Borrelia burgdorferi infection induces long-term memory-like responses in macrophages with tissue-wide consequences in the heart.

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.

A 1-Year-Old with Mycobacterium tuberculosis Endocarditis with Mass Spectrometry Analysis of Cardiac Vegetation Composition.

In this study, we report the first case of Mycobacterium tuberculosis endocarditis in an immunocompetent child born in the United States. Mass spectrometry of the vegetation identified coagulation, humoral immune proteins, neutrophil granule proteins, and histones. Few neutrophils on histopathology suggest that neutrophil extracellular traps may contribute to tuberculous endocardiac mass formation.

Moraxella osloensis, an emerging pathogen of endocarditis in immunocompromised patients?

We report two cases of endocarditis due to Moraxella osloensis. Only one previous case of such infection has been described. These infections occurred in immunocompromised patients (B-cell chronic lymphocytic leukaemia and kidney graft associated with Hodgkin's disease) and both patients had a favourable outcome with a complete cure of their infectious endocarditis. This bacterium could be an emerging pathogen revealed by MALDI-TOF. Indeed, its characterisation within the Moraxella group by use of biochemistry-based methods is difficult. Moreover, this strain could be particularly involved in immunocompromised patients.

Nontyphoidal cardiac salmonellosis: two case reports and a review of the literature.

Nontyphoidal Salmonella, especially Salmonella enterica, is a rare cause of endocarditis and pericarditis that carries a high mortality rate. Proposed predisposing conditions include immunodeficiency states, congenital heart defects, and cardiac valve diseases. We present 2 cases of cardiovascular salmonellosis. The first case is that of a 73-year-old woman with mechanical mitral and bioprosthetic aortic valves who died from sequelae of nontyphoidal Salmonella mitral valve vegetation, aortic valve abscess, and sepsis. The second case is that of a 62-year-old man with a recent systemic lupus erythematosus exacerbation treated with oral steroids, who presented with obstructive features of tamponade and sepsis secondary to a large S. enteritidis purulent pericardial cyst. He recovered after emergent pericardial drainage and antibiotic therapy. Identifying patients at risk of cardiovascular salmonellosis is important for early diagnosis and treatment to minimize sequelae and death. We reviewed the literature to identify the predisposing risk factors of nontyphoidal Salmonella cardiac infection.

Monocyte responses in the context of Q fever: from a static polarized model to a kinetic model of activation.

BACKGROUND: Q fever is caused by Coxiella burnetii, a bacterium that persists in M2-polarized macrophages. We wondered whether the concept of M1/M2 polarization is applicable to Q fever patients. METHODS: Monocytes from healthy controls were cultured with IFN-γ and IL-4, agonists of M1 and M2 macrophages, respectively, and their gene expression was assessed using whole-genome microarrays. Selected biomarkers were assessed in blood from Q fever patients by real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Monocytes exhibited early (6-hour) patterns of activation specific to IFN-γ or IL-4 and a late (18-hour) pattern of common activation. Because these responses were not reducible to M1/M2 polarization, we selected biomarkers and tested their relevance in Q fever patients. The early genes NLRC5, RTP4, and RHOH, which were modulated in response to IFN-γ, were up-regulated in patients with acute Q fever, and the expression levels of the late genes ALOX15, CLECSF1, CCL13, and CCL23 were specifically increased in patients with Q fever endocarditis. The RHOH and ALOX15 genes were associated with the activity of acute Q fever and Q fever endocarditis, respectively. CONCLUSIONS: Our results show that the kinetic model of monocyte activation enables a dynamic approach for the evaluation of Q fever patients.

Delayed diagnosis of chronic Q fever and cardiac valve surgery.

Untreated chronic Q fever causes a high number of complications and deaths. We present cases of chronic Q fever that were not diagnosed until after the patients underwent cardiac valve surgery. In epidemic areas, Q fever screening of valve surgery patients secures early initiation of treatment and can prevent illness and death.

