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Forensic pathologists often encounter cases of acute subdural hematoma (SDH) due to trauma, whereas those attributable to endogenous causes are rare. Here, we report a case of the latter type in a 42-year-old man who was found dead at home after several months of fever and malaise. Postmortem computed tomography (PMCT) and autopsy were undertaken to clarify the cause of death. PMCT images revealed a fatal SDH and a localized hyper-density area in the right parietal lobe; macroscopic and microscopic examinations revealed SDH due to rupture of a mycotic aneurysm (MA) associated with meningitis. The PMCT images also indicated thickening and calcification of the mitral valve, while autopsy demonstrated infective endocarditis (IE). In addition, PMCT demonstrated a low-density area in the spleen, which was shown to be a splenic abscess at autopsy. PMCT also demonstrated tooth cavities. Based on the findings of autopsy, the cause of death was considered to be SDH due to rupture of the MA resulting from meningitis with IE and splenic abscess. Although PMCT was unable to clarify the significance of any individual feature, a retrospective review of the PMCT images might have suggested IE, bacteremia, or ruptured MA leading to SDH. This case suggests that, instead of interpreting individual features demonstrated on PMCT images, integrated interpretation of overall PMCT findings might provide clues for identifying causes of death, despite the fact that PMCT lacks diagnostic accuracy for infectious diseases such as IE and meningitis., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

A dog was presented for lameness, fever, and extreme lethargy. On physical exam, a new heart murmur, arrhythmia, and joint effusion were detected. These findings were not detected two months prior. A diagnostic work-up confirmed septic suppurative inflammation in multiple joints. Echocardiogram revealed aortic valvular endocarditis along with a communication, as a consequence of a fistula, that extended from just below the aortic sinotubular junction to the left atrial lumen. Due to a poor prognosis, humane euthanasia was elected. Necropsy and histopathology confirmed infective endocarditis of the aortic valve and an aorto-left atrial fistulous tract extending from the left coronary sinus of the aortic valve to the lumen of left atrium., (Published by Elsevier B.V.)

Infective endocarditis (IE) is a complex multisystemic disease resulting from infection of the endocardium, the prosthetic valves, or an implantable cardiac electronic device. The clinical presentation of patients with IE varies, ranging from acute and rapidly progressive symptoms to a more chronic disease onset. Because of its severe morbidity and mortality rates, it is necessary for radiologists to maintain a high degree of suspicion in evaluation of patients for IE. Modified Duke criteria are used to classify cases as "definite IE," "possible IE," or "rejected IE." However, these criteria are limited in characterizing definite IE in clinical practice. The use of advanced imaging techniques such as cardiac CT and nuclear imaging has increased the accuracy of these criteria and has allowed possible IE to be reclassified as definite IE in up to 90% of cases. Cardiac CT may be the best choice when there is high clinical suspicion for IE that has not been confirmed with other imaging techniques, in cases of IE and perivalvular involvement, and for preoperative treatment planning or excluding concomitant coronary artery disease. Nuclear imaging may have a complementary role in prosthetic IE. The main imaging findings in IE are classified according to the site of involvement as valvular (eg, abnormal growths [ie, "vegetations"], leaflet perforations, or pseudoaneurysms), perivalvular (eg, pseudoaneurysms, abscesses, fistulas, or prosthetic dehiscence), or extracardiac embolic phenomena. The differential diagnosis of IE includes evaluation for thrombus, pannus, nonbacterial thrombotic endocarditis, Lambl excrescences, papillary fibroelastoma, and caseous necrosis of the mitral valve. The location of the lesion relative to the surface of the valve, the presence of a stalk, and calcification or enhancement at contrast-enhanced imaging may offer useful clues for their differentiation. © RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

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.

In the COVID-19 pandemic, to minimize aerosol-generating procedures, cardiac magnetic resonance imaging (CMR) was utilized at our institution as an alternative to transesophageal echocardiography (TEE) for diagnosing infective endocarditis (IE). This retrospective study evaluated the clinical utility of CMR for detecting IE among 14 patients growing typical microorganisms on blood cultures or meeting modified Duke Criteria. Seven cases were treated for IE. In 2 cases, CMR results were notable for possible leaflet vegetations and were clinically meaningful in guiding antibiotic therapy, obtaining further imaging, and/or pursuing surgical intervention. In 2 cases, vegetations were missed on CMR but detected on TEE. In 3 cases, CMR was non-diagnostic, but patients were treated empirically. There was no difference in antibiotic duration or outcomes over 1 year. CMR demonstrated mixed results in diagnosing valvular vegetations and guiding clinical decision-making. Further prospective controlled trials of CMR Vs TEE are warranted., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Papillary muscle rupture due to infective endocarditis is a rare event and proper management of this condition has not been described in the literature. Our case aims to shed light on treatment strategies for these patients using the current guidelines., Case Presentation: This case presents a 58-year-old male with acute heart failure secondary to papillary muscle rupture. He underwent an en bloc resection of his mitral valve with a bioprosthetic valve replacement. Specimen pathology later showed necrotic papillary muscle due to infective endocarditis. The patient was further treated with antibiotic therapy. He recovered well post-operatively and continued to do well after discharge., Conclusion: In patients who present with papillary muscle rupture secondary to infective endocarditis, clinical symptoms should drive the treatment strategy. Despite the etiology, early mitral valve surgery remains treatment of choice for patients who have papillary muscle rupture leading to acute heart failure. Culture-guided prolonged antibiotic treatment is vital in this category of patients, especially those who have a prosthetic valve implanted., (© 2022. The Author(s).)

