From cat scratch disease to endocarditis, the possible natural history of Bartonella henselae infection

Bartonella Endocarditis: A Missed Diagnosis in Medical Practice

Here, we present the case of a 52-year-old patient who presented with fever, chills, and weight loss. Further workup revealed Bartonella endocarditis of the aortic valve. After six weeks of antibiotics, a follow-up transthoracic echocardiogram showed a decrease in the size of vegetation. Serologic testing based on epidemiologic history should be obtained for the workup of blood culture-negative endocarditis.

Bartonella Species, an Emerging Cause of Blood-Culture-Negative Endocarditis

Since the reclassification of the genus Bartonella in 1993, the number of species has grown from 1 to 45 currently designated members. Likewise, the association of different Bartonella species with human disease continues to grow, as does the range of clinical presentations associated with these bacteria. Among these, blood-culture-negative endocarditis stands out as a common, often undiagnosed, clinical presentation of infection with several different Bartonella species. The limitations of laboratory tests resulting in this underdiagnosis of Bartonella endocarditis are discussed. The varied clinical picture of Bartonella infection and a review of clinical aspects of endocarditis caused by Bartonella are presented. We also summarize the current knowledge of the molecular basis of Bartonella pathogenesis, focusing on surface adhesins in the two Bartonella species that most commonly cause endocarditis, B. henselae and B. quintana. We discuss evidence that surface adhesins are important factors for autoaggregation and biofilm formation by Bartonella species. Finally, we propose that biofilm formation is a critical step in the formation of vegetative masses during Bartonella-mediated endocarditis and represents a potential reservoir for persistence by these bacteria.

Bartonella henselae is usually not viable in lymph nodes of patients with cat scratch disease

Bartonella henselae, the agent of cat scratch disease (CSD), appears to be a common organism responsible for lymphadenitis in both adults and children. There is a very low isolation rate for B. henselae from lymph nodes of patients with CSD. Our objective was to evaluate B. henselae viability in a large series of lymph nodes from patients with CSD. From January to November 2016, we analyzed lymph node biopsy samples from patients diagnosed with CSD. We used reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to detect B. henselae RNA, as well as cultures, histological analyses, and fluorescence in situ hybridization (FISH). We tested 87 lymph nodes positive for B. henselae DNA but only 8 (9%) presented with B. henselae RNA. We did not find a significant difference for the pap threshold cycle (C_T) values between RNA-positive and RNA-negative lymph nodes (p = 0.5). Cultures, histological analyses, and FISH were negative for all the tested samples. We provide evidence that B. henselae are not or are rarely viable in most cases in the lymph nodes of patients with CSD.

Infektionen

In diesem Kapitel werden zunächst die für die Neurointensivmedizin wesentlichen bakteriellen Infektionen (Meningitis, spinale und Hirnabszesse, Spondylodiszitis, septisch-embolische Herdenzephalitis) abgehandelt, die trotz gezielt eingesetzter Antibiotika und neurochirurgischer Therapieoptionen noch mit einer erheblichen Morbidität und Mortalität behaftet sind. Besonderheiten wie neurovaskuläre Komplikationen, die Tuberkulose des Nervensystems, Neuroborreliose, Neurosyphilis und opportunistische Infektionen bei Immunsuppressionszuständen finden hierbei besondere Berücksichtigung. Der zweite Teil dieses Kapitels behandelt akute und chronische Virusinfektionen des ZNS sowie in einem gesonderten Abschnitt die HIVInfektion und HIV-assoziierte Krankheitsbilder sowie Parasitosen und Pilzinfektionen, die in Industrieländern seit Einführung der HAART bei HIV zwar eher seltener, aber mit zunehmender Globalisierung auch in unseren Breiten immer noch anzutreffen sind.

Visceral cat scratch disease with endocarditis in an immunocompetent adult: a case report and review of the literature

Infective endocarditis and hepatosplenic abscesses are rare manifestations of cat scratch disease (CSD), especially among immunocompetent adults. An otherwise healthy woman who presented with fever and abdominal pain was diagnosed with multiple abscesses in the spleen and the liver, as well as a mitral valve vegetation. PCR on spleen tissue was positive for Bartonella henselae. Prolonged treatment with doxycycline and gentamicin led to complete recovery. Review of the literature revealed 18 cases of hepatosplenic CSD in immunocompetent adults; the majority presented with fever of unknown origin and abdominal pain. In most cases the causative organism was B. henselae and the pathological findings were necrotizing granulomas, similar to the pathological features in classic CSD. Concomitant endocarditis was diagnosed in one case. Because Bartonella is one of the leading pathogens of culture-negative endocarditis, we raise the question of whether a comprehensive evaluation for endocarditis is needed in cases of systemic CSD.

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.

Infektionen

Trotz Weiterentwicklung moderner Antibiotika in den letzten Jahren sind die Letalitätszahlen der bakteriellen (eitrigen) Meningitis weiterhin hoch; Überlebende haben häufig neurologische Residuen. Die ungünstigen klinischen Verläufe der bakteriellen Meningitis sind meist Folge intrakranieller Komplikationen, wie z. B. eines generalisierten Hirnödems, einer zerebrovaskulären arteriellen oder venösen Beteiligung oder eines Hydrozephalus.