Differences in cytokine stimulation between methicillin-susceptible and methicillin-resistant Staphylococcus aureus in an experimental endocarditis model.

The present study focused on the impact of methicillin resistance of Staphylococcus aureus on cytokine production by monocytes. Cytokine stimulation was studied by 20 heat-killed isolates, 10 methicillin-susceptible Staphylococcus aureus (MSSA) and 10 methicillin-resistant Staphylococcus aureus (MRSA). Bacterial endocarditis was induced in 27 male rabbits by challenge with 1 MSSA isolate and 1 MRSA isolate. Blood was sampled for estimation of tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) and stimulation of monocytes. MSSA induced greater stimulation of TNF-α than MRSA, as shown after addition of a Toll-like receptor-4 (TLR4) antagonist. Survival of rabbits challenged by MRSA was prolonged compared to those challenged by MSSA. Serum MDA was greater after MSSA stimulation. Serum of animals challenged by MRSA stimulated greater release of interleukin (IL)-8 and IL-10 compared with MSSA: the opposite was observed for TNF-α. It is concluded that MSSA and MRSA induce a different pattern of TNF-α stimulation through a TLR4-independent mechanism, leading to shorter survival in experimental endocarditis.

Use of a human-like low-grade bacteremia model of experimental endocarditis to study the role of Staphylococcus aureus adhesins and platelet aggregation in early endocarditis.

Animal models of infective endocarditis (IE) induced by high-grade bacteremia revealed the pathogenic roles of Staphylococcus aureus surface adhesins and platelet aggregation in the infection process. In humans, however, S. aureus IE possibly occurs through repeated bouts of low-grade bacteremia from a colonized site or intravenous device. Here we used a rat model of IE induced by continuous low-grade bacteremia to explore further the contributions of S. aureus virulence factors to the initiation of IE. Rats with aortic vegetations were inoculated by continuous intravenous infusion (0.0017 ml/min over 10 h) with 10(6) CFU of Lactococcus lactis pIL253 or a recombinant L. lactis strain expressing an individual S. aureus surface protein (ClfA, FnbpA, BCD, or SdrE) conferring a particular adhesive or platelet aggregation property. Vegetation infection was assessed 24 h later. Plasma was collected at 0, 2, and 6 h postinoculation to quantify the expression of tumor necrosis factor (TNF), interleukin 1α (IL-1α), IL-1ß, IL-6, and IL-10. The percentage of vegetation infection relative to that with strain pIL253 (11%) increased when binding to fibrinogen was conferred on L. lactis (ClfA strain) (52%; P = 0.007) and increased further with adhesion to fibronectin (FnbpA strain) (75%; P < 0.001). Expression of fibronectin binding alone was not sufficient to induce IE (BCD strain) (10% of infection). Platelet aggregation increased the risk of vegetation infection (SdrE strain) (30%). Conferring adhesion to fibrinogen and fibronectin favored IL-1ß and IL-6 production. Our results, with a model of IE induced by low-grade bacteremia, resembling human disease, extend the essential role of fibrinogen binding in the initiation of S. aureus IE. Triggering of platelet aggregation or an inflammatory response may contribute to or promote the development of IE.

Bartonella and Coxiella infective endocarditis in Brazil: molecular evidence from excised valves from a cardiac surgery referral center in Rio de Janeiro, Brazil, 1998 to 2009.

PCR was used to detect Coxiella burnetii and Bartonella spp in heart valves obtained during the period 1998-2009 from patients operated on for blood culture-negative endocarditis in a cardiac surgery hospital in Brazil. Of the 51 valves tested, 10 were PCR-positive; two were positive for Bartonella and one for C. burnetii.