Whipple's disease (WD) is a chronic multisystemic infection caused by Tropheryma whipplei . If this bacterium presents an intracellular localization, associated with rare diseases and without pathognomonic signs, it is often subject to a misunderstanding of its physiopathology, often a misdiagnosis or simply an oversight. Here, we report the case of a patient treated for presumed rheumatoid arthritis. Recently, this patient presented to the hospital with infectious endocarditis. After surgery and histological analysis, we discovered the presence of T. whipplei . Electron microscopy allowed us to discover an atypical bacterial organization with a very large number of bacteria present in the extracellular medium in vegetation and valvular tissue. This atypical presentation we report here might be explained by the anti-inflammatory treatment administrated for our patient's initial diagnosis of rheumatoid arthritis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Hannachi, Arregle, Lepidi, Baudoin, Gouriet, Martel, Hubert, Desnues, Riberi, Casalta, Habib and Camoin-Jau.)

Background: Histopathologic differentiation of bacterial endocarditis from yeast-like fungal endocarditis is usually straightforward; however, an underappreciated phenomenon is the effect of antimicrobial therapy on bacterial size, shape and septa (cross-wall) formation resulting in bacterial forms that mimic yeast-like fungi. In this article we illustrate the alterations that occur in antibiotic-treated Staphylococcus aureus endocarditis and compare these changes to histopathologic findings in unaltered S. aureus and Histoplasma endocarditis, respectively., Methods: Resected valves from three cases of endocarditis were compared based on the type ofinflammatory reaction, organism morphology and culture results. Case 1 was S. aureus endocarditis initially misclassified as Histoplasma due to its atypical morphologic and histopathologic features. The two cases included for comparison were an S. aureus endocarditis with more classic features and an Histoplasma capsulatum endocarditis. Hematoxylin and eosin (H&E), Gram, periodic acid Schiff (PAS), Gomori-Grocott methenamine silver stains (GMS), and culture results were compared in all cases. Molecular and immunohistochemistry tests were used for confirmation of first case. High power oil-immersion was used to visualize organisms' characteristics in all three cases., Results: Case 1 and Case 3 (Histoplasma-infected valves) had fibrinous exudates with scattered macrophages. The microorganisms observed in the first case of methicillin-sensitive S. aureus (MSSA) were ∼ 2-3 μm by GMS stain and had prominent septations. Histoplasma yeast were round to oval, ∼ 3-4 μm in size and demonstrated budding. S. aureus without alterations were round, ∼ 1 μm in size, and lacked prominent septations. Necrotizing purulent inflammation was present in the unaltered case of MSSA. The MSSA case with alterations from antibiotic treatment did not stain well with the Gram stain and organisms were best visualized with the PAS and GMS stains., Conclusions: Antibiotic therapy for bacterial endocarditis can alter the inflammatory reaction to infection, bacterial size, septa formation, and staining characteristics. Knowledge of these therapy-related effects and use of high-power magnification helps to avoid misclassification as yeast-like fungi., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Streptococcus gordonii and Streptococcus sanguinis are primary colonizers of tooth surfaces and are generally associated with oral health, but can also cause infective endocarditis (IE). These species express "Siglec-like" adhesins that bind sialylated glycans on host glycoproteins, which can aid the formation of infected platelet-fibrin thrombi (vegetations) on cardiac valve surfaces. We previously determined that the ability of S. gordonii to bind sialyl T-antigen (sTa) increased pathogenicity, relative to recognition of sialylated core 2 O-glycan structures, in an animal model of IE. However, it is unclear when and where the sTa structure is displayed, and which sTa-modified host factors promote valve colonization. In this study, we identified sialylated glycoproteins in the aortic valve vegetations and plasma of rat and rabbit models of this disease. Glycoproteins that display sTa vs. core 2 O-glycan structures were identified by using recombinant forms of the streptococcal Siglec-like adhesins for lectin blotting and affinity capture, and the O-linked glycans were profiled by mass spectrometry. Proteoglycan 4 (PRG4), also known as lubricin, was a major carrier of sTa in the infected vegetations. Moreover, plasma PRG4 levels were significantly higher in animals with damaged or infected valves, as compared with healthy animals. The combined results demonstrate that, in addition to platelet GPIbα, PRG4 is a highly sialylated mucin-like glycoprotein found in aortic valve vegetations and may contribute to the persistence of oral streptococci in this protected endovascular niche. Moreover, plasma PRG4 could serve as a biomarker for endocardial injury and infection., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Infective endocarditis (IE) is a heart valve infection with high mortality rates. IE results from epithelial lesions, inducing sterile healing vegetations consisting of platelets, leucocytes, and fibrin that are susceptible for colonization by temporary bacteremia. Clinical testing of new treatments for IE is difficult and fast models sparse. The present study aimed at establishing an in vitro vegetation simulation IE model for fast screening of novel treatment strategies. A healing promoting platelet and leucocyte-rich fibrin patch was used to establish an IE organoid-like model by colonization with IE-associated bacterial isolates Staphylococcus aureus, Streptococcus spp (S. mitis group), and Enterococcus faecalis. The patch was subsequently exposed to tobramycin, ciprofloxacin, or penicillin. Bacterial colonization was evaluated by microscopy and quantitative bacteriology. We achieved stable bacterial colonization on the patch, comparable to clinical IE vegetations. Microscopy revealed uneven, biofilm-like colonization of the patch. The surface-associated bacteria displayed increased tolerance to antibiotics compared to planktonic bacteria. The present study succeeded in establishing an IE simulation model with the relevant pathogens S. aureus, S. mitis group, and E. faecalis. The findings indicate that the IE model mirrors the natural IE process and has the potential for fast screening of treatment candidates., (© 2021 Scandinavian Societies for Medical Microbiology and Pathology.)

