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Infective Endocarditis (infective + endocarditis)

Distribution by Scientific Domains

Medical Sciences	97%

Selected Abstracts

Extremely Rapid Formation of Mitral Valve Ring Abscess in Infective Endocarditis

ECHOCARDIOGRAPHY, Issue 6 2004
Balaram Shrestha M.D., Ph.D.
A patient with infective endocarditis (IE) due to methicillin-resistant staphylococcus aureus (MRSA) was found to have conversion of the hypoechoic region of the posterior mitral valve ring apparatus into a clearly delineated echolucent space by repeating transthoracic echocardiography at an interval of 1 week. Color Doppler showed features of blood entry into this space. Abscess formation in IE due to MRSA may be quick and repeated echocardiography may help detect the complications of IE. Semiurgent mitral valve plasty was performed for the associated prolapse of the posterior mitral leaflet using a hand-made, rolled, twisted autologous pericardial ring. [source]

Diagnosing Infective Endocarditis by Emergency Department Echocardiogram

ACADEMIC EMERGENCY MEDICINE, Issue 6 2009
Brooks Walsh MD
No abstract is available for this article. [source]

Massive Cerebral Embolism Originated from Ruptured Infective Mitral Annular Calcification in a Chronic Hemodialysis Patient

ECHOCARDIOGRAPHY, Issue 1 2009
Junichi Nishida M.D.
Infective endocarditis of mitral annular calcification (MAC) has been reported, however, little attention has been given to the possibility of cerebral-embolism based infective endocarditis of MAC. We report a chronic hemodialysis patient of massive cerebral embolism originated from ruptured infective MAC. [source]

Infective endocarditis in a hemodialysis patient: A dreaded complication

HEMODIALYSIS INTERNATIONAL, Issue 4 2007
Claudia SCHUBERT
Abstract Infection is the most common cause of death in hemodialysis patients, after cardiovascular disease. Dialysis access infections, with secondary septicemia, contribute significantly to patient mortality. The most common source is temporary catheterization. Bacteremia occurs commonly in patients receiving hemodialysis, with infective endocarditis being a relatively uncommon, but potentially lethal complication. Valvular calcification is the most significant risk factor. The diagnosis of infective endocarditis is made clinically and confirmed with the echocardiographic modified Duke's criteria. The most common pathogen is Staphylococcus aureus and the mitral valve is the most common site. Staphylococcus aureus infective endocarditis is commonly associated with embolic phenomenon. A high index of suspicion is critical in the early recognition and management of infective endocarditis. However, prevention of bacteremia is undoubtedly the best strategy with the early placement of arteriovenous fistulae. In the case of temporary catheterization, the use of topical mupirocin or polysporin and gentamicin and/or citrate locking is beneficial. Although catheter salvage has not been studied in randomized trials, catheter removal remains standard therapy during bacteremia. [source]

Infective endocarditis: NICE-ly tied up in knots

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 4 2009
G. Jackson
No abstract is available for this article. [source]

Pacemaker Lead Endocarditis Caused by Staphylococcus Hominis

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2006
MUSTAFA SUNBUL
Infective endocarditis related to pacemaker is a rare but serious condition in permanent venous tracing. A 65-year-old man was admitted to the hospital with high fever and chills. A DDD pacemaker had been implanted via the right subclavian vein because of sick sinus syndrome 6 years earlier. Transesophageal echocardiogram identified an oscillating round hyperechoic mass with a stalk near the tricuspid valve. Blood cultures grew Staphylococcus hominis. The patient was treated with antibiotics and operated on after the acute phase of the illness had subsided. We hereby report a case of lead endocarditis caused by S. hominis in a patient with pacemaker, which has been rarely reported in the English literature. [source]

Infective endocarditis after transcatheter closure of a patent foramen ovale

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2004
Marco Calachanis MD
Abstract Infection of devices for percutaneous transcatheter closure of atrial septal defects are exceedingly rare. Two cases of device-associated endocarditis have been reported, which were both operated on. We describe the successful treatment with antibiotics of a device-associated endocarditis. Catheter Cardiovasc Interv 2004;63:351,354. © 2004 Wiley-Liss, Inc. [source]

Infective endocarditis in Greece: a changing profile.

