PCR amplification of Bartonella koehlerae from human blood and enrichment blood cultures

Geographical distribution of Bartonella spp in the countries of the WHO Eastern Mediterranean Region (WHO-EMRO)

Bartonellosis is a vector-borne and zoonotic diseases in humans, especially in immunocompromised individuals. However, there is no complete data about the geographical distribution of different species of Bartonella, as well as the status of its reservoirs, vectors, and human cases in most parts of the world. In this study, published reports related to Bartonella species from WHO-EMRO region countries were searched in different databases until October 2023. The eighteens different species of Bartonella were reported in WHO-EMRO countries including Bartonella henselae, Bartonella quintana, Bartonella elizabethae, Bartonella bovis, Bartonella clarridgeiae, Bartonella vinsonii, Bartonella doshiae, Bartonella taylorii, Bartonella rochalimae, Bartonella tribocorum, Bartonella rattimassiliensis, candidatus Bartonella merieuxii, candidatus Bartonella dromedarii, Bartonella acomydis, Bartonella jaculi, Bartonella coopersplainsensis and Bartonella koehlerae. Also, only human cases of B. henselae and B. quintana infections were reported from WHO-EMRO countries. The infections of Bartonella are important in the WHO-EMRO region, but they have been neglected by clinicians and healthcare systems.

Viability and Desiccation Resistance of Bartonella henselae in Biological and Non-Biological Fluids: Evidence for Pathogen Environmental Stability

Pathogen environmental stability is an often-neglected research priority for pathogens that are known to be vector-transmitted. Bartonella henselae, the etiologic agent of Cat Scratch Disease, has become a "pathogen of interest" in several serious human illnesses, which include neoplastic, cardiovascular, neurocognitive, and rheumatologic conditions. Survival in the flea gut and feces as well as the association with a biofilm in culture-negative endocarditis provides insight into this organism's ability to adjust to environmental extremes. The detection of B. henselae DNA in blood and tissues from marine mammals also raises questions about environmental stability and modes of pathogen transmission. We investigated the ability of B. henselae to survive in fluid matrices chosen to mimic potential environmental sources of infective materials. Feline whole blood, serum and urine, bovine milk, and physiologic saline inoculated with a laboratory strain of B. henselae San Antonio 2 were subsequently evaluated by culture and qPCR at specified time intervals. Bacterial viability was also assessed following desiccation and reconstitution of each inoculated fluid matrix. Bartonella henselae SA2 was cultured from feline urine up to 24 h after inoculation, and from blood, serum, cow's milk, and physiologic saline for up to 7 days after inoculation. Of potential medical importance, bacteria were cultured following air-desiccation of all fluid inoculates. The viability and stability of Bartonella within biological and non-biological fluids in the environment may represent a previously unrecognized source of infection for animals and human beings.

Risk Factors for Bartonella Seroreactivity Among Veterinary Workers in the Pacific Northwest

Background: Exposure to zoonotic diseases is a significant occupational risk in veterinary medicine. In this study, we characterized personal protective equipment use, injury frequency, and Bartonella seroreactivity in Washington State veterinary workers. Methods: Using a risk matrix developed to reflect occupational risk factors for exposure to Bartonella and multiple logistic regression, we explored determinants of risk for Bartonella seroreactivity. Results: Depending on the titer cutoff used, Bartonella seroreactivity was between 24.0% and 55.2%. No significant predictors of seroreactivity were found, although the relationship between high-risk status and increased seroreactivity for some Bartonella species approached significance. Serology for other zoonotic and vector borne pathogens did not identify consistent cross reactivity with Bartonella antibodies. Conclusion: The predictive power of the model was likely limited by the small sample size and high level of exposure to risk factors for most participants. Given the high proportion of veterinarians seroreactive to one or more of the three Bartonella spp. known to infect dogs and cats in the United States, as well as seroreactivity to other zoonoses, and the unclear relationship between occupational risk factors, seroreactivity, and disease expression, more research is needed in this area.

Blood Supplementation Enhances Bartonella henselae Growth and Molecular Detection of Bacterial DNA in Liquid Culture

Bacteria of the genus Bartonella, a member of the Alphaproteobacteria, are fastidious, Gram-negative, aerobic bacilli that comprise numerous species, subspecies, and genotypes. Bartonella henselae, with a worldwide distribution, infects cats, dogs, horses, humans, and other mammals. Diagnostically, direct detection of Bartonella henselae in patient blood specimens by culture or molecular methods is required to confirm infection with this bacterium. Enrichment blood culture combined with quantitative PCR (qPCR) or ddPCR enhances the sensitivity of direct detection. The addition of sheep blood to liquid culture media increased the Bartonella henselae DNA concentration compared to controls, additionally improving PCR direct detection sensitivity. IMPORTANCE This study aims to improve diagnostic detection of Bartonella henselae. Patient samples are combined with enriched bacterial cultures aimed at growing Bartonella henselae for the best possible chance at detection. However, current Bartonella growth methods could be improved. The DNA extraction method used by most laboratories should also be optimized. Sheep blood was added to increase the growth of Bartonella henselae and multiple DNA extraction methods were to be compared to each other.