We present a case of bacterial endocarditis with both methicillin-sensitive and methicillin-resistant Staphylococcus aureus, which based on typing, originated from two distinct clones. Such a case may be misinterpreted by microbiology lab automation to be a monoclonal multi-drug resistant Staphylococcus aureus, while simple microbiology techniques will instantly reveal distinct clonality., (© 2021. The Author(s).)

Background: This case report describes the clinical process of a shepherd who suffered brucellosis-related endocarditis (BE) and spondylitis (BS) and was infected with Brucella melitensis biovar 3 (B. melitensis biovar 3)., Case Presentation: A 55-year-old male patient was admitted to The First Affiliated Hospital of Shihezi University on October 11, 2018, due to over 3 months of intermittent fever, back pain, and heart trouble. The Rose Bengal Plate test was positive, the standard agglutination test titer for brucellosis was 1/800, and the blood culture was positive for B. melitensis biovar 3. Three instances of transthoracic echocardiography examination at days 1, 25, and 376 after admission to the hospital and magnetic resonance imaging (MRI) and computed tomography (CT) checks at days 5 and 38 revealed that the size of the vegetation on the posterior leaflet of the mitral valve increased from 0.7 × 1.4 cm to 1.2 × 1.5 cm and that the left atrium and ventricle were enlarged. The MRI and CT results showed hyperplasia of the second and third vertebra, a cold abscess formed on both sides of the psoas major muscles, and the vertebra hyperplasia became aggravated at a later time point. The patient's situation deteriorated, and heart failure was discovered on October 22, 2019. At the moment of submission of this manuscript, the patient remains in bed at home because of severe debility caused by brucellosis., Conclusions: This is the first reported case of endocarditis combined with spondylitis caused by B. melitensis biovar 3 in a shepherd. Brucellosis infection can cause work-power losses because of misdiagnosis or a lack of proper treatment. Early diagnosis and treatment are essential for a successful outcome.

Infective endocarditis (IE) remains a severe illness with high mortality rate, despite advances in antibiotic therapy and cardiac surgery. If infectious bacteria and platelets are two key players of human IE vegetation developmental process, their interactions and respective roles in fully developed late-stage IE vegetations remain obscure. The objective of this study was to better understand the organization of the different components of the IE vegetation and to provide a detailed description of this vegetation ultrastructure. A late stage Staphylococcal endocarditic vegetation was provided from a 13 years teenager patient. After reception of the surgical piece, we carried out a histological study using routine methods, notably the hematoxylin-eosin-saffron staining. Labeling with the anti-CD 61 antibody was also carried out. In a second step, we used transmission electron microscopy to describe the different regions making up the vegetation. Our ultrastructural study revealed vegetation was clearly composed by three different regions and identified the specific location of the bacteria and platelets in the vegetation tissues. Histological analysis showed that platelets and Staphylococcus aureus were not co-localized. Electron microscopy study confirmed that S. aureus were found at distance from platelets, as well from immune cells, embedded in a biofilm and/or a necrotic area. These results reveal a development of a deep bacteria-only niche in vegetation, raising questions about medication access to these microorganisms. Vegetation composed of three regions: a region rich in bacteria incorporated into the necrotic tissue, the second region composed of fibrin filaments and the third region rich in platelets and free of bacteria.

