè LS, Merlo M, Perotto M, Dolso E, Maurel C, Lovecchio A, Dal Bo E, Lagatolla C, Marini B, Ippodrino R, Sanson G. Aspirin and Infection: A Narrative Review. Biomedicines 2022; 10:biomedicines10020263. [PMID: 35203473 PMCID: PMC8868581 DOI: 10.3390/biomedicines10020263] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 02/01/2023] Open
Abstract
Acetylsalicylic acid (ASA) is one of the most commonly used drugs in the world. It derives from the extract of white willow bark, whose therapeutic potential was known in Egypt since 1534 BC. ASA’s pharmacological effects are historically considered secondary to its anti-inflammatory, platelet-inhibiting properties; however, human studies demonstrating a pro-inflammatory effect of ASA exist. It is likely that we are aware of only part of ASA’s mechanisms of action; moreover, the clinical effect is largely dependent on dosages. During the past few decades, evidence of the anti-infective properties of ASA has emerged. We performed a review of such research in order to provide a comprehensive overview of ASA and viral, bacterial, fungal and parasitic infections, as well as ASA’s antibiofilm properties.
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Affiliation(s)
- Stefano Di Bella
- Clinical Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (S.D.B.); (R.L.); (L.S.C.); (M.M.); (M.P.); (G.S.)
| | - Roberto Luzzati
- Clinical Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (S.D.B.); (R.L.); (L.S.C.); (M.M.); (M.P.); (G.S.)
| | - Luigi Principe
- Clinical Pathology and Microbiology Unit, “S. Giovanni di Dio” Hospital, 88900 Crotone, Italy;
| | - Verena Zerbato
- Infectious Diseases Unit, Trieste University Hospital, 34149 Trieste, Italy; (V.Z.); (E.D.); (C.M.); (A.L.)
| | - Elisa Meroni
- Clinical Microbiology and Virology Unit, “A. Manzoni” Hospital, 23900 Lecco, Italy;
| | - Mauro Giuffrè
- Clinical Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (S.D.B.); (R.L.); (L.S.C.); (M.M.); (M.P.); (G.S.)
- Correspondence: ; Tel.: +39-040-3994-305
| | - Lory Saveria Crocè
- Clinical Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (S.D.B.); (R.L.); (L.S.C.); (M.M.); (M.P.); (G.S.)
| | - Marco Merlo
- Clinical Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (S.D.B.); (R.L.); (L.S.C.); (M.M.); (M.P.); (G.S.)
| | - Maria Perotto
- Clinical Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (S.D.B.); (R.L.); (L.S.C.); (M.M.); (M.P.); (G.S.)
| | - Elisabetta Dolso
- Infectious Diseases Unit, Trieste University Hospital, 34149 Trieste, Italy; (V.Z.); (E.D.); (C.M.); (A.L.)
| | - Cristina Maurel
- Infectious Diseases Unit, Trieste University Hospital, 34149 Trieste, Italy; (V.Z.); (E.D.); (C.M.); (A.L.)
| | - Antonio Lovecchio
- Infectious Diseases Unit, Trieste University Hospital, 34149 Trieste, Italy; (V.Z.); (E.D.); (C.M.); (A.L.)
| | - Eugenia Dal Bo
- Cardiothoracic-Vascular Department, Azienda Sanitaria Universitaria Integrata, Cattinara University Hospital, 34149 Trieste, Italy;
| | - Cristina Lagatolla
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy;
| | - Bruna Marini
- Ulisse BioMed Labs, Area Science Park, 34149 Trieste, Italy; (B.M.); (R.I.)
| | - Rudy Ippodrino
- Ulisse BioMed Labs, Area Science Park, 34149 Trieste, Italy; (B.M.); (R.I.)
| | - Gianfranco Sanson
- Clinical Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy; (S.D.B.); (R.L.); (L.S.C.); (M.M.); (M.P.); (G.S.)
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6
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Butt JH, Fosbøl EL, Verhamme P, Gerds TA, Iversen K, Bundgaard H, Bruun NE, Larsen AR, Petersen A, Andersen PS, Skov RL, Gislason GH, Torp-Pedersen C, Køber L, Olesen JB. Dabigatran and the Risk of Staphylococcus aureus Bacteremia: A Nationwide Cohort Study. Clin Infect Dis 2021; 73:480-486. [PMID: 32478836 DOI: 10.1093/cid/ciaa661] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/26/2020] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Treatment with dabigatran, an oral direct thrombin inhibitor, reduces the virulence of Staphylococcus aureus in in vitro and in vivo models. However, it remains to be determined whether dabigatran reduces the risk of S. aureus infections in humans. We investigated the incidence rate of S. aureus bacteremia (SAB) in patients with atrial fibrillation treated with the direct thrombin inhibitor dabigatran compared with patients treated with the factor Xa-inhibitors rivaroxaban, apixaban, and edoxaban. METHODS In this observational cohort study, 112 537 patients with atrial fibrillation who initiated treatment with direct oral anticoagulants (August 2011-December 2017) were identified from Danish nationwide registries. The incidence rates of SAB in patients treated with dabigatran versus patients treated with the factor Xa-inhibitors were examined by multivariable Cox regression accounting for time-dynamic changes in exposure status during follow-up. RESULTS A total of 112 537 patients were included. During a median follow-up of 2.0 years, 186 patients in the dabigatran group and 356 patients in the factor Xa-inhibitor group were admitted with SAB. The crude incidence rate of SAB was lower in the dabigatran group compared with the factor Xa-inhibitor group (22.8 [95% confidence interval [CI], 19.7-26.3] and 33.8 [95% CI, 30.5-37.6] events per 10 000 person-years, respectively). In adjusted analyses, dabigatran was associated with a significantly lower incidence rate of SAB compared with factor Xa-inhibitors (incidence rate ratio, .76; 95% CI, .63-.93). CONCLUSIONS Treatment with dabigatran was associated with a significantly lower incidence rate of SAB compared with treatment with factor Xa-inhibitors.
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Affiliation(s)
- Jawad H Butt
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Emil L Fosbøl
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Peter Verhamme
- Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Thomas A Gerds
- Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark.,The Danish Heart Foundation, Copenhagen, Denmark
| | - Kasper Iversen
- Department of Cardiology, Herlev and Gentofte University Hospital, Herlev, Denmark
| | - Henning Bundgaard
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Niels Eske Bruun
- Department of Cardiology, Zealand University Hospital, Roskilde, Denmark.,Institute of Clinical Medicine, Copenhagen University, Copenhagen, Denmark.,Clinical Institute, Aalborg University, Aalborg, Denmark
| | | | | | - Paal S Andersen
- Statens Serum Institut, Copenhagen, Denmark.,Department of Veterinary and Animal Sciences, Faculty of Health and Medical Science, University of Copenhagen, Frederiksberg, Denmark
| | | | - Gunnar H Gislason
- The Danish Heart Foundation, Copenhagen, Denmark.,Department of Cardiology, Herlev and Gentofte University Hospital, Hellerup, Denmark
| | - Christian Torp-Pedersen
- Department of Cardiology and Clinical Investigation, Nordsjællands Hospital, Hillerød, Denmark.,Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark
| | - Lars Køber
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Jonas B Olesen
- Department of Cardiology, Herlev and Gentofte University Hospital, Hellerup, Denmark
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7
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Page MJ, Pretorius E. A Champion of Host Defense: A Generic Large-Scale Cause for Platelet Dysfunction and Depletion in Infection. Semin Thromb Hemost 2020; 46:302-319. [PMID: 32279287 PMCID: PMC7339151 DOI: 10.1055/s-0040-1708827] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Thrombocytopenia is commonly associated with sepsis and infections, which in turn are characterized by a profound immune reaction to the invading pathogen. Platelets are one of the cellular entities that exert considerable immune, antibacterial, and antiviral actions, and are therefore active participants in the host response. Platelets are sensitive to surrounding inflammatory stimuli and contribute to the immune response by multiple mechanisms, including endowing the endothelium with a proinflammatory phenotype, enhancing and amplifying leukocyte recruitment and inflammation, promoting the effector functions of immune cells, and ensuring an optimal adaptive immune response. During infection, pathogens and their products influence the platelet response and can even be toxic. However, platelets are able to sense and engage bacteria and viruses to assist in their removal and destruction. Platelets greatly contribute to host defense by multiple mechanisms, including forming immune complexes and aggregates, shedding their granular content, and internalizing pathogens and subsequently being marked for removal. These processes, and the nature of platelet function in general, cause the platelet to be irreversibly consumed in the execution of its duty. An exaggerated systemic inflammatory response to infection can drive platelet dysfunction, where platelets are inappropriately activated and face immunological destruction. While thrombocytopenia may arise by condition-specific mechanisms that cause an imbalance between platelet production and removal, this review evaluates a generic large-scale mechanism for platelet depletion as a repercussion of its involvement at the nexus of responses to infection.
