1
|
Hoerr V, Franz M, Pletz MW, Diab M, Niemann S, Faber C, Doenst T, Schulze PC, Deinhardt-Emmer S, Löffler B. S. aureus endocarditis: Clinical aspects and experimental approaches. Int J Med Microbiol 2018. [PMID: 29526448 DOI: 10.1016/j.ijmm.2018.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Infective endocarditis (IE) is a life-threatening disease, caused by septic vegetations and inflammatory foci on the surface of the endothelium and the valves. Due to its complex and often indecisive presentation the mortality rate is still about 30%. Most frequently bacterial microorganisms entering the bloodstream are the underlying origin of the intracardiac infection. While the disease was primarily restricted to younger patients suffering from rheumatic heart streptococci infections, new at risk categories for Staphylococcus (S.) aureus infections arose over the last years. Rising patient age, increasing drug resistance, intensive treatment conditions such as renal hemodialysis, immunosuppression and long term indwelling central venous catheters but also the application of modern cardiac device implants and valve prosthesis have led to emerging incidences of S. aureus IE in health care settings and community. The aetiologic change has impact on the pathophysiology of IE, the clinical presentation and the overall patient management. Despite intensive research on appropriate in vitro and in vivo models of IE and gained knowledge about the fundamental mechanisms in the formation of bacterial vegetations and extracardiac complications, improved understanding of relevant bacterial virulence factors and triggered host immune responses is required to help developing novel antipathogenic treatment strategies and pathogen specific diagnostic markers. In this review, we summarize and discuss the two main areas affected by the changing patient demographics and provide first, recent knowledge about the pathogenic strategies of S. aureus in the induction of IE, including available experimental models of IE used to study host-pathogen interactions and diagnostic and therapeutic targets. In a second focus we present diagnostic (imaging) regimens for patients with S. aureus IE according to current guidelines as well as treatment strategies and surgical recommendations.
Collapse
Affiliation(s)
- V Hoerr
- Institute of Medical Microbiology, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany.
| | - M Franz
- Department of Internal Medicine I, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| | - M W Pletz
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| | - M Diab
- Department of Cardiothoracic Surgery, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| | - S Niemann
- Institute of Medical Microbiology, University Hospital Münster, Domagkstr. 10, 48149 Münster, Germany
| | - C Faber
- Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A16, 48149 Münster, Germany
| | - T Doenst
- Department of Cardiothoracic Surgery, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| | - P C Schulze
- Department of Internal Medicine I, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| | - S Deinhardt-Emmer
- Institute of Medical Microbiology, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| | - B Löffler
- Institute of Medical Microbiology, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| |
Collapse
|
2
|
Panizzi P, Stone JR, Nahrendorf M. Endocarditis and molecular imaging. J Nucl Cardiol 2014; 21:486-95. [PMID: 24797384 PMCID: PMC4106242 DOI: 10.1007/s12350-014-9902-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 04/03/2014] [Indexed: 10/25/2022]
Affiliation(s)
- Peter Panizzi
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA
| | - James R. Stone
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Simches Research Building, 185 Cambridge St., Boston, MA 02114, USA
| | - Matthias Nahrendorf
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Simches Research Building, 185 Cambridge St., Boston, MA 02114, USA
| |
Collapse
|
3
|
Eggleston H, Panizzi P. Molecular imaging of bacterial infections in vivo: the discrimination of infection from inflammation. INFORMATICS (MDPI) 2014; 1:72-99. [PMID: 26985401 PMCID: PMC4790455 DOI: 10.3390/informatics1010072] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Molecular imaging by definition is the visualization of molecular and cellular processes within a given system. The modalities and reagents described here represent a diverse array spanning both pre-clinical and clinical applications. Innovations in probe design and technologies would greatly benefit therapeutic outcomes by enhancing diagnostic accuracy and assessment of acute therapy. Opportunistic pathogens continue to pose a worldwide threat, despite advancements in treatment strategies, which highlights the continued need for improved diagnostics. In this review, we present a summary of the current clinical protocol for the imaging of a suspected infection, methods currently in development to optimize this imaging process, and finally, insight into endocarditis as a model of infectious disease in immediate need of improved diagnostic methods.