Infectious endocarditis is a life-threatening disease, and diagnostics are urgently needed to accurately diagnose this disease especially in the case of prosthetic valve endocarditis. We show here that maltohexaose conjugated to indocyanine green (MH-ICG) can detect Staphylococcus aureus (S. aureus) infection in a rat model of infective endocarditis. The affinity of MH-ICG to S. aureus was determined and had a Km and Vmax of 5.4 μM and 3.0 X 10-6 μmol/minutes/108 CFU, respectively. MH-ICG had no detectable toxicity to mammalian cells at concentrations as high as 100 μM. The in vivo efficiency of MH-ICG in rats was evaluated using a right heart endocarditis model, and the accumulation of MH-ICG in the bacterial vegetations was 2.5 ± 0.2 times higher than that in the control left ventricular wall. The biological half-life of MH-ICG in healthy rats was 14.0 ± 1.3 minutes, and approximately 50% of injected MH-ICG was excreted into the feces after 24 hours. These data demonstrate that MH-ICG was internalized by bacteria with high specificity and that MH-ICG specifically accumulated in bacterial vegetations in a rat model of endocarditis. These results demonstrate the potential efficacy of this agent in the detection of infective endocarditis., Competing Interests: Kiyoko Takemiya, W. Robert Taylor, Niren Murthy, and Mark M. Goodman have equity interest in Microbial Medical, Inc which is related to this study. Joachim J. Røise, Maomao He, Chung Taing, and Alexander G. Rodriguez have no conflict of interest. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: Isolated pulmonary valve endocarditis (IPE) is rare, accounting for 1.5-2% of all cases of infective endocarditis. Herein, we describe a case of isolated pulmonary valve endocarditis with rapid progression in a 28-year-old male. Unlike most patients reported previously who were cured with only anti-infective therapy, without surgery at an early stage, multiple complications occurred in this patient in less than 2 weeks., Case Presentation: The patient was diagnosed with pulmonary valve endocarditis with blood cultures showing Staphylococcus aureus and echocardiography revealing 2 masses (measuring 14*13 mm、11*16 mm in size). Only 12 days later, acute massive pulmonary embolism occurred. Then, repeated echocardiography revealed multiple masses attached to the pulmonary valve with severe pulmonary insufficiency and the possibility of pulmonary valve destruction. Finally, pulmonary valve replacement, vegetation removal, and right pulmonary thromboendarterectomy together with resection of the middle and lower lobes of the right lung were performed., Conclusions: The role of surgery at an early stage might need to be reconsidered, and it may be viable to combine medical and surgical approaches.

Bacterial binding to platelets is a key step in the development of infective endocarditis (IE). Sialic acid, a common terminal carbohydrate on host glycans, is the major receptor for streptococci on platelets. So far, all defined interactions between streptococci and sialic acid on platelets are mediated by serine-rich repeat proteins (SRRPs). However, we identified Streptococcus oralis subsp. oralis IE-isolates that bind sialic acid but lack SRRPs. In addition to binding sialic acid, some SRRP- isolates also bind the cryptic receptor β-1,4-linked galactose through a yet unknown mechanism. Using comparative genomics, we identified a novel sialic acid-binding adhesin, here named AsaA (associated with sialic acid adhesion A), present in IE-isolates lacking SRRPs. We demonstrated that S. oralis subsp. oralis AsaA is required for binding to platelets in a sialic acid-dependent manner. AsaA comprises a non-repeat region (NRR), consisting of a FIVAR/CBM and two Siglec-like and Unique domains, followed by 31 DUF1542 domains. When recombinantly expressed, Siglec-like and Unique domains competitively inhibited binding of S. oralis subsp. oralis and directly interacted with sialic acid on platelets. We further demonstrated that AsaA impacts the pathogenesis of S. oralis subsp. oralis in a rabbit model of IE. Additionally, we found AsaA orthologues in other IE-causing species and demonstrated that the NRR of AsaA from Gemella haemolysans blocked binding of S. oralis subsp. oralis, suggesting that AsaA contributes to the pathogenesis of multiple IE-causing species. Finally, our findings provide evidence that sialic acid is a key factor for bacterial-platelets interactions in a broader range of species than previously appreciated, highlighting its potential as a therapeutic target., Competing Interests: The authors have declared that no competing interests exist.

Lyme carditis is an extracutaneous manifestation of Lyme disease characterized by episodes of atrioventricular block of varying degrees and additional, less reported cardiomyopathies. The molecular changes associated with the response to Borrelia burgdorferi over the course of infection are poorly understood. Here, we identify broad transcriptomic and proteomic changes in the heart during infection that reveal a profound down-regulation of mitochondrial components. We also describe the long-term functional modulation of macrophages exposed to live bacteria, characterized by an augmented glycolytic output, increased spirochetal binding and internalization, and reduced inflammatory responses. In vitro, glycolysis inhibition reduces the production of tumor necrosis factor (TNF) by memory macrophages, whereas in vivo, it produces the reversion of the memory phenotype, the recovery of tissue mitochondrial components, and decreased inflammation and spirochetal burdens. These results show that B. burgdorferi induces long-term, memory-like responses in macrophages with tissue-wide consequences that are amenable to be manipulated in vivo., Competing Interests: The authors have declared that no competing interests exist.

A 68-year-old man with cerebral infarction and right hemiplegia was diagnosed with active infective endocarditis, and multiple large vegetations and more than moderate valve regurgitation by three different valves were detected using transthoracic echocardiography. An urgent surgical intervention was selected, and aortic and mitral valve replacements using bioprostheses were initially performed due to large vegetation on both these valves with valve cusp destruction. Residual severe regurgitation persisted despite tricuspid valve plasty; therefore, tricuspid valve replacement using a tissue valve was performed, and triple valve replacement was eventually accomplished without any serious hemodynamic compromise. The postoperative clinical course was fair and the patient was discharged after 3 months of inpatient strict management and cardiac rehabilitation. However, he died approximately 9 months after the initial surgery due to multiple organ failure. We herein presented a rare surgical case of triple valve replacement for triple valve endocarditis with multiple large vegetations.

