Dogs are more permissive than cats or guinea pigs to experimental infection with a human isolate of Bartonella rochalimae

Bartonella rochalimae was first isolated from the blood of a human who traveled to Peru and was exposed to multiple insect bites. Foxes and dogs are likely natural reservoirs for this bacterium. We report the results of experimental inoculation of two dogs, five cats and six guinea pigs with the only human isolate of this new Bartonella species. Both dogs became bacteremic for 5–7 weeks, with a peak of 10³–10⁴ colony forming units (CFU)/mL blood. Three cats had low bacteremia levels (< 200 CFU/mL) of 6–8 weeks’ duration. One cat that remained seronegative had two bacterial colonies isolated at a single culture time point. A fifth cat never became bacteremic, but seroconverted. None of the guinea pigs became bacteremic, but five seroconverted. These results suggest that dogs could be a reservoir of this strain of B. rochalimae, in contrast to cats and guinea pigs.     

Co-isolation of Bartonella henselae and Bartonella vinsonii subsp. berkhoffii from blood, joint and subcutaneous seroma fluids from two naturally infected dogs

This report describes the clinical presentation, isolation and treatment of two dogs naturally infected with Bartonella henselae and Bartonella vinsonii subsp. berkhoffii. Chronic and progressive polyarthritis was the primary complaint for dog #1, from which B. henselae and B. vinsonii subsp. berkhoffii were cultured on three independent occasions from blood and joint fluid samples, despite administration of nearly 4 months of non-consecutive antibiotic therapy. A clinically atypical and progressively severe trauma-associated seroma was the primary complaint for dog #2, from which B. henselae and B. vinsonii subsp. berkhoffii were isolated from serum, blood and seroma fluid. Dogs can be co-infected with two Bartonella spp. and infection with these organisms should not be ruled out if specific antibodies are not detected. Specialized culture techniques should be used for isolation and to assess antibiotic efficacy.     

Flea species infesting dogs in Florida and Bartonella spp. prevalence rates

Several Bartonella spp. associated with fleas can induce a variety of clinical syndromes in both dogs and humans. However, few studies have investigated the prevalence of Bartonella in the blood of dogs and their fleas. The objectives of this study were to determine the genera of fleas infesting shelter dogs in Florida, the prevalence of Bartonella spp. within the fleas, and the prevalence of Bartonella spp. within the blood of healthy dogs from which the fleas were collected. Fleas, serum, and EDTA-anti-coagulated whole blood were collected from 80 healthy dogs, and total DNA was extracted for PCR amplification of Bartonella spp. The genera of fleas infesting 43 of the dogs were determined phenotypically. PCR amplicons from blood and flea pools were sequenced to confirm the Bartonella species. Amplicons for which sequencing revealed homology to Bartonella vinsonii subsp. berkhoffii (Bvb) underwent specific genotyping by targeting the 16S–23S intergenic spacer region.A total of 220 fleas were collected from 80 dogs and pooled by genus (43 dogs) and flea species. Bartonella spp. DNA was amplified from 14 of 80 dog blood samples (17.5%) and from 9 of 80 pooled fleas (11.3%). B. vinsonii subsp. berkhoffii DNA was amplified from nine dogs and five of the flea pools. Bartonella rochalimae (Br) DNA was amplified from six dogs and two flea pools. One of 14 dogs was co-infected with Bvb and Br. The dog was infested with Pulex spp. fleas containing Br DNA and a single Ctenocephalides felis flea. Of the Bvb bacteremic dogs, five and four were infected with genotypes II and I, respectively. Of the Bvb PCR positive flea pools, three were Bvb genotype II and two were Bvb genotype I.Amplification of Bvb DNA from Pulex spp. collected from domestic dogs, suggests that Pulex fleas may be a vector for dogs and a source for zoonotic transfer of this pathogen from dogs to people. The findings of this study provide evidence to support the hypothesis that flea-infested dogs may be a reservoir host for Bvb and Br and that ectoparasite control is an important component of shelter intake protocols.     

