Invasive Endocarditis Research Articles

Partial heart transplantation for destructive infective endocarditis

Infective endocarditis frequently spreads beyond the valve tissue, especially in the aortic location. Invasive endocarditis may lead to abscess formation or fistula, with substantial tissue loss. Here, the case of a 31-year-old male patient with destructive aortic and pulmonary valve endocarditis and a subaortic mural defect who underwent patch closure of the ventricular septal defect and aortic and pulmonary root replacement and right coronary artery bypass graft is presented. This is an uncommon condition and stress is placed on imaging of the technical aspects of the case.

Aortic Endocarditis: Further Evidence for Early Surgical Intervention

In this issue of The Annals of Thoracic Surgery, Witten and colleagues1 present an in-depth look at advanced, invasive endocarditis in 43 patients involving the aortic valve treated over a 17-month span. The authors describe excellent results, including survival to discharge in all but 1 patient, which add to this group’s prior superb results in this difficult population. Where this current work truly stands apart is in the detailed pathologic examination and clinical correlates for this cohort of patients, particularly with regard to the relationship of operative findings to microscopic pathology.

Aortic allograft infection risk

ObjectiveIntrinsic risk of infection of cryopreserved allograft aortic root replacements remains poorly understood despite their long history of use. The objective of this study was to determine this intrinsic risk of allograft infection and its risk factors when allografts are implanted for both nonendocarditis indications and infective endocarditis. MethodsFrom January 1987 to January 2017, 2042 patients received 2110 allograft aortic valves at a quaternary medical center, 1124 (53%) for nonendocarditis indications and 986 (47%) for endocarditis indications (670 [68%] prosthetic valve endocarditis). Staphylococcus aureus caused 193 of 949 cases of endocarditis (20%), 71 (7.3%) in persons who injected drugs. Periodic surveillance and cross-sectional follow-up achieved 85% of possible follow-up time. The primary end point was allograft infection in patients with nonendocarditis and endocarditis indications. Risk factors were identified by hazard function decomposition and machine learning. ResultsDuring follow-up, 30 allografts (26 explanted) became infected in patients in the nonendocarditis group and 49 (41 explanted) in patients with endocarditis. At 20 years, the probability of allograft infection was 5.6% in patients in the nonendocarditis group and 14% in patients with endocarditis. Risk factors for allograft infection in patients in the nonendocarditis group were younger patient age and older donor age. Risk factors for allograft infection in patients with endocarditis were earlier implant year, injection drug use, and younger age. In patients with endocarditis, 18% of allograft infections were caused by the original organism. ConclusionsThe low infection rates, both in patients without and with endocarditis, support continued use of allografts in the modern era, in particular for the treatment of invasive endocarditis of the aortic root.

An autopsy view of the Hemi-commando procedure.

Invasive endocarditis involving the fibrous skeleton of the heart requires complex high-risk surgical management. For combined aortic and mitral infection in whom the posterior mitral leaflet and at least the free edge of anterior mitral valve could be spared, a modification of the Commando procedure was suggested: the "Hemi-commando procedure." We report the autopsy images of a Hemi-commando procedure after in unfortunate death in a 24 years old man 17 days after surgery.

Staphylococcus lugdunensis Endocarditis in a Patient Being Treated for Pyelonephritis

Staphylococcus lugdunensis
 Endocarditis in a Patient Being Treated for Pyelonephritis
 
 Christopher
 M Peake1, Nicholas Faure-Walker2, Elli DeMertzi2
 
 1St George’s University Hospital,
 Blackshaw Road, Tooting, London, UK
 
 2Kingston Hospital, Galsworthy Road,
 Kingston-upon-Thames, UK
 
  
 
