1
|
Del Giudice C, Vaia E, Liccardo D, Marzano F, Valletta A, Spagnuolo G, Ferrara N, Rengo C, Cannavo A, Rengo G. Infective Endocarditis: A Focus on Oral Microbiota. Microorganisms 2021; 9:1218. [PMID: 34199916 PMCID: PMC8227130 DOI: 10.3390/microorganisms9061218] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/17/2021] [Accepted: 06/02/2021] [Indexed: 02/06/2023] Open
Abstract
Infective endocarditis (IE) is an inflammatory disease usually caused by bacteria entering the bloodstream and settling in the heart lining valves or blood vessels. Despite modern antimicrobial and surgical treatments, IE continues to cause substantial morbidity and mortality. Thus, primary prevention and enhanced diagnosis remain the most important strategies to fight this disease. In this regard, it is worth noting that for over 50 years, oral microbiota has been considered one of the significant risk factors for IE. Indeed, among the disparate recommendations from the American heart association and the European Society of Cardiology, there are good oral hygiene and prophylaxis for high-risk patients undergoing dental procedures. Thus, significant interest has grown in the role of oral microbiota and it continues to be a subject of research interest, especially if we consider that antimicrobial treatments can generate drug-resistant mutant bacteria, becoming a severe social problem. This review will describe the current knowledge about the relationship between oral microbiota, dental procedures, and IE. Further, it will discuss current methods used to prevent IE cases that originate from oral pathogens and how these should be focused on improving oral hygiene, which remains the significant persuasible way to prevent bacteremia and systemic disorders.
Collapse
Affiliation(s)
- Carmela Del Giudice
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University of Naples, 80131 Naples, Italy; (C.D.G.); (E.V.); (A.V.); (G.S.)
| | - Emanuele Vaia
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University of Naples, 80131 Naples, Italy; (C.D.G.); (E.V.); (A.V.); (G.S.)
| | - Daniela Liccardo
- Department of Translational Medical Sciences, Medicine Federico II University of Naples, 80131 Naples, Italy; (D.L.); (N.F.); (G.R.)
| | - Federica Marzano
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy;
| | - Alessandra Valletta
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University of Naples, 80131 Naples, Italy; (C.D.G.); (E.V.); (A.V.); (G.S.)
| | - Gianrico Spagnuolo
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University of Naples, 80131 Naples, Italy; (C.D.G.); (E.V.); (A.V.); (G.S.)
- Institute of Dentistry, I. M. Sechenov First Moscow State Medical University, 119435 Moscow, Russia
| | - Nicola Ferrara
- Department of Translational Medical Sciences, Medicine Federico II University of Naples, 80131 Naples, Italy; (D.L.); (N.F.); (G.R.)
- Istituti Clinici Scientifici ICS-Maugeri, 82037 Telese Terme, Italy
| | - Carlo Rengo
- Department of Prosthodontics and Dental Materials, School of Dental Medicine, University of Siena, 53100 Siena, Italy;
| | - Alessandro Cannavo
- Department of Translational Medical Sciences, Medicine Federico II University of Naples, 80131 Naples, Italy; (D.L.); (N.F.); (G.R.)
| | - Giuseppe Rengo
- Department of Translational Medical Sciences, Medicine Federico II University of Naples, 80131 Naples, Italy; (D.L.); (N.F.); (G.R.)