CLINICAL MICROBIOLOGY AND INFECTION, Issue 6 2004
Epidemiological, microbiological, therapeutic data
Abstract The epidemiology, and clinical and microbiological spectrum, of infective endocarditis (IE) in Greece was analysed in a prospective 4-year study in a tertiary hospital and a heart surgery centre in Athens. In total, 101 cases of IE (71 men, 30 women, aged 54.4 ± 17.1 years) were studied, with a follow-up period of 3 months. Seventy-seven cases were definite and 24 possible; 59 involved native valves (native valve endocarditis; NVE), 31 prosthetic valves (prosthetic valve endocarditis; PVE), of which nine were early and 22 late, and 11 permanent pacemakers (pacemaker endocarditis; PME). There was a predominant involvement of aortic (48/101) and mitral (40/101) valves. Seven patients had rheumatic valvular disease, two had mitral valve prolapse, and eight had a previous history of IE. Thirteen and six patients had undergone dental and endoscopic procedures, respectively. In 13 patients, intravenous catheters were used within the 3 months before diagnosis of IE. There were three intravenous drug users among the patients. Staphylococcus aureus was the most important pathogen, isolated in 22% of cases, followed by viridans streptococci (19%) and coagulase-negative staphylococci (16%). Enterococcus spp. were responsible for 3%, HACEK group for 2%, and fungi for 6% of cases. Viridans streptococci were the leading cause of NVE (29%), Staphylococcus epidermidis of PVE (16%), and S. aureus of PME (54.5%). Six of 22 S. aureus and ten of 16 S. epidermidis isolates were methicillin-resistant. Surgical intervention, including total pacemaker removal, was performed in 51.5% of patients. Overall mortality was 16%, but was 29% with PVE, and was significantly higher with medical than with combined surgical and medical therapy (24.5% vs. 8%). Compared with previous studies, there were changing trends in the epidemiology, microbiology, treatment and prognosis of IE in Greece. [source]

I PREVENT Bacterial Resistance.

DERMATOLOGIC SURGERY, Issue 10 2009
An Update on the Use of Antibiotics in Dermatologic Surgery
BACKGROUND AND OBJECTIVES Prophylaxis may be given to prevent a surgical wound infection, infective endocarditis (IE), or infection of a prosthetic joint, but its use before cutaneous surgery is controversial. Our aim was to review the current literature and provide a mnemonic to assist providers in appropriately prescribing prophylactic antibiotics. METHODS AND MATERIALS We reviewed the current literature, including the new guidelines provided by the American Heart Association (AHA). RESULTS The new AHA guidelines recommend prophylaxis for patients with high risk of an adverse outcome from IE instead of high risk of developing IE. The American Academy of Orthopedic Surgeons and the American Dental Association also provide guidelines. Given the paucity of conclusive studies, prophylaxis against a surgical wound infection is based more on clinical judgment. CONCLUSION The mnemonic we propose, "I PREVENT," represents: Immunosuppressed patients; patients with a Prosthetic valve; some patients with a joint Replacement; a history of infective Endocarditis; a Valvulopathy in cardiac transplant recipients; Endocrine disorders such as uncontrolled diabetes mellitus; Neonatal disorders including unrepaired cyanotic heart disorders (CHDs), repaired CHD with prosthetic material, or repaired CHD with residual defects; and the Tetrad of antibiotics: amoxicillin, cephalexin, clindamycin, and ciprofloxacin. [source]