 ABSTRACT
 
 A 35
 years old female with known chronic left pelvo-ureteric junction (PUJ)
 obstruction presented with recurrent pyrexia and left loin pain and was treated
 for pyelonephritis. She had a history of severe aortic valve (AV)
 regurgitation. After five days of broad spectrum antibiotics and a percutaneous
 nephrostomy, her fevers persisted. Staphylococcus
 lugdunensis was isolated from her blood culture and she was diagnosed with
 mitral valve endocarditis following an echocardiogram. She was transferred to a
 tertiary cardiothoracic unit where she underwent a mitral and aortic mechanical
 valve repair. After 6 weeks of intravenous antibiotic treatment she was
 discharged without signs of infection but with poor cardiac function. S. lugdunensis is a virulent organism
 which is thought to be underdiagnosed and is associated with aggressive and
 destructive endocarditis. An awareness of the organism as well as prompt
 diagnosis and treatment with effective multi-disciplinary management is needed
 to avoid substantial morbidity in these patients. 
 
 Whilst
 S. lugdunensis is known to cause
 invasive endocarditis, it has never been reported following pyelonephritis. The
 significance of this case is that despite receiving appropriate and timely
 treatment the patient was left with deteriorating cardiac function. This is an
 important reminder that this organism must be taken seriously when isolated in
 the context of infection. J Microbiol
 Infect Dis 2018; 8(1):37-40
 
 Keywords: Staphylococcus lugdunensis, endocarditis,
 pyelonephritis, heart valves, urinary tract

Successful Management of a Case of Electrical Storm Due to Invasive Endocarditis

We present a 44-year-old man with invasive aortic and tricuspid valve endocarditis complicated by electrical storm, which was immediately diagnosed and successfully treated due to the patient's telemetry electrocardiogram (ECG). This case highlights a rare but potentially fatal complication in patients with invasive endocarditis and the need for very careful clinical evaluation and monitoring of these patients.

Characterization of clinical strains of MSSA, MRSA and MRSE isolated from skin and soft tissue infections and the antibacterial activity of ZnO nanoparticles

Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), is an important cause of pyogenic skin and soft tissue infections (SSTIs). MRSA is an important pathogen in the healthcare sector that has neither been eliminated from the hospital nor community environment. In humans, S. aureus causes superficial lesions in the skin and localized abscesses, pyogenic meningitis/encephalitis, osteomyelitis, septic arthritis, invasive endocarditis, pneumonia, urinary tract infections and septicemia. Investigations focused in the search of other alternatives for the treatment of MRSA infections are in progress. Among the range of compounds whose bactericidal activity is being investigated, ZnO nanoparticles (ZnO-NPs) appears most promising new unconventional antibacterial agent that could be helpful to confront this and other drug-resistant bacteria. The aim of present study is to investigate the antibacterial potential of ZnO-NPs against Staphylococcus species isolated from the pus and wounds swab from the patients with skin and soft tissue infections in a tertiary care hospital of north India. ZnO-NPs (≈19.82 nm) synthesized by sol-gel process were characterized using scanning electron microscopy, X-ray diffraction , and Atomic force microscopy. The antibacterial potential was assessed using time-dependent growth inhibition assay, well diffusion test, MIC and MBC test and colony forming units methods. ZnO-NPs inhibited bacterial growth of methicillin-sensitive S. aureus (MSSA), MRSA and methicillin-resistant S. epidermidis (MRSE) strains and were effective bactericidal agents that were not affected by drug-resistant mechanisms of MRSA and MRSE.

Successful Surgical Intervention for the Management of Endocarditis due to Multidrug Resistant Candida parapsilosis: Case Report and Literature Review

Candida parapsilosis is an uncommon cause of invasive endocarditis. This pathogen induces severe complications and carries a high mortality rate. We describe a case of C. parapsilosis endocarditis in a 54-year-old man with a history of HIV and Hepatitis C infection who previously underwent prosthetic valve replacement due to bacterial endocarditis. The patient presented with prolonged febrile episodes and fungemia with repeat blood cultures positive for C. parapsilosis. The patient failed multiple regimens of antifungal therapy and the C. parapsilosis isolate progressively acquired resistance to a number of drugs. Due to the multidrug resistant nature of the isolate, replacement of the infected valve was required to resolve his fungemia, and the patient remained asymptomatic for two years. This case is unusual due to the multidrug resistant nature of the isolate requiring both combined medical and surgical intervention. A review of published reports indicates that endocarditis due to C. parapsilosis responds well to a combination of medical and surgical interventions; the latter is particularly suitable for immunocompromised hosts.

