Bartonella spp. infection in people with Mild Cognitive Impairment: A pilot study

Mild Cognitive Impairment (MCI) is a neurological disorder at the transition between normal cognitive decline and dementia. Despite the potential role of neuroinflammation in the pathogenesis of MCI, infectious triggers remain mostly unknown. Infection with Bartonella spp., a zoonotic bacterium, has recently been associated with diffuse neurological and psychiatric symptoms. Given the preferential endothelial localization of Bartonella spp. and the role of vascular changes in neurocognitive decline, we hypothesized that there is an association between Bartonella spp. infection and pathologically accelerated decline in cognitive function in aging. To test this hypothesis, we collected serological and molecular markers of past and present Bartonella spp. infection in a sample of older people with and without MCI. Samples were processed in a blinded way to exclude laboratory biases. Contrary to our hypothesis, people with MCI were not more likely than people without MCI to have an active Bartonella spp. infection as measured by droplet digital PCR (p = 0.735) and quantitative PCR (p = 1). In addition, there was no significant difference in positive serological results between cases and controls (p = 0.461). Overall, higher-than-expected active Bartonella spp. infection (37% by ddPCR) and seroreactivity (71% by indirect fluorescent antibody assay) were found in people without MCI. Conclusions require caution, as our study was limited by the small number of cases with MCI. Overall, our results identified a higher than previously recognized rate of exposure and infection with Bartonella spp. in this older study population but does not support a specific role for such infection in MCI.

Microbes and Mental Illness: Past, Present, and Future

A review of the association between microbes and mental illness is performed, including the history, relevant definitions, infectious agents associated with mental illnesses, complex interactive infections, total load theory, pathophysiology, psychoimmunology, psychoneuroimmunology, clinical presentations, early-life infections, clinical assessment, and treatment. Perspectives on the etiology of mental illness have evolved from demonic possession toward multisystem biologically based models that include gene expression, environmental triggers, immune mediators, and infectious diseases. Microbes are associated with a number of mental disorders, including autism, schizophrenia, bipolar disorder, depressive disorders, and anxiety disorders, as well as suicidality and aggressive or violent behaviors. Specific microbes that have been associated or potentially associated with at least one of these conditions include Aspergillus, Babesia, Bartonella, Borna disease virus, Borrelia burgdorferi (Lyme disease), Candida, Chlamydia, coronaviruses (e.g., SARS-CoV-2), Cryptococcus neoformans, cytomegalovirus, enteroviruses, Epstein-Barr virus, hepatitis C, herpes simplex virus, human endogenous retroviruses, human immunodeficiency virus, human herpesvirus-6 (HHV-6), human T-cell lymphotropic virus type 1, influenza viruses, measles virus, Mycoplasma, Plasmodium, rubella virus, Group A Streptococcus (PANDAS), Taenia solium, Toxoplasma gondii, Treponema pallidum (syphilis), Trypanosoma, and West Nile virus. Recognition of the microbe and mental illness association with the development of greater interdisciplinary research, education, and treatment options may prevent and reduce mental illness morbidity, disability, and mortality.

From (Cat) Scratch: A Unique Presentation of Central Nervous System Bartonella Infection

Central nervous system manifestations of Bartonella species are rare and include meningitis, neuroretinitis, encephalitis, and isolated optic neuritis. We present the case of a 28-year-old woman who presented with a four-month history of progressive, asymmetric, bilateral painless vision loss. Her past medical history was significant for systemic lupus erythematosus. Notably, she had been on a high dose of prednisone for her immunosuppressive regimen. Brain MRI showed numerous contrast-enhancing lesions scattered throughout bilateral cerebral and cerebellar hemispheres and brainstem. She underwent a brain biopsy, and infection with Bartonella henselae was confirmed via a polymerase chain reaction. The patient was started on doxycycline and rifampin with improvement in vision and resolution of lesions as confirmed by a follow-up brain MRI. The literature review did not reveal any cases of multiple brain abscesses due to central nervous system Bartonella. Our case report aims to promote consider Bartonella infection as a cause of multiple brain abscesses in immunocompromised patients. It is essential to note that Bartonella can imitate other central nervous system infections, including toxoplasmosis, cryptococcosis, cysticercosis, and tuberculomas. Early identification is crucial as prompt treatment can lead to a complete cure.