Abiotrophia defectiva is a rare pathogen of infective endocarditis (IE) but is frequently involved in embolic complication and valvular dysfunction. IE caused by A. defectiva in children is poorly studied. This study reports four cases of A. defectiva IE in children and reviews previously reported five pediatric cases of A. defectiva IE. Most of the patients presented with a subacute course, with prolonged fever or atypical symptoms. Eight patients had embolic complications at presentation. All nine children were treated with combination antimicrobial therapy and six of them received surgical intervention. All patients recovered well without relapse. A. defectiva should be considered in children with infective endocarditis, especially in those with atypical presentations. As complications are frequent and more than half of the patients need surgical treatment, prompt diagnosis along with appropriate treatment is necessary.

Invasive endocarditis of the aortic and mitral valves with involvement of the intervalvular fibrosa is a particular surgical challenge. We describe a technique for aortic and mitral valve replacement with concomitant reconstruction of the intervalvular fibrosa, utilizing a folded bovine pericardial patch (Commando operation).

Infectious endocarditis (IE) remains one of the deadliest heart diseases with a high death rate, generally following thrombo-embolic events. Today, therapy is based on surgery and antibiotic therapy. When thromboembolic complications in IE patients persist, this is often due to our lack of knowledge regarding the pathophysiological development and organization of cells in the vegetation, most notably the primordial role of platelets and further triggered hemostasis, which is related to the diversity of infectious microorganisms involved. Our objective was to study the organization of IE vegetations due to different bacteria species in order to understand the related pathophysiological mechanism of vegetation development. We present an approach for ultrastructural analysis of whole-infected heart valve tissue based on scanning electron microscopy and energy-dispersive X-ray spectroscopy. Our approach allowed us to detect differences in cell organization between the analyzed vegetations and revealed a distinct chemical feature in viridans Streptococci ones. Our results illustrate the benefits that such an approach may bring for guiding therapy, considering the germ involved for each IE patient.

Streptococcus gordonii and Streptococcus sanguinis belong to the Mitis group streptococci, which mostly are commensals in the human oral cavity. Though they are oral commensals, they can escape their niche and cause infective endocarditis, a severe infection with high mortality. Several virulence factors important for the development of infective endocarditis have been described in these two species. However, the background for how the commensal bacteria, in some cases, become pathogenic is still not known. To gain a greater understanding of the mechanisms of the pathogenic potential, we performed a comparative analysis of 38 blood culture strains, S. sanguinis (n = 20) and S. gordonii (n = 18) from patients with verified infective endocarditis, along with 21 publicly available oral isolates from healthy individuals, S. sanguinis (n = 12) and S. gordonii (n = 9). Using whole genome sequencing data of the 59 streptococci genomes, functional profiles were constructed, using protein domain predictions based on the translated genes. These functional profiles were used for clustering, phylogenetics and machine learning. A clear separation could be made between the two species. No clear differences between oral isolates and clinical infective endocarditis isolates were found in any of the 675 translated core-genes. Additionally, random forest-based machine learning and clustering of the pan-genome data as well as amino acid variations in the core-genome could not separate the clinical and oral isolates. A total of 151 different virulence genes was identified in the 59 genomes. Among these homologs of genes important for adhesion and evasion of the immune system were found in all of the strains. Based on the functional profiles and virulence gene content of the genomes, we believe that all analysed strains had the ability to become pathogenic.

This retrospective study aimed to clarify the short- and mid-term outcomes of elderly patients who underwent surgery to treat left-sided native valve infective endocarditis (LSNIE). Between July 2005 and September 2015, 179 patients underwent surgical treatment for active LSNIE at a single institution. Patients were classified into two groups: ≥65 years (elderly group) and <65 years (non-elderly group). Clinical features, surgical information, postoperative complications, and three-year survival rates were compared. The average ages were 74.2 ± 6.4 and 45.2 ± 12.6 years in the elderly and non-elderly groups, respectively. The elderly group had a higher predicted mortality rate and a lower incidence of preoperative septic emboli-related complications. Echocardiographic assessments of infected valves were generally homogenous between the groups. The elderly patients had a higher in-hospital mortality rate than the non-elderly patients (26.3% vs. 5.7%, P = 0.001). For patients who survived to discharge, the three-year cumulative survival rates were 75.0% ± 8.2% and 81.2% ± 3.4% in the elderly and non-elderly groups, respectively (P = 0.484). In conclusion, elderly patients are at a higher risk of in-hospital mortality after surgery for LSNIE. However, once elderly patients are stabilized by surgical treatment and survive to discharge, the mid-term outcomes are promising.