- Istituti Clinici Scientifici ICS-Maugeri, 82037 Telese Terme, Italy
| |
Collapse
|
2
|
Liesenborghs L, Meyers S, Vanassche T, Verhamme P. Coagulation: At the heart of infective endocarditis. J Thromb Haemost 2020; 18:995-1008. [PMID: 31925863 DOI: 10.1111/jth.14736] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022]
Abstract
Infective endocarditis is a life-threatening and enigmatic disease with a mortality of 30% and a pathophysiology that is poorly understood. However, at its core, an endocarditis lesion is mainly a fibrin and platelet blood clot infested with bacteria, clinging at the cardiac valves. Infective endocarditis therefore serves as a paradigm of immunothrombosis gone wrong. Immunothrombosis refers to the entanglement of the coagulation system with innate immunity and the role of coagulation in the isolation and clearance of invading pathogens. However, in the case of infective endocarditis, instead of containing the infection, immunothrombosis inadvertently creates the optimal shelter from the immune system and allows some bacteria to grow almost unimpeded. In every step of the disease, the coagulation system is heavily involved. It mediates the initial adhesion of bacteria to the leaflets, fuels the growth and maturation of a vegetation, and facilitates complications such as embolization and valve destruction. In addition, the number one cause of infective endocarditis, Staphylococcus aureus, has proven to be a true manipulator of immunothrombosis and thrives in the fibrin rich environment of an endocarditis vegetation. Considering its central role in infective endocarditis, the coagulation system is an attractive therapeutic target for this deadly disease. There is, however, a very delicate balance at play and the use of antithrombotic drugs in patients with endocarditis is often accompanied with a high bleeding risk.
Collapse
Affiliation(s)
- Laurens Liesenborghs
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Severien Meyers
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Thomas Vanassche
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Peter Verhamme
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| |
Collapse
|
3
|
He Z, Jiang L, Zhang T, Zhou M, Wu D, Yuan T, Yuan Y, Cheng Y. Efficient increase of the novel recombinant human plasminogen activator expression level and stability through the use of homozygote transgenic rabbits. Int J Mol Med 2018; 42:2269-2275. [PMID: 30015826 DOI: 10.3892/ijmm.2018.3754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 06/19/2018] [Indexed: 11/05/2022] Open
Abstract
Expression efficacy of recombinant protein in current expression systems is generally low. Therefore, the expression levels of recombinant proteins in the breast milk of transgenic animals are typically low. In view of this, the present study aimed to construct homozygous transgenic rabbits with a high expression level of recombinant human plasminogen activator (rhPA) during the entire lactation period. Homozygous transgenic rabbits were obtained using an effective rhPA mammary‑specific expression vector PCL25/rhPA. The expression level and thrombolytic ability of rhPA in the milk of both homozygous and hemizygous rabbits were detected by enzyme‑linked immunosorbent and fibrin agarose plate assays. It was observed that the expression of rhPA was constant during the entire lactation period in homozygous rabbits, while the expression of rhPA declined slowly in hemizygote rhPA transgenic rabbits during the lactation period. In addition, the expression of rhPA in homozygous transgenic rabbit was ~950 µg/ml, which was markedly higher in comparison with that in hemizygote rabbits. Furthermore, increased gene copy number was observed to increase the expression level of rhPA at the same integration vector.
Collapse
Affiliation(s)
- Zhengyi He
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, P.R. China
| | - Lei Jiang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, P.R. China
| | - Ting Zhang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, P.R. China
| | - Minya Zhou
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, P.R. China
| | - Daijin Wu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, P.R. China
| | - Tingting Yuan
- Medical College of Yangzhou University, Yangzhou, Jiangsu 225009, P.R. China
| | - Yuguo Yuan
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, P.R. China
| | - Yong Cheng
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, P.R. China
| |
Collapse
|
4
|
Abstract
BACKGROUND Fungal endocarditis (FE) remains an uncommon but life-threatening complication of invasive fungal infections. As data on neonatal FE are scant, we aimed to review all published experience regarding this serious infection. METHODS Neonatal FE cases published in PubMed (1971-2013) as single cases, or case series were identified using the terms "fungal endocarditis, neonates and cardiac vegetation." Data on predefined criteria including demographics, predisposing factors, mycology, sites of cardiac involvement, therapy and outcome were collected and analyzed. RESULTS The dataset comprised 71 neonates with FE. Median birth weight was 940 g [interquartile range (IQR): 609], median gestational age 27 weeks (IQR: 6) and median postnatal age at diagnosis 20 days (IQR: 20). Ninety-two percent of the patients were premature. Right atrium was the most common vegetation site (63%). Seventy-one percent of the cases reported were associated with previous central venous catheters. Candida albicans was the most predominant fungal species (59%). Amphotericin B monotherapy was used in 42.2% and fluconazole in 2.8%. Amphotericin B with flucytosine (25.3%) was the most frequent combined regimen. Surgical treatment was conducted in 28%. Overall mortality was 42.2%. Initiation with combined antifungal treatment was associated with lower mortality than monotherapy (24.2% vs. 51.7%, respectively, P = 0.036). CONCLUSIONS Neonatal FE most frequently occurs in very premature infants and is associated with central venous catheters. C. albicans is the predominant fungus. Although outcome has been dismal, it may be improved with combined antifungal therapy.