The Effectiveness of Microdosed Psilocybin in the Treatment of Neuropsychiatric Lyme Disease: A Case Study

Lyme disease can result in severe neuropsychiatric symptoms that may be resistant to treatment. The pathogenesis of neuropsychiatric Lyme disease is associated with autoimmune induced neuroinflammation. This case report describes an immunocompetent male with serologically positive neuropsychiatric Lyme disease who did not tolerate antimicrobial or psychotropic medications and whose symptoms remitted when he began psilocybin in microdosed (sub-hallucinogenic) amounts. A literature review of its therapeutic benefits reveals that psilocybin is both serotonergic and anti-inflammatory and therefore may offer significant therapeutic benefits to patients with mental illness secondary to autoimmune inflammation. The role of microdosed psilocybin in the treatment of neuropsychiatric Lyme disease and autoimmune encephalopathies warrants further study.

Identification of microbial taxa present in Ctenocephalides felis (cat flea) reveals widespread co-infection and associations with vector phylogeny

BACKGROUND

Ctenocephalides felis, the cat flea, is the most common ectoparasite of cats and dogs worldwide. As a cause of flea allergy dermatitis and a vector for two genera of zoonotic pathogens (Bartonella and Rickettsia spp.), the effect of the C. felis microbiome on pathogen transmission and vector survival is of substantial medical importance to both human and veterinary medicine. The aim of this study was to assay the pathogenic and commensal eubacterial microbial communities of individual C. felis from multiple geographic locations and analyze these findings by location, qPCR pathogen prevalence, and flea genetic diversity.

METHODS

16S Next Generation Sequencing (NGS) was utilized to sequence the microbiome of fleas collected from free-roaming cats, and the cox1 gene was used for flea phylogenetic analysis. NGS data were analyzed for 168 individual fleas from seven locations within the US and UK. Given inconsistency in the genera historically reported to constitute the C. felis microbiome, we utilized the decontam prevalence method followed by literature review to separate contaminants from true microbiome members.

RESULTS

NGS identified a single dominant and cosmopolitan amplicon sequence variant (ASV) from Rickettsia and Wolbachia while identifying one dominant Bartonella clarridgeiae and one dominant Bartonella henselae/Bartonella koehlerae ASV. Multiple less common ASVs from these genera were detected within restricted geographical ranges. Co-detection of two or more genera (Bartonella, Rickettsia, and/or Wolbachia) or multiple ASVs from a single genus in a single flea was common. Achromobacter, Peptoniphilus, and Rhodococcus were identified as additional candidate members of the C. felis microbiome on the basis of decontam analysis and literature review. Ctenocephalides felis phylogenetic diversity as assessed by the cox1 gene fell within currently characterized clades while identifying seven novel haplotypes. NGS sensitivity and specificity for Bartonella and Rickettsia spp. DNA detection were compared to targeted qPCR.

CONCLUSIONS

Our findings confirm the widespread coinfection of fleas with multiple bacterial genera and strains, proposing three additional microbiome members. The presence of minor Bartonella, Rickettsia, and Wolbachia ASVs was found to vary by location and flea haplotype. These findings have important implications for flea-borne pathogen transmission and control.

Into the Unknown: Diagnosing Mysterious Brain Lesions

The case discussed involves a 49-year-old male with simultaneous pancreas-kidney transplant who presented with fever, headache and was found to have multifocal brain lesion on brain imaging. This article is protected by copyright. All rights reserved.