Molecular and serological diagnosis of Bartonella infection in 61 dogs from the United States

Background: Molecular diagnosis of canine bartonellosis can be extremely challenging and often requires the use of an enrichment culture approach followed by PCR amplification of bacterial DNA. Hypotheses: (1) The use of enrichment culture with PCR will increase molecular detection of bacteremia and will expand the diversity of Bartonella species detected. (2) Serological testing for Bartonella henselae and Bartonella vinsonii subsp. berkhoffii does not correlate with documentation of bacteremia. Animals: Between 2003 and 2009, 924 samples from 663 dogs were submitted to the North Carolina State University, College of Veterinary Medicine, Vector Borne Diseases Diagnostic Laboratory for diagnostic testing with the Bartonellaα‐Proteobacteria growth medium (BAPGM) platform. Test results and medical records of those dogs were retrospectively reviewed. Methods: PCR amplification of Bartonella sp. DNA after extraction from patient samples was compared with PCR after BAPGM enrichment culture. Indirect immunofluorescent antibody assays, used to detect B. henselae and B. vinsonii subsp. berkhoffii antibodies, were compared with PCR. Results: Sixty‐one of 663 dogs were culture positive or had Bartonella DNA detected by PCR, including B. henselae (30/61), B. vinsonii subsp. berkhoffii (17/61), Bartonella koehlerae (7/61), Bartonella volans‐like (2/61), and Bartonella bovis (2/61). Coinfection with more than 1 Bartonella sp. was documented in 9/61 dogs. BAPGM culture was required for PCR detection in 32/61 cases. Only 7/19 and 4/10 infected dogs tested by IFA were B. henselae and B. vinsonii subsp. berkhoffii seroreactive, respectively. Conclusions and Clinical Importance: Dogs were most often infected with B. henselae or B. vinsonii subsp. berkhoffii based on PCR and enrichment culture, coinfection was documented, and various Bartonella species were identified. Most infected dogs did not have detectable Bartonella antibodies.     

Prevalence of Bartonella henselae and Bartonella clarridgeiae in cats and dogs in Korea

Blood, saliva, and nail samples were collected from 54 dogs and 151 cats and analyzed for the presence of Bartonella henselae with a novel nested polymerase chain reaction (PCR) method. Bartonella (B.) henselae was detected in feral cat blood (41.8%), saliva (44.1%), and nail (42.7%) samples. B. henselae was also detected in pet cat blood (33.3%), saliva (43.5%), and nail (29.5%) samples and in pet dog blood (16.6%), saliva (18.5%), and nail (29.6%) samples. Nine samples were infected with B. clarridgeiae and 2 were co-infected with B. henselae and B. clarridgeiae of blood samples of dogs. This report is the first to investigate the prevalence of B. henselae and B. clarridgeiae in dogs and cats in Korea, and suggests that dogs and cats may serve as potential Bartonella reservoirs.     

Bartonella spp. in cats from Buenos Aires,Argentina

In Argentina, data on the presence of members of the genus Bartonella is scarce. To increase knowledge about these zoonotic pathogens in this country, the presence and variability of Bartonella spp. was investigated in cats and dogs from Buenos Aires. Bartonella spp. was detected in 17.8% of cats, while all dogs tested negative by PCR and Reverse Line Blot. B. henselae was the most frequent species, being detected in 11.9% (14/101), while B. clarridgeiae was found in only 5.9% (6/101) of the cats. Afterwards, B. henselae isolates and positive blood samples were characterized by Multiple Locus Sequence Typing (MLST) and Multiple Locus Variable Number Tandem Repeats Analysis (MLVA). As result, four different MLST sequence types (ST) and eight MLVA profiles were identified. ST 1 was the most frequent variant found in cats, followed by ST 8. Interestingly, some of the MLVA profiles that were detected in this study have been previously associated with human disease, and represents a potential risk of infection. Veterinarians and physicians should consider the presence of these emerging pathogens in their diagnostic routine.     

