Bartonella henselae infection in a dog with recalcitrant ineffective erythropoiesis.

Ineffective erythropoiesis was diagnosed in an 8-year-old male castrated Labrador Retriever. Despite treatment with immunosuppressive therapy for suspected immune-mediated erythrocyte maturation arrest, resolution of the nonregenerative anemia was not achieved. Following documentation of Bartonella henselae bacteremia by Bartonella alpha proteobacteria growth medium (BAPGM) enrichment blood culture, immunosuppressive therapy was discontinued, and the anemia resolved following prolonged antibiotic therapy. Bartonella immunofluorescent antibody testing was negative, whereas B henselae western blot was consistently positive. The contribution of B henselae bacteremia to ineffective erythropoiesis remains unknown; however, the potential role of B henselae in the pathophysiology of bone marrow dyscrasias warrants additional investigation.

Infections by pathogens with different transmission modes in feral cats from urban and rural areas of Korea.

In this study, we examine prevalences of three infectious pathogens with different transmission modes (Bartonella henselae, hemoplasma, and Toxoplasma gondii) in feral cats from urban and rural habitats. Infection status of the three pathogens in blood samples (n = 117) was determined through molecular or serological diagnostic methods. Overall prevalence of hemoplasma, Toxoplasma gondii, and Bartonella henselae was 47.9%, 50%, and 35.7%, respectively. Comparing the two habitats, only seroprevalence of Bartonella henselae was significantly higher in urban cats. Based on the results, we discuss how pathogens with distinct transmission modes may show different prevalence between urban and rural habitat types.

Bartonella henselae in canine cavitary effusions: prevalence, identification, and clinical associations.

BACKGROUND: Previous reports suggest an association between Bartonella infection and effusions in dogs and human beings. OBJECTIVES: The aims of this study were to determine the prevalence of Bartonella infection in canine effusions and to investigate historic and clinical parameters predictive of Bartonella in dogs with effusions. METHODS: Canine cavitary effusions submitted for analysis and, if available, paired EDTA blood, were screened for Bartonella infection using the Bartonella α-proteobacteria growth medium enrichment culture/PCR diagnostic platform (Bartonella enrichment PCR or ePCR) at Galaxy Diagnostics, Inc. RESULTS: Bartonella henselaeDNA was PCR-amplified and sequenced from 15% (12/80) of sampled dogs. Enrichment culture prior to PCR testing was required for Bartonella detection in 92% (11/12) of cases. Twenty percent (4/20), 13% (8/60), and 0% (0/4) of dogs with pleural, peritoneal, and pericardial effusions, respectively, tested positive. Bartonella henselae was detected most frequently in the fall, and young and middle-aged dogs appeared to be overrepresented. Golden Retrievers and Yorkshire/Silky Terriers each comprised 25% of infected dogs (odds ratio 3.4 for Golden Retrievers). There was a weak association with hemorrhagic effusions. Fifty percent of Bartonella-positive dogs had hemorrhage as a component of their effusion compared to 37% of PCR-negative dogs (odds ratio 1.7). CONCLUSIONS: Viable B henselae organisms occur in pleural and peritoneal effusions of dogs; the clinical relevance of which remains unclear and may represent opportunistic infection. Associations found in this study included seasonal variation, age, breed, and site of effusion.

[Molecular Epidemiology of Bartonella henselae in Stray and Sheltered Cats of Zaragoza, Spain]. / Epidemiología molecular de Bartonella henselae en gatos callejeros y de albergue en Zaragoza, España.