Collapse
|
5
|
Fan J, Zhang Y, Chuang-Smith ON, Frank KL, Guenther BD, Kern M, Schlievert PM, Herzberg MC. Ecto-5'-nucleotidase: a candidate virulence factor in Streptococcus sanguinis experimental endocarditis. PLoS One 2012; 7:e38059. [PMID: 22685551 PMCID: PMC3369921 DOI: 10.1371/journal.pone.0038059] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 05/02/2012] [Indexed: 11/18/2022] Open
Abstract
Streptococcus sanguinis is the most common cause of infective endocarditis (IE). Since the molecular basis of virulence of this oral commensal bacterium remains unclear, we searched the genome of S. sanguinis for previously unidentified virulence factors. We identified a cell surface ecto-5′-nucleotidase (Nt5e), as a candidate virulence factor. By colorimetric phosphate assay, we showed that S. sanguinis Nt5e can hydrolyze extracellular adenosine triphosphate to generate adenosine. Moreover, a nt5e deletion mutant showed significantly shorter lag time (P<0.05) to onset of platelet aggregation than the wild-type strain, without affecting platelet-bacterial adhesion in vitro (P = 0.98). In the absence of nt5e, S. sanguinis caused IE (4 d) in a rabbit model with significantly decreased mass of vegetations (P<0.01) and recovered bacterial loads (log10CFU, P = 0.01), suggesting that Nt5e contributes to the virulence of S. sanguinis in vivo. As a virulence factor, Nt5e may function by (i) hydrolyzing ATP, a pro-inflammatory molecule, and generating adenosine, an immunosuppressive molecule to inhibit phagocytic monocytes/macrophages associated with valvular vegetations. (ii) Nt5e-mediated inhibition of platelet aggregation could also delay presentation of platelet microbicidal proteins to infecting bacteria on heart valves. Both plausible Nt5e-dependent mechanisms would promote survival of infecting S. sanguinis. In conclusion, we now show for the first time that streptococcal Nt5e modulates S. sanguinis-induced platelet aggregation and may contribute to the virulence of streptococci in experimental IE.