Bartonella spp. in households with cats: Risk factors for infection in cats and human exposure

The aim of this study was to estimate the occurrence of Bartonella spp. per household in cats and the risk factors for Bartonella spp. positivity in cats and their owners from Valdivia, Chile. A total of 464 cats (distributed within 324 households) and 326 humans (control group [n = 112] and cat owner [n = 214]) distributed in 262 households were sampled. From the cat owners (n = 214), 128 humans were in households where the cat was also sampled, totaling 84 households with dual sampling. Real-time PCR (qPCR) was used for Bartonella spp. detection in blood from cats and humans, and immunofluorescent immunoassay (IFA) anti-Bartonella henselae was performed in human serum samples. Out of the total of 324 households, 20.43% presented at least one Bartonella positive cat. From the households with dual sampling, 29.7% (25/84) presented at least one qPCR-Bartonella spp. positive cat. However, Bartonella DNA was not amplified in humans, and in 7.3% (6/82) of the households was found at least one of the cat's owners exposed to B. henselae. Cats younger than one year (Odds Ratio (OR) = 5.3), non-neutered (OR 3.46), sampled at home (OR 5.82), and with improper application of tick/flea control products (OR 3.13) showed a higher risk for Bartonella spp. presence. Humans with occupational exposure involving animal contact, were more likely to exhibit B. henselae seropositivity (OR 7.5). Bartonella spp. was present in the cats a moderate number of households, but Bartonella DNA was not detected in owners' blood, inferring that there is a low risk of recent human infection in the studied population.

Comparison of Biological Activities of BafA Family Autotransporters within Bartonella Species Derived from Cats and Rodents

Bartonella species are hemotropic, facultative intracellular bacteria, some of which cause zoonoses, that are widely disseminated among many mammals, including humans. During infection in humans, vascular endothelial cells play a crucial role as a replicative niche for Bartonella, and some are capable of promoting vascular proliferation. Along with well-studied pathogenic factors such as a trimeric autotransporter adhesin BadA or VirB/D4 type IV secretion system, bacteria-secreted protein BafA is also involved in Bartonella-induced vasoproliferation. Genes encoding BafA orthologs have been found in the genomes of most Bartonella species, but their functionality remains unclear. In this study, we focused on three cat-derived zoonotic species (B. henselae, B. koehlerae, and B. clarridgeiae) and two rodent-derived species (B. grahamii and B. doshiae) and compared the activity of BafA derived from each species. Recombinant BafA proteins of B. henselae, B. koehlerae, B. clarridgeiae, and B. grahamii, species that also cause human disease, induced cell proliferation and tube formation in cultured endothelial cells, while BafA derived from B. doshiae, a species that is rarely found in humans, showed neither activity. Additionally, treatment of cells with these BafA proteins increased phosphorylation of both vascular endothelial growth factor receptor 2 and extracellular signal-regulated kinase 1/2, with the exception of B. doshiae BafA. Differential bafA mRNA expression and BafA secretion among the species likely contributed to the differences in the cell proliferation phenotype of the bacteria-infected cells. These findings suggest that the biological activity of BafA may be involved in the infectivity or pathogenicity of Bartonella species in humans.

Contemporary diagnostics for medically relevant fastidious microorganisms belonging to the genera Anaplasma, Bartonella, Coxiella, Orientia, and Rickettsia

Many of the human infectious pathogens—especially the zoonotic or vector-borne bacteria—are fastidious organisms that are difficult to cultivate because of their strong adaption to the infected host culminating in their near-complete physiological dependence on this environment. These bacterial species exhibit reduced multiplication rates once they are removed from their optimal ecological niche. This fact complicates the laboratory diagnosis of the disease and hinders the detection and further characterization of the underlying organisms, e.g. at the level of their resistance to antibiotics due to their slow growth. Here, we describe the current state of microbiological diagnostics for five genera of human pathogens with a fastidious laboratory lifestyle. For Anaplasma spp., Bartonella spp., Coxiella burnetii, Orientia spp. and Rickettsia spp., we will summarize the existing diagnostic protocols, the specific limitations for implementation of novel diagnostic approaches and the need for further optimization or expansion of the diagnostic armamentarium. We will reflect upon the diagnostic opportunities provided by new technologies including mass spectrometry and next-generation nucleic acid sequencing. Finally, we will review the (im)possibilities of rapidly developing new in vitro diagnostic tools for diseases of which the causative agents are fastidiously growing and therefore hard to detect.

Development of a Multiplex Droplet Digital PCR Assay for the Detection of Babesia, Bartonella, and Borrelia Species

We describe the development, optimization, and validation of a multiplex droplet digital PCR (ddPCR) assay for the simultaneous detection of Babesia, Bartonella, and Borrelia spp. DNA from several sample matrices, including clinical blood samples from animals and humans, vectors, in-vitro infected human and animal cell lines, and tissues obtained from animal models (infected with Bartonella and/or B. burgdorferi). The multiplex ddPCR assay was able to detect 31 Bartonella, 13 Borrelia, and 24 Babesia species, including Theileria equi, T. cervi, and Cytauxzoon felis. No amplification of Treponema or Leptospira spp. was observed. Sensitivity of 0.2-5 genome equivalent DNA copies per microliter was achieved for different members of the Bartonella and Borrelia genus, depending on the species or matrix type (water or spiked blood DNA) tested. The ddPCR assay facilitated the simultaneous detection of co-infections with two and three vector-borne pathogens comprising four different genera (Babesia, Bartonella, Borrelia, and Theileria) from clinical and other sample sources.