Discovery of Medically Significant Lantibiotics

The emergence of drug-resistant pathogens such as staphylococci and enterococci in the hospital setting has long being recognized as a serious clinical problem. Staphylococcus aureus is the causative agent of many nosocomial infections from minor skin abscesses to serious, potentially life threatening diseases such as bone and soft tissue intra-surgical infections, sepsis and invasive endocarditis, while enterococci are responsible for nosocomial bacteraemia, surgical wound infections and endocarditis. The most infamous drug-resistant forms of these include MRSA (methicillin resistant S. aureus), VISA (vancomycin insensitive S. aureus), hVISA (heterogenous vancomycin insensitive S. aureus) and VRE (vancomycin resistant S. aureus). While enhanced hygiene awareness is essential to any solution, the identification of effective novel antimicrobial compounds remains a major goal in eradicating these and other infections caused by multi-drug resistant pathogens. In recent years a class of antimicrobial peptides, the Lantibiotics, have been the focus of an ever increasing level of attention. This interest has been prompted by an enhanced appreciation of the mode of action of these peptides (including, in many cases, the ability to bind lipid II) and their frequently high levels of antimicrobial activity. Here we review lantibiotic-related issues in drug discovery, outline the strategies that have been employed to identify these peptides and summarize the use of bioengineering to generate enhanced forms of these peptides as well as the application of the associated biological machinery to generate novel forms of existing pharmaceutical compounds. In so doing we highlight how some, or all, of these approaches have the potential to result in the development of clinically important drugs.

Surgimiento y diseminación de Staphylococcus aureus meticilinorresistente

Nosocomial infections due to methicillin-resistant Staphylococcus aureus (MRSA) is an important health problem worldwide. This microorganism causes a variety of clinical infections, including osteomyelitis, invasive endocarditis, septic arthritis and septicemia. Antimicrobial resistance is a factor that influences the persistence of MRSA in the hospital environment. The introduction of molecular typing techniques in epidemiological investigations has provided new tools for identifying the microorganism's origin and routes of dissemination. One of the most important conclusions that have resulted from these types of studies is that a small number of clones are responsible for most of the staphylococcal infections throughout the world.

Vaccination with a recombinant fragment of collagen adhesin provides protection against Staphylococcus aureus-mediated septic death.

Staphylococcus aureus is a major cause of nosocomial and community-acquired infections. Morbidity and mortality due to infections such as sepsis, osteomyelitis, septic arthritis, and invasive endocarditis remain high despite the use of antibiotics. The emergence of antibiotic resistant super bugs mandates that alternative strategies for the prevention and treatment of S. aureus infections are developed. We investigated the ability of vaccination with a recombinant fragment of the S. aureus collagen adhesin to protect mice against sepsis-induced death. Actively immunized NMRI mice were intravenously inoculated with the S. aureus clinical isolate strain Phillips. 14 d after inoculation, mortality in the collagen adhesin-vaccinated group was only 13%, compared with 87% in the control antigen immunized group (P < 0.001). To determine if the protective effect was antibody mediated, we passively immunized naive mice with collagen adhesin-specific antibodies. Similar to the active immunization strategy, passive transfer of collagen adhesin-specific antibodies protected mice against sepsis-induced death. In vitro experiments indicated that S. aureus opsonized with sera from collagen adhesin immunized mice promoted phagocytic uptake and enhanced intracellular killing compared with bacteria opsonized with sera from control animals. These results indicate that the collagen adhesin is a viable target in the development of immunotherapeutics against S. aureus.