Collapse
Affiliation(s)
- Jingyuan Fan
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Yongshu Zhang
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Olivia N. Chuang-Smith
- Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Kristi L. Frank
- Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Brian D. Guenther
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Marissa Kern
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Patrick M. Schlievert
- Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Mark C. Herzberg
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, United States of America
- Mucosal and Vaccine Research Center, Minneapolis Veterans Affairs Medical Center, Minneapolis, Minnesota, United States of America
- * E-mail:
| |
Collapse
|
6
|
Herzberg MC, Nobbs A, Tao L, Kilic A, Beckman E, Khammanivong A, Zhang Y. Oral streptococci and cardiovascular disease: searching for the platelet aggregation-associated protein gene and mechanisms of Streptococcus sanguis-induced thrombosis. J Periodontol 2006; 76:2101-5. [PMID: 16277582 DOI: 10.1902/jop.2005.76.11-s.2101] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Pathogenic mechanisms in infective endocarditis, disseminated intravascular coagulation, and cardiovascular events involve the aggregation of platelets into thrombi. Attendant infection by oral bacteria contributes to these diseases. We have been studying how certain oral streptococci induce platelet aggregation in vitro and in vivo. Streptococcus sanguis expresses a platelet aggregation-associated protein (PAAP), which contributes little to adhesion to platelets. When specific antibodies or peptides block PAAP, S. sanguis fails to induce platelet aggregation in vitro or in vivo. METHODS We used subtractive hybridization to identify the gene encoding for PAAP. RESULTS After subtraction of strain L50 (platelet aggregation-negative), four strain 133-79 specific sequences were characterized. Sequence agg4 encoded a putative collagen-binding protein (CbpA), which was predicted to contain two PAAP collagen-like octapeptide sequences. S. sanguis CbpA- mutants were constructed and tested for induction of platelet aggregation in vitro. Platelet aggregation was substantially inhibited when compared to the wild-type using platelet-rich plasma from the principal donor, but adhesion was unaffected. Other donor platelets responded normally to the CbpA- strain, suggesting additional mechanisms of response to S. sanguis. In contrast, CshA- and methionine sulfoxide reductase-negative (MsrA-) strains neither adhered nor induced platelet aggregation. CONCLUSIONS CbpA was suggested to contribute to site 2 interactions in our two-site model of platelet aggregation in response to S. sanguis. Platelet polymorphisms were suggested to contribute to the thrombogenic potential of S. sanguis.
Collapse
Affiliation(s)
- Mark C Herzberg
- Department of Oral Sciences, School of Dentistry and the Mucosal and Vaccine Research Center, University of Minnesota, Minneapolis, MN 55455, USA.
| | | | | | | | | | | | | |
Collapse
|
7
|
Ortega-Carnicer J, Ruiz-Lorenzo F, Benedicto A. Thrombolytic therapy for acute myocardial infarction in unsuspected infective endocarditis. Int J Cardiol 2005; 103:108-10. [PMID: 16061133 DOI: 10.1016/j.ijcard.2004.08.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2004] [Revised: 07/08/2004] [Accepted: 08/07/2004] [Indexed: 11/19/2022]
|
8
|
Levitas A, Zucker N, Zalzstein E, Sofer S, Kapelushnik J, Marks KA. Successful treatment of infective endocarditis with recombinant tissue plasminogen activator. J Pediatr 2003; 143:649-52. [PMID: 14615739 DOI: 10.1067/s0022-3476(03)00499-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES In a prospective study, we examined the effect of treatment with recombinant tissue plasminogen activator (r-TPA) on survival and morbidity in a series of high-risk children with infectious endocarditis (IE) after prolonged treatment with indwelling catheters. We hypothesized that r-TPA is an adjunctive therapy for dissolution of infected thrombi in drug-resistant IE. STUDY DESIGN In the prospective 3-year study (1998-2001), we identified high-risk children with chronic illness and prolonged treatment with indwelling catheters who developed IE and overwhelming sepsis. Patients were allocated to receive r-TPA after persistent and enlarging intracardiac vegetations and failure to respond to conventional medical management. Complications associated with treatment, survival, and cardiac morbidity were observed. RESULTS Seven infants were treated prospectively with r-TPA. All infants responded promptly to treatment, with resolution of the intracardiac vegetations within 3 to 4 days of commencement and without any adverse complications. All patients survived without long-term cardiac morbidity. CONCLUSION Recombinant tissue plasminogen activator may offer a safe alternative to surgical intervention in the high-risk infant with IE.