Exposure of Domestic Cats to Three Zoonotic Bartonella Species in the United States

Cat-associated Bartonella species, which include B. henselae, B. koehlerae, and B. clarridgeiae, can cause mild to severe illness in humans. In the present study, we evaluated 1362 serum samples obtained from domestic cats across the U.S. for seroreactivity against three species and two strain types of Bartonella associated with cats (B. henselae type 1, B. henselae type 2, B. koehlerae, and B. clarridgeiae) using an indirect immunofluorescent assay (IFA). Overall, the seroprevalence at the cutoff titer level of ≥1:64 was 23.1%. Seroreactivity was 11.1% and 3.7% at the titer level cutoff of ≥1:128 and at the cutoff of ≥1:256, respectively. The highest observation of seroreactivity occurred in the East South-Central, South Atlantic, West North-Central, and West South-Central regions. The lowest seroreactivity was detected in the East North-Central, Middle Atlantic, Mountain, New England, and Pacific regions. We observed reactivity against all four Bartonella spp. antigens in samples from eight out of the nine U.S. geographic regions.

Bartonella infections in cats and dogs including zoonotic aspects

Bartonellosis is a vector-borne zoonotic disease with worldwide distribution that can infect humans and a large number of mammals including small companion animals (cats and dogs). In recent years, an increasing number of studies from around the world have reported Bartonella infections, although publications have predominantly focused on the North American perspective. Currently, clinico-pathological data from Europe are more limited, suggesting that bartonellosis may be an infrequent or underdiagnosed infectious disease in cats and dogs. Research is needed to confirm or exclude Bartonella infection as a cause of a spectrum of feline and canine diseases. Bartonella spp. can cause acute or chronic infections in cats, dogs and humans. On a comparative medical basis, different clinical manifestations, such as periods of intermittent fever, granulomatous inflammation involving the heart, liver, lymph nodes and other tissues, endocarditis, bacillary angiomatosis, peliosis hepatis, uveitis and vasoproliferative tumors have been reported in cats, dogs and humans. The purpose of this review is to provide an update and European perspective on Bartonella infections in cats and dogs, including clinical, diagnostic, epidemiological, pathological, treatment and zoonotic aspects.

Bartonella DNA in heart tissues of bats in central and eastern Europe and a review of phylogenetic relations of bat-associated bartonellae

Background

Bats are among the most widely distributed mammals worldwide and can represent hosts or reservoirs for a number of different pathogens. Bartonella spp. are opportunistic bacterial pathogens, which are transmitted by a large variety of arthropods. The aim of this study was to investigate the presence and host-associations of these Gram-negative bacteria in heart tissues of bats collected in four different countries from eastern and central Europe and to analyze their phylogenetic relationship with other bat-associated bartonellae.

Results

The results of this study show for the first time the presence of Bartonella spp. DNA in heart tissues of bats from central and eastern Europe. The overall prevalence of the infection was 1.38%. Phylogenetic analysis identified four new Bartonella spp. sequences, which were closely related with other Bartonella previously isolated from bats in Europe and North America.

Conclusions

The gltA sequences of Bartonella spp. showed considerable heterogeneity in the phylogenetic analysis resulting in six different clades. Our study demonstrated the presence of Bartonella spp. only in heart tissues of bats from Romania, with two new bat species recorded as hosts (Myotis cf. alcathoe and Pipistrellus pipistrellus).

Electronic supplementary material

The online version of this article (10.1186/s13071-018-3070-7) contains supplementary material, which is available to authorized users.

Molecular assessment of Bartonella in Gerbillus nanus from Saudi Arabia reveals high levels of prevalence, diversity and co-infection

Bartonellae bacteria are associated with several re-emerging human diseases. These vector-borne pathogens have a global distribution, yet data on Bartonella prevalence and diversity in the Arabian Peninsula are limited. In this study we assessed the Bartonella infection status of the Baluchistan gerbil (Gerbillus nanus), a species associated with pastoral communities throughout the Middle East region, using a multi-gene PCR screening approach. The results demonstrated that 94 (68.1%) of the 138 gerbils trapped on a monthly basis, over a period of one year, were PCR-positive. Sequencing of the gltA gene region confirmed the presence of four discrete Bartonella lineages (I-IV) and high levels of co-infection (33.0%). Each of the four lineages, varied in overall abundance (7.5%-47.9%) and had discernible seasonal peaks. Bartonella status was significantly correlated with ectoparasite presence, but not with sex, nor with season. Statistical analyses further revealed that co-infected individuals had a significantly higher relative body condition. Multi-locus sequence analysis (MLSA) performed with a concatenated dataset of three genetic loci (gltA, nuoG, and rpoB), 1452 nucleotides (nt) in length confirmed that lineage IV, which occurred in 24 PCR-positive animals (25.5%), is most closely related to zoonotic B. elizabethae. The remaining three lineages (I-III) formed a monophyletic clade which, on the basis of gltA was shown to contain bartonellae from diverse Gerbillinae species from the Middle East, suggestive of a gerbil-associated species complex in this region. Lineage I was identical to a Candidatus B. sanaae strain identified previously in Bushy-tailed jirds (Sekeetamys calurus) from Egypt, wherease MLSA indicate that lineages II and III are novel. The high levels of infection and co-infection, together with the presence of multiple Bartonella lineages indicate that Gerbillus nanus is likely a natural reservoir of Bartonella in the Arabian Peninsula.

