Cure of bartonella endocarditis of a prosthetic aortic valve without surgery: value of serologic follow-up

A case of Bartonella henselae native valve endocarditis presenting with crescentic glomerulonephritis

Bartonella endocarditis is often an elusive diagnosis, usually derived from evaluating multiple laboratory tests and assessment of presenting symptoms. Herein we describe a case of Bartonella henselae native mitral valve endocarditis with an initial presentation of volume overload and renal failure. The Bartonella organism is tedious to isolate from culture medium, causing most diagnoses to be delayed. Due to the destructive nature of B. henselae endocarditis, the need for rapid identification remains prudent. This therefore creates an opportunity for Next Generation Sequencing (NGS) to be used. We further summarize the varied presentations that may be associated with B. henselae endocarditis, and hope that this will heighten the clinicians' awareness of this entity when presented with acute onset renal failure and culture negative vegetations.

Early post-transplant cutaneous bacillary angiomatosis in a kidney recipient: Case report and review of the literature

Bacillary angiomatosis (BA) is an uncommon systemic disease caused by Bartonella henselae (BH) or Bartonella quintana (BQ) that occurs primarily in immunocompromised hosts. Few cases of BA recipients have been reported in adult solid transplant recipients over the years, with most cases presenting years after transplant. We describe a case of a kidney transplant recipient who developed cutaneous BA very early in the post-transplant period despite not having any exposures. Retrospective testing of donor and recipient's serum was performed and raised the concern for possible donor-derived infection. A literature review encompassing 1990 to present was also performed in order to better understand the clinical presentation, diagnostics and therapeutic approach of this unusual disease. Combined serology, histopathology and molecular testing (polymerase chain reaction [PCR]) were useful in diagnosing BA in our patient as serology alone might be unreliable. Macrolides or doxycycline for at least 3 months is the recommended therapeutic strategy; however, the optimal duration of treatment is not well established in transplant recipients. In our patient, we decided to use doxycycline for 1 year due to gradual resolution of lesions and ongoing immunosuppression. Patient responded successfully without any documented relapse.

Management of Bartonella Prosthetic Valve Endocarditis without Cardiac Surgery

Two cases of Bartonella prosthetic valve endocarditis were cured when treated for 2 weeks with gentamicin and 3 months with doxycycline. Clinical cure correlated with decreased Bartonella antibody titers. This report suggests a strategy to monitor, treat, and cure Bartonella prosthetic valve endocarditis.

Prosthetic Valve Endocarditis Caused by Bartonella henselae: A Case Report of Molecular Diagnostics Informing Nonsurgical Management

Identifying the pathogen responsible for culture-negative valve endocarditis often depends on molecular studies performed on surgical specimens. A patient with Ehlers-Danlos syndrome who had an aortic graft, a mechanical aortic valve, and a mitral anulloplasty ring presented with culture-negative prosthetic valve endocarditis and aortic graft infection. Research-based polymerase chain reaction (PCR)/electrospray ionization mass spectrometry on peripheral blood samples identified Bartonella henselae. Quantitative PCR targeting the16S-23S ribonucleic acid intergenic region and Western immunoblotting confirmed this result. This, in turn, permitted early initiation of pathogen-directed therapy and subsequent successful medical management of B henselae prosthetic valve endocarditis and aortic graft infection.

Bartonella Endocarditis and Pauci-Immune Glomerulonephritis: A Case Report and Review of the Literature

Among culture-negative endocarditis in the United States, Bartonella species are the most common cause, with Bartonella henselae and Bartonella quintana comprising the majority of cases. Kidney manifestations, particularly glomerulonephritis, are common sequelae of infectious endocarditis, with nearly half of all Bartonella patients demonstrating renal involvement. Although a pauci-immune pattern is a frequent finding in infectious endocarditis-associated glomerulonephritis, it is rarely reported in Bartonella endocarditis. Anti-neutrophil cytoplasmic antibody (ANCA) positivity can be seen with many pathogens causing endocarditis and has been previously reported with Bartonella species. In addition, ANCA-associated vasculitis can also present with renal and cardiac involvement, including noninfectious valvular vegetations and pauci-immune glomerulonephritis. Given the overlap in their clinical presentation, it is difficult to differentiate between Bartonella endocarditis and ANCA-associated vasculitis but imperative to do so to guide management decisions. We present a case of ANCA-positive Bartonella endocarditis with associated pauci-immune glomerulonephritis that was successfully treated with medical management alone.