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Affiliation(s)
- Martin J Page
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Etheresia Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
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8
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El-Laithy HM, Badawi A, Abdelmalak NS, Elsayyad NME. Stabilizing excipients for engineered clopidogrel bisulfate procubosome derived in situ cubosomes for enhanced intestinal dissolution: Stability and bioavailability considerations. Eur J Pharm Sci 2019; 136:104954. [DOI: 10.1016/j.ejps.2019.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/29/2022]
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9
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Abstract
The main strategies used by pathogenic bacteria to infect eukaryotic tissue include their adherence to cells and the extracellular matrix (ECM), the subsequent colonization and invasion as well as the evasion of immune defences. A variety of structurally and functionally characterized adhesins and binding proteins of gram-positive bacteria facilitate these processes by specifically recognizing and interacting with various components of the host ECM, including different collagens, fibronectin and other macromolecules. The ECM affects the cellular physiology of our body and is critical for adhesion, migration, proliferation, and differentiation of many host cell types, but also provides the support for infiltrating pathogens, particularly under conditions of injury and trauma. Moreover, microbial binding to a variety of adhesive components in host tissue fluids leads to structural and/or functional alterations of host proteins and to the activation of cellular mechanisms that influence tissue and cell invasion of pathogens. Since the diverse interactions of gram-positive bacteria with the ECM represent important pathogenicity mechanisms, their characterization not only allows a better understanding of microbial invasion but also provides clues for the design of novel therapeutic strategies to manage infectious diseases.
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10
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Lerche CJ, Christophersen LJ, Goetze JP, Nielsen PR, Thomsen K, Enevold C, Høiby N, Jensen PØ, Bundgaard H, Moser C. Adjunctive dabigatran therapy improves outcome of experimental left-sided Staphylococcus aureus endocarditis. PLoS One 2019; 14:e0215333. [PMID: 31002679 PMCID: PMC6474597 DOI: 10.1371/journal.pone.0215333] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/29/2019] [Indexed: 12/13/2022] Open
Abstract
Background Staphylococcus aureus is the most frequent and fatal cause of left-sided infective endocarditis (IE). New treatment strategies are needed to improve the outcome. S. aureus coagulase promotes clot and fibrin formation. We hypothesized that dabigatran, could reduce valve vegetations and inflammation in S. aureus IE. Methods We used a rat model of severe aortic valve S. aureus IE. All infected animals were randomized to receive adjunctive dabigatran (10 mg/kg b.i.d., n = 12) or saline (controls, n = 11) in combination with gentamicin. Valve vegetation size, bacterial load, cytokine, cell integrins expression and peripheral platelets and neutrophils were assessed 3 days post-infection. Results Adjunctive dabigatran treatment significantly reduced valve vegetation size compared to controls (p< 0.0001). A significant reduction of the bacterial load in aortic valves was seen in dabigatran group compared to controls (p = 0.02), as well as expression of key pro-inflammatory markers keratinocyte-derived chemokine, IL-6, ICAM-1, TIMP-1, L-selectin (p< 0.04). Moreover, the dabigatran group had a 2.5-fold increase of circulating platelets compared to controls and a higher expression of functional and activated platelets (CD62p+) unbound to neutrophils. Conclusion Adjunctive dabigatran reduced the vegetation size, bacterial load, and inflammation in experimental S. aureus IE.
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Affiliation(s)
- Christian J. Lerche
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, University of Copenhagen, Denmark
- * E-mail:
| | - Lars J. Christophersen
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Jens Peter Goetze
- Department of Clinical Biochemistry, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Pia R. Nielsen
- Department of Pathology, Zealand University Hospital, Roskilde, Denmark
| | - Kim Thomsen
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Christian Enevold
- Institute for Inflammation Research, Department of Rheumatology and Spine Disease, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Niels Høiby
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, University of Copenhagen, Denmark
| | - Peter Ø. Jensen
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, University of Copenhagen, Denmark
- Institute for Inflammation Research, Department of Rheumatology and Spine Disease, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Henning Bundgaard
- Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Claus Moser
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, University of Copenhagen, Denmark
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11
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Levin J. The Evolution of Mammalian Platelets. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00001-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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12
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The Role of Platelets in Antimicrobial Host Defense. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00029-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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13
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Impact of Escherichia coli K12 and O18:K1 on human platelets: Differential effects on platelet activation, RNAs and proteins. Sci Rep 2018; 8:16145. [PMID: 30385858 PMCID: PMC6212526 DOI: 10.1038/s41598-018-34473-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/08/2018] [Indexed: 12/12/2022] Open
Abstract
Blood platelets can interact with bacteria, possibly leading to platelet activation, cytokine and microparticle release and immune signalling. Besides, bacteria can also affect the platelet RNA content. We investigated the impact of non-pathogenic K12 and pathogenic O18:K1 Escherichia (E.) coli strains on platelet activation, RNA expression patterns, and selected proteins. Depending on bacteria concentration, contact of platelets with E. coli K12 lead to an increase of P-selectin (24–51.3%), CD63 (15.9–24.3%), PAC-1 (3.8–14.9%) and bound fibrinogen (22.4–39%) on the surface. E. coli O18:K1 did not affect these markers. Sequencing analysis of total RNA showed that E. coli K12 caused a significant concentration change of 103 spliced mRNAs, of which 74 decreased. For the RNAs of HMBS (logFC = +5.73), ATP2C1 (logFC = −3.13) and LRCH4 (logFC = −4.07) changes were detectable by thromboSeq and Tuxedo pipelines. By Western blot we observed the conversion of HMBS protein from a 47 kDA to 40 kDa product by E. coli K12, O18:K1 and by purified lipopolysaccharide. While ATP2C1 protein was released from platelets, E. coli either reduced the secretion or broke down the released protein making it undetectable by antibodies. Our results demonstrate that different E. coli strains influence activation, RNA and protein levels differently which may affect platelet-bacteria crosstalk.
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Gurtman A, Begier E, Mohamed N, Baber J, Sabharwal C, Haupt RM, Edwards H, Cooper D, Jansen KU, Anderson AS. The development of a staphylococcus aureus four antigen vaccine for use prior to elective orthopedic surgery. Hum Vaccin Immunother 2018; 15:358-370. [PMID: 30215582 DOI: 10.1080/21645515.2018.1523093] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is a challenging bacterial pathogen which can cause a range of diseases, from mild skin infections, to more serious and invasive disease including deep or organ space surgical site infections, life-threatening bacteremia, and sepsis. S. aureus rapidly develops resistance to antibiotic treatments. Despite current infection control measures, the burden of disease remains high. The most advanced vaccine in clinical development is a 4 antigen S. aureus vaccine (SA4Ag) candidate that is being evaluated in a phase 2b/3 efficacy study in patients undergoing elective spinal fusion surgery (STaphylococcus aureus suRgical Inpatient Vaccine Efficacy [STRIVE]). SA4Ag has been shown in early phase clinical trials to be generally safe and well tolerated, and to induce high levels of bactericidal antibodies in healthy adults. In this review we discuss the design of SA4Ag, as well as the proposed clinical development plan supporting licensure of SA4Ag for the prevention of invasive disease caused by S. aureus in elective orthopedic surgical populations. We also explore the rationale for the generalizability of the results of the STRIVE efficacy study (patients undergoing elective open posterior multilevel instrumented spinal fusion surgery) to a broad elective orthopedic surgery population due to the common pathophysiology of invasive S. aureus disease and commonalties of patient and procedural risk factors for developing postoperative S. aureus surgical site infections.