Collapse
Affiliation(s)
- Aviva Levitas
- Department of Pediatric Cardiology, the Pediatric Intensive Care Unit, Faculty of Health Sciences, Ben-Gurion University, Soroka Medical Center, Beer Sheva, Israel.
| | | | | | | | | | | |
Collapse
|
9
|
Yokota M, Basi DL, Herzberg MC, Meyer MW. Anti-fibrin antibody binding in valvular vegetations and kidney lesions during experimental endocarditis. Microbiol Immunol 2002; 45:699-707. [PMID: 11762752 DOI: 10.1111/j.1348-0421.2001.tb01304.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In Streptococcus sanguinis (sanguis) induced experimental endocarditis, we sought evidence that the development of aortic valvular vegetation depends on the availability of fibrin. Endocarditis was induced in New Zealand white rabbits by catheter placement into the left ventricle and inoculation of the bacteria. Fibrin was localized in the developing vegetation with 99mTechnetium (Tc)-labeled anti-fibrin antibody one or three days later. When rabbit anti-fibrin antibody was given intravenously on day 1, the mass of aortic valvular vegetation was significantly reduced at day 3; infusion of non-specific rabbit IgG showed no effect. The 99mTc-labeled anti-fibrin antibody also labeled kidneys that showed macroscopic subcapsular hemorrhage. To learn if the deposition of fibrin in the kidneys was a consequence of endocarditis required a comparison of farm-bred and specific pathogen-free rabbits before and after the induction of endocarditis. Before induction, the kidneys of farm-bred rabbits were labeled, but specific pathogen-free rabbits were free of labeling and signs of macroscopic hemorrhage. After 3 days of endocarditis, kidneys of 10 of 14 specific pathogen-free rabbits labeled with 99mTc-labeled anti-fibrin antibody and showed hemorrhage. Kidney lesions were suggested to be a frequent sequellae of S. sanguinis infective endocarditis. For the first time, fibrin was shown to be required for the continued development of aortic valvular vegetations.
Collapse
Affiliation(s)
- M Yokota
- Laboratory of Molecular Physiology, School of Dentistry, University of Minnesota, Minneapolis 55455, USA.
| | | | | | | |
Collapse
|
10
|
Meyer MW, Gong K, Herzberg MC. Streptococcus sanguis-induced platelet clotting in rabbits and hemodynamic and cardiopulmonary consequences. Infect Immun 1998; 66:5906-14. [PMID: 9826372 PMCID: PMC108748 DOI: 10.1128/iai.66.12.5906-5914.1998] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/1998] [Accepted: 09/11/1998] [Indexed: 11/20/2022] Open
Abstract
By mimicking hemostatic structural domains of collagen, Streptococcus sanguis (aggregation-positive phenotype; Agg+) induces platelets to aggregate in vitro. To test the hypothesis that aggregation occurs in vivo, S. sanguis (Agg+ or Agg- suspension) was infused intravenously into rabbits. The extent of hemodynamic and cardiopulmonary changes and the fate of circulating platelets were Agg+ strain dose dependent. Within 45 to 50 s of the start of infusion, 40 x 10(8) CFU of the Agg+ strain caused increased blood pressure. Thirty seconds after infusion, other changes occurred. Intermittent electrocardiographic abnormalities (13 of 15 rabbits), ST-segment depression (10 of 15 rabbits), and preventricular contractions (7 of 15 rabbits) manifested at 3 to 7 min, with frequencies dose dependent. Respiratory rate and cardiac contractility increased during this phase. Blood catecholamine concentration, thrombocytopenia, accumulation of 111Indium-labeled platelets in the lungs, and ventricular axis deviation also showed dose dependency. Rabbits were unaffected by inoculation of an Agg- strain. Therefore, Agg+ S. sanguis induced platelet aggregation in vitro. Platelet clots caused hemodynamic changes, acute pulmonary hypertension, and cardiac abnormalities, including ischemia.