Staphylococcus aureus Infective Endocarditis Mimicking a Hydatid Cyst

ECHOCARDIOGRAPHY, Issue 8 2010
Jeroen Walpot M.D.
We report an atypical echocardiographic presentation of Staphylococcus aureus infective endocarditis (IE) of the mitral valve in an octogenarian female. Echocardiography revealed perforation of the anterior mitral valve leaflet (AMVL), with a large cystic mass seemingly attached to the AMVL and surrounded by a thin membranous structure. These images were strongly reminiscent of a hydatid cyst. The significant comorbidity of the patient did not justify an urgent surgical approach, and the patient subsequently expired of cardiogenic and septic shock. Autopsy revealed a large vegetation attached to the interatrial septum in the immediate proximity of the AMVL, without signs of the membranous structure and without pathological evidence for septic embolism. This atypical presentation of IE prompted us to discuss a brief review of intracardiac cystic masses. (Echocardiography 2010;27:E80-E82) [source]

Massive Cerebral Embolism Originated from Ruptured Infective Mitral Annular Calcification in a Chronic Hemodialysis Patient

Unusual Cause of Heart Failure in a 65-Year-Old Woman

ECHOCARDIOGRAPHY, Issue 10 2008
Mirela Tomescu M.D., Ph.D.
Left ventricular (LV) free wall rupture is a potentially lethal mechanical complication after myocardial infarction (MI). Pericardial adhesions or slow extracardiac leak and pericardial inflammation may result in a contained cardiac rupture. LV pseudoaneurysm is a relatively uncommon clinical entity. It may occur after MI, but also as a complication of infective endocarditis, cardiac surgery, or trauma. Patients developing LV pseudoaneurysm after MI may present angina pectoris or signs of congestive heart failure (HF) but often are asymptomatic. Surgery is the treatment of choice for LV pseudoaneurysms diagnosed in the first months after MI. The management of chronic LV pseudoaneurysms is still subject of debate. This report highlights a 65-year-old patient newly hospitalized for acute decompensated HF who was diagnosed with a large chronic LV pseudoaneurysm and severe mitral regurgitation. The patient underwent successful resection of the pseudoaneurysm and patch repair of the ruptured ventricular wall. [source]

Phialemonium curvatum Prosthetic Valve Endocarditis with an Unusual Echocardiographic Presentation

ECHOCARDIOGRAPHY, Issue 6 2006
Azriel Osherov M.D.
Phialemonium species, an opportunistic fungal pathogen rarely causes invasive disease, have been described as opportunistic infection agents in humans, mainly as a result of immunosuppression and very rarely involves the heart. We present a case of a patient with Phialemonium curvatum prosthetic aortic valve endocarditis with an unusual initial transesophageal echocardiography (TEE) presentation, illustrating the important role of repeat TEE for the proper diagnosis and management of infective endocarditis. [source]

Extremely Rapid Formation of Mitral Valve Ring Abscess in Infective Endocarditis

The Rupture of Periaortic Infective Aneurysm into the Left Atrium and the Left Ventricular Outflow Tract: Preoperative Diagnosis by Transthoracic Echocardiography

ECHOCARDIOGRAPHY, Issue 3 2002
Ewa Lastowiecka M.D.
We present a rare complication of infective endocarditis, perforated periaortic abscess with fistulous communication between the aortic root, the left atrium, and the left ventricular outflow tract. Preoperative transthoracic echocardiographic diagnosis was confirmed intraoperatively. The patient was treated successfully by aortic homograft implantation. [source]

Active Vegetations Can Be Differentiated from Chronic Vegetations by Visual Inspection of Standardized Two-Dimensional Echocardiograms