Autoimmunity as a possible predisposing factor for Stenotrophomonas maltophilia endocarditis / Autoinmunidad como posible factor predisponente para endocarditis por Stenotrophomonas maltophilia

Only 40 cases of Stenotrophomonas maltophilia (S. maltophilia) endocarditis have been reported to date, and there is no description in patients with underlying autoimmunity. A 23-year-old woman with systemic lupus erythematosus (SLE) overlapping rheumatoid arthritis (RA) and no risk factors for endocarditis was admitted in our hospital because of community-acquired tricuspid valve endocarditis. During hospitalization, she was complicated with pulmonary thromboembolism and pneumonia. Laboratory showed autoimmune diathesis featured by anti-cyclic citrullinated peptide (anti-CCP), anti-Sm, anti-Ro/SSA, anti-cardiolipin, anti-(β2 glycoprotein 1, and antinuclear antibodies, rheumatoid factor (RF), low complement, lymphopenia and C-reactive protein (CRP) of 425 mg/L. S. maltophilia grew in serial blood culture sets. Empirical broad-spectrum antimicrobials were ineffective until trimethoprim/sulfamethoxazole (TMP/SMX) was added to therapy. One month after admission, the patient underwent successful surgical replacement of the tricuspid valve and the subsequent course was satisfactory, allowing her to be discharged 14 days after. Nowadays, she remains free of complaints and her cardiac, renal and pulmonary functioning is stable. Noteworthy is that all auto-antibodies have been persistently raised over time. Here, we present a compilation of the available information about S. maltophilia endocarditis, and suggest that autoimmunity could be included as a novel predisposing factor for S. maltophilia endocarditis.

Actualmente sólo existen 40 casos descritos de endocarditis por Stenotrophomonas maltophilia (S. maltophilia), ninguno de los cuales tenía una enfermedad autoinmune subyacente. Una mujer de 23 años con imbricación de lupus eritematoso sistémico (LES) y artritis reuma-Artritis reumatoide; toide (AR), ingresó a nuestro Instituto por endocarditis de la válvula tricúspide adquirida en México comunidad. La paciente presentó como complicaciones tromboembolia pulmonar y neumonía, se encontraron anticuerpos contra péptidos cíclicos citrulinados (anti-CCP), antinucleares, anti-Sm, anti-Ro/SSA, anti-cardiolipina y anti-(β2 glucoproteína 1, factor reumatoide (FR), complementopenia, linfopenia y proteína C reactiva (PCR) de 425 mg/L. Se observó crecimiento de S. maltophilia en hemocultivos seriados y el tratamiento antimicrobiano empírico no fue efectivo, sino hasta que se incluyó trimetoprim/sulfametoxazol (TMP/SMX). Después de un mes de hospitalización, la paciente fue sometida a remplazo quirúrgico de la válvula tricúspide y la evolución clínica subsecuente fue satisfactoria, permitiendo su egreso 14 días después. Actualmente, la paciente se encuentra asintomática y su función cardiaca, renal y pulmonar es estable. Llama la atención que todos los autoanticuerpos han permanecido elevados a través del tiempo. Presentamos una recopilación de la información disponible acerca de la endocarditis por S. maltophilia, y proponemos que la autoinmunidad podría ser incluida como un nuevo factor de predisposición para esta entidad.

Immunity to Staphylococcus aureus secreted proteins protects rabbits from serious illnesses.

Staphylococcus aureus causes significant illnesses throughout the world, including toxic shock syndrome (TSS), pneumonia, and infective endocarditis. Major contributors to S. aureus illnesses are secreted virulence factors it produces, including superantigens and cytolysins. This study investigates the use of superantigens and cytolysins as staphylococcal vaccine candidates. Importantly, 20% of humans and 50% of rabbits in our TSS model cannot generate antibody responses to native superantigens. We generated three TSST-1 mutants; G31S/S32P, H135A, and Q136A. All rabbits administered these TSST-1 toxoids generated strong antibody responses (titers>10,000) that neutralized native TSST-1 in TSS models, both in vitro and in vivo. These TSST-1 mutants lacked detectable residual toxicity. Additionally, the TSST-1 mutants exhibited intrinsic adjuvant activity, increasing antibody responses to a second staphylococcal antigen (ß-toxin). This effect may be due to TSST-1 mutants binding to the immune co-stimulatory molecule CD40. The superantigens TSST-1 and SEC and the cytolysin α-toxin are known to contribute to staphylococcal pneumonia. Immunization of rabbits against these secreted toxins provided complete protection from highly lethal challenge with a USA200 S. aureus strain producing all three exotoxins; USA200 strains are common causes of staphylococcal infections. The same three exotoxins plus the cytolysins ß-toxin and γ-toxin contribute to infective endocarditis and sepsis caused by USA200 strains. Immunization against these five exotoxins protected rabbits from infective endocarditis and lethal sepsis. These data suggest that immunization against toxoid proteins of S. aureus exotoxins protects from serious illnesses, and concurrently superantigen toxoid mutants provide endogenous adjuvant activity.