Molecular evidence of vector-borne pathogens in dogs and cats and their ectoparasites in Algiers,Algeria

In Algeria, only limited information is currently available on the prevalence of emergent canine and feline vector-borne diseases. The aim of the present work was to detect by qPCR vector-associated bacteria in stray dogs and cats and their ectoparasites from Algiers.18/117 (15.38%) dogs and 2/107 (1.87%) cats were positive for at least one vector-borne agent. Coxiella burnetii and Bartonella henselae were identified in 1/117 (0.85%) dog individually. Ehrlichia canis DNA was detected in 17/117 (14.52%) dogs. 1/107 (0.93%) cat was positive to C. burnetii and another 1/107 (0.93%) to B. henselae.DNA of Rickettsia massiliae, Rickettsia conorii and E. canis was detected in Rhipicephalus sanguineus. Cat fleas were infected with Rickettsia felis, B. henselae and Bartonella clarridgeiae. B. vinsonii subsp. berkhoffii was identified in Xenopsylla cheopis collected from dogs.The findings of this study indicate that dogs and cats from Algeria are exposed to multiple tick and flea-borne pathogens.     

Polymerase chain reaction detection of Bartonella spp. in dogs from Spain with blood culture-negative infectious endocarditis

Objectives

The presence of Bartonella spp. was detected by polymerase chain reaction (PCR) in dogs from Spain with blood culture-negative endocarditis. The aim of this study is to add information about canine infectious endocarditis in Europe.

Bartonella Seroepidemiology in Dogs from North America, 2008–2014

Background

Improved understanding of Bartonella species seroepidemiology in dogs may aid clinical decision making and enhance current understanding of naturally occurring arthropod vector transmission of this pathogen.

Objectives

To identify demographic groups in which Bartonella exposure may be more likely, describe spatiotemporal variations in Bartonella seroreactivity, and examine co‐exposures to other canine vector‐borne diseases (CVBD).

Animals

A total of 15,451 serology specimens from dogs in North America were submitted to the North Carolina State University, College of Veterinary Medicine Vector Borne Disease Diagnostic Laboratory between January 1, 2008, and December 31, 2014.

Methods

Bartonella henselae, Bartonella koehlerae, and Bartonella vinsonii subspecies berkhoffii indirect fluorescent antibody (IFA) serology results, as well as results from a commercial assay kit screening for Dirofilaria immitis antigen and Ehrlichia species, Anaplasma phagocytophilum, and Borrelia burgdorferi antibodies, and Ehrlichia canis, Babesia canis, Babesia gibsoni, and Rickettsia species IFA results were reviewed retrospectively.

Results

Overall, 3.26% of dogs were Bartonella spp. seroreactive; B. henselae (2.13%) and B. koehlerae (2.39%) were detected more frequently than B. vinsonii subsp. berkhoffii (1.42%, P < 0.0001). Intact males had higher seroreactivity (5.04%) than neutered males (2.87%, P < 0.0001) or intact or spayed females (3.22%, P = 0.0003). Mixed breed dogs had higher seroreactivity (4.45%) than purebred dogs (3.02%, P = 0.0002). There was no trend in seasonal seroreactivity; geographic patterns supported broad distribution of exposure, and co‐exposure with other CVBD was common.

Conclusions and Clinical Importance

Bartonella spp. exposure was documented throughout North America and at any time of year. Male intact dogs, mixed breed dogs, and dogs exposed to other CVBD have higher seroreactivity to multiple Bartonella species.     

Analysis of Seroreactivity against Cell Culture–Derived Bartonella spp. Antigens in Dogs

Background

Little is known about the specificity of Bartonella spp. immunofluorescent antibody (IFA) assays in dogs. Bacteremia in sick dogs most often has been associated with Bartonella henselae (Bh), Bartonella vinsonii subspecies berkhoffii (Bvb), and Bartonella koehlerae (Bk). Clarification of the diagnostic utility of IFA serology when testing against these organisms is needed.

Objective

To evaluate the specificity of Bartonella IFA assays utilizing 6 cell culture–grown antigen preparations.

Animals

Archived sera from SPF dogs (n = 29) and from dogs experimentally infected with Bvb (n = 10) and Bh (n = 3).

Methods

Antibodies (Abs) to Bvb genotypes I, II, and III, Bh serotype I, strains H‐1 and SA2, and to Bk were determined by IFA testing.