Collapse
Affiliation(s)
- M W Meyer
- School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | | | | |
Collapse
|
11
|
Herzberg MC, Weyer MW. Dental plaque, platelets, and cardiovascular diseases. ANNALS OF PERIODONTOLOGY 1998; 3:151-60. [PMID: 9722699 DOI: 10.1902/annals.1998.3.1.151] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cardiovascular diseases, including atherosclerosis and myocardial ischemia, occur as a result of a complex set of genetic and environmental factors. During periodontitis, dental plaque microorganisms may disseminate through the blood to infect the vascular endothelium and contribute to the occurrence of atherosclerosis and risk of myocardial ischemia and infarction. Myocardial ischemia and infarction are often preceded by acute thromboembolic events. In an in vitro model of thrombosis, certain dental plaque bacteria induce platelets to aggregate. Aggregation of platelets is induced by the platelet aggregation-associated protein [PAAPJ expressed on plaque bacteria, including Streptococcus sanguis and Porphyromonas gingivalis. Intravenous infusion of S. sanguis into rabbits has been shown previously to cause changes in the electrocardiogram (ECG), heart rate, blood pressure, and cardiac contractility. These changes are consistent with the occurrence of myocardial infarction. The ECG changes are now shown to begin within 30 seconds after infusion of PAAP+ S. sanguis, followed by alterations in blood pressure and respiratory rate. These changes occurred intermittently over a 30-minute period and changed within one heartbeat to a normal pattern and suddenly back to abnormal. Intermittent ECG abnormalities were seen in 13 of 15 rabbits, including left axis deviation, ST-segment depression, preventricular contractions, alternans, and bigemnia. Dose-dependent thrombocytopenia, accumulation of 111Indium-labeled platelets in the lungs, and tachypnea also occurred. No changes occurred with the PAAp- strain. The data indicated that PAPP+ S. sanguis interacts with circulating platelets, inducing thromboemboli to cause the pulmonary and cardiac abnormalities. During periodontitis, therefore, PAAP+ S. sanguis and P. gingivalis bacteremia may contribute to the chance of acute thromboembolic events.
Collapse
Affiliation(s)
- M C Herzberg
- School of Dentistry, University of Minnesota, Minneapolis, USA.
| | | |
Collapse
|
12
|
Herzberg MC, Meyer MW, Kiliç A, Tao L. Host-pathogen interactions in bacterial endocarditis: streptococcal virulence in the host. Adv Dent Res 1997; 11:69-74. [PMID: 9524444 DOI: 10.1177/08959374970110011901] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To identify streptococcal genes that are expressed during experimental endocarditis, we developed a promoter-less dual reporter gene-fusion (amy, cat) plasmid, pAK36. Chromosomal DNA from S. gordonii V288 was digested with Sau3A1. The resulting fragments were ligated into pAK36. Following transformation into S. gordonii, the library of random gene fusion clones was inoculated into a rabbit to induce experimental endocarditis. Chloramphenicol treatment effected positive selection. Upon euthanization of the rabbits, the valvular vegetations were excised in a sterile field. Surviving clones were isolated and screened in vitro for chloramphenicol sensitivity and negative amylase activity. From the 48 randomly picked, double-negative clones, DNA was isolated and analyzed by Southern hybridization with labeled pAK36 probe. Different insertion patterns were identified, suggesting that no fewer than 13 S. gordonii genes were induced. Therefore, S. gordonii genes are induced during experimental endocarditis, which may contribute to virulence.