Rheumatological presentation of Bartonella koehlerae and Bartonella henselae bacteremias: A case report

INTRODUCTION

Systemic Bartonella spp. infections are being increasingly reported in association with complex medical presentations. Individuals with frequent arthropod exposures or animal contact appear to be at risk for acquiring long standing infections with Bartonella spp.

CASE REPORT

This case report describes infections with Bartonella koehlerae and Bartonella henselae in a female veterinarian whose symptoms were predominantly rheumatologic in nature. Infection was confirmed by serology, polymerase chain reaction (PCR), enrichment blood culture, and DNA sequencing of amplified B koehlerae and B henselae DNA. Long-term medical management with antibiotics was required to achieve elimination of these infections and was accompanied by resolution of the patient's symptoms. Interestingly, the patient experienced substantial improvement in the acquired joint hypermobility mimicking Ehlers-Danlos Syndrome (EDS) type III.

CONCLUSION

To facilitate early and directed medical interventions, systemic bartonellosis should potentially be considered as a differential diagnosis in patients with incalcitrant rheumatological symptoms and frequent arthropod exposures or extensive animal contact.

Prevalence of Bartonella spp. by culture, PCR and serology, in veterinary personnel from Spain

Background

The genus Bartonella includes fastidious, facultative intracellular bacteria mainly transmitted by arthropods and distributed among mammalian reservoirs. Bartonella spp. implicated as etiological agents of zoonoses are increasing. Apart from the classical Bartonella henselae, B. bacilliformis or B. quintana, other species (B. elizabethae, B. rochalimae, B. vinsonii arupensis and B. v. berkhoffii, B. tamiae or B. koehlerae, among others) have also been associated with human and/or animal diseases. Laboratory techniques for diagnosis (culture, PCR assays and serology) usually show lack of sensitivity. Since 2005, a method based on a liquid enrichment Bartonella alphaproteobacteria growth medium (BAPGM) followed by PCRs for the amplification of Bartonella spp. has been developed. We aimed to assess culture, molecular and serological prevalence of Bartonella infections in companion animal veterinary personnel from Spain.

Methods

Each of 89 participants completed a questionnaire. Immunofluorescence assays (IFA) using B. vinsonii berkhoffii (genotypes I, II and III), B. henselae, B. quintana and B. koehlerae as antigens were performed. A cut-off of 1:64 was selected as a seroreactivity titer. Blood samples were inoculated into BAPGM and subcultured onto blood agar plates. Bartonella spp. was detected using conventional and quantitative real-time PCR assays and DNA sequencing.

Results

Among antigens corresponding to six Bartonella spp. or genotypes, the lowest seroreactivity was found against B. quintana (11.2%) and the highest, against B. v. berkhoffii genotype III (56%). A total of 27% of 89 individuals were not seroreactive to any test antigen. Bartonella spp. IFA seroreactivity was not associated with any clinical sign or symptom. DNA from Bartonella spp., including B. henselae (n = 2), B. v. berkhoffii genotypes I (n = 1) and III (n = 2), and B. quintana (n = 2) was detected in 7/89 veterinary personnel. PCR and DNA sequencing findings were not associated with clinical signs or symptoms. No co-infections were observed. One of the two B. henselae PCR-positive individuals was IFA seronegative to all tested antigens whereas the other one was not B. henselae seroreactive. The remaining PCR-positive individuals were seroreactive to multiple Bartonella spp. antigens.

Conclusions

High serological and molecular prevalences of exposure to, or infection with, Bartonella spp. were found in companion animal veterinary personnel from Spain. More studies using BAPGM enrichment blood culture and PCR are needed to clarify the finding of Bartonella PCR-positive individuals lacking clinical symptoms.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2483-z) contains supplementary material, which is available to authorized users.

First description of Bartonella koehlerae infection in a Spanish dog with infective endocarditis

BACKGROUND

Bartonella koehlerae has been recently described as a new cat- and cat fleas-associated agent of culture-negative human endocarditis. It has been also encountered in one dog from Israel and six dogs from the USA, but other clinically relevant reports involving this bacterium are lacking.

RESULTS

A 7-year-old intact male mixed dog presented with clinico-pathological signs consistent with mitral endocarditis and cutaneous hemangiosarcoma. Molecular studies revealed the presence of Bartonella koehlerae DNA in samples from blood and mitral valve tissue.

CONCLUSIONS

This is the first description of B. koehlerae in Spain, corroborating that it can also be detected in dogs. Bartonella koehlerae infection should also be considered in Spain in humans and dogs presenting with clinical disease suggestive of it, such as culture-negative endocarditis.