Results

Serum from naïve SPF dogs shown to be negative for Bartonella bacteremia did not react with any of the 6 Bartonella antigens by IFA testing. Dogs experimentally infected with Bvb genotype I developed Abs against homologous antigens, with no cross‐reactivity to heterologous Bvb genotypes, Bh H‐1, SA2 strains, or to Bk. Dogs experimentally infected with Bh serotype I developed Abs against Bh H‐1, but not to Bh SA2 strain with no cross‐reactive Abs to Bvb genotypes I–III or to Bk.

Conclusions and Clinical Importance

Bartonella spp. Ab responses during acute experimental infections are species and type specific.     

Bartonella spp. DNA in cardiac tissues from dogs in Colorado and Wyoming

Background: Several Bartonella species (spp.) have been identified in dogs diagnosed with infectious endocarditis (IE) or myocarditis. Objective: To interrogate cardiac tissues of dogs with suspected IE for the presence of Bartonella spp. DNA of dogs in the Rocky Mountain states. Animals: Nine dogs with a clinical diagnosis of endocarditis from January 1990 to June 2008 were included. Methods: In this retrospective study, medical records at the Veterinary Teaching Hospital were searched. Animals were excluded if there was no diagnosis of IE in the original necropsy report. Paraffin embedded tissue blocks and medical records were available from 9 dogs. Total DNA was extracted from the cardiac tissues and assessed for Bartonella spp. DNA by 3 polymerase chain reaction (PCR) methods. For positive samples, the Bartonella spp. were determined by genetic sequencing or fluorogenic real‐time PCR. Results: Bartonella henselae DNA was amplified from the tissues of 7 dogs; Bartonella vinsonii subsp berkhoffii DNA was amplified concurrently from 3 dogs. Six dogs were from Colorado and 1 was from Wyoming. Flea or tick infestations were reported in 2 dogs. Conclusions and Clinical Importance: Bartonella spp. should be on the differential list for dogs in the Rocky Mountain states. The results emphasize the need for routine use of external parasite control products even in regions perceived to have low risk for flea and tick infestations.     

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.     

Ecological fitness and strategies of adaptation of Bartonella species to their hosts and vectors

Bartonella spp. are facultative intracellular bacteria that cause characteristic host-restricted hemotropic infections in mammals and are typically transmitted by blood-sucking arthropods. In the mammalian reservoir, these bacteria initially infect a yet unrecognized primary niche, which seeds organisms into the blood stream leading to the establishment of a long-lasting intra-erythrocytic bacteremia as the hall-mark of infection. Bacterial type IV secretion systems, which are supra-molecular transporters ancestrally related to bacterial conjugation systems, represent crucial pathogenicity factors that have contributed to a radial expansion of the Bartonella lineage in nature by facilitating adaptation to unique mammalian hosts. On the molecular level, the type IV secretion system VirB/VirD4 is known to translocate a cocktail of different effector proteins into host cells, which subvert multiple cellular functions to the benefit of the infecting pathogen. Furthermore, bacterial adhesins mediate a critical, early step in the pathogenesis of the bartonellae by binding to extracellular matrix components of host cells, which leads to firm bacterial adhesion to the cell surface as a prerequisite for the efficient translocation of type IV secretion effector proteins. The best-studied adhesins in bartonellae are the orthologous trimeric autotransporter adhesins, BadA in Bartonella henselae and the Vomp family in Bartonella quintana. Genetic diversity and strain variability also appear to enhance the ability of bartonellae to invade not only specific reservoir hosts, but also accidental hosts, as shown for B. henselae. Bartonellae have been identified in many different blood-sucking arthropods, in which they are typically found to cause extracellular infections of the mid-gut epithelium. Adaptation to specific vectors and reservoirs seems to be a common strategy of bartonellae for transmission and host diversity. However, knowledge regarding arthropod specificity/restriction, the mode of transmission, and the bacterial factors involved in arthropod infection and transmission is still limited.     