OBJECTIVE: Bartonella henselae is responsible for the Cat Scratch Disease in humans, being it underdiagnosed. This study aims to detect and quantify the load of B. henselae DNA in oral and whole blood samples from stray and shelthered cats from Zaragoza (Spain), and analyze associations with epidemiological and clinical factors. METHODS: 47 cats entered in the estudy. Real time PCR was used to detect B. henselae DNA in blood and oral samples. The SPSS software was applied to the statistical analysis of positivity of paired samples and its relationship with variables as age, sex, origin, month of sampling and fleas/ticks observation in fur and clinical factors (health status and observation of oral lesions). To know the relationship between the presence in blood and oral cavity a logistic regression analysis was performed. RESULTS: A 23.40% of blood samples and the 27.65% of the oral swabs carried the B. henselae DNA. A fair agreement between paired samples was observed (kappa value = 0.33, p less than 0.05). Bacterial DNA detected in oral and blood samples were not significantly associated to any of the epidemiological and clinical factors. Positive cats having oral lesions carried higher loads (3,12/1x1,000,000 cells) of bacterial DNA in their oral cavity than those without lesions (2,58/1x1,000,000 cells) being p=0.032. CONCLUSIONS: Carriage of the B. henselae DNA in the blood samples appears not to be related with carriage of the DNA of the bacteria in mouth and vice versa. Positive cats having oral lesions carry a higher load of B. henselae DNA and may suppose a higher risk of transmission to people handling them.

OBJETIVO: Bartonella henselae produce la enfermedad del arañazo del gato en las personas y se considera infradiagnosticada. El objetivo fue detectar y cuantificar la carga de ácido desoxiribonucleico (ADN) de B. henselae en muestras de sangre y orales de gatos callejeros y de albergue de Zaragoza, España y analizar su relación con factores epidemiológicos y clínicos. METODOS: Se estudiaron 47 gatos. El ADN de B. henselae,se detectó mediante reacción en cadena de la polimerasa en tiempo real (qPCR) en sangre y muestras orales. Se usó el paquete estadístico SPSS para analizar la positividad de las muestras pareadas y su relación con factores epidemiológicos (edad, sexo, origen, mes de muestreo, presencia de pulgas/garrapatas) y clínicos (estado de salud y presencia de lesiones orales). Se realizó un análisis de regresión logística para conocer la asociación entre la presencia en sangre y cavidad oral y el resto de las variables. RESULTADOS: El 23,40% de las muestras de sangre y el 27,65% de las orales portaba el ADN de B. henselae. Se observó débil correlación de la positividad de las muestras pareadas (kappa=0,33; p inferior a 0,05). No se detectó asociación estadística entre la presencia de ADN de B. henselae en las muestras y los factores epidemiológicos y clínicos. Los gatos con lesiones orales portaban una carga más elevada de ADN (3,12/1x1.000.000 células) en la boca que los que no tenían lesiones (2,58/1por 1.000.000 células),(p=0,032). CONCLUSIONES: La detección de ADN de B. henselae en sangre no parece estar relacionada con su presencia en cavidad oral y viceversa. Los gatos positivos con lesiones orales pueden significar mayor riesgo de infección por B. henselae para las personas que los manejan.

Concurrent Bartonella henselae infection in a dog with panniculitis and owner with ulcerated nodular skin lesions.

BACKGROUND: Bartonella henselae, a Gram-negative, zoonotic Alphaproteobacteria that infects erythrocytes, endothelial cells and dendritic cells, has previously been implicated as a cause of panniculitis in dogs and a human. ANIMAL AND OWNER: An 8-year-old, spayed female Labrador retriever and its 78-year-old male owner living in the same household. METHODS AND RESULTS: When preliminary and advanced testing failed to identify the cause of near-simultaneous-onset dermatological lesions, Bartonella serology, Bartonella Alphaproteobacteria growth medium (BAPGM) enrichment blood culture/PCR and immunohistochemistry were used to test specimens from the dog and owner. Bartonella henselae, genotype San Antonio 2 DNA was amplified and sequenced from the man's BAPGM enrichment blood culture and the dog's panniculitis lesion. The bacterium was visualized by immunohistochemistry in the dog's panniculitis lesion; however, neither the dog nor the owner was B. henselae seroreactive. Antibiotic therapy elicited dermatological improvement in both dog and owner. CONCLUSIONS AND CLINICAL IMPORTANCE: Bartonella henselae is an emerging zoonotic pathogen that induces granulomatous inflammatory lesions in various tissues of animals, including humans. We conclude that this bacterium had a contributory or causative role in the development of the dermatological lesions in the dog and owner.