ECHOCARDIOGRAPHY, Issue 2 2000
PH.D., TAHIR TAK M.D.
The ability to differentiate active from chronic valvular vegetations (VEGs) by digital image processing and by visual observation was evaluated in 18 patients with a clinical diagnosis of infective endocarditis (IE). Two-dimensional echocardiographic (2-DE) examinations were performed on all patients at diagnosis and after a mean period of 52 days. Two comparable images (active and chronic) from the same patient and in the same phase of the cardiac cycle were digitized, magnified, and displayed on a high resolution monitor. The mean pixel intensity (MPI) was 72 ± 14 in the active stage and 143 ± 23 in the chronic stage (P < 0.0001). The VEG size was 0.64 ± 0.15 cm2 in the active stage and decreased to 0.46 ± 0.17 cm2 in the chronic stage (P < 0.001). Two experienced echocar-diographers, who were blinded to the age of the VEGs, identified each echocardiographic image as active or chronic based on visual observation of density of the VEGs. The VEGs were correctly identified as active or chronic in 17 out of the 18 patients. In summary, although digital image processing of 2-DE may be useful, the density of VEGs assessed by visual inspection will help differentiate between active and chronic VEGs of IE. The standardization procedure at the time of the initial study and use of identical gain settings in subsequent studies are key factors in making this distinction. [source]

Neurobrucellosis as an exceptional cause of transient ischemic attacks

EUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2006
A. Bingöl
We report a series of four cases presented with transient ischemic attacks (TIA) or ischemic stroke as the predominant manifestation of neurobrucellosis (NB). Three of the patients were 20,28 years of age, and one patient was 53 years old. They all used to consume unpasteurized milk or its products. Two patients had systemic brucellosis in the past and received antibiotic treatment. Other causes of TIA including cardiac embolism, hypercoagulability, vascular malformations, systemic vasculitis, and infective endocarditis were excluded. NB was diagnosed with serological tests or cultures for Brucella in the cerebrospinal fluid. None of the patients had any further TIA after the initiation of specific treatment. NB should always be sought in young patients with TIA or ischemic stroke, especially if they have no risk factors for stroke and live in an endemic area for brucellosis, even if they do not have other systemic signs of brucellosis. [source]

Implantable cardioverter defibrillator in maintenance hemodialysis patients with ventricular tachyarrhythmias: A single-center experience

HEMODIALYSIS INTERNATIONAL, Issue 1 2009
Itaru ITO
Abstract Patients with hemodialysis (HD) are at risk of death due to cardiac arrhythmias, worsening congestive heart failure (CHF), and noncardiac causes. This study reviews our experience with the use of implantable cardioverter defibrillators (ICDs) in patients with ventricular tachycardia who are under maintenance HD. We retrospectively reviewed 71 consecutive patients who underwent an ICD implantation in our hospital. There were 11 patients under maintenance HD and 60 patients without HD. The group of patients with HD (HD group) was compared with the patients without HD (control group). The mean follow-up period was 30±9 vs. 39±4 months in the HD group vs. the control group, respectively. Among these patients, 6 in the HD group and 26 in the control group received appropriate ICD therapies. There was no difference in appropriate ICD therapy, time to the first therapy, and electrical storm between the 2 groups. In the HD group, 1 patient underwent surgical removal of the ICD system due to infective endocarditis. There were 5 deaths in the HD group (4 from CHF) and 8 deaths in the control group (4 from CHF). There were no sudden cardiac deaths or arrhythmic deaths in both groups of patients during the follow-up period. However, the overall death rate was significantly higher in the HD group (P<0.01). In HD patients, ICD therapy prevented arrhythmic death, but their rate of nonarrhythmic adverse outcomes was high. This risk-benefit association should be considered before implantation of the device. [source]

