Unrecognized pre-transplant disseminated Coxiella burnetti infection diagnosed in a post-transplant heart-kidney recipient.

To the best of our knowledge, we report the first case of pre-transplant unrecognized disseminated Coxiella burnetii infection, unmasked in the post-transplant period leading to both heart and kidney allograft dysfunction. A 59 year old man with a history of simultaneous heart-kidney transplantation due to end stage heart failure from severe aortic regurgitation (AR) and cryoglobulinemic immune complex mediated concentric necrotizing glomerulonephritis (GN), presents with a history of intermittent fevers and fatigue. Prior to transplantation he was treated for multiple episodes of culture negative endocarditis requiring bio-prosthetic valve replacement. Evaluation of fever included a transesophageal echocardiogram (TEE) that revealed a large hyperechoic mass on the anterior mitral leaflet with perforation, severe mitral regurgitation and moderate AR. Blood cultures were negative at that time. Owing to development of allograft mitral and aortic valve insufficiency, he underwent allograft bio-prosthetic mitral valve (MV) replacement and aortic valvuloplasty 2 years following his transplantation. Pathologic examination of the allograft mitral valve demonstrated fibrinopurulent exudate with degenerating bacterial organisms, consistent with vegetation and myxoid degenerative changes. Due to a high suspicion for native heart C. burnetii prosthetic valve endocarditis prior to transplantation, we re-evaluated the native explanted heart histopathology, as well as the explanted allograft MV. Cardiac allograft and native MV were positive for C. burnetii by real-time PCR. C. burnetii serology was consistent with persistent infection as well.

Near-complete aortic mechanical valve dehiscence due to endocarditis reinfection.

Prosthetic valve infective endocarditis (IE) is one of the most serious postimplantation complications. Prosthetic aortic valve IE constitutes 1%-6% of all prosthetic valve IE cases. We present a dramatic echocardiographic case of prosthetic aortic valve IE leading to near-complete valve dehiscence. Echocardiographic evidence of prosthetic aortic valve rocking motion is indicative of significant dehiscence. Aside from IE, other causes and risk factors for prosthetic aortic valve dehiscence include inflammatory and autoimmune vasculitides, concomitant ascending aorta aneurysm, and aortic root calcification.

Probiotics and infective endocarditis in patients with hereditary hemorrhagic telangiectasia: a clinical case and a review of the literature.

BACKGROUND: In the last decades, probiotics have been widely used as food supplements because of their putative beneficial health effects. They are generally considered safe but rare reports of serious infections caused by bacteria included in the definition of probiotics raise concerns on their potential pathogenic role in patients with particular predisposing factors. Patients with hereditary hemorrhagic telangiectasia (HHT) are exposed to infections because of telangiectasias and arteriovenous malformations (AVMs). We describe what is, to our knowledge, the first case of infective endocarditis (IE) caused by Lactobacillus rhamnosus in a patient with HHT. A systematic review of the relevant medical literature is presented. CASE PRESENTATION: A patient with HHT and an aortic bioprosthesis was admitted because of prolonged fever not responding to antibiotics. The patient had a history of repeated serious infections with hospitalizations and prolonged use of antibiotics, and used to assume large amounts of different commercial products containing probiotics. Weeks before the onset of symptoms the patient had been treated with nasal packings and with surgical closure of a nasal bleeding site because of recurrent epistaxis. A diagnosis of IE of the aortic bioprosthesis was made. All blood coltures were positive for L. rhamnosus. The patients responded to a cycle of 6 weeks of amoxicillin/clavulanate plus gentamicin. A systematic review of IE linked to consumption of probiotics, and of infective endocarditis in patients with HHT was conducted. 10 cases of IE linked to probiotics consumption and 6 cases of IE in patients with HHT were found. CONCLUSIONS: Consumption of probiotics can pose a risk of serious infections in patients with particular predisposing factors. Patients with HHT can be considered at risk because of their predisposition to infections. Prophylaxis with antibiotics before nasal packings in patients with HHT can be considered.