Bilateral mandibular pyogranulomatous lymphadenitis and pulmonary nodules in a dog with Bartonella henselae bacteremia.

This report describes a 2-year-old collie dog with pulmonary nodules, visualized by computed tomographic (CT) scan, with evidence of Bartonella henselae bacteremia and pyogranulomatous lymphadenitis. Clinical signs resolved with antimicrobial therapy.

Lymphadénite pyogranulomateuse mandibulaire latérale et nodules pulmonaires chez un chien atteint de bactériémie àBartonella henselae. Ce rapport décrit un chien Collie âgé de 2 ans atteint de nodules pulmonaires, visualisés par tomodensitométrie, avec des signes de bactériémie à Bartonella henselae et de lymphadénite pyogranulomateuse. Les signes cliniques se sont résorbés avec un traitement antimicrobien.(Traduit par Isabelle Vallières).

Comparative microbiological features of Bartonella henselae infection in a dog with fever of unknown origin and granulomatous lymphadenitis.

We report the first documented case of Bartonella henselae infection in a dog from France and the first isolation of B. henselae from a dog with fever of unknown origin. This observation contributes to the "One Health" concept focusing on zoonotic pathogens emerging from companion animals. A 1-year-old female German shepherd dog was referred for evaluation of fever of unknown origin of 1 month duration. Diagnostic investigations confirmed diffuse pyogranulomatous lymphadenitis. The dog became afebrile, and lymph node size normalized in response to a 6-week course of doxycycline. Retrospectively, Bartonella DNA was amplified from an EDTA-anticoagulated blood sample obtained before antimicrobial therapy, with the gtlA fragment sharing 99 % identity with the 350-bp gtlA fragment of the B. henselae Houston-1 strain. The same strain was isolated in the blood of three healthy cats from the household. Two months after discontinuation of doxycycline, the dog experienced a febrile relapse. Bartonella DNA was again amplified from blood prior to and immediately after administration of a 6-week course azithromycin therapy. However, without administration of additional medications, PCR was negative 9 months after azithromycin therapy and the dog remains clinically healthy 12 months following the second course of antibiotics. The medical management of this case raises several clinically relevant comparative infectious disease issues, including the extent to which Bartonella spp. contribute to fever of unknown origin and pyogranulomatous inflammatory diseases in dogs and humans, and the potential of doxycycline and azithromycin treatment failures. The possibility that dogs could constitute an underestimated reservoir for B. henselae transmission to people is also discussed.

A flea and tick collar containing 10% imidacloprid and 4.5% flumethrin prevents flea transmission of Bartonella henselae in cats.

BACKGROUND: Bartonella henselae is transmitted amongst cats by Ctenocephalides felis and is associated with multiple clinical syndromes in cats and people. In a previous study, monthly spot-on administration of 10% imidacloprid/1% moxidectin was shown to block transmission of B. henselae amongst cats experimentally exposed to infected C. felis. The purpose of this study was to determine whether application of a flea and tick collar containing 10% imidacloprid and 4.5% flumethrin would lessen C. felis transmission of B. henselae amongst cats for 8 months. METHODS: Specific pathogen free cats (n = 19) were housed in three adjoining enclosures that were separated by mesh to allow C. felis to pass among groups but prevent cats in different enclosures from contacting one another. One group of 4 cats was inoculated intravenously with B. henselae and after infection was confirmed in all cats based on positive PCR assay results, the cats were housed in the middle enclosure. The B. henselae infected cat group was flanked by a group of 8 cats that had the collar placed and maintained for the duration of the study and a group of 7 cats that were not treated. Ctenocephalides felis (50 males and 50 females) raised in an insectary were placed on each of the 4 cats in the B. henselae infected group monthly for 7 applications and then every 2 weeks for 4 applications starting the day the collar was applied. Blood was collected from all cats weekly for Bartonella spp. PCR, serology and culture. RESULTS: While side-effects associated with the collars were not noted, persistent fever necessitating enrofloxacin therapy occurred in two of the untreated cats. While B. henselae infection was ultimately confirmed in 4 of 7 of the untreated cats, none of the cats with collars became infected (P = 0.026). CONCLUSIONS: In this study design, use of a collar containing 10% imidacloprid and 4.5% flumethrin was well tolerated and prevented C. felis transmission of B. henselae amongst cats for 8 months.