Background: The data on infective endocarditis after transcatheter aortic valve implantation (TAVI) is scarce and limited to case reports and case series in the literature. It is the need of the hour to analyze the available data on post-TAVI infective endocarditis from the available literature. The objectives of this systematic review were to evaluate the incidence of infective endocarditis after transcatheter aortic valve implantation, its microbiological profile and clinical outcomes. It will help us to improve the antibiotic prophylaxis strategies and treatment options for infective endocarditis in the context of TAVI., Methods: EMBASE, Medline and the CENTRAL trials registry of the Cochrane Collaboration were searched for articles on infective endocarditis in post-TAVI patients till October 2018. Eleven articles were included in the systematic review. The outcomes assessed werethe incidence of infective endocarditis, its microbiological profile andclinical outcomes including major adverse cardiac event (MACE), net adverse clinical event (NACE), surgical intervention and valve-in-valve procedure., Results: The incidence of infective endocarditis varied from 0%-14.3% in the included studies, the mean was3.25%. The average duration of follow-up was 474 days (1.3 years). Enterococci were the most common causative organism isolated from 25.9% of cases followed by Staphylococcus aureus (16.1%) and coagulase-negative Staphylococcus species (14.7%). The mean in-hospital mortality and mortality at follow-up was 29.5% and 29.9%, respectively. The cumulative incidence of heart failure, stroke and major bleeding were 37.1%, 5.3% and 11.3%,respectively. Only a single study by Martinez-Selles et al. reported arrhythmias in 20% cases. The septic shock occurred in 10% and 27.7% post-TAVI infective endocarditis patients according to 2 studies. The surgical intervention and valve-in-valve procedure were reported in 11.4% and 6.4% cases, respectively., Conclusion: The incidence of post-TAVI infective endocarditis is low being 3.25% but it is associated with high mortality and complications. The most common complication is heart failure with a cumulative incidence of 37.1%. Enterococciare the most common causative organism isolated from 25.9% of cases followed by Staphylococcus aureus in 16.1% of cases. Appropriate measures should be taken to prevent infective endocarditis in post-TAVI patients including adequate antibiotics prophylaxis directed specifically against these organisms., Study Registration: PROSPERO registration number CRD42018115943., Competing Interests: The authors have declared that no competing interests exist.

A 15-year-old, female cockatoo ( Cacatua alba ) was presented with a history of intermittent cloacal prolapse of 1-year duration. After each prolapse, the owner would digitally reduce the distended cloacal tissue within approximately 12-24 hours, for short-term resolution. The cockatoo was examined 3 times over a 7-month period and received supportive care with leuprolide acetate, behavioral modification, and diet change. After the third examination, the owner decided to proceed with a surgical cloacopexy. Five days after the last examination and before the procedure was scheduled, the cockatoo was reexamined for acute onset of weakness, anorexia, lethargy, and right-leg paresis. Despite supportive treatment, the cockatoo's clinical condition declined, and it went into respiratory arrest. Resuscitative efforts, including manual ventilation and cardiovascular support, were unsuccessful, and the bird died. Results of postmortem examination revealed vegetative endocarditis with intralesional bacteria cultured as Staphylococcus aureus , right-hindlimb myonecrosis, hepatitis, and nephritis. We suspect that the source of the hematogenous S aureus infection in this cockatoo was translocation from the owner's skin from the repeated manual manipulation and replacement of the prolapsed cloacal tissue.

BACKGROUND Immediate evaluation, diagnosis, and treatment of a patient with infective endocarditis, an infection of the endocardium and/or integral structures found within the heart, is essential to patient survival. CASE REPORT We present the case of a 41-year-old man who was brought to the Emergency Department for altered mental status and fever. He was found to have methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia complicated with severe respiratory failure and metabolic encephalopathy, necessitating intubation and mechanical ventilation. As part of the workup for persistent Staphylococcal bacteremia, 2 transthoracic echocardiograms (TTE) failed to reveal any valvular abnormalities. However, a transesophageal echocardiogram (TEE) detected a 30×30 mm large vegetation on the anterior mitral valve leaflet. Due to the overall size and risk of systemic embolization, and the fact that the patient developed new-onset heart failure, the mitral valve was replaced using an open approach. The patient tolerated the procedure well and was discharged after an extended period of hospitalization. CONCLUSIONS Although the literature emphasizes that the sensitivity of TTE significantly increases when the vegetation size is above 1 cm, it is of utmost importance for clinicians to keep in mind that this is not always true, and clinicians should consider performing a TEE to rule out infective endocarditis whenever a TTE is unable to detect any vegetation in a patient with persistent Staphylococcal bacteremia. This is clearly demonstrated by the present case, in which two TTEs failed to detect a 30×30 mm vegetation.

Our studies reveal that the oral colonizer and cause of infective endocarditis Streptococcus oralis subsp. dentisani displays a striking monolateral distribution of surface fibrils. Furthermore, our data suggest that these fibrils impact the structure of adherent bacterial chains. Mutagenesis studies indicate that these fibrils are dependent on three serine-rich repeat proteins (SRRPs), here named f ibril- a ssociated p rotein A (FapA), FapB, and FapC, and that each SRRP forms a different fibril with a distinct distribution. SRRPs are a family of bacterial adhesins that have diverse roles in adhesion and that can bind to different receptors through modular nonrepeat region domains. Amino acid sequence and predicted structural similarity searches using the nonrepeat regions suggested that FapA may contribute to interspecies interactions, that FapA and FapB may contribute to intraspecies interactions, and that FapC may contribute to sialic acid binding. We demonstrate that a fapC mutant was significantly reduced in binding to saliva. We confirmed a role for FapC in sialic acid binding by demonstrating that the parental strain was significantly reduced in adhesion upon addition of a recombinantly expressed, sialic acid-specific, carbohydrate binding module, while the fapC mutant was not reduced. However, mutation of a residue previously shown to be essential for sialic acid binding did not decrease bacterial adhesion, leaving the precise mechanism of FapC-mediated adhesion to sialic acid to be defined. We also demonstrate that the presence of any one of the SRRPs is sufficient for efficient biofilm formation. Similar structures were observed on all infective endocarditis isolates examined, suggesting that this distribution is a conserved feature of this S. oralis subspecies., (Copyright © 2019 American Society for Microbiology.)