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Affiliation(s)
- A Gurtman
- a Pfizer Vaccine Research and Development , Pfizer, Inc ., Pearl River , NY , USA
| | - E Begier
- a Pfizer Vaccine Research and Development , Pfizer, Inc ., Pearl River , NY , USA
| | - N Mohamed
- a Pfizer Vaccine Research and Development , Pfizer, Inc ., Pearl River , NY , USA
| | - J Baber
- b Pfizer Vaccine Research and Development , Sydney , NSW , Australia
| | - C Sabharwal
- a Pfizer Vaccine Research and Development , Pfizer, Inc ., Pearl River , NY , USA
| | - R M Haupt
- c Medical Development, Scientific and Clinical Affairs , Pfizer, Inc ., Collegeville , PA , USA
| | - H Edwards
- d World Wide Regulatory Affairs , Pfizer Inc ., Walton Oaks , UK
| | - D Cooper
- a Pfizer Vaccine Research and Development , Pfizer, Inc ., Pearl River , NY , USA
| | - K U Jansen
- a Pfizer Vaccine Research and Development , Pfizer, Inc ., Pearl River , NY , USA
| | - A S Anderson
- a Pfizer Vaccine Research and Development , Pfizer, Inc ., Pearl River , NY , USA
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15
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Abstract
Staphylococcus aureus causes severe disease in humans for which no licensed vaccine exists. A novel vaccine is in development that targets multiple elements of the bacteria since single-component vaccines have not shown efficacy to date. How these multiple components alter the immune response raised by the vaccine is not well studied. We found that the addition of two protein components did not alter substantially the antibody responses raised with respect to function or mobilization of B cells. There was also not a substantial change in the activity of T cells, another part of the adaptive response. This study showed that protection by this vaccine may be mediated primarily by antibody protection. Staphylococcus aureus causes severe disease in humans for which no licensed vaccine exists. A novel S. aureus vaccine (SA4Ag) is in development, targeting the capsular polysaccharides (CPs) and two virulence-associated surface proteins. Vaccine-elicited antibody responses to CPs are efficacious against serious infection by other encapsulated bacteria. Studies of natural S. aureus infection have also shown a role for TH17 and/or TH1 responses in protection. Single-antigen vaccines, including CPs, have not been effective against S. aureus; a multiantigen vaccine approach is likely required. However, the impact of addition of protein antigens on the immune response to CPs has not been studied. Here, the immune response induced by a bivalent CP conjugate vaccine (to model the established mechanism of action of vaccine-induced protection against Gram-positive pathogens) was compared to the response induced by SA4Ag, which contains both CP conjugates and protein antigens, in cynomolgus macaques. Microengraving, flow cytometry, opsonophagocytic assays, and Luminex technology were used to analyze the B-cell, T-cell, functional antibody, and innate immune responses. Both the bivalent CP vaccine and SA4Ag induced cytokine production from naive cells and antigen-specific memory B-cell and functional antibody responses. Increases in levels of circulating, activated T cells were not apparent following vaccination, nor was a TH17 or TH1 response evident. However, our data are consistent with a vaccine-induced recruitment of T follicular helper (TFH) cells to lymph nodes. Collectively, these data suggest that the response to SA4Ag is primarily mediated by B cells and antibodies that abrogate important S. aureus virulence mechanisms. IMPORTANCEStaphylococcus aureus causes severe disease in humans for which no licensed vaccine exists. A novel vaccine is in development that targets multiple elements of the bacteria since single-component vaccines have not shown efficacy to date. How these multiple components alter the immune response raised by the vaccine is not well studied. We found that the addition of two protein components did not alter substantially the antibody responses raised with respect to function or mobilization of B cells. There was also not a substantial change in the activity of T cells, another part of the adaptive response. This study showed that protection by this vaccine may be mediated primarily by antibody protection.
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16
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Abstract
Thrombocytopenia is common in patients with invasive bacterial infections. Bacteria can activate platelets, but it is unclear if this affects platelet count. The aim of this study was to examine whether bacteraemia with Staphylococcus aureus, which readily activate human platelets, was more likely to be complicated by thrombocytopenia than bacteraemia with Escherichia coli or Streptococcus pneumoniae with different abilities to activate platelets.We compared information from 600 adult patients with community-acquired bacteraemia with S. aureus (n = 140), E. coli (n = 420) and S. pneumoniae (n = 40) in Southern Sweden, 2012, linking information on positive blood cultures from microbiological databases and medical charts. The proportion of patients with thrombocytopenia (platelet count <150 × 109/ml) was calculated. Logistic regression was used to estimate the odds ratios (OR) for thrombocytopenia according to bacterial species adjusted for confounders.The proportion of thrombocytopenia was 29% in S. aureus, 28% in E. coli and 20% in S. pneumonia bacteraemia (P = 0.50), corresponding to an OR of 1.2 (95% confidence interval 0.7-1.9) for thrombocytopenia for S. aureus as compared with E. coli or S. pneumoniae, adjusted for confounders.This study indicates that platelet activation by bacteria is not a major causative mechanism in sepsis-associated thrombocytopenia.
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17
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Costa-Filho RC, Bozza FA. Platelets: an outlook from biology through evidence-based achievements in critical care. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:449. [PMID: 29264366 PMCID: PMC5721222 DOI: 10.21037/atm.2017.11.04] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 11/01/2017] [Indexed: 12/29/2022]
Abstract
Since the original observations by Bizzozero and Osler, we have seen tremendous advances in the understanding of platelets far beyond haemostasis and the restoration of injured endothelium. In this mini-review on platelets, we will briefly outline their historical description and the importance of their evolution, focusing on a 450 million years old living fossil of Limulus polyphemus, a marine chelicerate arthropod, which helped researchers explain the basis for the immunity role of platelets and make correlations with platelet ultrastructure and function. In addition, the impact of the Limulus Amoebocyte Lysate (LAL) test for modern medicine is highlighted. The role of platelets in cardiovascular diseases, their relevance in arterial and venous thrombosis, and the utilization of antithrombotic drugs as therapeutic agents are also reported. Furthermore, platelet receptors are crucial in aggravating or mitigating other diseases, such as cancer and infections, which can recruit cells and have numerous interactions in a process recently coined "NETosis formation", which is also briefly depicted.
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Affiliation(s)
- Rubens C. Costa-Filho
- Department of Critical Care, Hospital Pro Cardíaco, Rua Gal. Polidoro, Rio de Janeiro RJ, Brazil
- Trombocore, Haemostasis & Thrombosis Studies with roTEM thromboelastometry directed to critically ill patients, Rua Dona Mariana, Botafogo, Rio de Janeiro RJ, Brazil
| | - Fernando A. Bozza
- Instituto D’Or de Pesquisa e Ensino (IDOR), Rua Diniz Cordeiro, Rio de Janeiro RJ, Brazil
- Instituto Nacional de Infectologia Evandro Chagas, FIOCRUZ, Estr. de Manguinhos, Manguinhos, Rio de Janeiro RJ, Brazil
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18
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Liu X, Liu H, Luo X, Zhang P, Gao Y, Xie S, Xu K, Chang J, Ma L. Strains of Group B streptococci from septic patients induce platelet activation via Toll-like Receptor 2. Clin Exp Pharmacol Physiol 2017; 44:335-343. [PMID: 27885699 DOI: 10.1111/1440-1681.12707] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 11/16/2016] [Accepted: 11/19/2016] [Indexed: 11/28/2022]
Abstract
Group B Streptococcus (GBS) causes life-threatening bacterial sepsis, especially in newborns and pregnant women. Patients suffering from sepsis often display low platelet counts, characterized by thrombocytopenia, because of platelet activation. In the present study, the roles of six GBS strains from septic patients in platelet aggregation, as well as the underlying mechanisms, were investigated. Incubation of platelets with three of the strains induced platelet aggregation, increased the secretion of cellular adhesin molecule CD62P and activation of GPIIb/IIIa. Furthermore, the GBS strains that induced platelet activation also caused an increase in the expression of Toll-like receptor (TLR) 2 in platelets. Pre-incubation of platelets with anti-TLR2 monoclonal antibody, but not anti-TLR4 monoclonal antibody, inhibited these functional responses induced by GBS. TLR2 stimulation also activated the phosphoinositide 3-kinase (PI3-K)/Akt signalling pathway in platelets, and inhibition of PI3-K significantly reduced GBS-induced platelet responses. Our results indicate that three of the GBS strains from the septic patients can trigger platelet activation by interacting with platelets, which involves the elevation of platelet TLR2 expression.