Susceptibility of Polish Bartonella henselae strains.

Due to the fastidious nature of B. henselae and the limited number of available isolates worldwide, there are few data on its in vitro susceptibility to antibiotics. We determined the minimal inhibitory concentrations (MIC) of ten antimicrobial agents against 11 feline isolates of B. henselae by Etest method. The lowest MICs were obtained for rifampicin < or = 0.002 mg/L. MICs of all isolates were < 0.016 mg/L for ampicilin, amoxicillin/clavulanic acid, tetracycline and ranged from 0.016 to 0.032 mg/L for azithromycin. The MICs for two tested fluoroquinolones: ciprofloxacin and levofloxacin ranged from 0.016 to 0.125 mg/L. The highest MICs were obtained for gentamicin ranging from 0.025 to 2.0 mg/L. Sulphonamide resistance genes sul 1, sul 2, sul 3 were not found in any of the tested isolates. Etest methodology seems to be a reliable method for determination of B. henselae susceptibility, however standardization is strongly desired.

Bartonella vinsonii subsp. berkhoffii and Bartonella henselae as potential causes of proliferative vascular diseases in animals.

Bartonella species are highly fastidious, vector borne, zoonotic bacteria that cause persistent intraerythrocytic bacteremia and endotheliotropic infection in reservoir and incidental hosts. Based upon prior in vitro research, three Bartonella sp., B. bacilliformis, B. henselae, and B. quintana can induce proliferation of endothelial cells, and each species has been associated with in vivo formation of vasoproliferative tumors in human patients. In this study, we report the molecular detection of B. vinsonii subsp. berkhoffii, B. henselae, B. koehlerae, or DNA of two of these Bartonella species simultaneously in vasoproliferative hemangiopericytomas from a dog, a horse, and a red wolf and in systemic reactive angioendotheliomatosis lesions from cats and a steer. In addition, we provide documentation that B. vinsonii subsp. berkhoffii infections induce activation of hypoxia inducible factor-1 and production of vascular endothelial growth factor, thereby providing mechanistic evidence as to how these bacteria could contribute to the development of vasoproliferative lesions. Based upon these results, we suggest that a fourth species, B. vinsonii subsp. berkhoffii, should be added to the list of bartonellae that can induce vasoproliferative lesions and that infection with one or more Bartonella sp. may contribute to the pathogenesis of systemic reactive angioendotheliomatosis and hemangiopericytomas in animals.

Detection of Bartonella henselae IgM in serum of experimentally infected and naturally exposed cats.

BACKGROUND: Results of Bartonella henselae blood culture, polymerase chain reaction (PCR) assay on blood, or IgG antibody assays do not always correlate with the presence or absence of clinical disease in cats, and B. henselae IgG antibodies in serum do not always correlate with bacteremia. However, little is known concerning Bartonella spp. IgM antibodies in naturally exposed cats. HYPOTHESIS: Bartonella spp. IgM antibodies in serum are associated with fever, stomatitis, and bacteremia based on PCR assay results in experimentally infected or client-owned cats. ANIMALS: Stored sera from cats experimentally infected with B. henselae by exposure to Ctenocephalides felis, client-owned cats with and without fever, and client-owned cats with and without stomatitis were studied. METHODS: A Bartonella spp. IgM ELISA was titrated with samples from experimentally infected cats and then test sera from client-owned cats were assayed. Associations among IgM ELISA results, clinical findings, and bacteremia as defined by Bartonella spp. PCR assay were assessed. RESULTS: All experimentally infected cats developed Bartonella spp. IgM antibodies. Bartonella spp. IgM antibody assay results were not always in agreement with PCR assay results in client-owned cats (60%). Bartonella spp. DNA in blood, IgM antibodies, and IgG antibodies were not associated with the presence of fever or stomatitis. CONCLUSIONS AND CLINICAL IMPORTANCE: Because Bartonella spp. IgM antibodies as measured by this assay were not associated with fever or stomatitis and were not always in agreement with PCR assay results, there appears to be little need for assessing individual client-owned cats for this antibody class alone.