Mycoplasma bovis is a microorganism associated with pneumonia, mastitis, arthritis and otitis media of cattle; however, there are no reports of this organism causing bovine endocarditis. Five adult cattle with endocarditis characterized by caseated lesions (diameter 5-12 cm) of the endocardial surface of the left atrium, but without lesions in heart valves or affecting the right side of the heart, were identified in slaughterhouses in Japan. M. bovis was successfully isolated from the lesions and M. bovis antigen was detected immunohistochemically within the lesions. The results suggest that the lesions may have been associated with M. bovis alone. To our knowledge, this is the first demonstration of bovine endocarditis associated with M. bovis., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Query fever (Q fever), caused by Coxiella burnetii , was first described in southern California in 1947. It was found to be endemic and enzoonotic to the region and associated with exposure to livestock. We describe a series of 20 patients diagnosed with Q fever at a Veterans Affairs hospital in southern California, with the aim of contributing toward the understanding of Q fever in this region. Demographics, laboratory data, diagnostic imaging, risk factors, and treatment regimens were collected via a retrospective chart review of patients diagnosed with Q fever at our institution between 2000 and 2016. Cases were categorized as acute or chronic and confirmed or probable. The majority presented with an acute febrile illness (90%). There was a delay in ordering diagnostic serology from the time of symptom onset (acute cases, average 31.9 days; chronic cases, average 63 days), and 15% progressed from acute to chronic infection. Of the chronic cases, 22.2% had endocarditis, 22.2% had endovascular infection, and 11.1% had both endocarditis and endovascular infection. The geographic distribution revealed that 20% resided in rural areas. Of the cases of Q fever that died, death attributed to Q fever was associated with an average diagnostic delay of 65.5 days. Acute Q fever is underreported in this region largely because of its often nonspecific clinical presentation.

Streptococcus gordonii and Streptococcus sanguinis are primary colonizers of the tooth surface. Although generally non-pathogenic in the oral environment, they are a frequent cause of infective endocarditis. Both streptococcal species express a serine-rich repeat surface adhesin that mediates attachment to sialylated glycans on mucin-like glycoproteins, but the specific sialoglycan structures recognized can vary from strain to strain. Previous studies have shown that sialoglycan binding is clearly important for aortic valve infections caused by some S. gordonii, but this process did not contribute to the virulence of a strain of S. sanguinis. However, these streptococci can bind to different subsets of sialoglycan structures. Here we generated isogenic strains of S. gordonii that differ only in the type and range of sialoglycan structures to which they adhere and examined whether this rendered them more or less virulent in a rat model of endocarditis. The findings indicate that the recognition of specific sialoglycans can either enhance or diminish pathogenicity. Binding to sialyllactosamine reduces the initial colonization of mechanically-damaged aortic valves, whereas binding to the closely-related trisaccharide sialyl T-antigen promotes higher bacterial densities in valve tissue 72 hours later. A surprising finding was that the initial attachment of streptococci to aortic valves was inversely proportional to the affinity of each strain for platelets, suggesting that binding to platelets circulating in the blood may divert bacteria away from the endocardial surface. Importantly, we found that human and rat platelet GPIbα (the major receptor for S. gordonii and S. sanguinis on platelets) display similar O-glycan structures, comprised mainly of a di-sialylated core 2 hexasaccharide, although the rat GPIbα has a more heterogenous composition of modified sialic acids. The combined results suggest that streptococcal interaction with a minor O-glycan on GPIbα may be more important than the over-all affinity for GPIbα for pathogenic effects., Competing Interests: The authors have declared that no competing interests exist.

Background: In patients with active infective endocarditis (IE), the relationship between timing of surgery and survival is uncertain. The objective was to evaluate clinical characteristics associated with timing of surgery and the association between surgical timing and 6-month survival in complicated, left-sided IE., Methods: In a prospective, multicenter, observational registry (The International Collaboration on Endocarditis-PLUS, registry from 2008 to 2012), clinical factors associated with timing of surgery during the index hospitalization were determined among 485 adult patients with definite, complicated, left-sided IE who underwent cardiac surgery during their index hospitalization. The relationship between early surgical intervention (<7 days from admission to surgery center) and outcome after surgery was analyzed. The primary end point of the study was 6-month survival., Results: The median time to surgery from admission to surgical center was 7 (interquartile range 2-15) days. Patients who underwent earlier surgery were more likely transferred to the surgical center (74.2% vs 46.4%, P < .001) and had a lower percentage of preexisting heart failure (before IE diagnosis) (6.0% vs 17.3%, P < .001) but higher rate of acute heart failure (53.2% vs 38.4%, P = .001). Variables independently associated with surgery <7 days from admission were patient transfer, acute heart failure, and nonelective surgical status (C-index = 0.84), but predicted operative risk was not. Cox proportional hazards modeling with inverse probability of treatment weighting found that earlier surgery was associated with a trend toward higher 6-month mortality compared with later surgery (hazard ratio = 1.68, 95% CI 0.97-2.96; P = .065), particularly surgery within 2 days of admission or transfer. Mortality was significantly associated with operative risk and complicated IE, including Staphylococcus aureus infection and presence of abscess., Conclusions: Earlier surgery in IE is strongly associated with acute heart failure and surgical urgency. After adjustment for operative risk and IE complications, earlier surgery <7 days from admission was associated with a trend toward higher 6-month overall mortality compared with surgery later in the index hospitalization., (Copyright © 2019 Elsevier Inc. All rights reserved.)