Prosthetic valve endocarditis: positron emission tomography/computed tomography as a new golden grail.

Prosthetic valve endocarditis (PVE) is a serious infection with potentially fatal consequences. Early detection is crucial for successful management and outcome. The diagnosis of PVE is challenging and is based on the Duke criteria (DC) in which echocardiography plays a crucial role. However, transthoracic and transoesophageal echocardiography have less diagnostic value in PVE compared to native valve endocarditis. Combined computed tomography and fluorodeoxyglucose positron emission is a new technique providing improved diagnostic accuracy in PVE. This paper presents a case and reviews on the role of positron emission tomography/computed tomography in PVE.

Bacterial adherence to graft tissues in static and flow conditions.

BACKGROUND: Various conduits and stent-mounted valves are used as pulmonary valve graft tissues for right ventricular outflow tract reconstruction with good hemodynamic results. Valve replacement carries an increased risk of infective endocarditis (IE). Recent observations have increased awareness of the risk of IE after transcatheter implantation of a stent-mounted bovine jugular vein valve. This study focused on the susceptibility of graft tissue surfaces to bacterial adherence as a potential risk factor for subsequent IE. METHODS: Adhesion of Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus sanguinis to bovine pericardium (BP) patch, bovine jugular vein (BJV), and cryopreserved homograft (CH) tissues was quantified under static and shear stress conditions. Microscopic analysis and histology were performed to evaluate bacterial adhesion to matrix components. RESULTS: In general, similar bacteria numbers were recovered from CH and BJV tissue surfaces for all strains, especially in flow conditions. Static bacterial adhesion to the CH wall was lower for S sanguinis adhesion (P < .05 vs BP patch). Adhesion to the BJV wall, CH wall, and leaflet was decreased for S epidermidis in static conditions (P < .05 vs BP patch). Bacterial adhesion under shear stress indicated similar bacterial adhesion to all tissues, except for lower adhesion to the BJV wall after S sanguinis incubation. Microscopic analysis showed the importance of matrix component exposure for bacterial adherence to CH. CONCLUSIONS: Our data provide evidence that the surface composition of BJV and CH tissues themselves, bacterial surface proteins, and shear forces per se are not the prime determinants of bacterial adherence.

Comparison of Outcome of Possible Versus Definite Infective Endocarditis Involving Prosthetic or Bioprosthetic Heart Valves.

The objectives of this study were to describe and compare the clinical characteristics and outcomes of patients with definite and possible infective endocarditis (IE) involving prosthetic heart valve, and to identify prognostic factors for long-term mortality, using data from an unselected cohort of consecutive patients. We studied data from 133 consecutive patients with IE involving prosthetic heart valve seen in an academic institution between 1990 and 2012. Patients were classified according to the modified Duke criteria for IE: patients with possible IE (n = 47, 35%) and patients with definite IE (n = 86, 65%). Overall, 55 patients died over a mean ± SD follow-up of 3.6 ± 4.1 years (median 1.8, interquartile range 4.4 years). Patients with definite IE had a higher risk of death (hazard ratio [HR] 2.21, 95% confidence interval [CI] 1.20 to 4.17 p = 0.01). Independent predictors of long-term mortality were increasing age (HR 1.05, 95% CI 1.02 to 1.08, p = 0.002), Staphylococcus aureus infection (HR 3.40, 95% CI 1.00 to 11.76; p = 0.05), infection with unknown microorganism (HR 12.50, 95% CI 2.97 to 52.63; p = 0.0006), and definite IE (HR 8.70, 95% CI 3.55 to 21.28; p <0.0001), whereas infection on pacemaker or defibrillator (HR 0.30, 95%CI 0.10 to 0.87; p = 0.03) was associated with a better prognosis. Patients with definite IE and those with possible IE who underwent surgery had a nonsignificantly better prognosis than their counterparts with no surgery. In conclusion, patients with definite IE (Duke criteria) on a prosthetic heart valve independently had a worse prognosis than those with possible IE.