Schizophrenia and Bartonella spp. Infection: A Pilot Case-Control Study

Recently, infections with emerging zoonotic bacteria of the genus Bartonella have been reported in association with a range of central nervous system (CNS) symptoms. Currently, it remains unknown if Bartonella spp. infection is associated with symptoms of schizophrenia/schizoaffective disorder (SCZ/SAD). The objective of this study was to determine if there is an association between Bartonella species infection and SCZ/SAD. A secondary objective was to determine if SCZ/SAD symptoms were more severe among participants with documented Bartonella spp. infection. Using a case-control study design, 17 cases and 13 controls were evaluated with a series of clinical and cognitive assessments. Blood samples were collected and tested for Bartonella spp. infection using serological, microbiological, and molecular techniques. People with SCZ/SAD were more likely than healthy volunteers to have Bartonella spp. DNA in their bloodstream, with 11 of 17 cases (65%) positive by Bartonella spp. droplet digital PCR (ddPCR). In comparison, only one healthy volunteer was Bartonella spp. ddPCR positive (8%, p = 0.0024). Based on serology, Bartonella spp. exposure was common among people with SCZ/SAD (12 of 17) as well as among healthy volunteers (12 of 13), with no significant difference between the groups (p = 0.196). Within the case group of people with SCZ/SAD, there was no significant difference in SCZ/SAD severity scores between people with and without ddPCR evidence of Bartonella spp. infection. This pilot study provides preliminary evidence in support of future investigations that should examine a potential contribution of Bartonella spp. infection to SCZ/SAD.

Anorexia Nervosa Caused by Polymicrobial Tick-Borne Infections: A Case Study

The etiology of anorexia nervosa (AN) is multifactorial, and infections may play a contributory and possibly a prominent role. A case is presented which is indicative of a causal association between tick-borne infections and AN. This adolescent female was diagnosed with AN at an eating disorder clinic after excessive food restriction and an irrational fear of weight gain necessitating nasogastric tube feeding. Her history was consistent with systemic infections and she tested serologically positive to Borrelia burgdorferi, Babesia microti, and Mycoplasma pneumoniae; in addition, her clinical presentation was consistent with a Bartonella infection. After treatment with oral and intravenous antimicrobials, she stopped food restriction and no longer had body image concerns. Physicians should be aware of the possibility that tick-borne infections could underly a diagnosis of AN. The role of tick-borne infections in the etiology of AN warrants further study.

Cat Scratch Disease and Bartonellaceae: The Known, the Unknown and the Curious

Since the early 1900s, Bartonella species were known only to cause human disease resulting from very restricted geographic (bartonellosis) or environmental influences ("trench fever"). In the 1990s, and in parallel, cat scratch disease and bacillary angiomatosis were definitively linked to Bartonella species. Subsequently, widespread use of modern diagnostic methods revealed the broad ecologic niche of this organism and greatly expanded our knowledge of the epidemiology and clinical presentations associated with this genus. A large number of reservoirs and vectors involved with Bartonella propagation and transmission to humans have been identified; cats and various arthropods remain the most well-studied to date. Though not completely understood, it appears that specific immune-modulated interactions between the infecting species and host-related factors play a major role in the observed breadth of human clinical syndromes associated with Bartonellae, the large differences in immunopathologic features of tissue samples among different syndromes and potentially the varied responses to antimicrobial therapy. Further, the clinical management for cat scratch disease in particular is quite variable among clinicians, reflecting a poor evidence base. No preventive measures have been developed beyond suggestions to avoid at-risk behavior with known vectors.

[Canine meningoencephalitis and meningitis: retrospective analysis of a veterinary hospital population]

OBJECTIVE

Characterization of the etiology of meningoencephalitis and meningitis in dogs through an analysis of a veterinary hospital population.

MATERIAL AND METHODS

Retrospective study (2011-2016) with evaluation of clinical and diagnostic data of dogs with cerebrospinal fluid (CSF) pleocytosis (> 5/µl). Only dogs with cytological evaluation of CSF or pathological examination of CNS were included. Results of CSF cytology and examination for infectious diseases were reviewed.

RESULTS

A total of 62 dogs met the inclusion criteria. 14.5 % (n = 9) were classified as reactive CSF pleocytosis due to other structural CNS disease, such as neoplasia or infarct. Meningoencephalitis or meningitis of unknown origin was diagnosed in 56.5 % (n = 35). In 29.0 % (n = 18), investigations for infectious diseases or presence of bacteria in CSF cytology (n = 5) indicated an infectious etiology. This infectious etiology appeared reliable in 6 dogs (9.7 %) based on the examination findings, in 9 dogs (14.5 %), there was only a suspicion of infectious meningoencephalitis or meningitis and in 3 dogs (4.8 %), the findings were of uncertain significance.