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Affiliation(s)
- Xiaoyan Liu
- Department of Hematology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hongyun Liu
- Department of Hematology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xianming Luo
- Department of Hematology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ping Zhang
- Department of Hematology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yanmin Gao
- Department of Hematology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shuangfeng Xie
- Department of Hematology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Kang Xu
- Department of General surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jianxing Chang
- Department of General surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Liping Ma
- Department of Hematology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
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Acetylsalicylic acid differentially limits the activation and expression of cell death markers in human platelets exposed to Staphylococcus aureus strains. Sci Rep 2017; 7:5610. [PMID: 28717145 PMCID: PMC5514152 DOI: 10.1038/s41598-017-06024-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 06/07/2017] [Indexed: 12/14/2022] Open
Abstract
Beyond their hemostatic functions, platelets alter their inflammatory response according to the bacterial stimulus. Staphylococcus aureus is associated with exacerbated inflammation and thrombocytopenia, which is associated with poor prognosis during sepsis. Acetylsalicylic acid and statins prevent platelet aggregation and decrease the mortality rate during sepsis. Therefore, we assessed whether these two molecules could reduce in vitro platelet activation and the inflammatory response to S. aureus. Platelets were exposed to clinical strains of S. aureus in the presence or absence of acetylsalicylic acid or fluvastatin. Platelet activation, aggregation, and release of soluble sCD62P, sCD40 Ligand, RANTES and GROα were assessed. Platelet cell death was evaluated by analyzing the mitochondrial membrane potential, phosphatidylserine exposure, platelet microparticle release and caspase-3 activation. All S. aureus strains induced platelet activation but not aggregation and decreased the platelet count, the expression of cell death markers and the release of RANTES and GROα. Acetylsalicylic acid but not fluvastatin limited platelet activation and inflammatory factor release and restored the platelet count by protecting platelets from Staphylococcus-induced expression of cell death markers. This study demonstrates that acetylsalicylic acid limits S. aureus-induced effects on platelets by reducing cell death, revealing new strategies to reduce the platelet contribution to bacteremia-associated inflammation.
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20
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Wei XB, Liu YH, He PC, Yu DQ, Tan N, Zhou YL, Chen JY. The impact of admission neutrophil-to-platelet ratio on in-hospital and long-term mortality in patients with infective endocarditis. Clin Chem Lab Med 2017; 55:899-906. [PMID: 27987356 DOI: 10.1515/cclm-2016-0527] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 10/31/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Infective endocarditis (IE) is associated with increased neutrophil and reduced platelet counts. We assessed the relationship between the neutrophil-to-platelet ratio (NPR) on admission and adverse outcomes in patients with IE. METHODS Patients diagnosed with IE between January 2009 and July 2015 (n=1293) were enrolled, and 1046 were finally entered into the study. Study subjects were categorized into four groups according to NPR quartiles: Q1<18.9 (n=260); Q2: 18.9-27.7 (n=258); Q3: 27.7-43.3 (n=266); and Q4>43.3 (n=262). Cox proportional hazards regression was performed to identify risk factors for long-term mortality; the optimal cut-off was evaluated by receiver operating characteristic curves. RESULTS Risk of in-hospital death increased progressively with NPR group number (1.9 vs. 5.0 vs. 9.8 vs. 14.1%, p<0.001). The follow-up period was a median of 28.8 months, during which 144 subjects (14.3%) died. Long-term mortality increased from the lowest to the highest NPR quartiles (7.6, 11.8, 17.4, and 26.2%, respectively, p<0.001). Multivariate Cox proportional hazard analysis revealed that lgNPR (HR=2.22) was an independent predictor of long-term mortality. Kaplan-Meier survival curves showed that subjects in Q4 had an increased long-term mortality compared with the other groups. CONCLUSIONS Increased NPR was associated with in-hospital and long-term mortality in patients with IE. As a simple and inexpensive index, NPR may be a useful and rapid screening tool to identify IE patients at high risk of mortality.
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Affiliation(s)
- Xue-Biao Wei
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R
| | - Yuan-Hui Liu
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R
| | - Peng-Cheng He
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R
| | - Dan-Qing Yu
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R
| | - Ning Tan
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R
| | - Ying-Ling Zhou
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R
| | - Ji-Yan Chen
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R
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21
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Siritapetawee J, Talabnin C, Vanichtanankul J, Songsiriritthigul C, Thumanu K, Chen CJ, Komanasin N. Characterization of the binding of a glycosylated serine protease from Euphorbia cf. lactea latex to human fibrinogen. Biotechnol Appl Biochem 2017; 64:862-870. [PMID: 28150441 DOI: 10.1002/bab.1555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/25/2017] [Indexed: 12/22/2022]
Abstract
In this study, the binding of a glycosylated serine protease (EuP-82) with human fibrinogen was investigated by isothermal titration calorimetry (ITC). ITC analysis indicated that the binding of EuP-82 to fibrinogen in the conditions with or without the activator (Ca2+ ) was an exothermic reaction (dominant negative enthalpy), which tended to be driven by hydrogen bonding and van der Waals interactions. In contrast, the binding of fibrinogen-EuP-82 in the condition with the inhibitor (Zn2+ ) was an unfavorable endothermic reaction. EuP-82 could not inhibit the platelet activity in citrated whole blood via the ADP-receptor pathways (mainly, P2Y1 and P2Y12), but it could enhance the platelet aggregation. The ITC together with whole blood platelet aggregation suggested that EuP-82 provided multiple fibrinogen-binding sites that were not related to the arginine-glycine-aspartate (RGD) and the dodecapeptide sequences of fibrinogen. In addition, EuP-82 had neither thrombin-like activity nor anticoagulant activity. The SR-FTIR spectra revealed that EuP-82 was a glycoprotein. Deglycosylation of EuP-82 did not affect its proteolytic activity. Moreover, EuP-82 did not exhibit any toxicity to the living cells (NIH-3T3). This study supports that EuP-82 may be useful for wound-healing material through stabilizing the clot via the platelet induction for the first process.
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Affiliation(s)
- Jaruwan Siritapetawee
- School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Chutima Talabnin
- School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Jarunee Vanichtanankul
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Thailand Science Park, Khlong Luang, Pathum Thani, Thailand
| | | | - Kanjana Thumanu
- Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima, Thailand
| | - Chun-Jung Chen
- Life Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Nantarat Komanasin
- Department of Clinical Microscopy, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Cardiovascular Research Group, Khon Kaen University, Khon Kaen, Thailand
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22
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23
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Misawa Y, Kelley KA, Wang X, Wang L, Park WB, Birtel J, Saslowsky D, Lee JC. Staphylococcus aureus Colonization of the Mouse Gastrointestinal Tract Is Modulated by Wall Teichoic Acid, Capsule, and Surface Proteins. PLoS Pathog 2015. [PMID: 26201029 PMCID: PMC4511793 DOI: 10.1371/journal.ppat.1005061] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus colonizes the nose, throat, skin, and gastrointestinal (GI) tract of humans. GI carriage of S. aureus is difficult to eradicate and has been shown to facilitate the transmission of the bacterium among individuals. Although staphylococcal colonization of the GI tract is asymptomatic, it increases the likelihood of infection, particularly skin and soft tissue infections caused by USA300 isolates. We established a mouse model of persistent S. aureus GI colonization and characterized the impact of selected surface antigens on colonization. In competition experiments, an acapsular mutant colonized better than the parental strain Newman, whereas mutants defective in sortase A and clumping factor A showed impaired ability to colonize the GI tract. Mutants lacking protein A, clumping factor B, poly-N-acetyl glucosamine, or SdrCDE showed no defect in colonization. An S. aureus wall teichoic acid (WTA) mutant (ΔtagO) failed to colonize the mouse nose or GI tract, and the tagO and clfA mutants showed reduced adherence in vitro to intestinal epithelial cells. The tagO mutant was recovered in lower numbers than the wild type strain in the murine stomach and duodenum 1 h after inoculation. This reduced fitness correlated with the in vitro susceptibility of the tagO mutant to bile salts, proteases, and a gut-associated defensin. Newman ΔtagO showed enhanced susceptibility to autolysis, and an autolysin (atl) tagO double mutant abrogated this phenotype. However, the atl tagO mutant did not survive better in the mouse GI tract than the tagO mutant. Our results indicate that the failure of the tagO mutant to colonize the GI tract correlates with its poor adherence and susceptibility to bactericidal factors within the mouse gut, but not to enhanced activity of its major autolysin. Staphylococcus aureus persistently colonizes ~20% of the human population, and 40–60% of humans are intermittently colonized by this bacterium. The most common reservoir for S. aureus is the anterior nares, and the incidence of staphylococcal disease in higher in individuals who are colonized. Rectal colonization by S. aureus isolates, reflecting gastrointestinal (GI) carriage, has recently been recognized as an important reservoir from which person to person transmission occurs. We developed a murine model of S. aureus GI colonization to investigate bacterial factors that promote staphylococcal colonization of the gut. We identified several surface-associated S. aureus antigens that modulate colonization of the GI tract and identified a surface glycopolymer (cell wall teichoic acid) as critical for the early steps in colonization. The failure of the teichoic acid mutant to colonize the GI tract can be attributed to its defects in bacterial adherence and to its enhanced susceptibility to mammalian host defenses unique to the gastrointestinal tract. Efforts to develop antimicrobials that target WTA may lead to an overall reduction in asymptomatic colonization by antibiotic-resistant S. aureus and may impact the incidence of invasive disease.