FDG PET/CT in Aortic Valve Bioprosthesis Infection.

A 62-year-old man presented with persistent fever, weakness, and retrosternal pain 3 years after aortic valve bioprosthesis (AVR). His white blood cell count was 11,000/µL and C-reactive protein was 13.6 mg/dL. Consecutive blood cultures isolated Staphylococcus epidermidis and capitis. Transesophageal echocardiography demonstrated small aortic valve prosthesis vegetation. F-FDG PET/CT revealed prominent AVR activity, SUVmax = 12.2. He was treated with daptomycin, meropenem, and gentamicin for 1 month and followed by daptomycin and carbapenem for 3 months. Follow-up F-FDG PET/CT at 6 months demonstrated complete clearing of AVR activity associated with full asymptomatic recovery.

Fungal prosthetic valve endocarditis with mycotic aneurysm: Case report.

Fungal prosthetic valve endocarditis is an extremely severe form of infective endocarditis, with poor prognosis and high mortality despite treatment. Candida albicans is the most common etiological agent for this rare but increasingly frequent condition. We present a case of fungal prosthetic valve endocarditis due to C. albicans following aortic and pulmonary valve replacement in a 38-year-old woman with a history of surgically corrected tetralogy of Fallot, prior infective endocarditis and acute renal failure with need for catheter-based hemodialysis. Antifungal therapy with liposomal amphotericin B was initiated prior to cardiac surgery, in which the bioprostheses were replaced by homografts, providing greater resistance to recurrent infection. During hospitalization, a mycotic aneurysm was diagnosed following an episode of acute arterial ischemia, requiring two vascular surgical interventions. Despite the complications, the patient's outcome was good and she was discharged on suppressive antifungal therapy with oral fluconazole for at least a year. The reported case illustrates multiple risk factors for fungal endocarditis, as well as complications and predictors of poor prognosis, demonstrating its complexity.

Cerebral Aneurysm from Cardiobacterium hominis Endocarditis.

A 43-year-old male with a history of bioprosthetic aortic valve replacement and tricuspid valve annuloplasty presented with vertigo and was found to have an acute infarct in the left superior cerebellum, as well as a left-middle cerebral artery mycotic aneurysm. Blood cultures grew Cardiobacterium hominis and bioprosthetic aortic valve vegetation was found on transthoracic echocardiogram.

Fungal Infections in Boston Keratoprosthesis Patients: Lessons Learned and Novel Developments on the Horizon.

The Boston Keratoprosthesis (B-KPro) is a widely accepted modality of corneal restoration in eyes where traditional penetrating keratoplasty has little chance of success. It is the most commonly used keratoprosthesis worldwide. While the introduction of broad-spectrum antibiotic prophylaxis has virtually eliminated cases of bacterial endophthalmitis, fungal colonization and infections are a growing concern. This review of the literature summarizes risk factors for fungal infections in KPro eyes, rates of fungal infection and colonization, clinical presentation, causative organisms, management, and outcomes. We also focus on current recommendations for antifungal prophylaxis, and highlight the role of translational research at the Massachusetts Eye and Ear Infirmary (MEEI, Boston, USA) with its aim of developing novel strategies for reducing rates of fungal infections in KPro patients.

Multicenter prospective randomized study comparing the technique of using a bovine pericardium biological prosthesis reinforcement in parietal herniorrhaphy (Tutomesh TUTOGEN) with simple parietal herniorrhaphy, in a potentially contaminated setting.