Prevalence, hematological findings and genetic diversity of Bartonella spp. in domestic cats from Valdivia, Southern Chile

The present study determined the prevalence, hematological findings and genetic diversity of Bartonella spp. in domestic cats from Valdivia, Southern Chile. A complete blood count and nuoG gene real-time quantitative PCR (qPCR) for Bartonella spp. were performed in 370 blood samples from cats in Valdivia, Southern Chile. nuoG qPCR-positive samples were submitted to conventional PCR for the gltA gene and sequencing for species differentiation and phylogenetic analysis. Alignment of gltA gene was used to calculate the nucleotide diversity, polymorphic level, number of variable sites and average number of nucleotide differences. Bartonella DNA prevalence in cats was 18·1% (67/370). Twenty-nine samples were sequenced with 62·0% (18/29) identified as Bartonella henselae, 34·4% (10/29) as Bartonella clarridgeiae, and 3·4% (1/29) as Bartonella koehlerae. Bartonella-positive cats had low DNA bacterial loads and their hematological parameters varied minimally. Each Bartonella species from Chile clustered together and with other Bartonella spp. described in cats worldwide. Bartonella henselae and B. clarridgeiae showed a low number of variable sites, haplotypes and nucleotide diversity. Bartonella clarridgeiae and B. koehlerae are reported for the first time in cats from Chile and South America, respectively.

Identification of Novel Zoonotic Activity of Bartonella spp., France

These bacteria may cause paucisymptomatic bacteremia and endocarditis in humans.

Certain Bartonella species are known to cause afebrile bacteremia in humans and other mammals, including B. quintana, the agent of trench fever, and B. henselae, the agent of cat scratch disease. Reports have indicated that animal-associated Bartonella species may cause paucisymptomatic bacteremia and endocarditis in humans. We identified potentially zoonotic strains from 6 Bartonella species in samples from patients who had chronic, subjective symptoms and who reported tick bites. Three strains were B. henselae and 3 were from other animal-associated Bartonella spp. (B. doshiae, B. schoenbuchensis, and B. tribocorum). Genomic analysis of the isolated strains revealed differences from previously sequenced Bartonella strains. Our investigation identifed 3 novel Bartonella spp. strains with human pathogenic potential and showed that Bartonella spp. may be the cause of undifferentiated chronic illness in humans who have been bitten by ticks.

Isolation of Bartonella henselae and Two New Bartonella Subspecies, Bartonellakoehlerae Subspecies boulouisii subsp. nov. and Bartonella koehlerae Subspecies bothieri subsp. nov. from Free-Ranging Californian Mountain Lions and Bobcats

Domestic cats are the natural reservoir of Bartonella henselae, B. clarridgeiae and B. koehlerae. To determine the role of wild felids in the epidemiology of Bartonella infections, blood was collected from 14 free-ranging California mountain lions (Puma concolor) and 19 bobcats (Lynx rufus). Bartonella spp. were isolated from four (29%) mountain lions and seven (37%) bobcats. These isolates were characterized using growth characteristics, biochemical reactions, molecular techniques, including PCR-RFLP of selected genes or interspacer region, pulsed-field gel electrophoresis (PFGE), partial sequencing of several genes, and DNA-DNA hybridization. Two isolates were identical to B. henselae genotype II. All other isolates were distinguished from B. henselae and B. koehlerae by PCR-RFLP of the gltA gene using endonucleases HhaI, TaqI and AciI, with the latter two discriminating between the mountain lion and the bobcat isolates. These two novel isolates displayed specific PFGE profiles distinct from B. henselae, B. koehlerae and B. clarridgeiae. Sequences of amplified gene fragments from the three mountain lion and six bobcat isolates were closely related to, but distinct from, B. henselae and B. koehlerae. Finally, DNA-DNA hybridization studies demonstrated that the mountain lion and bobcat strains are most closely related to B. koehlerae. We propose naming the mountain lion isolates B. koehlerae subsp. boulouisii subsp. nov. (type strain: L-42-94), and the bobcat isolates B. koehlerae subsp. bothieri subsp. nov. (type strain: L-17-96), and to emend B. koehlerae as B. koehlerae subsp. koehlerae. The mode of transmission and the zoonotic potential of these new Bartonella subspecies remain to be determined.

Bartonella henselae as a cause of acute-onset febrile illness in cats

Case series summary

At different time points spanning 6 months, three adopted feral flea-infested cats, residing in the household of a veterinary technician, became acutely anorexic, lethargic and febrile. Enrichment blood culture/PCR using Bartonella alpha Proteobacteria growth medium (BAPGM) confirmed initial infection with the same Bartonella henselae genotype in all three cases. With the exception of anemia and neutropenia, complete blood counts, serum biochemical profiles and urinalysis results were within reference intervals. Also, tests for feline leukemia virus, feline immunodeficiency virus, Toxoplasma gondii and feline coronavirus antibodies were negative. Serial daily temperature monitoring in one case confirmed a cyclic, relapsing febrile temperature pattern during 1 month, with resolution during and after treatment with azithromycin. Bartonella henselae Western immunoblot (WB) results did not consistently correlate with BAPGM enrichment blood culture/PCR results or B henselae indirect fluorescent antibody (IFA) titers, and WB titration results were not informative for establishing antibiotic treatment failure. During the respective follow-up periods, no illnesses or additional febrile episodes were reported, despite repeat documentation of B henselae bacteremia in two cats available for follow-up (one with the same genotype and the other with a different B henselae genotype); one cat was, unfortunately, killed by dogs before follow-up testing.

Relevance and novel information

We conclude that microbiological diagnosis and treatment of B henselae infection in cats can be challenging, that antibody titration results and resolution of clinical abnormalities may not correlate with a therapeutic cure, and that fever and potentially neutropenia should be differential diagnostic considerations for young cats with suspected bartonellosis.