Infective endocarditis in a hemodialysis patient: A dreaded complication

Ten-year study of bacteremia in hemodialysis patients in a single center

HEMODIALYSIS INTERNATIONAL, Issue 1 2005
J.A. Park
Background:,The incidence of infection in patients on chronic hemodialysis in higher than that of the general population. Infection is known to be a major cause of morbidity and mortality in these patients. The vascular access is important for hemodialysis, but infection through this route is the most common source of bacteremia and can be lethal to the patients. Despite the high morbidity and mortality of bacteremia in patients on chronic hemodialysis, the clinical characteristics of bacteremia in hemodialysis patients is rarely reported yet in Korea. Methods:,We included 696 hemodialysis patients from January 1993 to December 2003 at Uijongbu St. Mary's Hospital. We investigated incidence, source, causative organisms, clinical manifestations, complication, and mortality of bacteremia. We compared clinical factors, morbidity, and mortality between arteriovenous fistula and central venous catheter groups. Results:,Total 52 cases of bacteremia occurred in 43 patients. The major source of infection was vascular access (48%). Staphylococcus aureus was most common organism isolated. Major complications were septic shock (9.6%), pneumonia (9.6%), infective endocarditis (3.8%), and aortic pseudoaneurysm (1.9%). Nine patients died from septic shock (n = 4), aspiration pneumonia (n = 2), hypoxic brain injury (n = 1), gastrointestinal bleeding (n = 1), and rupture of aortic pseudoaneurysm. The central venous catheter group (n = 22) had higher incidences of vascular access as a source of infection (81.8% vs 23.3%, p < 0.001) and staphylococcus as a causative organism (77.2% vs 50.0%, p = 0.042) than the arteriovenous group. Conclusion:, This data shows that bacteremia causes high incidence of fatal complications and mortality. Therefore, careful management of vascular access as well as early detection of bacteremia is an important factor for the prevention of infection and proper antibiotic therapy should be started early. [source]

Mycotic aneurysm of the superior mesenteric artery in a young woman

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2005
P-H Chu
Summary Aneurysm of the superior mesenteric artery (SMA) is rare. We, in this study, present the case of a 21-year-old woman with a history of heroin abuse who was admitted to our hospital for infective endocarditis complicated by floating vegetation at the posterior mitral valve. After receiving 2-week antibiotic treatment, the patient had acute abdominal pain. Computed tomography demonstrated an aneurysm at the SMA. The mycotic aneurysm was resected and the mitral valve was repaired successfully. This report reviews the pathophysiology of mycotic aneurysms of the SMA and role of computed tomography in the differential diagnosis of this condition from acute mesenteric ischaemia. [source]

The oral health of children considered very high risk for infective endocarditis

INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 3 2010
RICHARD BALMER
International Journal of Paediatric Dentistry 2010; 20: 173,178 Background., Children with previous experience of infective endocarditis or with prosthetic heart valve are considered at very high risk for infective endocarditis. Aim., The aim of this study was to compare the dental health of a group of these children with a group of healthy controls and to determine parental awareness of the importance of good oral health. Design., Oral examination was carried out in 28 children with previous infective endocarditis or a prosthetic heart valve to assess oral health. Findings were compared to a healthy control group of 28. Questionnaires were distributed to the parents to assess awareness of oral health. Results., There was no significant difference in DMFT scores of study and control group (2.43 +/- 3.72 and 1.36 +/- 2.5 respectively) or in DMFT scores of study and control group (1.5 +/- 1.73 and 1.15 +/- 1.42 respectively), 36% of the study group had untreated caries. Parental knowledge of the link between oral health and infective endocarditis was excellent. Conclusions., There were no significant differences between the oral health of cardiac children and healthy children although the dmft and DMFT scores of the study group were high. Of concern was the proportion of children with untreated caries in spite of good dental awareness and attendance. [source]

Antimicrobial Resistance and Aging: Beginning of the End of the Antibiotic Era?

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2002
Thomas T. Yoshikawa MD
Throughout the history of mankind, infectious diseases have remained a major cause of death and disability. Although industrialized nations, such as the United States, have experienced significant reductions in infection-related mortality and morbidity since the beginning of the "antibiotic era," death and complications from infectious diseases remain a serious problem for older persons. Pneumonia is the major infection-related cause of death in older persons, and urinary tract infection is the most common bacterial infection seen in geriatric patients. Other serious and common infections in older people include intra-abdominal sepsis, bacterial meningitis, infective endocarditis, infected pressure ulcers, septic arthritis, tuberculosis, and herpes zoster. As a consequence, frequent prescribing of antibiotics for older patients is common practice. The large volume of antibiotics prescribed has contributed to the emergence of highly resistant pathogens among geriatric patients, including methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci, and multiple-drug-resistant gram-negative bacilli. Unless preventive strategies coupled with newer drug development are established soon, eventually clinicians will be encountering infections caused by highly resistant pathogens for which no effective antibiotics will be available. Clinicians could then be experiencing the same frustrations of not being able to treat infections effectively as were seen in the "pre-antibiotic era." [source]

Does Aortic Root Enlargement Impair the Outcome of Patients With Small Aortic Root?