Collapse
Affiliation(s)
- Heather Eggleston
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849
| | - Peter Panizzi
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849
| |
Collapse
|
4
|
Mercier RC, Rybak MJ, Bayer AS, Yeaman MR. Influence of platelets and platelet microbicidal protein susceptibility on the fate of Staphylococcus aureus in an in vitro model of infective endocarditis. Infect Immun 2000; 68:4699-705. [PMID: 10899875 PMCID: PMC98414 DOI: 10.1128/iai.68.8.4699-4705.2000] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several lines of evidence indicate that platelets protect against endovascular infections such as infective endocarditis (IE). It is highly likely that a principal mechanism of this platelet host defense role is the release of platelet microbicidal proteins (PMPs) in response to agonists generated at sites of endovascular infection. We studied the ability of platelets to limit the colonization and proliferation of Staphylococcus aureus in an in vitro model of IE. Three isogenic S. aureus strains, differing in their in vitro susceptibility to thrombin-induced platelet microbicidal protein-1 (tPMP), were used: ISP479C (parental strain; highly susceptible to tPMP [tPMP(s)]); ISP479R (transposon mutant derived from ISP479; tPMP resistant [tPMP(r)]); or 757-5 (tPMP(r) transductant of the ISP479R genotype in the ISP479 parental background). Time-kill assays and in vitro IE models were used to examine the temporal relationship between thrombin-induced platelet activation and S. aureus killing. In time-kill studies, early platelet activation (30 min prior to bacterial exposure) correlated with a significant bactericidal effect against tPMP(s) ISP479C (r(2) > 0.90, P < 0.02) but not against tPMP(r) strains, ISP479R or 757-5. In the IE model, thrombin activation significantly inhibited proliferation of ISP479C within simulated vegetations compared to strains ISP479R or 757-5 (P < 0.05). The latter differences were observed despite there being no detectable differences among the three S. aureus strains in initial colonization of simulated vegetations. Collectively, these data indicate that platelets limit intravegetation proliferation of tPMP(s) but not tPMP(r) S. aureus. These findings underscore the likelihood that platelets play an important antimicrobial host defense role in preventing and/or limiting endovascular infections due to tPMP(s) pathogens.
Collapse
Affiliation(s)
- R C Mercier
- The Anti-Infective Research Laboratory, Detroit Receiving Hospital/University Health Center and College of Pharmacy, Detroit, Michigan 48201, USA.
| | | | | | | |
Collapse
|
5
|
Kang SL, Rybak MJ. Pharmacodynamics of RP 59500 alone and in combination with vancomycin against Staphylococcus aureus in an in vitro-infected fibrin clot model. Antimicrob Agents Chemother 1995; 39:1505-11. [PMID: 7492094 PMCID: PMC162771 DOI: 10.1128/aac.39.7.1505] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The bactericidal activity and emergence of resistance to RP 59500 (quinupristin/dalfopristin) when it was administered alone and in combination with vancomycin against fibrin clots that have been infected with methicillin-susceptible Staphylococcus aureus ATCC 25923 or methicillin-resistant S. aureus (MRSA) 67 were evaluated in an in vitro pharmacodynamic infected fibrin clot model. Fibrin clots were infected with S. aureus to achieve an inoculum of approximately 10(9) CFU/g. Antibiotics were administered to simulate pharmacokinetics in humans: RP 59500 (7.5 mg/kg of body weight) every 8 h and vancomycin (15 mg/kg) every 12 h over 72 h. Preliminary test tube time-kill experiments with an inoculum of approximately 10(5) CFU/ml suggested that RP 59500 was more rapid in achieving a 99.9% reduction in the number of CFU per milliliter than vancomycin against ATCC 25923 (6.94 versus 24 h; P = 0.0003) and MRSA 67 (6.77 versus 17.03 h; P = 0.004). At a higher inoculum (approximately 10(8) CFU/ml), 99.9% kill was achieved only with the combination regimen against ATCC 25923 and MRSA 67 (10.9 and 10.5 h, respectively), with total reductions of 6.35 and 6.33 log10 CFU/ml over 24 h, respectively. In the fibrin clot model, RP 59500 was more effective than vancomycin in reducing organism titers over 72 h. In the fibrin clot model, the most optimal therapy was the combination regimen.
Collapse
Affiliation(s)
- S L Kang
- Department of Pharmacy Services, Detroit Receiving Hospital, University Health Center, Michigan, USA
| | | |
Collapse
|
6
|
Fantin B, Leclercq R, Ottaviani M, Vallois JM, Maziere B, Duval J, Pocidalo JJ, Carbon C. In vivo activities and penetration of the two components of the streptogramin RP 59500 in cardiac vegetations of experimental endocarditis. Antimicrob Agents Chemother 1994; 38:432-7. [PMID: 8203835 PMCID: PMC284476 DOI: 10.1128/aac.38.3.432] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We evaluated the in vivo activity and the diffusion of radiolabelled RP 57669 (RPI) and RP 54476 (RPII), the two components of the injectable streptogramin RP 59500, alone or in combination, in aortic vegetations from experimental endocarditis in rabbits. RPI and RPII demonstrated in vitro bacteriostatic and bactericidal synergy against a clinical strain of Staphylococcus aureus resistant to methicillin and susceptible to erythromycin. In experimental staphylococcal endocarditis, RP 59500 was as effective as vancomycin and significantly more effective than RPI (P < 0.01) and RPII (P < 0.05). Autoradiography studies showed different patterns of distribution into cardiac vegetations infected with Streptococcus sanguis for [14C]RPI and [14C]RPII. [14C]RPI was homogeneously distributed throughout the vegetations whereas [14C]RPII showed a decreasing gradient of concentration between the periphery and the core of the vegetation, with an approximately 2:1 ratio. [14C]RPI diffused approximately 2 to 4 times more than [14C]RPII into the core of the vegetations. Since the injected ratio of RPI and RPII is 30:70 in RP 59500, the actual RPI:RPII ratio in the core of the vegetation may range from 0.8 to 1.7, a ratio which remains compatible with the in vivo synergism demonstrated between the two components.
Collapse
Affiliation(s)
- B Fantin
- Institut National de la Santé et de la Recherche Médicale, Hôpital Bichat, Université Paris, VII, France
| | | | | | | | | | | | | | | |
Collapse
|