The use of parietal synthetic prosthetic reinforcement material in potentially contaminated settings is not recommended, as there is a risk that the prosthesis may become infected. Thus, simple parietal herniorrhaphy, is the conventional treatment, even though there is a significant risk that the hernia may recur. Using new biomaterials of animal origin presently appears to offer a new therapeutic solution, but their effectiveness has yet to be demonstrated. The purpose of this multicenter prospective randomized single-blind study was to compare the surgical treatment of inguinal hernia or abdominal incisional hernia by simple parietal herniorrhaphy without prosthetic reinforcement (Group A), with Tutomesh TUTOGEN biological prosthesis reinforcement parietal herniorrhaphy (Group B), in a potentially contaminated setting. We examined early postoperative complications in the first month after the operation, performed an assessment after one year of survival without recurrence and analyzed the quality of life and pain of the patients (using SF-12 health status questionnaire and Visual Analog Pain Scale) at 1, 6, and 12 months, together with an economic impact study. Hundred and thirty four patients were enrolled between January 2009 and October 2010 in 20 French hospitals. The groups were comparable with respect to their enrollment characteristics, their history, types of operative indications and procedures carried out. At one month post-op, the rate of infectious complications (n(A) = 11(18.33%) vs. n(B) = 12(19.05%), p = 0.919) was not significantly different between the two groups. The assessment after one year of survival without recurrence revealed that survival was significantly greater in Group B (Group A recurrence: 10, Group B: 3; p = 0.0475). No difference in the patients' quality of life was demonstrated at 1, 6, or 12 months. However, at the 1 month follow-up, the "perceived health" rating seemed better in the group with Tutomesh (p = 0.022). No significant difference between the two parietal repair groups was observed during the follow-ups with respect to the criterion of pain (using a visual analog scale). There was a significant difference between the two parietal repair groups with regard to the number of days spent in intensive care unit, in favor of the Tutomesh technique (p = 0.010). The use of a Tutomesh bioprosthesis for hernia repair or postincisional hernia in a potentially contaminated workplace reduces the risk of short-term recurrence without increasing overall comorbidity.

Which prosthesis is more resistant to vascular graft infection: polytetrafluoroethylene or Omniflow II biosynthetic grafts?

PURPOSE: The aim of this study was to determine whether polytetrafluoroethylene grafts or Omniflow II biosynthetic grafts are more resistant to infection caused by Staphylococcus aureus. METHODS: Sixty rats were divided into six groups. In Groups 1A, 1B and 1C, a polytetrafluoroethylene graft was implanted in each rat, and, in Groups 2A, 2B and 2C, a biosynthetic graft was implanted in each rat. Staphylococcus aureus was inoculated into Groups 1B, 1C, 2B and 2C, and the rats in Groups 1C and 2C were treated with teicoplanin. One week later, the rats were euthanized, the grafts were removed and a microbiological count was performed. A histopathological examination was subsequently carried out, and the C-reactive protein, prealbumin and leukocyte levels were investigated. RESULTS: There were no significant differences in the C-reactive protein, prealbumin and leukocyte levels. The differences in the results of the microbiological evaluations between the groups were significant. The quantitative culture results showed no bacterial growth in Groups 1A, 1C and 2A. The number of bacteria in Group 1B was statistically lower than that in Group 2B. When the groups receiving treatment were compared, Group 2C had bacterial growth, whereas Group 1C did not. The histopathological examinations showed similar results. CONCLUSIONS: Omniflow II grafts are more susceptible to infection than polytetrafluoroethylene grafts.

Selective propensity of bovine jugular vein material to bacterial adhesions: An in-vitro study.

BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) using Melody valve made of bovine jugular vein is safe and effective. However, infective endocarditis has been reported for unclear reasons. We sought to assess the impact of valvular substrates on selective bacterial adhesion. METHODS: Three valved stents (Melody valve, homemade stents with bovine and porcine pericardium) were tested in-vitro for bacterial adhesion using Staphylococcus aureus and Streptococcus sanguinis strains. RESULTS: Bacterial adhesion was higher on bovine jugular venous wall for S. aureus and on Melody valvular leaflets for S. sanguinis in control groups and significantly increased in traumatized Melody valvular leaflets with both bacteria (traumatized vs non traumatized: p=0.05). Bacterial adhesion was lower on bovine pericardial leaflets. CONCLUSION: Selective adhesion of S. aureus and S. sanguinis pathogenic strains to Melody valve tissue was noted on healthy tissue and increased after implantation procedural steps.