JOURNAL OF CARDIAC SURGERY, Issue 5 2006
Hasan Ardal
The aim of this study was to evaluate long-term results of the posterior root enlargement. Methods: Between 1985 and 2002, 124 patients underwent aortic valve replacement with a posterior root enlargement. The main indication was a small aortic valve orifice area to patient body surface area (indexed valve area < 0.85 cm2/m2). Fifty-four (44%) patients were male, and 70 (56%) were female with a mean age 39.1 ± 14.3 years. Indications for operation were severe calcified aortic valve stenosis (37.1%), severe aortic insufficiency (25.8%), or combination (37.1%). Seventy-five (60%) patients received double-valve replacement. A pericardial patch was used in 100 patients (80.6%) and a Dacron patch was used in 24 patients. Results: Operative mortality was 6.4% (8 patients). The causes of hospital mortality were low cardiac output syndrome (LCOS) (in 6 patients), cerebrovascular events (in 1 patient) and multiple organ failure (in 1 patient). Multivariate analysis demonstrated concomitant coronary revascularization to be a significant (p = 0.03) predictor for early mortality. There were six (5.4%) late deaths. Cox proportional hazards regression analysis demonstrated LCOS (p = 0.013) and infective endocarditis (p = 0.003) to be significant predictors for late mortality. Atrioventricular block required a permanent pacemaker was observed in 4 patients (3.2%). Conclusions: Posterior aortic root enlargement techniques can be easily applied without additional risks. Long-term survival and freedoms from valve-related complications are satisfactory. [source]

A Technique of Snaring Method for Fitting a Prosthetic Valve into the Annulus

JOURNAL OF CARDIAC SURGERY, Issue 1 2005
Shigeo Nagasaka M.D.
We modified the previously reported method and designed a simpler tying technique. Patients: We performed 11 aortic (AVR: including four cases for calcified aortic stenosis (AS) with a small annulus and one cases for infective endocarditis with intramuscular abscess cavity), eight mitral valve replacements (MVR), and one tricuspid valve replacement (TVR: for corrected transposition of the great arteries). Techniques and Results: A PV was implanted using 2-0 polyester mattress sutures with a pledget. Each of the two tourniquets held a suture at the bottom of the annulus and at the opposite position to fit a PV. The sutures between each snare were tied down from the bottom to the top. In MVR, after seating of a PV with two tourniquets, we could make sure that no native tissue of any preserved mitral apparatus disturbed PV leaflet motion. In calcific AS, a PV had a good fitting into the annulus because of tourniquets applied to unseated part during tying sutures. In AVR for infective endocarditis, mattress sutures supported by a Teflon pledget were placed to close the abscess cavity. After snaring on one of these sutures, we tied down the sutures, ensuring that they did not cut through the friable tissues. In TVR, we found that native leaflets interfered with PV motion after seating down the prosthesis and those leaflets were resected before tying down the sutures. Postoperative transesophageal echocardiography showed no paravalvular leakage in any patients and excellent PV functions. [source]

Transcatheter Closure of Congenital Ventricular Septal Defects: Experience with Various Devices