[A case of native valve infective endocarditis in an immunocompromised patient]. / Um caso de endocardite infecciosa de válvula nativa em doente imunocomprometido.

Infective endocarditis continues to be associated with high mortality, despite the medical and surgical therapeutic options available. Surgical intervention is indicated in cases of heart failure or uncontrolled infection and sometimes for the prevention of embolic phenomena. The authors present the case of a 56-year-old male patient, with fibro-calcific mitral-aortic valve disease, splenectomized and with recently relapsed Hodgkin's lymphoma, who was admitted with infective endocarditis due to Streptococcus dysgalactiae. On the thirtieth day of directed antibiotic therapy, the mitral vegetation showed a significant increase in size and mobility. Surgery was considered at this point. However, given the patient's clinical stability and laboratory results, it was decided to adopt a conservative approach and to extend antibiotic therapy. The vegetation had regressed considerably seven days later. Given this atypical vegetation behavior, with slower than usual regression for the causative agent, the authors suggest that antibiotic therapy should be extended in patients with some degree of immunosuppression.

Oral inflammatory process and general health. Part 1: The focal infection and the oral inflammatory lesion.

A focal infection is a localized or generalized infection caused by the dissemination of microorganisms or toxic products from a focus of infection in various organic districts, including the oral district. In the Part 1 of this two-part review article, after historical signs, the Authors describe the current pathogenic concepts like the "immuno-allergic theory" and the formation of auto-antibodies in human body, contributing to the genesis of autoimmune illnesses sustained by individual reactivity linked to eredo-constitutionality. Some theories suppose a focal origin even for general pathology such as cancer, sarcoidosis, multiple sclerosis, amyotrophic lateral sclerosis, autism, Guillain-Barré syndrome, Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS), Tourette's syndrome, myasthenia gravis, polycystic kidney disease, obesity, Alzheimer's disease and diabetes mellitus. Laboratory analyses (leucocytic formula, protein electrophoresis, C-reactive protein, REUMA test VES, TAS, etc.) are suggestive of the presence of an inflammatory process or of the presence of an aspecific answer to an inflammatory situation. The DNA-Polymerase Chain Reaction method (PCR) is fundamental for the diagnosis of bacterial and viral infections, particularly for those that have non-culturable microorganisms or in cases where are present but in extremely small number in the sample to be analyzed. A positive result confirms the diagnosis, but negative result is not indicator of the absence of illness. Even for oral inflammatory lesions, different basic mechanisms concerning the possible association with systemic diseases exist. They concern local spread, metastatic spread or immunologic cross-reactivity. In this case we assume that most of the ailments come from dental or periodontal foci, as in the bacterial endocarditis, but instead of considering them as possible pathogenetic mechanism of an immune nature, we consider them as originated by the body's response to the presence of bacterial antigens through the formation of specific antibodies. Much researche, sometimes contrasting, has evaluated periodontal pathogens in atheromatous plaques isolated from patients with chronic periodontitis. Oral inflammatory lesions have been shown unequivocally to contribute to elevated systemic inflammatory responses. In some researches intensive periodontal therapy showed a significant reduction of lymphocyte formula, of CRP levels, of interleukin-6 (IL-6) and of LDL cholesterol after two months.