Collapse
Affiliation(s)
- M C Herzberg
- Department of Preventive Sciences, School of Dentistry, University of Minnesota, Minneapolis 55455, USA
| | | | | | | |
Collapse
|
13
|
Herzberg MC, Meyer MW. Effects of oral flora on platelets: possible consequences in cardiovascular disease. J Periodontol 1996; 67:1138-42. [PMID: 8910832 DOI: 10.1902/jop.1996.67.10s.1138] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
During episodes of dental bacteremia, viridans group streptococci encounter platelets. Among these microorganisms, certain Streptococcus sanguis induce human and rabbit platelets to aggregate in vitro. In experimental rabbits, circulating streptococci induced platelets to aggregate, triggering the accumulation of platelets and fibrin into the heart valve vegetations of endocarditis. At necropsy, affected rabbit hearts showed ischemic areas. We therefore hypothesized that circulating S. sanguis might cause coronary thrombosis and signs of myocardial infarction (MI). Signs of MI were monitored in rabbits after infusion with platelet-aggregating doses of 4 to 40 x 10(9) cells of S. sanguis 133-79. Infusion resulted in dose-dependent changes in electrocardiograms, blood pressure, heart rate, and cardiac contractility. These changes were consistent with the occurrence of MI. Platelets isolated from hyperlipidemic rabbits showed an accelerated in vitro aggregation response to strain 133-79. Cultured from immunosuppressed children with septic shock and signs of disseminated intravascular coagulation, more than 60% of isolates of viridans streptococci induced platelet aggregation when tested in vitro. The data are consistent with a thrombogenic role for S. sanguis in human disease, contributing to the development of the vegetative lesion in infective endocarditis and a thrombotic mechanism to explain the additional contributed risk of periodontitis to MI.
Collapse
Affiliation(s)
- M C Herzberg
- Department of Preventive Sciences, School of Dentistry, University of Minnesota, Minneapolis, USA
| | | |
Collapse
|
14
|
Herzberg MC. Platelet-streptococcal interactions in endocarditis. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1996; 7:222-36. [PMID: 8909879 DOI: 10.1177/10454411960070030201] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Infective endocarditis is characterized by the formation of septic masses of platelets on the surfaces of heart valves and is most commonly caused by viridans streptococci. Streptococcal virulence in endocarditis involves factors that promote infectivity and pathogenicity. Adhesins and exopolysaccharide (glycocalyx) contribute to infectivity. Although many factors may contribute to pathogenicity, the platelet aggregation-associated protein (PAAP) of Streptococcus sanguis contributes directly to the development of experimental endocarditis. PAAP is synthesized as a rhamnose-rich glycoprotein of 115 kDa and contains a collagen-like platelet-interactive domain, pro-gly-glu-gln-gly-pro-lys. Expressed on the cell wall of platelet aggregation-inducing strains (Agg+) of S. sanguis, PAAP apparently interacts with a signal-transducing receptor complex on platelets, which includes a novel 175-kDa alpha 2-integrin-associated protein and a 65-kDa collagen-binding component. From available data, the role of PAAP in the pathogenesis of experimental endocarditis may be explained by a proposed mechanistic model. On injured heart valves, PAAP first enhances platelet accumulation into a fibrin-enmeshed thrombus (vegetation), within which S. sanguis colonizes. Colonizing bacteria must resist platelet microbicidal protein (PMPR). The aggregation of platelets on the heart valve may be potentiated by an ectoATPase expressed on the surface of the S. sanguis and platelet alpha-adrenoreceptors that respond to endogenous catecholamines. The expression of PAAP may be modified during infection. Collagen is exposed on damaged heart valves; fever (heat shock) occurs during endocarditis. In response to heat shock or collagen in vitro, PAAP expression is altered. After colonization, streptococcal exotoxin(s) may cause fever. Proteases and other enzymes from streptococci and host sources may directly destroy the heart valves. When PAAP is unexpressed or neutralized with specific antibodies, experimental endocarditis runs a milder course and vegetations are smaller. The data suggest strongly, therefore, that the role of PAAP may overlap the colonization function of putative adhesins such as FimA or SsaB. Finally, PAAP also contributes to the development of the characteristic septic mural thrombus (vegetation) of infective endocarditis and the signs of valvular pathology.
Collapse
Affiliation(s)
- M C Herzberg
- Department of Preventive Sciences, School of Dentistry, University of Minnesota, Minneopolis 55455, USA
| |
Collapse
|
15
|
Kikuchi K, Shimizu K. Therapeutic Problems in Viridans Streptococcal Endocarditis. J Infect Chemother 1996. [DOI: 10.1007/bf02355192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|