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2003
RAMESH ARORA D.M.
Transcatheter closure of congenital ventricular septal defect (VSD) using various devices is gaining acceptance in selected cases of perimembranous and muscular defects, avoiding the inherent risks of cardiopulmonary bypass. The procedure was attempted in 137 patients having congenital defects using Rashkind Umbrella Device (RUD) in 29 patients, Amplatzer ventricular septal occluder (AVSO) in 107 patients, and Detachable Coil in one. All patients were selected using stringent criteria by detailed transthoracic echocardiography and/or transesophageal echocardiography. The location of VSD was perimembranous in 91 patients and was muscular trabecular in 46 patients. Seven patients had left ventricle (LV) to right atrium (RA) communication. Thirty-five patients with perimembranous and two with muscular VSD had aneurysm formation. The patients were 3 to 33 years old, and the diameter of VSD ranged from 3 to 12 mm. The pulmonary to systemic flow ratio was ,2:1 in 47 (34.3%) patients. The procedure was successful in 130 (94.8%) patients, with a success rate of 86.2% with RUD and 97.1% with AVSO. Residual shunt at 24 hours was seen in eight (32%) patients with RUD and in one patient (0.9%) with AVSO. Three (2.8%) developed transient bundle branch block, and two (1.9%) patients had complete heart block. New tricuspid stenosis and tricuspid regurgitation was observed in one patient each with AVSO. After immediate balloon dilatation, the mean pressure gradient across tricuspid valve decreased from 11 to 3 mmHg in the patient with tricuspid stenosis. On a follow-up of 1 to 66(mean 35.2 ± 10.7)months, the device was in position in all. None developed late conduction defect, aortic regurgitation, infective endocarditis, or hemolysis. At 9-month follow-up, the mean pressure gradient across the tricuspid valve was 3 mmHg in the patient with tricuspid stenosis. Complete occlusion of the shunt was achieved in 129 (99.2%) patients. One patient with RUD having persistent residual shunt underwent a second procedure with AVSO. Three out of 107 patients with AVSO had an unsuccessful procedure where the defect was perimembranous with a superior margin of defect less than 3 mm away from the aortic valve, and the specially designed perimembranous AVSO had to be retrieved because of hemodynamic compromise due to significant acute aortic regurgitation, whereas in all others, the defect was either ,3 mm away from the aortic valve or had aneurysm formation. All seven patients with LV to RA communication showed complete abolition of the shunt. Thus, in properly selected cases of perimembranous and muscular ventricular septal defects, the transcatheter closure is safe and efficacious using appropriate devices. The success rate is higher with AVSO compared with the previously used devices, as well as more successful for the muscular defects than those that are perimembranous in location. (J Interven Cardiol 2003;16:83,91) [source]

Fibronectin-binding proteins of Staphylococcus aureus mediate activation of human platelets via fibrinogen and fibronectin bridges to integrin GPIIb/IIIa and IgG binding to the Fc,RIIa receptor

MOLECULAR MICROBIOLOGY, Issue 1 2006
J. Ross Fitzgerald
Summary Staphylococcus aureus is a leading cause of infective endocarditis (IE). Platelet activation promoted by S. aureus resulting in aggregation and thrombus formation is an important step in the pathogenesis of IE. Here, we report that the fibrinogen/fibronectin-binding proteins FnBPA and FnBPB are major platelet-activating factors on the surface of S. aureus from the exponential phase of growth. Truncated derivatives of FnBPA, presenting either the fibrinogen-binding A domain or the fibronectin-binding BCD region, each promoted platelet activation when expressed on the surface of S. aureus or Lactococcus lactis, indicating two distinct mechanisms of activation. FnBPA-promoted platelet activation is mediated by fibrinogen and fibronectin bridges between the A domain and the BCD domains, respectively, to the low affinity form of the integrin GPIIb/IIIa on resting platelets. Antibodies recognizing the FnBPA A domain or the complex between the FnBPA BCD domains and fibronectin were essential for activation promoted by bacteria expressing the A domain or the BCD domain respectively. Activation was inhibited by a monoclonal antibody (IV-3) specific for the Fc,RIIa IgG receptor on platelets. We propose that the activation of quiescent platelets by bacteria expressing FnBPs involves the formation of a bridge between the bacterial cell and the platelet surface by (i) fibronectin and fibrinogen interacting with the low affinity form of GPIIb/IIIa and (ii) by antibodies specific to FnBPs that engage the platelet Fc receptor Fc,RIIa. Platelet activation by S. aureus clinical IE isolates from both the exponential and stationary phases of growth was completely inhibited by monoclonal antibody IV-3 suggesting that the IgG,Fc,RIIa interaction is of fundamental importance for platelet activation mediated by this organism. This suggests new avenues for development of therapeutics against vascular infections. [source]