Gammopathy in a Spanish dog infected with Bartonella henselae.

Generalised pyogranulomatous disease and hyperviscosity syndrome associated with a presumed monoclonal gammopathy was diagnosed in a three-year-old intact female Pomeranian. The Bartonella henselae antibody titer was 1:64 and Bartonella species DNA was amplified from the splenic tissue. Monoclonal gammopathies in dogs are typically associated with plasma cell and lymphoid dyscrasias and other inflammatory or infectious diseases such as ehrlichiosis and leishmaniosis. Based on this case report, infection with Bartonella species should also be added to the differential diagnoses for gammopathy in dogs. To the authors' knowledge, this is the first report of molecular evidence of Bartonella species infection in a sick dog in Spain.

Evaluation of topical application of 10% imidacloprid-1% moxidectin to prevent Bartonella henselae transmission from cat fleas.

OBJECTIVE: To determine whether monthly topical administration of a combination of 10% imidacloprid and 1% moxidectin would lessen flea (Ctenocephalides felis) transmission of Bartonella henselae among cats. DESIGN: Controlled trial. ANIMALS: 18 specific pathogen-free cats housed in 3 groups of 6. PROCEDURES: 3 enclosures were separated by mesh to allow fleas to pass among groups yet prevent cats from contacting one another. One group was inoculated IV with B henselae, and after infection was confirmed, the cats were housed in the middle enclosure. This infected group was flanked by a group that was treated topically with 10% imidacloprid-1% moxidectin monthly for 3 months and by an untreated group. On days 0, 15, 28, and 42, 100 fleas/cat were placed on each of the 6 cats in the B henselae-infected group. Blood samples were collected from all cats weekly for detection of Bartonella spp via PCR assay, bacterial culture, and serologic assay. RESULTS: B henselae infection was confirmed in the cats infected IV and in all untreated cats after flea exposure; none of the cats treated with the imidacloprid-moxidectin combination became infected. CONCLUSIONS AND CLINICAL RELEVANCE: In this setting, monthly topical administration of 10% imidacloprid-1% moxidectin reduced flea infestation, compared with infestation in untreated cats, and thus prevented flea transmission of B henselae to treated cats. Regular monthly use of this flea control product in cats may lessen the likelihood of humans acquiring B henselae infection.

Bacillary angiomatosis in an immunosuppressed dog.

A dog being treated with immunosuppressive doses of prednisone and azathioprine for pancytopenia of unknown origin, developed, over a 2-week period, multiple erythematous nodular lesions in the skin including footpads. Skin samples revealed lesions identical to those of human bacillary angiomatosis (BA). The nodules were composed of multifocal proliferations of capillaries, each lined by protuberant endothelial cells. The capillary clusters were separated by an oedematous connective tissue, lightly infiltrated with degenerate inflammatory cells, including neutrophils and macrophages. Tissue sections stained with Warthin-Starry silver stain revealed large numbers of positively stained bacilli in the stromal tissue, most heavily concentrated around the proliferating capillaries. Lesions of vascular degeneration and inflammation were evident. Bartonella vinsonii subsp. berkhoffii genotype 1 was independently amplified and sequenced from the blood and the skin tissue. The pathognomonic nature of the histological lesions, demonstration of compatible silver-stained bacilli in the tissue, and identification of B. vinsonii subsp. berkhoffii in the blood and tissue indicates that this is most likely the aetiologic agent responsible for the lesions. Antibiotic therapy was successful in resolving the nodules. It would appear that B. vinsonii subsp berkhoffii, like Bartonella henselae and Bartonella quintana, has the rare ability to induce angioproliferative lesions, most likely in association with immunosuppression. The demonstration of lesions identical to those of human BA in this dog is further evidence that the full range of clinical manifestations of human Bartonella infection occurs also in canines.