The uptake of apoptotic cells drives Coxiella burnetii replication and macrophage polarization: a model for Q fever endocarditis.

Patients with valvulopathy have the highest risk to develop infective endocarditis (IE), although the relationship between valvulopathy and IE is not clearly understood. Q fever endocarditis, an IE due to Coxiella burnetii, is accompanied by immune impairment. Patients with valvulopathy exhibited increased levels of circulating apoptotic leukocytes, as determined by the measurement of active caspases and nucleosome determination. The binding of apoptotic cells to monocytes and macrophages, the hosts of C. burnetii, may be responsible for the immune impairment observed in Q fever endocarditis. Apoptotic lymphocytes (AL) increased C. burnetii replication in monocytes and monocyte-derived macrophages in a cell-contact dependent manner, as determined by quantitative PCR and immunofluorescence. AL binding induced a M2 program in monocytes and macrophages stimulated with C. burnetii as determined by a cDNA chip containing 440 arrayed sequences and functional tests, but this program was in part different in monocytes and macrophages. While monocytes that had bound AL released high levels of IL-10 and IL-6, low levels of TNF and increased CD14 expression, macrophages that had bound AL released high levels of TGF-beta1 and expressed mannose receptor. The neutralization of IL-10 and TGF-beta1 prevented the replication of C. burnetii due to the binding of AL, suggesting that they were critically involved in bacterial replication. In contrast, the binding of necrotic cells to monocytes and macrophages led to C. burnetii killing and typical M1 polarization. Finally, interferon-gamma corrected the immune deactivation induced by apoptotic cells: it prevented the replication of C. burnetii and re-directed monocytes and macrophages toward a M1 program, which was deleterious for C. burnetii. We suggest that leukocyte apoptosis associated with valvulopathy may be critical for the pathogenesis of Q fever endocarditis by deactivating immune cells and creating a favorable environment for bacterial persistence.

Cytoplasmic antineutrophil cytoplasmic antibody positive pauci-immune glomerulonephritis associated with infectious endocarditis.

Renal deterioration often occurs in cases of infectious endocarditis (IE), but, IE- associated nephritis with rapidly progressive glomerulonephritis (RPGN) is rare. Patients with severe infection (e.g., IE) sometimes show positivity for cytoplasmic antineutrophil cytoplasmic antibodies (C-ANCA). Therefore, diagnosis and treatment are very difficult in cases of RPGN with IE and positivity for C-ANCA. Such cases are rare, only 12 have been reported in the English literature. Herein, we describe the case of a 50-year-old man who presented with RPGN with IE and tested positively for C-ANCA. He was referred to our hospital because of leg edema, purpura and renal dysfunction. Laboratory tests revealed serum creatinine elevation and positivity for C-ANCA and proteinase 3-specific (PR3)-ANCA. RPGN and acute renal failure were diagnosed. Hemodialysis and steroid therapy were started. Streptococcus oralis was isolated by blood culture. Transthoracic echocardiography revealed grade III mitral valve insufficiency with two vegetations. Therefore, IE was diagnosed. The steroid therapy was stopped, and antibiotic therapy was begun. Because there was no improvement, surgical therapy was performed. The operation was successful, but the patient died of brain hemorrhage. Our experience in this case indicates C/PR3-ANCA positive RPGN must be ruled out in patients with infectious disease, particularly IE, together with renal symptoms, and renal biopsy should be performed.

[Changes of immunological and cytogenetic indexes in lymphocytes of patients with bacterial endocarditis under the influence of laser therapy and a hyperbaric oxygen therapy].