CONCLUSION

The most common cause of CSF pleocytosis was meningoencephalitis or meningitis of unknown origin. Nevertheless, there was evidence of a possible infectious etiology in 29 % of the dogs. For a reliable diagnosis, it is important to assess the CSF cytology and to conduct investigations for infectious diseases.

CLINICAL RELEVANCE

Meningoencephalitis or meningitis of unknown origin requires immunosuppressive therapy. Therefore, CSF cytology and investigations for infectious diseases are important for an exclusion of infectious meningoencephalitis or meningitis.

Scratching Past Lymphadenopathy: A Case of Bartonella henselae Encephalitis

A previously healthy 6-year-old boy presented with new onset seizure activity and altered mental status. His prehospital course included prolonged fever, vague abdominal complaints, and unusual behavior. Neurological testing was unrevealing, and his symptoms slowly improved without intervention. His primary pediatrician had ordered serum antibody titers to Bartonella henselae for testing of prolonged fever in the setting of exposure to a kitten; these were found to be positive for both immunoglobulin G and immunoglobulin M. Further examination for organ involvement revealed splenic and liver micro-abscesses. After completion of his antibiotic course, the patient returned to his cognitive and neurologic baseline with resolution of his abdominal abscesses. This case emphasizes the importance of obtaining a thorough exposure history when evaluating for infectious causes of encephalitis. [Pediatr Ann. 2020;49(8):e359-e362.].

Is Bartonella a Cause of Primary Sclerosing Cholangitis? A Case Study

The etiology of primary sclerosing cholangitis (PSC) is unknown. I present a case which may be indicative of a causal link between Bartonella infection and PSC. The patient presented with complaints of abdominal pain and bloody diarrhea. A colonoscopy demonstrated chronic inflammation and changes consistent with ulcerative colitis. Routine laboratory studies revealed elevated liver function tests (LFTs); ultrasound and magnetic resonance imaging (MRI) confirmed the diagnosis of PSC. Bartonella serology was positive. It is established that Bartonella infection is associated with both gastrointestinal inflammation and autoimmunity; indeed, there is an animal model for Bartonella-induced PSC. Bartonella is susceptible to treatment with vancomycin and there are case reports and small series that demonstrate that PSC responds to treatment with oral vancomycin. Because of this, it is postulated that at least some cases of PSC may be associated with Bartonella infection. The patient in this report was treated with oral vancomycin and, since then, has been in remission for both colitis and PSC. Since vancomycin is not systemically absorbed, the premise is that he suffered from Bartonella colitis and an autoimmune reaction to Bartonella causing PSC. This premise warrants further study.

Bartonella henselae Bloodstream Infection in a Boy With Pediatric Acute-Onset Neuropsychiatric Syndrome

BACKGROUND

With the advent of more sensitive culture and molecular diagnostic testing modalities, Bartonella spp. infections have been documented in blood and/or cerebrospinal fluid specimens from patients with diverse neurological symptoms. Pediatric acute-onset neuropsychiatric syndrome (PANS) is characterized by an unusually abrupt onset of cognitive, behavioral, or neurological symptoms. Between October 2015 and January 2017, a 14-year-old boy underwent evaluation by multiple specialists for sudden-onset psychotic behavior (hallucinations, delusions, suicidal and homicidal ideation).

METHODS

In March 2017, Bartonella spp. serology (indirect fluorescent antibody assays) and polymerase chain reaction (PCR) amplification, DNA sequencing, and Bartonella enrichment blood culture were used on a research basis to assess Bartonella spp. exposure and bloodstream infection, respectively. PCR assays targeting other vector-borne infections were performed to assess potential co-infections.