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.

Co-infection with Anaplasma platys, Bartonella henselae, Bartonella koehlerae and 'Candidatus Mycoplasma haemominutum' in a cat diagnosed with splenic plasmacytosis and multiple myeloma

Anaplasma platys (Apl), 'Candidatus Mycoplasma haemominutum' (CMh), Bartonella henselae (Bh) and Bartonella koehlerae (Bk) were confirmed by polymerase chain reaction (PCR) amplification and DNA sequencing in a cat diagnosed with multiple myeloma. Other inconsistently documented hematologic abnormalities included anemia, thrombocytopenia, eosinophilia and hypoglycemia. Persistent Apl infection was confirmed for the first time in a North American cat by sequencing three bacterial genes (16S rRNA, p44 and GroEL) in peripheral blood samples collected 100 days apart. Following doxycycline treatment for Apl, multiple myeloma was diagnosed based upon a monoclonal gammopathy and splenic plasmacytosis, and the cat was treated with melphalan, chlorambucil and prednisolone. Apl DNA was not amplified from post-treatment blood samples and the hyperglobulinemia resolved temporarily following chemotherapy. Retrospective PCR analysis of stored DNA extracts identified CMh, Bk and Bh infections. Retrospective PCR for antigen receptor rearrangements (PARR) of splenic aspirates did not confirm B- or T-cell clonality. Co-infection with multiple vector-borne pathogens should be a diagnostic consideration in cats with chronic hypergammaglobulinemia, monoclonal gammopathy and splenic plasmacytosis.

Spontaneous onset of complex regional pain syndrome Type I in a woman infected with Bartonella koehlerae

After a short-term fever, complex regional pain syndrome, characterized by hyperalgesia, intermittent swelling, erythema and cyanosis of both feet, was diagnosed in a female veterinarian. The woman was infected with Bartonella koehlerae and she was also Bartonella vinsonii subsp. berkhoffii seroreactive. Having failed other treatments, symptoms resolved following initiation of antibiotics.

Phylogenetic diversity of bacteria isolated from sick dogs using the BAPGM enrichment culture platform

BACKGROUND

Bartonella alpha-Proteobacteria growth medium (BAPGM) enrichment culture has proven useful for documenting Bartonella species infection and has facilitated growth of other fastidious bacteria from human samples.

PURPOSE

To report non-Bartonella bacterial isolates obtained from canine samples cultured using BAPGM enrichment culture.

ANIMALS

Between 2004 and 2008, 695 specimens from 513 dogs were tested by the NCSU-IPRL using the BAPGM enrichment culture. Over the same period of time, blood samples from 270 dogs were cultured by the NCSU-CML using Bactec-Plus Aerobic/F media.

METHODS

BAPGM isolates were characterized using Bartonella genus primers and 16S rDNA primers followed by DNA sequencing. NCSU medical records were retrospectively reviewed. Blood culture results from the NCSU-CML were compared with BAPGM blood culture results.

RESULTS

Seventy-nine non-Bartonella isolates were obtained from 69/513 dogs. The most commonly isolated phylum was Proteobacteria (48.1%) with alpha-Proteobacteria being the most commonly isolated class. Staphylococcus and Sphingomonas were the most commonly isolated genera. The majority of the remaining isolates were bacteria that are rarely isolated from canine samples. Comparison of NCSU-CML and IPRL (BAPGM) blood culture isolates showed alpha-Proteobacteria were isolated more often from BAPGM.

CONCLUSIONS AND CLINICAL IMPORTANCE

Use of insect cell culture enrichment medium, such as BAPGM, appears to enhance the growth of alpha-Proteobacteria, but also results in isolation of non-alpha-Proteobacteria from sick dogs. Future studies are needed to elucidate the utility of BAPGM and other "nonconventional" growth media and methods for isolation of fastidious organisms and to determine if these organisms play a causal role in disease development.

Co-infection with Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum in a veterinarian

BACKGROUND

During a two year period, a 27-year-old female veterinarian experienced migraine headaches, seizures, including status epilepticus, and other neurological and neurocognitive abnormalities. Prior to and during her illness, she had been actively involved in hospital-based work treating domestic animals, primarily cats and dogs, in Grenada and Ireland and anatomical research requiring the dissection of wild animals (including lions, giraffe, rabbits, mongoose, and other animals), mostly in South Africa. The woman reported contact with fleas, ticks, lice, biting flies, mosquitoes, spiders and mites and had also been scratched or bitten by dogs, cats, birds, horses, reptiles, rabbits and rodents. Prior diagnostic testing resulted in findings that were inconclusive or within normal reference ranges and no etiological diagnosis had been obtained to explain the patient's symptoms.

METHODS

PCR assays targeting Anaplasma sp. Bartonella sp. and hemotopic Mycoplasma sp. were used to test patient blood samples. PCR positive amplicons were sequenced directly and compared to Gen Bank sequences. In addition, Bartonella alpha Proteobacteria growth medium (BAPGM) enrichment blood culture was used to facilitate bacterial growth and Bartonella spp. serology was performed by indirect fluorescent antibody testing.