Contribution of cell surface protein antigen c of Streptococcus mutans to platelet aggregation

MOLECULAR ORAL MICROBIOLOGY, Issue 5 2009
M. Matsumoto-Nakano
Introduction:,Streptococcus mutans is considered to be one of the pathogens that cause infective endocarditis. The purpose of the present study was to examine the properties of S. mutans with regard to platelet aggregation by focusing on its high molecular protein antigen c (PAc). Methods:, The platelet aggregation properties of six clinical strains and one isogenic mutant strain of S. mutans were analysed using an aggregometer and confocal microscopy, as well as with an inhibition assay of platelet aggregation using anti-PAc serum. Results:,S. mutans strains with PAc expression induced platelet aggregation, while a PAc-deficient mutant and two clinical isolates with no PAc expression did not. When platelets were pretreated with higher amounts of anti-PAc serum, the platelet aggregation rate was reduced in a dose-dependent manner, indicating that PAc binds directly to platelets. Conclusion:,S. mutans PAc is involved in human platelet aggregation and may be one of the virulence factors in the pathogenesis of infective endocarditis. [source]

Detection of serotype k Streptococcus mutans in Thai subjects

MOLECULAR ORAL MICROBIOLOGY, Issue 5 2009
J. Lapirattanakul
Introduction:,Streptococcus mutans, known to be a pathogen of dental caries as well as bacteremia and infective endocarditis, is classified into four serotypes, c, e, f and k, based on the structures of serotype-specific polysaccharides. Serotype k was recently designated using blood isolates from Japanese subjects and such strains are considered to be virulent in the bloodstream. The purpose of the present study was to analyse the serotype distribution of strains isolated from Thai subjects and determine whether serotype k strains were present. Methods:, A total of 250 S. mutans strains were isolated from 50 Thai subjects, and serotypes of all strains were determined. Then, molecular and biological analyses were carried out for serotype k strains. Results:, Immunodiffusion and polymerase chain reaction analyses showed that serotype c was the most prevalent (70%), followed by serotypes e (22.8%), f (4.4%) and k (2.8%), which indicated that serotype k S. mutans strains occurred in Thai individuals at a similar rate to that previously reported for Japanese and Finnish populations. Molecular analyses of the seven serotype k strains showed extremely low expression of rgpE, which is related to glucose side-chain formation in serotype-specific rhamnose-glucose polymers, similar to previous reports for those other populations. In addition, analysis of the biological properties of the seven serotype k strains demonstrated low levels of sucrose-dependent adhesion, cellular hydrophobicity, dextran-binding activity and phagocytosis susceptibility by human polymorphonuclear leukocytes, which are characteristics similar to those of serotype k strains previously isolated in Japan. Conclusion:, Our results indicate the possibility of a worldwide prevalence of serotype k strains with properties in common with those of previously reported strains. [source]

Rothia dentocariosa sepsis in a pediatric renal transplant recipient having post-transplant lymphoproliferative disorders

PEDIATRIC TRANSPLANTATION, Issue 3 2006
Silke Wiesmayr
Abstract: Background: Rothia dentocariosa (RD) is a Gram-positive rod that colonizes the human oral cavity and can cause infective endocarditis. Result: We report on a six-yr-old boy who underwent renal transplantation for polycystic kidney disease at the age of eight months. He developed post-transplant lymphoproliferative disorders after four yr and progressive graft failure. Following chemotherapy, the patient presented with neutropenia and sepsis. RD was isolated from blood and treatment with piperacillin/tazobactam was initiated; however, the child died because of multiorgan failure. Discussion: To the best of our knowledge, this is the first case of RD sepsis in a pediatric solid organ transplant recipient. [source]