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Affiliation(s)
- Yoshiki Misawa
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kathryn A. Kelley
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xiaogang Wang
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Linhui Wang
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Wan Beom Park
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Johannes Birtel
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David Saslowsky
- Department of Pediatrics, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jean C. Lee
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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24
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Ferrera C, Vilacosta I, Fernández C, López J, Sarriá C, Olmos C, Vivas D, Sáez C, Sánchez-Enrique C, Ortiz C, San Román JA. Usefulness of thrombocytopenia at admission as a prognostic marker in native valve left-sided infective endocarditis. Am J Cardiol 2015; 115:950-5. [PMID: 25708863 DOI: 10.1016/j.amjcard.2015.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/03/2015] [Accepted: 01/03/2015] [Indexed: 11/18/2022]
Abstract
In-hospital mortality of patients with infective endocarditis (IE) remains exceedingly high. Quick recognition of parameters accurately identifying high-risk patients is of paramount importance. The objective of this study was to analyze the incidence and severity of thrombocytopenia at presentation and its prognostic impact in patients with native valve left-sided IE. We studied a cohort of 533 consecutive episodes of native valve left-sided IE prospectively recruited. We distinguished 2 groups: group I (n = 175), episodes who had thrombocytopenia at admission, and group II (n = 358) gathered all the episodes who did not. Thrombocytopenia at admission was defined as a platelet count of <150,000/μl. No differences were found in the need for surgery, but in-hospital mortality was significantly higher in patients with thrombocytopenia (p <0.001). Mortality rate was associated with the degree of thrombocytopenia (p <0.001). In the multivariable analysis, thrombocytopenia at admission was an independent predictor of higher mortality (p = 0.002). A synergistic interaction between thrombocytopenia and Staphylococcus aureus on mortality risk was also observed (p = 0.04). In conclusion, thrombocytopenia at admission is an early risk marker of increased mortality in patients with native valve left-sided IE. Mortality rates increased with increasing severity of thrombocytopenia. Thrombocytopenia at admission should be used as an early marker for risk stratification in patients with native valve IE to identify those at risk of complicated in-hospital evolution and increased mortality.
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Affiliation(s)
- Carlos Ferrera
- Instituto Cardiovascular, Hospital Clínico San Carlos, Madrid, Spain.
| | - Isidre Vilacosta
- Instituto Cardiovascular, Hospital Clínico San Carlos, Madrid, Spain
| | | | - Javier López
- Instituto de Ciencias del Corazón (ICICOR), Hospital Universitario de Valladolid, Valladolid, Spain
| | - Cristina Sarriá
- Servicio de Medicina Interna, Hospital Universitario de la Princesa, Madrid, Spain
| | - Carmen Olmos
- Instituto Cardiovascular, Hospital Clínico San Carlos, Madrid, Spain
| | - David Vivas
- Instituto Cardiovascular, Hospital Clínico San Carlos, Madrid, Spain
| | - Carmen Sáez
- Servicio de Medicina Interna, Hospital Universitario de la Princesa, Madrid, Spain
| | | | - Carlos Ortiz
- Instituto de Ciencias del Corazón (ICICOR), Hospital Universitario de Valladolid, Valladolid, Spain
| | - José Alberto San Román
- Instituto de Ciencias del Corazón (ICICOR), Hospital Universitario de Valladolid, Valladolid, Spain
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25
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Association of mean platelet volume level with in-hospital major adverse events in infective endocarditis. Wien Klin Wochenschr 2015; 127:197-202. [PMID: 25777146 DOI: 10.1007/s00508-015-0746-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 01/20/2015] [Indexed: 10/23/2022]
Abstract
We hypothesised that increased on-admission and follow-up mean platelet volume (MPV) levels would correlate with adverse outcomes in patients with infective endocarditis (IE). A total of 108 consecutive patients were grouped into two according to median MPV level (≤ 8.6 and > 8.6 fL). Patients with MPV level of > 8.6 fL had a significantly higher rate of end-stage renal disease, Staphylococcus aureus infection, higher CRP levels, embolic events and in-hospital mortality compared to patients with MPV levels ≤ 8.6 fL. In multivariable Cox regression analysis, previous history of IE, S. aureus infection, end-stage renal disease, depressed LVEF, early surgical intervention, vegetation size ≥ 10 mm, presence of perivalvular abscess, higher on-admission platelet count, CRP and MPV levels emerged as independent predictors of in-hospital unfavourable outcomes. Patients with embolic events and in-hospital mortality revealed an incremental trend for MPV levels compared to patients without any adverse events. Our study results suggest that both on-admission and follow-up MPV levels may be a simple and available biomarker for risk stratification of IE patients.
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Hamzeh-Cognasse H, Damien P, Chabert A, Pozzetto B, Cognasse F, Garraud O. Platelets and infections - complex interactions with bacteria. Front Immunol 2015; 6:82. [PMID: 25767472 PMCID: PMC4341565 DOI: 10.3389/fimmu.2015.00082] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 02/11/2015] [Indexed: 12/29/2022] Open
Abstract
Platelets can be considered sentinels of vascular system due to their high number in the circulation and to the range of functional immunoreceptors they express. Platelets express a wide range of potential bacterial receptors, including complement receptors, FcγRII, Toll-like receptors but also integrins conventionally described in the hemostatic response, such as GPIIb–IIIa or GPIb. Bacteria bind these receptors either directly, or indirectly via fibrinogen, fibronectin, the first complement C1q, the von Willebrand Factor, etc. The fate of platelet-bound bacteria is questioned. Several studies reported the ability of activated platelets to internalize bacteria such as Staphylococcus aureus or Porphyromonas gingivalis, though there is no clue on what happens thereafter. Are they sheltered from the immune system in the cytoplasm of platelets or are they lysed? Indeed, while the presence of phagolysosome has not been demonstrated in platelets, they contain antimicrobial peptides that were shown to be efficient on S. aureus. Besides, the fact that bacteria can bind to platelets via receptors involved in hemostasis suggests that they may induce aggregation; this has indeed been described for Streptococcus sanguinis, S. epidermidis, or C. pneumoniae. On the other hand, platelets are able to display an inflammatory response to an infectious triggering. We, and others, have shown that platelet release soluble immunomodulatory factors upon stimulation by bacterial components. Moreover, interactions between bacteria and platelets are not limited to only these two partners. Indeed, platelets are also essential for the formation of neutrophil extracellular traps by neutrophils, resulting in bacterial clearance by trapping bacteria and concentrating antibacterial factors but in enhancing thrombosis. In conclusion, the platelet–bacteria interplay is a complex game; its fine analysis is complicated by the fact that the inflammatory component adds to the aggregation response.
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Affiliation(s)
| | - Pauline Damien
- GIMAP-EA3064, Université de Lyon , Saint-Etienne , France
| | - Adrien Chabert
- GIMAP-EA3064, Université de Lyon , Saint-Etienne , France
| | - Bruno Pozzetto
- GIMAP-EA3064, Université de Lyon , Saint-Etienne , France
| | - Fabrice Cognasse
- GIMAP-EA3064, Université de Lyon , Saint-Etienne , France ; Etablissement Français du Sang Auvergne-Loire , Saint-Etienne , France
| | - Olivier Garraud
- GIMAP-EA3064, Université de Lyon , Saint-Etienne , France ; Institut National de la Transfusion Sanguine , Paris , France
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Werdan K, Dietz S, Löffler B, Niemann S, Bushnaq H, Silber RE, Peters G, Müller-Werdan U. Mechanisms of infective endocarditis: pathogen–host interaction and risk states. Nat Rev Cardiol 2013; 11:35-50. [DOI: 10.1038/nrcardio.2013.174] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Anderson AS, Miller AA, Donald RGK, Scully IL, Nanra JS, Cooper D, Jansen KU. Development of a multicomponent Staphylococcus aureus vaccine designed to counter multiple bacterial virulence factors. Hum Vaccin Immunother 2012; 8:1585-94. [PMID: 22922765 PMCID: PMC3601133 DOI: 10.4161/hv.21872] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Staphylococcus aureus is a major cause of healthcare-associated infections and is responsible for a substantial burden of disease in hospitalized patients. Despite increasingly rigorous infection control guidelines, the prevalence and corresponding negative impact of S. aureus infections remain considerable. Difficulties in controlling S. aureus infections as well as the associated treatment costs are exacerbated by increasing rates of resistance to available antibiotics. Despite ongoing efforts over the past 20 years, no licensed S. aureus vaccine is currently available. However, learnings from past clinical failures of vaccine candidates and a better understanding of the immunopathology of S. aureus colonization and infection have aided in the design of new vaccine candidates based on multiple important bacterial pathogenesis mechanisms. This review outlines important considerations in designing a vaccine for the prevention of S. aureus disease in healthcare settings.