RESULTS

For 18 months, the boy remained psychotic despite 4 hospitalizations, therapeutic trials involving multiple psychiatric medication combinations, and immunosuppressive treatment for autoimmune encephalitis. Neurobartonellosis was diagnosed after cutaneous lesions developed. Subsequently, despite nearly 2 consecutive months of doxycycline administration, Bartonella henselae DNA was PCR amplified and sequenced from the patient's blood, and from Bartonella alphaproteobacteria growth medium enrichment blood cultures. B henselae serology was negative. During treatment with combination antimicrobial chemotherapy, he experienced a gradual progressive decrease in neuropsychiatric symptoms, cessation of psychiatric drugs, resolution of Bartonella-associated cutaneous lesions, and a return to all pre-illness activities.

CONCLUSIONS

This case report suggests that B henselae bloodstream infection may contribute to progressive, recalcitrant neuropsychiatric symptoms consistent with PANS in a subset of patients.

Testing for Bartonella ssp. DNA in cerebrospinal fluid of dogs with inflammatory central nervous system disease

BACKGROUND

Neurobartonellosis occurs in people. The role these organisms might play in inflammatory brain disease of dogs is unclear.

HYPOTHESIS/OBJECTIVES

That Bartonella spp. DNA would be amplified more commonly from the CSF of dogs with inflammatory disease compared to those with noninflammatory disease. To report the prevalence of Bartonella spp. in dogs with and without inflammatory CNS disease with a commercially available PCR assay.

ANIMALS

Cerebrospinal fluid (CSF) samples from 172 dogs from either Washington State University or Colorado State University.

METHODS

Retrospective study. A search was performed of all medical records from dogs with CSF samples submitted to CSU's Center for Companion Animal Studies or Veterinary Diagnostic Laboratory from CSU or WSU for Toxoplasma or Neospora PCR assay. Increased CSF nucleated cell counts and an adequate volume of CSF must have been present to evaluate Bartonella spp. by PCR assay.

RESULTS

Inflammatory CNS disease was confirmed in 65 dogs, none of which were positive for Bartonella spp. DNA. Of the other 107 dogs, one was positive for B. henselae DNA. The CSF from this dog contained red blood cells.

CONCLUSIONS AND CLINICAL IMPORTANCE

Failure to amplify Bartonella spp. DNA from the CSF of the dogs with inflammatory disease suggests the organism was not involved in the etiology of the disease, the organism was in the CNS tissues but not in the CSF, or the organism was present but in quantities undetectable by this PCR assay. The combination of PCR and culture is the most sensitive way to detect Bartonella spp. and the use of that technique should be considered in future studies.

Improvement of common variable immunodeficiency using embryonic stem cell therapy in a patient with lyme disease: a clinical case report

Bone marrow transplantation and stem cell therapies have been used for the treatment of common variable immunodeficiency (CVID) and other life-threatening medical disorders. This is the first known case report in the medical literature describing improvement of both Lyme disease and CVID with human embryonic stem cell therapy.

Bartonellosis, One Health and all creatures great and small

BACKGROUND

Bartonellosis is a zoonotic infectious disease of worldwide distribution, caused by an expanding number of recently discovered Bartonella spp.

OBJECTIVES

This review serves as an update on comparative medical aspects of this disease, including the epidemiology, pathogenesis, clinical diagnosis, treatment and challenges.

RESULTS

Of comparative medical importance, Bartonella spp. are transmitted by several arthropod vectors, including fleas, keds, lice, sand flies, ticks and, potentially, mites and spiders. Prior to 1990, there was only one named Bartonella species (B. bacilliformis), whereas there are now over 36, of which 17 have been associated with an expanding spectrum of animal and human diseases. Recent advances in diagnostic techniques have facilitated documentation of chronic bloodstream and dermatological infections with Bartonella spp. in healthy and sick animals, in human blood donors, and in immunocompetent and immunocompromised human patients. The field of Bartonella research remains in its infancy and is rich in questions, for which patient relevant answers are badly needed. Directed Bartonella research could substantially reduce a spectrum of chronic and debilitating animal and human diseases, and thereby reduce suffering throughout the world.

CONCLUSION

A One Health approach to this emerging infectious disease is clearly needed to define disease manifestations, to establish the comparative infectious disease pathogenesis of this stealth pathogen, to validate effective treatment regimens and to prevent zoonotic disease transmission.