An experimental comparison of the effects of bacterial colonization on biologic and synthetic meshes.

PURPOSE: Biologic meshes are being used with increasing frequency to repair contaminated abdominal wall defects despite high long-term recurrence and infection rates associated with their use. Recent clinical reports describing the success of lightweight, macroporous synthetic meshes in contaminated ventral hernia repairs have led some surgeons to challenge the belief that synthetics are contraindicated in contaminated fields. We aimed to determine whether a frequently used biologic mesh (Strattice(TM)) is more resistant to bacterial colonization than macroporous synthetic mesh (Parietex(TM) Progrip(TM)) after inoculation with two common pathogens. METHODS: Rats (n = 48) were implanted subcutaneously with Strattice(TM) or Progrip(TM). Meshes were inoculated with sterile saline or a suspension containing 10(6) colony-forming units of Staphylococcus aureus or Escherichia coli prior to wound closure (n = 8 per subgroup). Meshes were explanted at 4 weeks and underwent microbiologic and histologic analyses. RESULTS: Progrip(TM) demonstrated superior bacterial clearance compared to Strattice(TM) (E. coli, 88 vs. 17% clearance, p = 0.03; S. aureus, 75 vs. 50%, p = 0.61; combined bacterial strains, 81 vs. 36%, p = 0.02; respectively). In the Strattice(TM) group, severely degraded meshes were observed in 100% of animals inoculated with E. coli (but 0% inoculated with S. aureus). In contrast, all Progrip(TM) meshes remained intact regardless of inoculum. Scores for neovascularization were higher in the synthetic group irrespective of contamination (p < 0.05). CONCLUSIONS: Biologic meshes may not be more resistant to bacterial colonization than reduced-weight synthetics, and their resistance may differ in response to different pathogens. The routine use of biologics in contaminated ventral hernia repair should be questioned, particularly in the presence of E. coli.

One-year outcome following biological or mechanical valve replacement for infective endocarditis.

BACKGROUND: Nearly half of patients require cardiac surgery during the acute phase of infective endocarditis (IE). We describe the characteristics of patients according to the type of valve replacement (mechanical or biological), and examine whether the type of prosthesis was associated with in-hospital and 1-year mortality. METHODS AND RESULTS: Among 5591 patients included in the International Collaboration on Endocarditis Prospective Cohort Study, 1467 patients with definite IE were operated on during the active phase and had a biological (37%) or mechanical (63%) valve replacement. Patients who received bioprostheses were older (62 vs 54years), more often had a history of cancer (9% vs 6%), and had moderate or severe renal disease (9% vs 4%); proportion of health care-associated IE was higher (26% vs 17%); intracardiac abscesses were more frequent (30% vs 23%). In-hospital and 1-year death rates were higher in the bioprosthesis group, 20.5% vs 14.0% (p=0.0009) and 25.3% vs 16.6% (p<.0001), respectively. In multivariable analysis, mechanical prostheses were less commonly implanted in older patients (odds ratio: 0.64 for every 10years), and in patients with a history of cancer (0.72), but were more commonly implanted in mitral position (1.60). Bioprosthesis was independently associated with 1-year mortality (hazard ratio: 1.298). CONCLUSIONS: Patients with IE who receive a biological valve replacement have significant differences in clinical characteristics compared to patients who receive a mechanical prosthesis. Biological valve replacement is independently associated with a higher in-hospital and 1-year mortality, a result which is possibly related to patient characteristics rather than valve dysfunction.