Ultrastructure of a late-stage bacterial endocarditis valve vegetation

Baudoin, Jean-Pierre; Camoin-Jau, Laurence; Prasanth, Arsha; Habib, Gilbert; Lépidi, Hubert; Hannachi, Nadji

doi:10.1007/s11239-020-02232-2

Cited by 5 publications

(6 citation statements)

References 11 publications

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“…In the same sense, in a case report on a teenager suffering from endocarditis on an inflamed valve following sepsis, we observed that S. aureus were localized in a necrotic region, probably formed of traces of platelets and inflammatory cells, as proposed by Liesenborghs et al As the teenager's vegetation was in a late stage, two other regions were characterized, namely an amorphous region resembling a biofilm and a cell-rich region [60].…”

Section: Platelets Are Key Actor In the Formation Of Vegetationsupporting

confidence: 78%

The Role of Platelets in Infective Endocarditis

Braï

Hannachi

Gueddari

et al. 2023

IJMS

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Over the last decade, the incidence of infective endocarditis (IE) has increased, with a change in the frequency of causative bacteria. Early evidence has substantially demonstrated the crucial role of bacterial interaction with human platelets, with no clear mechanistic characterization in the pathogenesis of IE. The pathogenesis of endocarditis is so complex and atypical that it is still unclear how and why certain bacterial species will induce the formation of vegetation. In this review, we will analyze the key role of platelets in the physiopathology of endocarditis and in the formation of vegetation, depending on the bacterial species. We provide a comprehensive outline of the involvement of platelets in the host immune response, investigate the latest developments in platelet therapy, and discuss prospective research avenues for solving the mechanistic enigma of bacteria–platelet interaction for preventive and curative medicine.

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Section: Platelets Are Key Actor In the Formation Of Vegetationsupporting

confidence: 78%

The Role of Platelets in Infective Endocarditis

Braï

Hannachi

Gueddari

et al. 2023

IJMS

Self Cite

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“…Biofilm. Next, DIF and its analogues were assessed for their ability to mitigate biofilm production as this virulence phenotype is essential for human S. aureus infections, including infective endocarditis, prosthetic joint infection, and device-related infection [33][34][35][36][37][38]. As expected, DIF inhibited biofilm production in S. aureus strains by 9-73% compared with the no-compound control (Figure 5).…”

Section: Impact On Virulence Phenotypesmentioning

confidence: 65%

Diflunisal and Analogue Pharmacophores Mediating Suppression of Virulence Phenotypes in Staphylococcus aureus

et al. 2023

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Invasive methicillin-resistant Staphylococcus aureus (MRSA) infections are leading causes of morbidity and mortality that are complicated by increasing resistance to conventional antibiotics. Thus, minimizing virulence and enhancing antibiotic efficacy against MRSA is a public health imperative. We originally demonstrated that diflunisal (DIF; [2-hydroxy-5-(2,4-difluorophenyl) benzoic acid]) inhibits S. aureus virulence factor expression. To investigate pharmacophores that are active in this function, we evaluated a library of structural analogues for their efficacy to modulate virulence phenotypes in a panel of clinically relevant S. aureus isolates in vitro. Overall, the positions of the phenyl, hydroxyl, and carboxylic moieties and the presence or type of halogen (F vs. Cl) influenced the efficacy of compounds in suppressing hemolysis, proteolysis, and biofilm virulence phenotypes. Analogues lacking halogens inhibited proteolysis to an extent similar to DIF but were ineffective at reducing hemolysis or biofilm production. In contrast, most analogues lacking the hydroxyl or carboxylic acid groups did not suppress proteolysis but did mitigate hemolysis and biofilm production to an extent similar to DIF. Interestingly, chirality and the substitution of fluorine with chlorine resulted in a differential reduction in virulence phenotypes. Together, this pattern of data suggests virulence-suppressing pharmacophores of DIF and structural analogues integrate halogen, hydroxyl, and carboxylic acid moiety stereochemistry. The anti-virulence effects of DIF were achieved using concentrations that are safe in humans, do not impair platelet antimicrobial functions, do not affect S. aureus growth, and do not alter the efficacy of conventional antibiotics. These results offer proof of concept for using novel anti-virulence strategies as adjuvants to antibiotic therapy to address the challenge of MRSA infection.

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“…IE results from bacterial or fungal infections within the bloodstream that colonize damaged areas of heart valves. 9 Furthermore, non-infectious valvular vegetations should be included in the differential diagnosis of patients with incidental thrombi or valvular masses and negative blood culture results. 10 Some examples include antiphospholipid antibody syndrome and organized thrombus in Libman-Sachs endocarditis, non-bacterial thrombotic endocarditis, vasculitis, giant cell arteritis, connective tissue disease, cholesterol embolization syndrome, mural thrombi associated with cardiomyopathy or heart failure, Lambl's excrescences as well as vasculitis among others.…”

Section: Discussionmentioning

confidence: 99%

“…Infective endocarditis (IE) is another possibility, especially in cases where large vegetation is observed on cardiac valves. IE results from bacterial or fungal infections within the bloodstream that colonize damaged areas of heart valves 9 …”

Section: Discussionmentioning

confidence: 99%

Rheumatic heart disease of the mitral valve alongside the papillary fibroelastoma of the aortic valve: A case report

Khezerlouy Aghdam,

Delkhah,

Danayi

et al. 2024

Clinical Case Reports

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Key Clinical MessageBesides thromboses, it's crucial to also consider the rare possibility of tumors like papillary fibroelastomas when evaluating worsening cardiopulmonary symptoms in patients with severe rheumatic mitral stenosis and atrial fibrillation.AbstractCardiac papillary fibroelastoma is a rare and benign endocardial tumor typically found on the aortic valve. The simultaneous occurrence of rheumatic heart disease affecting the mitral valve and papillary fibroelastoma on the aortic valve is infrequent, with limited documented instances. This unique case can enhance our understanding of the clinical presentation, diagnostic approaches, management options, and implications for patient outcomes in these two conditions. We present the case of a 47‐year‐old woman who was admitted to the hospital due to worsening dyspnea and fatigue, during which time she discovered an aortic valve papillary fibroelastoma. Further investigations revealed two thrombi in her left atrium and left atrial appendage, along with significant rheumatic mitral valve stenosis. The patient underwent thrombectomy, mitral valve replacement, and valve‐sparing aortic valve tumor resection. Following surgery, the patient's recovery was unremarkable. This case report emphasizes the need for a comprehensive evaluation in patients with rheumatic mitral stenosis, considering all possible etiologies. While thrombi are typical in mitral stenosis and atrial fibrillation, the rare presence of tumors like papillary fibroelastomas should be recognized, underscoring the importance of further assessment when suspicion arises. Importantly, individuals with asymptomatic cardiac papillary fibroelastomas should undergo surgical treatment to minimize the potential risk of tumoral embolization.

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Ultrastructure of a late-stage bacterial endocarditis valve vegetation

Cited by 5 publications

References 11 publications

The Role of Platelets in Infective Endocarditis

The Role of Platelets in Infective Endocarditis

Diflunisal and Analogue Pharmacophores Mediating Suppression of Virulence Phenotypes in Staphylococcus aureus

Rheumatic heart disease of the mitral valve alongside the papillary fibroelastoma of the aortic valve: A case report

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