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A recombinant clumping factor A-containing vaccine induces functional antibodies to Staphylococcus aureus that are not observed after natural exposure. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1641-50. [PMID: 22896688 DOI: 10.1128/cvi.00354-12] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Staphylococcus aureus is a Gram-positive pathogen that causes devastating disease and whose pathogenesis is dependent on interactions with host cell factors. Staphylococcal clumping factor A (ClfA) is a highly conserved fibrinogen (Fg)-binding protein and virulence factor that contributes to host tissue adhesion and initiation of infection. ClfA is being investigated as a possible component of a staphylococcal vaccine. We report the development of an Fg-binding assay that is specific for ClfA-mediated binding. Using the assay, we show that despite the presence of anti-ClfA antibodies, human sera from unvaccinated subjects are unable to prevent the binding of S. aureus to an Fg-coated surface. In contrast, antibodies elicited by a recombinant ClfA-containing vaccine were capable of blocking the ClfA-dependent binding of a diverse and clinically relevant collection of staphylococcal strains to Fg. These functional antibodies were also able to displace S. aureus already bound to Fg, suggesting that the ligand-binding activity of ClfA can be effectively neutralized through vaccination.
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Collins J, van Pijkeren JP, Svensson L, Claesson MJ, Sturme M, Li Y, Cooney JC, van Sinderen D, Walker AW, Parkhill J, Shannon O, O'Toole PW. Fibrinogen-binding and platelet-aggregation activities of a Lactobacillus salivarius septicaemia isolate are mediated by a novel fibrinogen-binding protein. Mol Microbiol 2012; 85:862-77. [PMID: 22724453 DOI: 10.1111/j.1365-2958.2012.08148.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The marketplace for probiotic foods is burgeoning, measured in billions of euro per annum. It is imperative, however, that all bacterial strains are fully assessed for human safety. The ability to bind fibrinogen is considered a potential pathogenicity trait that can lead to platelet aggregation, serious medical complications, and in some instances, death. Here we examined strains from species frequently used as probiotics for their ability to bind human fibrinogen. Only one strain (CCUG 47825), a Lactobacillus salivarius isolate from a case of septicaemia, was found to strongly adhere to fibrinogen. Furthermore, this strain was found to aggregate human platelets at a level comparable to the human pathogen Staphylococcus aureus. By sequencing the genome of CCUG 47825, we were able to identify candidate genes responsible for fibrinogen binding. Complementing the genetic analysis with traditional molecular microbiological techniques enabled the identification of the novel fibrinogen receptor, CCUG_2371. Although only strain CCUG 47825 bound fibrinogen under laboratory conditions, homologues of the novel fibrinogen binding gene CCUG_2371 are widespread among L. salivarius strains, maintaining their potential to bind fibrinogen if expressed. We highlight the fact that without a full genetic analysis of strains for human consumption, potential pathogenicity traits may go undetected.
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Affiliation(s)
- James Collins
- Department of Microbiology and Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
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Vanassche T, Kauskot A, Verhaegen J, Peetermans WE, van Ryn J, Schneewind O, Hoylaerts MF, Verhamme P. Fibrin formation by staphylothrombin facilitates Staphylococcus aureus-induced platelet aggregation. Thromb Haemost 2012; 107:1107-21. [PMID: 22437005 DOI: 10.1160/th11-12-0891] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 03/01/2012] [Indexed: 11/05/2022]
Abstract
Interactions of Staphylococcus aureus (S. aureus) and platelets play an important role in the pathogenesis of intravascular infections such as infective endocarditis (IE). A typical feature of S. aureus is the ability to generate thrombin activity through the secretion of two prothrombin activating molecules, staphylocoagulase and von Willebrand factor-binding protein (vWbp), which bind to human prothrombin to form the enzymatically active staphylothrombin complex. The role of staphylothrombin in the interaction between S. aureus and platelets has not yet been studied. We found that in contrast with thrombin, staphylothrombin did not directly activate human platelets. However, the staphylothrombin-mediated conversion of fibrinogen to fibrin initiated platelet aggregation and secondary activation and facilitated S. aureus-platelet interactions. Both the genetic absence of staphylocoagulase and vWbp and pharmacological inhibition of staphylothrombin increased the lag time to aggregation, and reduced platelet trapping by S. aureus in high shear stress conditions. The combined inhibition of staphylothrombin and immunoglobulin binding to platelets completely abolished the ability of S. aureus to aggregate platelets in vitro. In conclusion, although staphylothrombin did not directly activate platelets, the formation of a fibrin scaffold facilitated bacteria-platelet interaction, and the inhibition of staphylothrombin resulted in a reduced activation of platelets by S. aureus.
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Affiliation(s)
- Thomas Vanassche
- Center for Molecular and Vascular Biology, University of Leuven, University Hospitals Leuven, B-3000 Leuven, Belgium.
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Jung EC, Kim JH, Lee KH, Yoon JA, Lee IS, Lee SH. Application of Gravitational Field-Flow Fractionation (GrFFF) for Monitoring of Clustering Behavior of Staphylococcus aureus. B KOREAN CHEM SOC 2012. [DOI: 10.5012/bkcs.2012.33.2.711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Johansson D, Shannon O, Rasmussen M. Platelet and neutrophil responses to Gram positive pathogens in patients with bacteremic infection. PLoS One 2011; 6:e26928. [PMID: 22140434 PMCID: PMC3226579 DOI: 10.1371/journal.pone.0026928] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 10/06/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Many Gram-positive pathogens aggregate and activate platelets in vitro and this has been proposed to contribute to virulence. Platelets can also form complexes with neutrophils but little is however known about platelet and platelet-neutrophil responses in bacterial infection. METHODOLOGY/PRINCIPAL FINDINGS We added isolates of Gram-positive bacteria from 38 patients with a bacteremic infection to blood drawn from the same patient. Aggregometry and flow cytometry were used to assess platelet aggregation and to quantify activation of platelets, neutrophils, and platelet-neutrophils complexes (PNCs) induced by the bacteria. Fifteen healthy persons served as controls. Most isolates of Staphylococcus aureus, beta hemolytic streptococci, and Enterococcus faecalis induced aggregation of platelets from their respective hosts, whereas pneumococci failed to do so. S. aureus isolates induced platelet aggregation more rapidly in patients than in controls, whereas platelet activation by S. aureus was lower in patients than in controls. PNCs were more abundant in baseline samples from patients than in healthy controls and most bacterial isolates induced additional PNC formation and neutrophil activation. CONCLUSION/SIGNIFICANCE We have demonstrated for the first time that bacteria isolated from patients with Gram-positive bacteremia can induce platelet activation and aggregation, PNC formation, and neutrophil activation in the same infected host. This underlines the significance of these interactions during infection, which could be a target for future therapies in sepsis.
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Affiliation(s)
- Daniel Johansson
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Oonagh Shannon
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
- * E-mail:
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Characterization of the fibrinogen binding domain of bacteriophage lysin from Streptococcus mitis. Infect Immun 2011; 79:3518-26. [PMID: 21690235 DOI: 10.1128/iai.05088-11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The binding of bacteria to human platelets is a likely central mechanism in the pathogenesis of infective endocarditis. Platelet binding by Streptococcus mitis SF100 is mediated in part by a lysin encoded by the lysogenic bacteriophage SM1. In addition to its role in the phage life cycle, lysin mediates the binding of S. mitis to human platelets via its interaction with fibrinogen on the platelet surface. To better define the region of lysin mediating fibrinogen binding, we tested a series of purified lysin truncation variants for their abilities to bind this protein. These studies revealed that the fibrinogen binding domain of lysin is contained within the region spanned by amino acid residues 102 to 198 (lysin(102-198)). This region has no sequence homology to other known fibrinogen binding proteins. Lysin(102-198) bound fibrinogen comparably to full-length lysin and with the same selectivity for the fibrinogen Aα and Bβ chains. Lysin(102-198) also inhibited the binding in vitro of S. mitis to human fibrinogen and platelets. When assessed by platelet aggregometry, the disruption of the lysin gene in SF100 resulted in a significantly longer time to the onset of aggregation of human platelets than that of the parent strain. The preincubation of platelets with purified lysin(102-198) also delayed the onset of aggregation by SF100. These results indicate that the binding of lysin to fibrinogen is mediated by a specific domain of the phage protein and that this interaction is important for both platelet binding and aggregation by S. mitis.