The purpose of the present work was the estimation of the therapeutic effect of the soft laser therapy and a hyperbaric oxygen therapy during their inclusion in a therapeutic complex for the treatment of bacterial endocarditis. 30 patients (II group) under our observation have passed the standard basic therapy, and for 45 patients (I group) of different age the intravenous laser and hyperbaric oxygenation were added into the therapeutic complex. The estimation was made by evaluation of immune status and cytogenetic markers before treatment. At the height of disease there was marked immune deficiency, basically at the expense of T-helpers, and also of the B- lymphocyte part. The phagocyte system efficiency indices were decreased. By the admission of patients in the clinic the number cells with aberrations of chromosomes was increased. After the treatment nn the I group of patients there was absolute and relative elevation on the number of T-and B- lymphocytes, T- helpers, also the decrease of leukocytes, T-lymphocyte index, the increase of blast transformation lymphocytes level on mytogen FGA. The phagocytosis was activated, the balanced level of different Ig classes occurred. Number of cells with aberrations of chromosomes sharply decreased, basically at the expense of aneuploidic cells. Obtained results show, that laser therapy and hyperbaric oxygen therapy can be included in the therapeutic complex for the treatment of bacterial endocarditis.

Glucosyltransferases of viridans group streptococci modulate interleukin-6 and adhesion molecule expression in endothelial cells and augment monocytic cell adherence.

Recruitment of monocytes plays important roles during vegetation formation and endocardial inflammation in the pathogenesis of infective endocarditis (IE). Bacterial antigens or modulins can activate endothelial cells through the expression of cytokines or adhesion molecules and modulate the recruitment of leukocytes. We hypothesized that glucosyltransferases (GTFs), modulins of viridans group streptococci, may act directly to up-regulate the expression of adhesion molecules and also interleukin-6 (IL-6) to augment monocyte attachment to endothelial cells. Using primary cultured human umbilical vein endothelial cells (HUVECs) as an in vitro model, we demonstrated that GTFs (in the cell-bound or free form) could specifically modulate the expression of IL-6, and also adhesion molecules, in a dose- and time-dependent manner. Results of inhibition assays suggested that enhanced expression of adhesion molecules was dependent on the activation of nuclear factor kappaB (NF-kappaB) and extracellular signal-regulated kinase and that p38 mitogen-activated protein kinase pathways also contributed to the release of IL-6. Streptococcus-infected HUVECs or treatment with purified IL-6 plus soluble IL-6 receptor alpha enhanced the expression of ICAM-1 and the adherence of the monocytic cell line U937. These results suggest that streptococcal GTFs might play an important role in recruiting monocytic cells during inflammation in IE through induction of adhesion molecules and IL-6, a cytokine involved in transition from neutrophil to monocyte recruitment.

Glucosyltransferases of viridans streptococci are modulins of interleukin-6 induction in infective endocarditis.

The glucosyltransferases (GTFs) of viridans streptococci, common pathogens of infective endocarditis, are extracellular proteins that convert sucrose into exopolysaccharides and glucans. GTFs B, C, and D of Streptococcus mutans are modulins that induce, in vitro and in vivo, the production of cytokines, in particular interleukin-6 (IL-6), from monocytes. The roles of S. mutans GTFs in infectivity and inflammation in situ were tested in a rat experimental model of endocarditis. No significant differences in infectivity, in terms of 95% infective dose and densities of bacteria inside vegetations, were observed between laboratory strain GS-5 and two clinical isolates or isogenic mutant NHS1DD, defective in the expression of GTFs. In aortic valves and surrounding tissues, IL-6 was detected by Western blots and immunostaining 24 h after GS-5 infection, was maintained over 72 h, and was followed by production of tumor necrosis factor alpha but not IL-1beta. Animals infected with NHS1DD showed markedly lower levels of IL-6 (less than 5% of that of parental GS-5-infected rats), while tumor necrosis factor alpha was unaffected. In contrast, animals infected with NHR1DD, another isogenic mutant expressing only GtfB, showed a much smaller reduction (down to 56%). These results suggest that GTFs are specific modulins that act during acute inflammation, inducing IL-6 from endothelial cells surrounding the infected valves without affecting bacterial colonization in vegetations, and that IL-6 might persist in chronic inflammation in endocarditis.