RESULTS

Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum DNA was amplified and sequenced from the woman's blood, serum or blood culture samples. Her serum was variably seroreactive to several Bartonella sp. antigens. Despite symptomatic improvement, six months of doxycycline most likely failed to eliminate the B. henselae infection, whereas A. platys and Candidatus M. haematoparvum DNA was no longer amplified from post-treatment samples.

CONCLUSIONS

As is typical of many veterinary professionals, this individual had frequent exposure to arthropod vectors and near daily contact with persistently bacteremic reservoir hosts, including cats, the primary reservoir host for B. henselae, and dogs, the presumed primary reservoir host for A. platys and Candidatus Mycoplasma haematoparvum. Physicians caring for veterinarians should be aware of the occupational zoonotic risks associated with the daily activities of these animal health professionals.

Bartonella henselae infection in a family experiencing neurological and neurocognitive abnormalities after woodlouse hunter spider bites

BACKGROUND

Bartonella species comprise a group of zoonotic pathogens that are usually acquired by vector transmission or by animal bites or scratches.

METHODS

PCR targeting the Bartonella 16S-23S intergenic spacer (ITS) region was used in conjunction with BAPGM (Bartonella alpha Proteobacteria growth medium) enrichment blood culture to determine the infection status of the family members and to amplify DNA from spiders and woodlice. Antibody titers to B. vinsonii subsp. berkhoffii (Bvb) genotypes I-III, B. henselae (Bh) and B. koehlerae (Bk) were determined using an IFA test. Management of the medical problems reported by these patients was provided by their respective physicians.

RESULTS

In this investigation, immediately prior to the onset of symptoms two children in a family experienced puncture-like skin lesions after exposure to and presumptive bites from woodlouse hunter spiders. Shortly thereafter, the mother and both children developed hive-like lesions. Over the ensuing months, the youngest son was diagnosed with Guillain-Barre (GBS) syndrome followed by Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). The older son developed intermittent disorientation and irritability, and the mother experienced fatigue, headaches, joint pain and memory loss. When tested approximately three years after the woodlouse hunter spider infestation, all three family members were Bartonella henselae seroreactive and B. henselae DNA was amplified and sequenced from blood, serum or Bartonella alpha-proteobacteria (BAPGM) enrichment blood cultures from the mother and oldest son. Also, B. henselae DNA was PCR amplified and sequenced from a woodlouse and from woodlouse hunter spiders collected adjacent to the family's home.

CONCLUSIONS

Although it was not possible to determine whether the family's B. henselae infections were acquired by spider bites or whether the spiders and woodlice were merely accidental hosts, physicians should consider the possibility that B. henselae represents an antecedent infection for GBS, CIDP, and non-specific neurocognitive abnormalities.

Bartonella henselae bacteremia in a mother and son potentially associated with tick exposure

BACKGROUND

Bartonella henselae is a zoonotic, alpha Proteobacterium, historically associated with cat scratch disease (CSD), but more recently associated with persistent bacteremia, fever of unknown origin, arthritic and neurological disorders, and bacillary angiomatosis, and peliosis hepatis in immunocompromised patients. A family from the Netherlands contacted our laboratory requesting to be included in a research study (NCSU-IRB#1960), designed to characterize Bartonella spp. bacteremia in people with extensive arthropod or animal exposure. All four family members had been exposed to tick bites in Zeeland, southwestern Netherlands. The mother and son were exhibiting symptoms including fatigue, headaches, memory loss, disorientation, peripheral neuropathic pain, striae (son only), and loss of coordination, whereas the father and daughter were healthy.

METHODS

Each family member was tested for serological evidence of Bartonella exposure using B. vinsonii subsp. berkhoffii genotypes I-III, B. henselae and B. koehlerae indirect fluorescent antibody assays and for bacteremia using the BAPGM enrichment blood culture platform.

RESULTS

The mother was seroreactive to multiple Bartonella spp. antigens and bacteremia was confirmed by PCR amplification of B. henselae DNA from blood, and from a BAPGM blood agar plate subculture isolate. The son was not seroreactive to any Bartonella sp. antigen, but B. henselae DNA was amplified from several blood and serum samples, from BAPGM enrichment blood culture, and from a cutaneous striae biopsy. The father and daughter were seronegative to all Bartonella spp. antigens, and negative for Bartonella DNA amplification.

CONCLUSIONS

Historically, persistent B. henselae bacteremia was not thought to occur in immunocompetent humans. To our knowledge, this study provides preliminary evidence supporting the possibility of persistent B. henselae bacteremia in immunocompetent persons from Europe. Cat or flea contact was considered an unlikely source of transmission and the mother, a physician, reported that clinical symptoms developed following tick exposure. To our knowledge, this is the first time that a B. henselae organism has been visualized in and amplified from a striae lesion. As the tick bites occurred three years prior to documentation of B. henselae bacteremia, the mode of transmission could not be determined.

Bartonella spp. bacteremia and rheumatic symptoms in patients from Lyme disease-endemic region

Prevalence of Bartonella spp. was high, especially among patients with a history of Lyme disease.