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Gafter-Gvili A, Mansur N, Bivas A, Zemer-Wassercug N, Bishara J, Leibovici L, Paul M. Thrombocytopenia in Staphylococcus aureus bacteremia: risk factors and prognostic importance. Mayo Clin Proc 2011; 86:389-96. [PMID: 21531882 PMCID: PMC3084641 DOI: 10.4065/mcp.2010.0705] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To identify risk factors and outcomes associated with thrombocytopenia at sepsis onset in Staphylococcus aureus bacteremia. PATIENTS AND METHODS This single-center, retrospective, cohort study consists of all adult patients with a first episode of clinical S aureus bacteremia between April 1, 1988, and September 30, 1994, and between January 1, 1999, and December 31, 2007. Thrombocytopenia was defined as a platelet count less than 150 × 10(9)/L. The primary outcome was 30-day all-cause mortality. Risk factors for 30-day all-cause mortality were identified using univariate and multivariable analyses. Multivariable analysis was conducted using forward step logistic regression analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for risk of death. RESULTS A total of 1052 patients had clinical S aureus bacteremia. Thrombocytopenia at sepsis onset was present in 235 patients (22.3%). Thrombocytopenia was associated with community-acquired bacteremia, infections caused by methicillin-sensitive S aureus, high-magnitude bacteremia (defined as >4 positive blood cultures [≥ 3 separate positive blood culture sets]), and endocarditis. Patients with thrombocytopenia presented more commonly with severe sepsis reflected by septic shock and acute renal failure. Thirty-day mortality was significantly higher among patients with thrombocytopenia (132/235 [56.2%]) vs those without thrombocytopenia (281/817 [34.4%]; P<.001). Higher mortality was associated with the degree of thrombocytopenia. In multivariable analysis, thrombocytopenia at baseline remained an independent risk factor for 30-day mortality (OR, 2.82; 95% CI, 1.87-4.24). The adjusted association between thrombocytopenia and death remained similar among the 917 patients with monomicrobial bacteremia (OR, 2.88; 95% CI, 1.83-4.53) and the 945 patients who did not die within the first 48 hours (OR, 2.88; 95% CI, 1.87-4.45.). CONCLUSION We observed a strong association between thrombocytopenia at sepsis onset and all-cause mortality in S aureus bacteremia, possibly related to mechanisms other than sepsis alone.
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Affiliation(s)
- Anat Gafter-Gvili
- Department of Medicine E, Rabin Medical Center, Beilinson Hospital, Petah-Tikva 49100, Israel.
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Whole-genome sequencing of Staphylococcus aureus strain RN4220, a key laboratory strain used in virulence research, identifies mutations that affect not only virulence factors but also the fitness of the strain. J Bacteriol 2011; 193:2332-5. [PMID: 21378186 DOI: 10.1128/jb.00027-11] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus RN4220, a cloning intermediate, is sometimes used in virulence, resistance, and metabolic studies. Using whole-genome sequencing, we showed that RN4220 differs from NCTC8325 and contains a number of genetic polymorphisms that affect both virulence and general fitness, implying a need for caution in using this strain for such studies.
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38
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Yeaman MR. Bacterial-platelet interactions: virulence meets host defense. Future Microbiol 2010; 5:471-506. [PMID: 20210555 DOI: 10.2217/fmb.09.112] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Platelets have historically been viewed as cell fragments that only mediate blood coagulation. Yet, platelets have as - or perhaps even more - important roles in tissue remodeling, modulation of inflammation and antimicrobial host defense. It is evident that platelets interact with prokaryotes directly and indirectly through multiple molecular and cellular mechanisms. The important roles of platelets in antibacterial host defense can be exemplified through contemporary themes in platelet immunobiology. Platelets have unambiguous structures and functions of host defense effector cells. Recent discoveries reveal platelet expression of toll-like and purinonergic receptors, which enable detection and response to bacterial infection, degranulation of an array of microbicidal peptides and coordination of other molecular and cellular host defenses. From multiple perspectives, platelets are now increasingly recognized as critical innate immune effector cells that also bridge and facilitate optimization of adaptive immunity. It follows that clinical deficiencies in platelet quantity or quality are now recognized correlates of increased risk and severity of bacterial and other infections. Along these lines, new evidence suggests that certain prokaryotic organisms may be capable of exploiting platelet interactions to gain a virulence advantage. Indeed, certain bacterial pathogens appear to have evolved highly coordinated means by which to seize opportunities to bind to surfaces of activated platelets, and exploit them to establish or propagate infection. Hence, it is conceivable that certain bacterial pathogens subvert platelet functions. From these perspectives, the net consequences of bacterial virulence versus platelet host defenses likely decide initial steps towards the ultimate result of infection versus immunity.
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Affiliation(s)
- Michael R Yeaman
- Department of Medicine, David Geffen School of Medicine at UCLA, Harbor-UCLA Medical Center, 1124 West Carson Street, RB-2, Torrance, CA 90502, USA.
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Abstract
Platelets interact with bacterial pathogens through a wide array of cellular and molecular mechanisms. The consequences of this interaction may significantly influence the balance between infection and immunity. On the one hand, recent data indicate that certain bacteria may be capable of exploiting these interactions to gain a virulence advantage. Indeed, certain bacterial pathogens appear to have evolved specific ways in which to subvert activated platelets. Hence, it is conceivable that some bacterial pathogens exploit platelet responses. On the other hand, platelets are now known to possess unambiguous structures and functions of host defense effector cells. Recent discoveries emphasize critical features enabling such functions, including expression of toll-like receptors that detect hallmark signals of bacterial infection, an array of microbicidal peptides, as well as other host defense molecules and functions. These concepts are consistent with increased risk and severity of bacterial infection as correlates of clinical abnormalities in platelet quantity and quality. In these respects, the molecular and cellular roles of platelets in host defense against bacterial pathogens are explored with attention on advances in platelet immunobiology.
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Affiliation(s)
- Michael R Yeaman
- Division of Infectious Diseases, St. John's Cardiovascular Research Center, Harbor-UCLA Medical Center, David Geffen School of Medicine at UCLA, Torrance, CA 90502, USA.
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Izumi Y, Nagasawa T, Umeda M, Kobayashi H, Takeuchi Y, Yashiro R, Hormdee D, Suda T, Ushida Y, Wara-aswapati N. Periodontitis and cardiovascular diseases: The link and relevant mechanisms. JAPANESE DENTAL SCIENCE REVIEW 2009. [DOI: 10.1016/j.jdsr.2009.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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[Platelet immunology and the immune response]. Transfus Clin Biol 2009; 16:106-17. [PMID: 19443253 DOI: 10.1016/j.tracli.2009.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 03/11/2009] [Indexed: 01/18/2023]
Abstract
Platelets exert not only hemostatic activities, but also pro-inflammatory effects. Platelet-linked inflammation seems essentially related to their capacity of secreting cytokines, chemokines and related molecules. This activity is important in terms of concentration of secreted products. This secretory function confers to platelets a regulatory role in immunity. Besides, platelets do exhibit non-self infectious danger detection molecules on their surfaces, belonging in particular to the "Toll-like receptor family"; through this property, platelets can bind infectious agents but also deliver differential signals for the secretion of cytokines and chemokines. Platelets, which are non-nucleated cells deprived of nuclear DNA, possess however some cellular machinery which permits intracellular signalling and even the production of RNA transcripts for certain cytokines. Last, platelets express variant surface determinants of hemostatic molecules (referred to as HPA antigens) along with HLA class I variant molecules, the function of which on platelets is still unknown. An intriguing question is to reconcile those diverse properties and to understand whether the pro-inflammatory secretory process can affect the immunogenicity of transfused, allogeneic, platelet components.