This case report details the unique cause of death of a 37-year-old Caucasian woman with a history significant for intravenous drug abuse. Before her death, she complained of extremity weakness and pain. Although her death was discovered to be the result of endocarditis, her symptoms were similar to that of a stroke. Autopsy revealed a large endocardial vegetation infecting both the tricuspid and mitral valves and a patent foramen ovale. The subsequent embolization of this vegetation caused blockages in the lungs, liver, and brain. An acute embolization of these vegetations to the bilateral middle cerebral arteries is the cause of the stroke presentation. Other comorbidities, such as cardiomegaly, microscopic evidence of myocardial infarction, and atherosclerotic disease, also contributed to the cause of death. As the opioid crisis continues in the United States, it is important to review cases involving the effects of drug use. The multiple interactions between endocarditis and the aforementioned conditions are documented to not only serve as references for future autopsies but also for the treatment of patients who have similar symptoms and comorbidities.

A comparative study of the behaviour of left-sided infective endocarditis (left-sided IE) due to Streptococcus agalactiae (GBS) with left-sided IE caused by Staphylococcus aureus (SA). A prospective, multicentre cohort study in eight public hospitals in Spain, from January 1984 to December 2015; comparative analysis and factors associated with mortality. In total, there were 1754 episodes of left-sided IE; 41 (2.3%) caused by GBS vs. 344 (19.6%) due to SA, definitive IE 39 vs. 324 cases, males, 25 vs. 213, respectively. There were no differences in age or comorbidity, and healthcare-associated acquirement was 10% vs. 43%, p 0.001. Transthoracic echocardiogram (TTE) was performed in 95% vs. 96.8% and a transesophageal echocardiogram (TEE) in 61% vs. 56%. Vegetations were detected in 80% and measured > 1 cm in a similar proportion. It affected native valves in 85.4% vs. 82.6% and late prosthetic valve in 14.6% vs. 9.6%. The course was acute in both groups. There were more skin manifestations in SA left-sided IE, 7.3% vs. 32%, p 0.001. Both groups had similar complications, but in SA, there was more renal failure, 24% vs. 45%, p 0.010. Surgical risk and operated patients were similar. Mortality was proportionally higher in the SA group, without significance 29% vs. 43% (150), p 0.09. Heart failure, septic shock and neurological deterioration conditioned mortality: HR 1.96, 1.69 and 1.37 (CI 95% 1.40-2.73; 1.19-2.39 and 0.99-1.88 respectively) and to a lesser degree SA as aetiology agent and age. Left-sided IE caused by GBS is similar in severity to left-sided IE caused by SA.

Objectives: Prediction of embolic events (EEs) in infective endocarditis (IE) could inform clinical decisions, such as surgical timing. We conducted a systematic review to more precisely define associations between risk factors and EEs., Methods: We searched two bibliographic databases (1994-2018) for observational studies that reported EEs in IE patients and considered clinical, microbiological or echocardiographic risk factors. Studies that did not use Duke criteria or only investigated a subset of IE patients were excluded. Study quality was assessed using the Newcastle-Ottawa scale. A pooled risk ratio (RR) for each risk factor was estimated using random-effects models; statistical heterogeneity was estimated using I 2 ., Results: Of 3862 unique citations, 47 cohort studies (11 215 IE cases) were included; 54 risk factors were analysed in at least two studies, with nine studies reporting other individual factors. Most studies were of high methodological quality. Major predictors of EEs were intravenous drug use (RR 1.69, 95% CI 1.32-2.17; I 2  = 46%), Staphylococcus aureus infection (RR 1.64, 95% CI 1.45-1.86, I 2  = 32%), mitral valve vegetation (RR 1.24, 95% CI 1.11-1.37, I 2  = 30%), and vegetation size >10 mm (RR 1.87, 95% CI 1.57-2.21, I 2  = 48%). EE risk was also higher with human immunodeficiency virus, chronic liver disease, elevated C-reactive protein, Staphylococcus spp. infection, vegetation presence, and multiple, mobile or prosthetic mechanical valve vegetation, and lower with Streptococcus spp. infection. Most findings were unchanged in sensitivity analyses that removed studies with pulmonary EEs from the outcome., Conclusions: Given the serious consequences of embolism, surgical evaluation may be considered in patients with these risk factors., (Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)