Bartonella spp. infection has been reported in association with an expanding spectrum of symptoms and lesions. Among 296 patients examined by a rheumatologist, prevalence of antibodies against Bartonella henselae, B. koehlerae, or B. vinsonii subsp. berkhoffii (185 [62%]) and Bartonella spp. bacteremia (122 [41.1%]) was high. Conditions diagnosed before referral included Lyme disease (46.6%), arthralgia/arthritis (20.6%), chronic fatigue (19.6%), and fibromyalgia (6.1%). B. henselae bacteremia was significantly associated with prior referral to a neurologist, most often for blurred vision, subcortical neurologic deficits, or numbness in the extremities, whereas B. koehlerae bacteremia was associated with examination by an infectious disease physician. This cross-sectional study cannot establish a causal link between Bartonella spp. infection and the high frequency of neurologic symptoms, myalgia, joint pain, or progressive arthropathy in this population; however, the contribution of Bartonella spp. infection, if any, to these symptoms should be systematically investigated.

Experimental infection of three laboratory mouse stocks with a shrew origin Bartonella elizabethae strain: an evaluation of bacterial host switching potential

BACKGROUND

Bartonella elizabethae has been reported as a causative agent of human illnesses and strains of this bacterium are commonly isolated from commensal small mammals in Asia.

METHODS

Since the zoonotic potential of a pathogen is often related to its host switching ability, we explored the capacity of a B. elizabethae strain to host switch by subcutaneously inoculating groups of Swiss Webster, BALB/c, and C57BL/6 mice with the bacteria at a range of doses.

RESULTS

A low number of mice in each of the three groups showed susceptibility to infection at high doses (10(5) and 10(6) bacteria), and developed bacteremias of 6-8 weeks duration.

CONCLUSION

The capacity of this B. elizabethae strain to switch hosts can have important public health consequences for humans in areas of Asia where many small mammal populations have high bartonellae infection prevalences and live as commensals with humans.

Association of Bartonella spp bacteremia with Chagas cardiomyopathy, endocarditis and arrhythmias in patients from South America

Infection with Bartonella spp may cause cardiac arrhythmias, myocarditis and endocarditis in humans. The aim of the present study was to evaluate a possible association between Bartonella spp bacteremia and endocarditis, arrhythmia and Chagas cardiomyopathy in patients from Brazil and Argentina. We screened for the presence of bacterial 16S rRNA in human blood by PCR using oligonucleotides to amplify a 185-bp bacterial DNA fragment. Blood samples were taken from four groups of subjects in Brazil and Argentina: i) control patients without clinical disease, ii) patients with negative blood-culture endocarditis, iii) patients with arrhythmias, and iv) patients with chronic Chagas cardiomyopathy. PCR products were analyzed on 1.5% agarose gel to visualize the 185-bp fragment and then sequenced to confirm the identity of DNA. Sixty of 148 patients (40.5%) with cardiac disease and 1 of 56 subjects (1.8%) from the control group presented positive PCR amplification for Bartonella spp, suggesting a positive association of the bacteria with these diseases. Separate analysis of the four groups showed that the risk of a Brazilian patient with endocarditis being infected with Bartonella was 22 times higher than in the controls. In arrhythmic patients, the prevalence of infection was 45 times higher when compared to the same controls and 40 times higher for patients with Chagas cardiomyopathy. To the best of our knowledge this is the first report of the association between Bartonella spp bacteremia and Chagas disease. The present data may be useful for epidemiological and prevention studies in Brazil and Argentina.

Intruders below the radar: molecular pathogenesis of Bartonella spp

Bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction with nucleated cells, and intraerythrocytic persistence. Infections with Bartonella are ubiquitous among mammals, and many species can infect humans either as their natural host or incidentally as zoonotic pathogens. Upon inoculation into a naive host, the bartonellae first colonize a primary niche that is widely accepted to involve the manipulation of nucleated host cells, e.g., in the microvasculature. Consistently, in vitro research showed that Bartonella harbors an ample arsenal of virulence factors to modulate the response of such cells, gain entrance, and establish an intracellular niche. Subsequently, the bacteria are seeded into the bloodstream where they invade erythrocytes and give rise to a typically asymptomatic intraerythrocytic bacteremia. While this course of infection is characteristic for natural hosts, zoonotic infections or the infection of immunocompromised patients may alter the path of Bartonella and result in considerable morbidity. In this review we compile current knowledge on the molecular processes underlying both the infection strategy and pathogenesis of Bartonella and discuss their connection to the clinical presentation of human patients, which ranges from minor complaints to life-threatening disease.

Bartonella species bacteremia in two patients with epithelioid hemangioendothelioma

Bartonella henselae and B. koehlerae bacteremia was documented in two epithelioid hemangioendothelioma patients and B. koehlerae bacteremia in an asymptomatic partner of one of the patients. Considering the biology and clinically variable natural history of epithelioid hemangioendothelioma, these results suggest that chronic Bartonella infection could have a role in the development of this vascular neoplasm. Bartonella spp. are known to induce vasoproliferative tumors in immunocompromised patients and may play a role in the development of epithelioid hemangioendothelioma in immunocompetent patients.

Hallucinations, sensory neuropathy, and peripheral visual deficits in a young woman infected with Bartonella koehlerae

A young woman experiencing depression, anxiety, mood swings, severe headaches, muscle spasms, interphalangeal joint stiffness, decreased peripheral vision, diminished tactile sensation, and hallucinations was persistently Bartonella koehlerae seroreactive and bacteremic. Following antibiotic treatment, B. koehlerae antibodies and DNA were not detected and all symptoms resolved.