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Platelet antistaphylococcal responses occur through P2X1 and P2Y12 receptor-induced activation and kinocidin release. Infect Immun 2008; 76:5706-13. [PMID: 18824536 DOI: 10.1128/iai.00935-08] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelets (PLTs) act in antimicrobial host defense by releasing PLT microbicidal proteins (PMPs) or PLT kinocidins (PKs). Receptors mediating staphylocidal efficacy and PMP or PK release versus isogenic PMP-susceptible (ISP479C) and -resistant (ISP479R) Staphylococcus aureus strains were examined in vitro. Isolated PLTs were incubated with ISP479C or ISP479R (PLT/S. aureus ratio range, 1:1 to 10,000:1) in the presence or absence of a panel of PLT inhibitors, including P2X and P2Y receptor antagonists of increasingly narrow specificity, and PLT adhesion receptors (CD41, CD42b, and CD62P). PLT-to-S. aureus exposure ratios of > or = 10:1 yielded significant reductions in the viability of both strains. Results from reversed-phase high-performance liquid chromatography indicated that staphylocidal PLT releasates contained PMPs and PKs. At ratios below 10:1, the PLT antistaphylococcal efficacy relative to the intrinsic S. aureus PMP-susceptible or -resistant phenotype diminished. Apyrase (an agent of ADP degradation), suramin (a general P2 receptor antagonist), pyridoxal 5'-phosphonucleotide derivative (a specific P2X(1) antagonist), and cangrelor (a specific P2Y(12) antagonist) mitigated the PLT staphylocidal response against both strains, correlating with reduced levels of PMP and PK release. Specific inhibition occurred in the presence and absence of homologous plasma. The antagonism of the thromboxane A(2), cyclooxygenase-1/cyclooxygenase-2, or phospholipase C pathway or the hindrance of surface adhesion receptors failed to impede PLT anti-S. aureus responses. These results suggest a multifactorial PLT anti-S. aureus response mechanism involving (i) a PLT-to-S. aureus ratio sufficient for activation; (ii) the ensuing degranulation of PMPs, PKs, ADP, and/or ATP; (iii) the activation of P2X(1)/P2Y(12) receptors on adjacent PLTs; and (iv) the recursive amplification of PMP and PK release from these PLTs.
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Li X, Iwai T, Nakamura H, Inoue Y, Chen Y, Umeda M, Suzuki H. An ultrastructural study of Porphyromonas gingivalis-induced platelet aggregation. Thromb Res 2008; 122:810-9. [PMID: 18448150 DOI: 10.1016/j.thromres.2008.03.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Revised: 12/23/2007] [Accepted: 03/04/2008] [Indexed: 10/22/2022]
Abstract
One of the major pathogens of periodontitis, Porphyromonas gingivalis (P. gingivalis), has the ability to aggregate human platelets. To investigate the interaction between P. gingivalis and human platelets in platelet rich plasma (PRP), platelet aggregation was measured by an aggregometer based on laser light scattering (LS) methods, and an ultrastructural study was performed using electron microscopy. A sharp and rapid increase of small-sized platelet aggregates was observed immediately after the addition of P. gingivalis to PRP, followed by the formation of medium- and large-sized aggregates in 2-3 min. In contrast, when Staphylococcus aureus (S. aureus) was used in the control experiment, only a slight increase in small-sized aggregates was detected. By electron microscopy, discoid-shaped platelets were observed prior to adding P. gingivalis. By 5 min after the addition of the bacteria, enormous platelet aggregates were observable. Most of the P. gingivalis were present between the adherent platelets, while some were internalized in platelet engulfment vacuoles. In contrast, when washed platelets were incubated with the bacteria under a non-stirring condition to prevent platelet aggregation, and stained with ruthenium red (RR) as an electron dense tracer of the cell surface including the open canalicular system (OCS), both RR-positive and -negative vacuoles containing P. gingivalis were identified in the activated platelets. Thus, this observation suggests that P. gingivalis residing in the RR-negative vacuoles is incorporated into the platelet cytoplasm by phagocytosis.
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Affiliation(s)
- Xiangfeng Li
- Department of Surgery, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
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Staphylococcal Presence Alters Thrombus Formation Under Physiological Shear Conditions in Whole Blood Studies. Ann Biomed Eng 2008; 36:349-55. [DOI: 10.1007/s10439-007-9434-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Accepted: 12/26/2007] [Indexed: 10/22/2022]
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45
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Kerrigan SW, Clarke N, Loughman A, Meade G, Foster TJ, Cox D. Molecular basis for Staphylococcus aureus-mediated platelet aggregate formation under arterial shear in vitro. Arterioscler Thromb Vasc Biol 2007; 28:335-40. [PMID: 18063809 DOI: 10.1161/atvbaha.107.152058] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Staphylococcus aureus is the most frequent causative organism of infective endocarditis (IE) and is characterized by thrombus formation on a cardiac valve that can embolize to a distant site. Previously, we showed that S. aureus clumping factor A (ClfA) and fibronectin-binding protein A (FnBPA) can stimulate rapid platelet aggregation. METHODS AND RESULTS In this study we investigate their relative roles in mediating aggregate formation under physiological shear conditions. Platelets failed to interact with immobilized wild-type S. aureus (Newman) at shear rates <500 s(-1) but rapidly formed an aggregate at shear rates >800 s(-1). Inactivation of the ClfA gene eliminated aggregate formation at any shear rate. Using surrogate hosts that do not interact with platelets bacteria overexpressing ClfA supported rapid aggregate formation under high shear with a similar profile to Newman whereas bacteria overexpressing FnBPA did not. Fibrinogen binding to ClfA was found to be essential for aggregate formation although fibrinogen-coated surfaces only allowed single-platelets to adhere under all shear conditions. Blockade of the platelet immunoglobulin receptor Fc gammaRIIa inhibited aggregate formation. CONCLUSIONS Thus, fibrinogen and IgG binding to ClfA is essential for aggregate formation under arterial shear conditions and may explain why S. aureus is the major cause of IE.
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Affiliation(s)
- Steven W Kerrigan
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
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Cheung AL. Isolation and Culture of Human Umbilical Vein Endothelial Cells (HUVEC). ACTA ACUST UNITED AC 2007; Appendix 4:Appendix 4B. [DOI: 10.1002/9780471729259.mca04bs4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Antimicrobial Host Defense. Platelets 2007. [DOI: 10.1016/b978-012369367-9/50802-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Abstract
It has been estimated that there are more microorganisms within and upon the human body than there are human cells. By necessity, every accessible niche must be defended by innate mechanisms to prevent invasive infection, and ideally that precludes the need for robust inflammatory responses. Yet the potential for pathogens to transcend the integument actively or passively and access the bloodstream emphasizes the need for rapid and potent antimicrobial defense mechanisms within the vascular compartment. Antimicrobial peptides from leukocytes have long been contemplated as being integral to defense against these infections. Recently, platelets are increasingly recognized for their likely multiple roles in antimicrobial host defense. Platelets and leukocytes share many structural and functional archetypes. Once activated, both cell types respond in specific ways that emphasize key roles for their antimicrobial peptides in host defense efficacy: (a) targeted accumulation at sites of tissue injury or infection; (b) direct interaction with pathogens; and (c) deployment of intracellular (leukocyte phagosomes) or extracellular (platelet secretion) antimicrobial peptides. Antimicrobial peptides from these cells exert rapid, potent, and direct antimicrobial effects against organisms that commonly access the bloodstream. Experimental models in vitro and in vivo show that antimicrobial peptides from these cells significantly contribute to prevent or limit infection. Moreover, certain platelet antimicrobial proteins are multifunctional kinocidins (microbicidal chemokines) that recruit leukocytes to sites of infection, and potentiate the antimicrobial mechanisms of these cells. In turn, pathogens pre-decorated by kinocidins may be more efficiently phagocytosed and killed by leukocytes and their antimicrobial peptide arsenal. Hence, multiple and relevant interactions between platelets and leukocytes have immunologic functions yet to be fully understood. A clearer definition of these interactions, and the antimicrobial peptide effectors contributing to these functions, will significantly advance our understanding of antimicrobial host defense against invasive infection. In addition, this knowledge may accelerate development of novel anti-infective agents and strategies against pathogens that have become refractory to conventional antimicrobials.
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Affiliation(s)
- M R Yeaman
- Division of Infectious Diseases, David Geffen School of Medicine at UCLA, LAC-Harbor UCLA Medical Center, Torrance 90502, USA.
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Widmer E, Que YA, Entenza JM, Moreillon P. New concepts in the pathophysiology of infective endocarditis. Curr Infect Dis Rep 2006; 8:271-9. [PMID: 16822370 DOI: 10.1007/s11908-006-0071-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Endocarditis pathogens colonize valves with pre-existing sterile vegetations or valves with minimal endothelial lesions. Inflamed endothelia produce cytokines, integrins, and tissue factor, which in turn attract fibronectin, monocytes, and platelets. Bacteria attaching to such structures further activate the cascade, becoming embedded and protected from host defenses. Staphylococcus aureus also actively invade the endothelium, causing apoptosis and endothelial damage. Knowledge of this interplay identifies host factors as potential therapeutic targets. Blocking infection by modulating host factors might be opportune because host factors are conserved. In contrast, interfering with bacterial virulence factors might be more complicated because they vary among different bacteria.
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Affiliation(s)
- Eleonora Widmer
- Department of Fundamental Microbiology, University of Lausanne, Biophore building, CH-1015 Lausanne, Switzerland
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