Neurological and immunological dysfunction in two patients with Bartonella henselae bacteremia

Recently, BAPGM enrichment culture has documented Bartonella bacteremia in previously healthy, "nonimmunocompromised" patients following arthropod exposures. Neurobartonellosis should be among the differential diagnoses for patients with persistent or recurrent neurological symptoms of undetermined etiology. Microbiological and immunological testing should be concurrently pursued to determine whether defective immune function accompanies Bartonella bacteremia.

Is there a Lyme-like disease in Australia? Summary of the findings to date

Lyme Borreliosis is a common tick-borne disease of the northern hemisphere caused by the spirochaetes of the Borrelia burgdorferi sensu lato (B. burgdorferi s. l.) complex. It results in multi-organ disease with arthritic, cardiac, neurological and dermatological manifestations. In the last twenty-five years there have been over 500 reports of an Australian Lyme-like syndrome in the scientific literature. However, the diagnoses of Lyme Borreliosis made in these cases have been primarily by clinical presentation and laboratory results of tentative reliability and the true cause of these illnesses remains unknown. A number of animals have been introduced to Australia that may act as B. burgdorferi s. l. reservoirs in Lyme-endemic countries, and there are some Australian Ixodes spp. and Haemaphysalis spp. ticks whose geographical distribution matches that of the Australian Lyme-like cases. Four published studies have searched for Borrelia in Australian ticks, with contradicting results. The cause of the potential Lyme-like disease in Australia remains to be defined. The evidence to date as to whether these illnesses are caused by a Borrelia species, another tick borne pathogen or are due to a novel or unrelated aetiology is summarised in this review.

Congenital Tick Borne Diseases: Is This An Alternative Route of Transmission of Tick-Borne Pathogens In Mammals?

Tick-borne diseases (TBDs) have become a popular topic in many medical journals. Besides the obvious participation of ticks in the transmission of pathogens that cause TBD, little is written about alternative methods of their spread. An important role is played in this process by mammals, which serve as reservoirs. Transplacental transfer also plays important role in the spread of some TBD etiological agents. Reservoir species take part in the spread of pathogens, a phenomenon that has extreme importance in synanthropic environments. Animals that accompany humans and animals migrating from wild lands to urban areas increase the probability of pathogen infections by ticks This article provides an overview of TBDs, such as tick-borne encephalitis virus (TBEV), and TBDs caused by spirochetes, α-proteobacteria, γ-proteobacteria, and Apicomplexa, with particular attention to reports about their potential to cross the maternal placenta. For each disease, the method of propagation, symptoms of acute and chronic phase, and complications of their course in adults, children, and animals are described in detail. Additional information about transplacental transfer of these pathogens, effects of congenital diseases caused by them, and the possible effects of maternal infection to the fetus are also discussed. The problem of vertical transmission of pathogens presents a new challenge for medicine. Transfer of pathogens through the placenta may lead not only to propagation of diseases in the population, but also constitute a direct threat to health and fetal development. For this reason, the problem of vertical transmission requires more attention and an estimation of the impact of placental transfer for each of listed pathogens.

Encephalitis with convulsive status in an immunocompetent pediatric patient caused by Bartonella henselae

Cat scratch's disease caused by Bartonella henselae, is known to be a self-limited benign process in immunocompetent children. The association with neurologic manifestations is very uncommon especially in patient with no immunologic defects and in cases without specific treatment. A 7 years old male patient, without any immunocompromised defect, presented an atypic presentation of the cat scratch disease. The patient came to the hospital in two opportunities in a status epilepticus, in both cases the diagnosis was encephalitis by Bartonella henselae and the evolution with treatment was monitored with PCR (polymerase chain reaction) in cerebrospinal fluid and blood, as well as IFI (IgM, IgG) serology (indirect immunofluorescence). The patient had a favorable clinical and laboratory evolution for 6 months showing no recurrence of the disease.