Prevalence of zoonotic Bartonella species among rodents and shrews in Thailand

We investigated the prevalence of Bartonella species in 10 rodent and one shrew species in Thailand. From February 2008 to May 2010, a total of 375 small animals were captured in 9 provinces in Thailand. Bartonella strains were isolated from 57 rodents (54 from Rattus species and 3 from Bandicota indica) and one shrew (Suncus murinus) in 7 of the 9 provinces, and identified to the species level. Sequence analysis of the citrate synthase and RNA polymerase β subunit genes identified the 58 isolates from each Bartonella-positive animal as B. tribocorum in 27 (46.6%) animals, B. rattimassiliensis in 17 (29.3%) animals, B. elizabethae in 10 (17.2%) animals and B. queenslandensis in 4 (6.9%) animals. R. norvegicus, R. rattus, and Suncus murinus carried B. elizabethae, which causes endocarditis in humans. The prevalence of Bartonella bacteremic animals by province was 42.9% of the animals collected in Phang Nga, 26.8% in Chiang Rai, 20.4% in Sa Kaeo, 16.7% in Nakhon Si Thammarat, 12.0% in Surat Thani, 9.1% in Mae Hong Son and Loei Provinces.     

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.     

Prevalence of Anaplasma,Bartonella and Borrelia Species in Haemaphysalis longicornis collected from goats in North Korea

North Korea is located on the northern part of the Korean Peninsula in East Asia. While tick-borne pathogens of medical and veterinary importance have been reported from China and South Korea, they have not been reported from North Korea. To screen for zoonotic tick-borne pathogens in North Korea, ticks were collected from domestic goats. A total of 292 (27 nymph, 26 male, 239 female) Haemaphysalis (H.) longicornis were collected and assayed individually for selected tick-borne pathogens. A total of 77 (26.4%) were positive for Anaplasma bovis, followed by Bartonella (B.) grahamii (15, 5.1%), Anaplasma phagocytophilum (12, 4.1%), Bartonella henselae (10, 3.4%), and Borrelia spp. (3, 1.0%) based on 16S ribosomal RNA and ITS species-specific nested polymerase chain reaction. Using the groEL-based nested PCR, a total of 6 and 1 H. longicornis were positive for B. grahamii and B. henselae, respectively. All products were sequenced and demonstrated 100% identity and homology with previously reported sequences from other countries in GenBank. This is the first report of the detection of tick-borne pathogens in the North Korea and suggests that farm animals may act as reservoirs for zoonotic tick-borne pathogens.     

The prevalence of Bartonella, hemoplasma, and Rickettsia felis infections in domestic cats and in cat fleas in Ontario

The prevalence of persistent bacteremic Bartonella spp. and hemoplasma infections was determined in healthy pet cats in Ontario. Blood samples from healthy cats sent to a diagnostic laboratory for routine health assessment over the course of 1 y were tested for Bartonella spp. using both polymerase chain reaction (PCR) and blood culture, and for the presence of hemoplasma by PCR. The overall prevalence of Bartonella spp. by PCR and by culture combined was 4.3% (28/646) [3.7% (24/646) Bartonella henselae, 0.6% (4/646) Bartonella clarridgeiae]. The novel B. henselae PCR developed for this study demonstrated nearly twice the sensitivity of bacterial isolation. The overall prevalence of hemoplasma was 4% (30/742) [3.3% (25/742) Candidatus Mycoplasma haemominutum, 0.7% (5/742) Mycoplasma haemofelis]. There was no significant difference between the prevalence of infection by season or by age (≤ 2 y, > 2 y). Candidatus Mycoplasma turicensis was identified, for the first time in Canada, in 1 cat. The prevalence of Bartonella (58%) and hemoplasma (47% M. haemofelis, 13% M. haemominutum) in blood from a small sampling (n = 45) of stray cats was considerably higher than that found in healthy pet cats.     