Peliosis hepatis in cats is not associated with Bartonella henselae infections.

Peliosis hepatis is a vasculoproliferative disorder of the liver with infectious and noninfectious causes. In humans and dogs, Bartonella henselae has been linked to peliosis hepatis. Although domestic cats are the natural reservoir of B. henselae and although peliosis hepatis is common in this species, an association between this condition and infection with B. henselae has never been investigated in cats. In this study, 26 cases of peliosis hepatis in cats were tested for B. henselae infection by nested polymerase chain reaction and immunohistochemistry. The authors failed to detect B. henselae nucleic acid or antigen in any of the affected liver specimens. These findings suggest that, unlike in humans and dogs, peliosis hepatis in cats may not be significantly associated with a B. henselae infection.

Comparative activity of pradofloxacin, enrofloxacin, and azithromycin against Bartonella henselae isolates collected from cats and a human.

Using Bartonella henselae isolates from cats and a human, the activity of pradofloxacin was compared with those of enrofloxacin and azithromycin. By Etest and disc diffusion assay, pradofloxacin showed greater antimicrobial activity than did other antibiotics. We conclude that pradofloxacin may prove useful for the treatment of B. henselae infections.

PCR detection of Bartonella bovis and Bartonella henselae in the blood of beef cattle.

Although an organism primarily associated with non-clinical bacteremia in domestic cattle and wild ruminants, Bartonella bovis was recently defined as a cause of bovine endocarditis. The purpose of this study was to develop a B. bovis species-specific PCR assay that could be used to confirm the molecular prevalence of Bartonella spp. infection. Blood samples from 142 cattle were tested by conventional PCR targeting the Bartonella 16S-23S intergenic spacer (ITS) region. Overall, Bartonella DNA was detected in 82.4% (117/142) of the cattle using either Bartonella genus primers or B. bovis species-specific primers. Based upon size, 115 of the 117 Bartonella genus ITS PCR amplicons were consistent with B. bovis infection, which was confirmed by PCR using B. bovis species-specific primers and by sequencing three randomly selected, appropriately sized Bartonella genus PCR amplicons. By DNA sequencing, Bartonella henselae was confirmed as the two remaining amplicons, showing sequence similarity to B. henselae URBHLIE 9 (AF312496) and B. henselae Houston 1 (NC_005956), respectively. Following pre-enrichment blood culture of 12 samples in Bartonella alpha Proteobacteria growth medium (BAPGM) B. henselae infection was found in another three cows. Four of the five cows infected with B. henselae were co-infected with B. bovis. To our knowledge this study describes the first detection of B. henselae in any large ruminant species in the world and supports the need for further investigation of prevalence and pathogenic potential of B. henselae and B. bovis in cattle.

Bartonella henselae in captive and hunter-harvested beluga (Delphinapterus leucas).

Previously, we reported the isolation of Bartonella henselae from the blood of harbor porpoises (Phocoena phocoena) and loggerhead sea turtles (Caretta caretta) from the North Carolina coast. Hematologic, pathologic, and microbiologic findings surrounding the death of a juvenile captive beluga in Vancouver initiated an outbreak investigation designed to define the molecular prevalence of Bartonella infection in belugas. Using polymerase chain reaction analyses targeting the intergenic spacer region (ITS), two B. henselae ITS strains were identified in 78% of captive and free-ranging hunter-harvested belugas. These findings may have public health implications and may influence aquarium management procedures for captive marine mammals.