Degenerative valve disease and bioprostheses: risk assessment, predictive diagnosis, personalised treatments

Aortic stenosis (AS) is the most frequent valvular heart disease. Severe AS results in concentric left ventricular hypertrophy, and ultimately, the heart dilates and fails. During a long period of time patients remain asymptomatic. In this period a pathology progression should be monitored and effectively thwarted by targeted measures. A cascade of cellular and molecular events leads to chronic degeneration of aortic valves. There are some molecular attributes characteristic for the process of valvular degeneration with clear functional link between shifted cell-cycle control, calcification and tissue remodelling of aortic valves. Bioactivity of implanted bioprosthesis is assumed to result in its dysfunction. Age, gender (females), smoking, Diabetes mellitus, and high cholesterol level dramatically shorten the re-operation time. Therefore, predictive and preventive measures would be highly beneficial, in particular for young female diabetes-predisposed patients. Molecular signature of valvular degeneration is reviewed here with emphases on clinical meaning, risk-assessment, predictive diagnosis, individualised treatments.

Identification of candidate proteins for the diagnosis of Bartonella henselae infections using an immunoproteomic approach

Bartonella henselae is an emerging gram-negative facultative intracellular pathogen transmitted via Ctenocephalides felis (cat fleas) or cat scratches. Bartonellosis is present mainly in the form of cat scratch disease (CSD), bacillary angiomatosis and infective endocarditis (IE). The methods used to diagnose B. henselae rely on culturing, immunofluorescent assays and molecular techniques. The objective of the present study was to identify candidate proteins for the serodiagnosis of bartonellosis with the differential discrimination of both clinical scenarios: CSD and IE. For this, an immunoproteomic approach combined with 2-DE, immunoblotting and matrix-assisted laser desorption/ionization time-of-flight MS has been developed. Immunoproteomic profiles of sera collected from patients with CSD and IE were compared with those of blood donors. We identified several candidate proteins as phage-encoding Pap31 protein and an outer membrane protein of BH11510 that, in our view, might be useful for the serodiagnosis of bartonellosis.

Emergent opportunities in humans: playful kittens, an arthropod vector, and a zoonotic agent

Bartonella henselae is implicated as the main etiologic agent of Cat scratch disease (CSD, Cat-scratch fever). A majority of domestic cats may harbor the intra-erythrocytic agent for extended periods without apparent disease. In humans, B. henselae most commonly results in a subacute, bacterial infection that presents with one or more reddish papules which may progress to pustules and regional lymph node enlargement. Usual features include fever, malaise, and a granulomatous lymphadenitis on biopsy. However, atypical clinical presentations occur, albeit with infrequence, and may result in a difficult and protracted diagnostic process. The infection in susceptible hosts such as immunocompromised or elderly patients may result in endocarditis, encephalitis, fever of unknown origin, and general malaise. It is not transmitted from person to person and quarantine is not necessary. The arthropod vector, Ctenocephalides felis, or the cat flea, plays a major role in transmission among cats and to humans. The transmission risk to humans can be substantially reduced through elimination of flea infestations in companion animals. There are numerous recent reviews and case reports in the veterinary and medical literature reflecting increased recognition of this zoonotic agent. All this notwithstanding, many physicians and other providers may not be familiar with this agent and the potential spectrum of human disease; this may lead to delays in diagnosis and unnecessary diagnostic procedures. This article emphasizes the aspects of B. henselae infection, including a typical case report and a table with selected human case reports of unusual clinical manifestations from the published literature.

[Bartonella henselae, an ubiquitous agent of proteiform zoonotic disease]

Bartonella henselae is the causative agent of cat scratch disease, a human infection usually characterized by persistent regional lymphadenopathy. It is transmitted to humans by cat scratches or bites. Cats are the major reservoir for this bacterium thus B. henselae has a worldwide distribution. The bacterial pathogenicity may bay emphasized by the immune status of the infected host. Angiomatosis or hepatic peliosis are the most frequent clinical manifestations in immunocompromised patients. B. henselae is also responsible for endocarditis in patients with valvular diseases, and may induce various clinical presentations such as: bacteriemia, retinitis, musculoskeletal disorders, hepatic or splenic diseases, encephalitis, or myocarditis. Several diagnostic tools are available; they may be combined and adapted to every clinical setting. B. henselae is a fastidious bacterium; its diagnosis is mainly made by PCR and blood tests. No treatment is required for the benign form of cat scratch disease. For more severe clinical presentations, the treatment must be adapted to every clinical presentation.

Culture negative endocarditis caused by Bartonella henselae in a child with congenital heart disease

A 9-year-old white male with congenital aortic and subaortic stenosis palliated by the Ross-Konno procedure presented with culture-negative endocarditis. Serologic studies and polymerase chain reaction testing of resected homograft valvular tissue provided evidence of Bartonella henselae as the etiology. B. henselae can cause endocarditis in children, particularly those with underlying valvular disease. Serologic testing for B. henselae should be considered in children with culture-negative endocarditis.