Infection and re-infection of domestic cats with various Bartonella species or types: B. henselae type I is protective against heterologous challenge with B. henselae type II

Four Bartonella species have been isolated from domestic cats, of which two serotypes/genotypes of Bartonella henselae and possibly B. clarridgeiae are human pathogens, causing cat scratch disease (CSD).Our objectives were to evaluate infection and potential cross-protection during re-infection in domestic cats with various Bartonella species or types.Thirty-six cats were primarily inoculated with B. henselae type I (n=16), B. henselae type II (n=10), B. clarridgeiae (n=6) or B. koehlerae (n=4). They were challenged with B. henselae type I (n=15), B. henselae type II (n=13) or B. clarridgeiae (n=8).All 36 cats became bacteremic (1.25x10(2)-1.44x10(6)CFU/ml) and bacteremia lasted from 37 to 582 days. Duration of bacteremia for cats inoculated with B. henselae type I was shorter than for cats inoculated with either B. henselae type II (P=0.025) or B. clarridgeiae (P=0.011).After challenge, 26 cats became bacteremic. Among the nine cats primarily inoculated with B. henselae type I and challenged with B. henselae type II, six cats stayed abacteremic. The three bacteremic cats had a transient low-level bacteremia. No bacteremia was observed in three cats primarily inoculated with B. henselae type I and challenged with another strain of B. henselae type I. Bacteremia levels in the 26 cats were significantly lower than for primary inoculation (P=0.022) and its duration was shorter (P=0.012). Among the eight cats challenged with B. clarridgeiae, duration of bacteremia in the four cats primarily inoculated with B. henselae type I was shorter than in the four cats primarily inoculated with B. henselae type II (P=0.01). Bartonella clarridgeiae inoculated cats were more likely to have relapses for both primary and secondary infections.This is the first demonstration of cross-protection, evidenced by absence of bacteremia, in cats primarily infected with B. henselae type I and challenged with B. henselae type II, whereas no cross-protection was previously shown for cats primarily infected with B. henselae type II and challenged with B. henselae type I. Such results are of major importance for future feline Bartonella vaccine development.     

Prevalence of hemoplasmas and Bartonella species in client-owned cats in Beijing and Shanghai,China

A year-round molecular epidemiological survey (2017 to 2018) was conducted on three hemoplasmas and two Bartonella species with zoonotic potential in client-owned cats in Beijing and Shanghai. Among 668 specimens, the overall hemoplasma-positive rate was 4.9% (3.4% for Candidatus Mycoplasma haemominutum, 0.9% for Mycoplasma haemofelis and 1.2% for Candidatus Mycoplasma turicensis). The overall Bartonella-positive rate was 8.5% (4.8% for B. henselae and 4.3% for B. clarridgeiae). Age, breed, ectoparasiticide use and stray history, but not city, season and gender, were significantly associated with the positive rates of one or more pathogens. This is also the first report on the prevalence of Candidatus Mycoplasma turicensis in cats in China.     

Bartonellae in animals and vectors in New Caledonia

Bartonellae are gram-negative facultative intracellular alpha-proteobacteria from the family Bartonellaceae. The natural history of bartonellae consists of a reservoir/host, which is a vertebrate with chronic intravascular infection with sustained bacteremia, and a vector (usually an arthropod) that transfers the bacteria from the reservoir to a susceptible yet uninfected host. In order to reveal the sources and reservoirs of Bartonella infection in animals and vectors in New Caledonia, we collected the blood samples of 64 dogs, 8 cats, 30 bovines, 25 horses and 29 wild deer Cervus timorensis russa and 308 associated blood-sucking parasites (14 keds Hippobosca equina, 258 ticks (22 Rhipicephalus microplus, 235 Rhipicephalus sanguineus, and 1 Haemaphysalis longicornis), 12 fleas Ctenocephalides felis and 24 dog lice Trichodectes canis). We isolated ten strains of Bartonella: four Bartonella henselae from cats and six Bartonella chomelii from cattle. The strains were characterized by sequencing of five genes (16S, ITS, rpoB, gltA and ftsZ). The six strains isolated from cattle were close to the reference strain of B. chomelii and were, probably, imported from France with cattle of Limousin race. PCR showed that 35% of keds collected from deer and 31% of deer were infected by B. aff. schoenbuchensis; all other samples were negative. Our data confirmed that in New Caledonia, as in other regions of the world, cats are the major reservoirs of B. henselae. We also confirmed that Hippoboscidae flies may serve as the vectors of ruminant-associated bartonellae.