Vasculitis, cerebral infarction and persistent Bartonella henselae infection in a child

Background

The genus Bartonella is comprised of a rapidly increasing number of pathogenic species that induce a seemingly diverse spectrum of neurological symptoms. During the 12 year period that followed the initial onset of neurological and gastrointestinal symptoms, an 11 year-old girl experienced a spectrum of neurological complaints including frequent headaches, visual and auditory hallucinations, anxiety, vision loss involving the lower left quadrant of both eyes, episodic bouts of generalized paralysis, facial palsy, chronic insomnia, seizures, dizziness, cognitive dysfunction, and memory loss. PCR assays targeting Bartonella spp. were used to test formalin-fixed, paraffin embedded brain tissue, patient blood specimens and Bartonella alpha Proteobacteria growth medium (BAPGM) enrichment blood cultures. PCR positive amplicons were sequenced directly and compared to GenBank sequences. Bartonella spp. serology was performed by indirect fluorescent antibody testing and confocal laser scanning microscopy was used to visualize B. henselae organisms in resected brain.

Results

Bartonella henselae DNA was independently PCR amplified and sequenced from the girl’s right parietal lobe, surgically resected in 2000 and from a blood specimen collected in 2012. Although causation cannot be established by a case report, prior diagnostic testing resulted in findings that were either inconclusive or within normal reference ranges and no etiological diagnosis had been obtained to explain the patient’s initial or progressive neurological symptoms.

Conclusions

As intravascular, intra-erythrocytic and endotheliotropic bacteria, it is possible that B. henselae initially induced a vasculitis, resulting in secondary cerebral infarction, tissue necrosis and surgical resection. Bartonella bacteremia, potentially spanning a 12-year time frame, in conjunction with the therapeutic administration of immunosuppressive drugs may have resulted in a progression and potentiation of the neurological disease that was partially reversible following antibiotic administration.

Bartonella endocarditis

Blood culture-negative endocarditis presents a clinical and diagnostic challenge. Here, we describe a patient with a delayed diagnosis of Bartonella henselae endocarditis. <Learning objective: The aim of this report is to highlight the importance of Bartonella species as a cause of culture-negative endocarditis and to illustrate the challenges it poses in diagnosis and treatment.>.

Did Bartonella henselae contribute to the deaths of two veterinarians?

Bartonella henselae, a flea-transmitted bacterium, causes chronic, zoonotic, blood stream infections in immunocompetent and immunocompromised patients throughout the world. As an intra-erythrocytic and endotheliotropic bacterium, B. henselae causes a spectrum of symptomatology ranging from asymptomatic bacteremia to fever, endocarditis and death. Veterinary workers are at occupational risk for acquiring bartonellosis. As an emerging, and incompletely understood, stealth bacterial pathogen, B. henselae may or may not have been responsible for the deaths of two veterinarians; however, recent evidence indicates that this genus is of much greater medical importance than is currently appreciated by the majority of the biomedical community.

Infection with Bartonella henselae in a Danish family

Bartonella species constitute emerging, vector-borne, intravascular pathogens that produce long-lasting bacteremia in reservoir-adapted (natural host or passive carrier of a microorganism) and opportunistic hosts. With the advent of more sensitive and specific diagnostic tests, there is evolving microbiological evidence supporting concurrent infection with one or more Bartonella spp. in more than one family member; however, the mode(s) of transmission to or among family members remains unclear. In this study, we provide molecular microbiological evidence of Bartonella henselae genotype San Antonio 2 (SA2) infection in four of six Danish family members, including a child who died of unknown causes at 14 months of age.

Serial testing from a 3-day collection period by use of the Bartonella Alphaproteobacteria growth medium platform may enhance the sensitivity of Bartonella species detection in bacteremic human patients

Patients with infection from bacteremic Bartonella spp., tested using Bartonella Alphaproteobacteria growth medium (BAPGM), were retrospectively categorized into one of two groups that included those whose blood was collected once (group 1; n = 55) or three times (group 2; n = 36) within a 1-week period. Overall, 19 patients (20.8%) were PCR positive for one or more Bartonella spp. using the BAPGM platform. Seven patients (12.7%) in group 1 tested positive, and 12 patients (33.3%) in group 2 tested positive. Detection was improved when the patients were tested three times within a 1-week period (odds ratio, 3.4 [95% confidence interval, 1.2 to 9.8]; P = 0.02). Obtaining three sequential blood samples during a 1-week period should be considered a diagnostic approach when bartonellosis is suspected.