Guidelines for the Prevention and Treatment of Opportunistic Infections among HIV-exposed and HIV-infected children: recommendations from CDC, the National Institutes of Health, the HIV Medicine Association of the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the American Academy of Pediatrics

This report updates and combines into one document earlier versions of guidelines for preventing and treating opportunistic infections (OIs) among HIV-exposed and HIV-infected children, last published in 2002 and 2004, respectively. These guidelines are intended for use by clinicians and other health-care workers providing medical care for HIV-exposed and HIV-infected children in the United States. The guidelines discuss opportunistic pathogens that occur in the United States and one that might be acquired during international travel (i.e., malaria). Topic areas covered for each OI include a brief description of the epidemiology, clinical presentation, and diagnosis of the OI in children; prevention of exposure; prevention of disease by chemoprophylaxis and/or vaccination; discontinuation of primary prophylaxis after immune reconstitution; treatment of disease; monitoring for adverse effects during treatment; management of treatment failure; prevention of disease recurrence; and discontinuation of secondary prophylaxis after immune reconstitution. A separate document about preventing and treating of OIs among HIV-infected adults and postpubertal adolescents (Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents) was prepared by a working group of adult HIV and infectious disease specialists. The guidelines were developed by a panel of specialists in pediatric HIV infection and infectious diseases (the Pediatric Opportunistic Infections Working Group) from the U.S. government and academic institutions. For each OI, a pediatric specialist with content-matter expertise reviewed the literature for new information since the last guidelines were published; they then proposed revised recommendations at a meeting at the National Institutes of Health (NIH) in June 2007. After these presentations and discussions, the guidelines underwent further revision, with review and approval by the Working Group, and final endorsement by NIH, CDC, the HIV Medicine Association (HIVMA) of the Infectious Diseases Society of America (IDSA), the Pediatric Infectious Disease Society (PIDS), and the American Academy of Pediatrics (AAP). The recommendations are rated by a letter that indicates the strength of the recommendation and a Roman numeral that indicates the quality of the evidence supporting the recommendation so readers can ascertain how best to apply the recommendations in their practice environments. An important mode of acquisition of OIs, as well as HIV infection among children, is from their infected mother; HIV-infected women coinfected with opportunistic pathogens might be more likely than women without HIV infection to transmit these infections to their infants. In addition, HIV-infected women or HIV-infected family members coinfected with certain opportunistic pathogens might be more likely to transmit these infections horizontally to their children, resulting in increased likelihood of primary acquisition of such infections in the young child. Therefore, infections with opportunistic pathogens might affect not just HIV-infected infants but also HIV-exposed but uninfected infants who become infected by the pathogen because of transmission from HIV-infected mothers or family members with coinfections. These guidelines for treating OIs in children therefore consider treatment of infections among all children, both HIV-infected and uninfected, born to HIV-infected women. Additionally, HIV infection is increasingly seen among adolescents with perinatal infection now surviving into their teens and among youth with behaviorally acquired HIV infection. Although guidelines for postpubertal adolescents can be found in the adult OI guidelines, drug pharmacokinetics and response to treatment may differ for younger prepubertal or pubertal adolescents. Therefore, these guidelines also apply to treatment of HIV-infected youth who have not yet completed pubertal development. Major changes in the guidelines include 1) greater emphasis on the importance of antiretroviral therapy for preventing and treating OIs, especially those OIs for which no specific therapy exists; 2) information about the diagnosis and management of immune reconstitution inflammatory syndromes; 3) information about managing antiretroviral therapy in children with OIs, including potential drug--drug interactions; 4) new guidance on diagnosing of HIV infection and presumptively excluding HIV infection in infants that affect the need for initiation of prophylaxis to prevent Pneumocystis jirovecii pneumonia (PCP) in neonates; 5) updated immunization recommendations for HIV-exposed and HIV-infected children, including hepatitis A, human papillomavirus, meningococcal, and rotavirus vaccines; 6) addition of sections on aspergillosis; bartonella; human herpes virus-6, -7, and -8; malaria; and progressive multifocal leukodystrophy (PML); and 7) new recommendations on discontinuation of OI prophylaxis after immune reconstitution in children. The report includes six tables pertinent to preventing and treating OIs in children and two figures describing immunization recommendations for children aged 0--6 years and 7--18 years. Because treatment of OIs is an evolving science, and availability of new agents or clinical data on existing agents might change therapeutic options and preferences, these recommendations will be periodically updated and will be available at http://AIDSInfo.nih.gov.

Development of an immunoglobulin M capture-based enzyme-linked immunosorbent assay for diagnosis of acute infections with Bartonella henselae

We describe the development of an immunoglobulin M-specific enzyme-linked immunosorbent assay for the detection of an early antibody response to Bartonella henselae, the causative agent of cat scratch disease, bacillary angiomatosis, and endocarditis. This assay discriminates between B. henselae-positive and -negative patient samples with sensitivity and specificity values of 100% and 97.1%, respectively.

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.