Development of an enzyme-linked immunosorbent assay for Bartonella henselae infection detection

Several serological diagnostics rely on enzyme-linked immunosorbent assay (ELISA) to detect bacterial infections. However, for some pathogens, including Bartonella henselae, diagnosis still depends on manually intensive, time-consuming assays including micro-immunofluorescence, Western blotting or indirect immunofluorescence. For such pathogens, there is obviously still a need to identify antigens to establish a reliable, fast and high-throughput assay (Dupon et al. ). We evaluated two B. henselae proteins to develop a novel serological ELISA: a well-known antigen, the 17-kDa protein, and GroEL, identified during this study by a proteomic approach. When serum IgG were tested, the specificity and sensitivity were 76 and 65·7% for 17-kDa, respectively, and 82 and 42·9% for GroEL, respectively. IgM were found to be more sensitive and specific for both proteins: 17-kDa protein, specificity 86·2% and sensitivity 75%; GroEL, specificity 97·7% and sensitivity 45·3%. IgM antibodies were also measured in lymphoma patients and patients with Mycobacterium tuberculosis infection to assess the usefulness of our ELISA to distinguish them from B. henselae infected patients. The resulting specificities were 89·1 and 93·5% for 17-kDa protein and GroEL, respectively. Combining the results from the two tests, we obtained a sensitivity of 82·8% and a specificity of 83·9%. Our work described and validated a proteomic approach suitable to identify immunogenic proteins useful for developing a serological test of B. henselae infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

A reliable serological assay for the diagnosis of Cat Scratch Disease (CSD) - a pathological condition caused by Bartonella henselae infection - has not yet been developed. Such an assay would be extremely useful to discriminate between CSD and other pathologies with similar symptoms but different aetiologies, for example lymphoma or tuberculosis. We investigate the use of two B. henselae proteins - GroEL and 17-kDa - to develop a serological-based ELISA, showing promising results with the potential for further development as an effective tool for the differential diagnosing of B. henselae infection.

Bartonella as a cause of mechanical prosthetic aortic root endocarditis

Bartonella henselae infection is typically associated with cat scratch disease. This microorganism can also lead to culture-negative infective endocarditis in immunocompromised patients. We present a rare case of a previously healthy 65-year-old man with B. henselae-associated endocarditis of a prosthetic aortic root. All blood cultures, as well as cultures of the resected aortic valve vegetations, remained negative. Polymerase chain reaction with specific bacterial primers with DNA sequencing was used to identify B. henselae as the etiologic agent. This was successfully managed by an aortic root re-replacement using a mechanical conduit, reimplantation of coronaries ostia, and antibiotic therapy.

Culture negative endocarditis: a diagnostic and therapeutic challenge!

Infective endocarditis remains a diagnostic and therapeutic challenge. The authors report an older male who presented with a lower extremities rash and signs of cardiac failure. Echocardiography showed vegetations attached to the bio-prosthetic aortic valve, however, with negative blood cultures. Further investigation revealed positive Bartonella serologies. The patient was diagnosed with Bartonella endocarditis affecting the prosthetic valve and started on appropriate antibiotics. Valvular surgery was refused by patient secondary to age and medical co-morbidities. The patient presented 10 days later with intracerebral haemorrhage and progression of the endocarditis as demonstrated on echocardiogram. Valve replacement was contraindicated at this occasion due to the intracerebral bleed. The patient had poor prognosis and a decision to withdraw care was made by the family. The authors demonstrate a case of complicated infective endocarditis caused by Bartonella species leading to multisystem involvement. This case highlights the need for urgent valve replacement in the setting of Bartonella endocarditis.

Bartonella henselae infection of prosthetic aortic valve associated with colitis

The diagnosis of infective endocarditis can be difficult, particularly with atypical presentation and negative blood cultures. A 61-year-old man with a porcine aortic valve presented with fever, intermittent confusion, diarrhea, and fatigue. In the community clinic setting, a colonoscopy performed for anemia demonstrated colitis. Symptoms progressed for months; elicitation of a history of significant kitten exposure and the finding of an axillary lymph node prompted testing for Bartonella henselae antibodies. High titer antibodies by indirect immunofluorescence assay indicated chronic B. henselae infection. Surgical valve replacement followed by prolonged doxycycline and rifampin led to cure. This case illustrates the complexities of infective endocarditis and is the first description B. henselae endocarditis associated with colitis in an immunocompetent adult.

Culture-negative infectious endocarditis caused by Bartonella spp.: 2 case reports and a review of the literature

Bartonella spp. are rare pathogens in humans and were recently recognized as important causative agents of culture-negative endocarditis. Here, we describe the 1st 2 documented cases of culture-negative endocarditis due to Bartonella henselae and Bartonella quintana encountered in a single hospital in Germany. Infection of the heart valve tissue was detected by broad-range polymerase chain reaction (PCR) and further confirmed by serologic testing. In particular, acute B. henselae infection with an impressive bacterial colonization of the infected cardiac valve was illustrated by transmission electron microscopy. B. henselae was further characterized by PCR assays targeting genotype-specific regions. Disease progression was initially monitored over the entire infection episode through inflammatory markers. In addition, a short overview of published detailed cases of Bartonella endocarditis in Europe within the last 7 years is given.

Bivalvular Bartonella henselae prosthetic valve endocarditis

Prosthetic valve endocarditis is an uncommon manifestation of infection with Bartonella species. Herein, we report a case of Bartonella henselae endocarditis involving prosthetic mitral and aortic valves. The patient had a favorable outcome with combined medical and surgical therapy. Concomitant crescentic glomerulonephritis led to an initial mistaken diagnosis of Wegener's granulomatosis.