Isolation of Bartonella washoensis from a dog with mitral valve endocarditis

Canine Bacterial Endocarditis: A Text Mining and Topics Modeling Analysis as an Approach for a Systematic Review

Bacterial endocarditis (BE) is a severe infection of the endocardium and cardiac valves caused by bacterial agents in dogs. Diagnosis of endocarditis is challenging due to the variety of clinical presentations and lack of definitive diagnostic tests in its early stages. This study aims to provide a research literature analysis on BE in dogs based on text mining (TM) and topic analysis (TA) identifying dominant topics, summarizing their temporal trend, and highlighting any possible research gaps. A literature search was performed utilizing the Scopus® database, employing keywords pertaining to BE to analyze papers published in English from 1990 to 2023. The investigation followed a systematic approach based on the PRISMA guidelines. A total of 86 records were selected for analysis following screening procedures and underwent descriptive statistics, TM, and TA. The findings revealed that the number of records published per year has increased in 2007 and 2021. TM identified the words with the highest term frequency-inverse document frequency (TF-IDF), and TA highlighted the main research areas, in the following order: causative agents, clinical findings and predisposing factors, case reports on endocarditis, outcomes and biomarkers, and infective endocarditis and bacterial isolation. The study confirms the increasing interest in BE but shows where further studies are needed.

Identification of Novel Bartonella washoensis Sequence Type 22 in Marmota himalayana - Jiuquan City, Gansu Province, China, 2021-2022

What is already known about this topic?

The prevalence of rodent-adapted Bartonella species has been increasing significantly. However, the specific Bartonella species carried by Marmota himalayana (M. himalayana), a large rodent species, and the potential risk it poses to human populations remain unknown.

What is added by this report?

Bartonella washoensis (B. washoensis), associated with human endocarditis, was initially identified in M. himalayana, exhibiting a detection rate of approximately one-third and demonstrating a predilection for the heart and lungs. The discovery of the novel Sequence Type 22 has expanded both the isolation source and genetic lineage of B. washoensis.

What are the implications for public health practice?

Individuals residing within the M. himalayana plague focus are at an elevated risk for B. washoensis infection. Consequently, there is a pressing need for public health warnings and efficient clinical case identification in this population.

A Review of Bartonella Infections in California-Implications for Public and Veterinary Health

Bartonella are vector-transmitted, intracellular bacteria that infect a wide variety of blood-feeding arthropods and their vertebrate hosts. In California, more than 13 species of Bartonella have been described from companion animals, livestock, and wildlife, of which four have been associated with human disease. Infections in humans cause a range of symptoms from relatively mild to severe, especially in immunocompromised individuals. Exposure to infected domestic animals and wildlife, and their ectoparasites, may increase the risk of cross-species transmission. The objective of this review was to compile and summarize published materials on human and animal Bartonella infections in California. Medical and veterinary case reports of bartonellosis were highlighted in an effort to increase the awareness of this poorly understood and potentially under-recognized disease among healthcare professionals and veterinarians.

Hedgehogs and Squirrels as Hosts of Zoonotic Bartonella Species

Free-living animals frequently play a key role in the circulation of various zoonotic vector-borne pathogens. Bacteria of the genus Bartonella are transmitted by blood-feeding arthropods and infect a large range of mammals. Although only several species have been identified as causative agents of human disease, it has been proposed that any Bartonella species found in animals may be capable of infecting humans. Within a wide-ranging survey in various geographical regions of the Czech Republic, cadavers of accidentally killed synurbic mammalian species, namely Eurasian red squirrel (Sciurus vulgaris), European hedgehog (Erinaceus europaeus) and Northern white-breasted hedgehog (Erinaceus roumanicus), were sampled and tested for Bartonella presence using multiple PCR reaction approach targeting several DNA loci. We demonstrate that cadavers constitute an available and highly useful source of biological material for pathogen screening. High infection rates of Bartonella spp., ranging from 24% to 76%, were confirmed for all three tested mammalian species, and spleen, ear, lung and liver tissues were demonstrated as the most suitable for Bartonella DNA detection. The wide spectrum of Bartonella spp. that were identified includes three species with previously validated zoonotic potential, B. grahamii, B. melophagi and B. washoensis, accompanied by ‘Candidatus B. rudakovii’ and two putative novel species, Bartonella sp. ERIN and Bartonella sp. SCIER.

Longitudinal Study of Bacterial Infectious Agents in a Community of Small Mammals in New Mexico

Background and Objectives: Vector-borne bacterial diseases represent a substantial public health burden and rodents have been recognized as important reservoir hosts for many zoonotic pathogens. This study investigates bacterial pathogens in a small mammal community of the southwestern United States of America. Methods: A total of 473 samples from 13 wild rodent and 1 lagomorph species were tested for pathogens of public health significance: Bartonella, Brucella, Yersinia, Borrelia, Rickettsia spp., and Anaplasma phagocytophilum. Results: Three animals were positive for Yersinia pestis, and one Sylvilagus audubonii had a novel Borrelia sp. of the relapsing fever group. No Brucella, Rickettsia, or A. phagocytophilum infections were detected. Bartonella prevalence ranged between 0% and 87.5% by animal species, with 74.3% in the predominant Neotoma micropus and 78% in the second most abundant N. albigula. The mean duration of Bartonella bacteremia in mark-recaptured N. micropus and N. albigula was 4.4 months, ranging from <1 to 18 months, and differed among Bartonella genogroups. Phylogenetic analysis of the Bartonella citrate synthase gene (gltA) revealed 9 genogroups and 13 subgroups. Seven genogroups clustered with known or previously reported Bartonella species and strains while two were distant enough to represent new Bartonella species. We report, for the first time, the detection of Bartonella alsatica in North America in Sylvilagus audubonii and expand the known host range of Bartonella washoensis to include Otospermophilus variegatus. Interpretation and Conclusion: This work broadens our knowledge of the hosts and geographic range of bacterial pathogens that could guide future surveillance efforts and improves our understanding of the dynamics of Bartonella infection in wild small mammals.

Molecular detection and phylogenetic analysis of 'Candidatus Bartonella merieuxii' in dogs and its effect on hematologic parameters

Emerging Bartonella spp. infection can result in clinical symptoms such as endocarditis in humans and animals. This study analyzed the genetic phylogeny of the Bartonella spp. circulating in Iranian dogs. Also, this is first study on the relationship of Bartonella spp. and haematological factors from dogs in Fars. Ninety-eight blood samples were collected from the dogs of Fars province, Iran. Two different PCRs targeting rpoB gene and ITS sequence of Bartonella spp., followed by sequencing were performed. In addition, CBC and the differential count of WBC were determined. The "prevalence" of Bartonella spp. was 12.2 % (95 % CI: 5.72-18.68 %) in this population and the sequences matched with a newly proposed species; 'Candidatus Bartonella merieuxii'. A significant increase in WBC due to neutrophilia and decreased RBC, Hct, and Hb concentrations were detected in Bartonella spp. infected dogs. The close contact between humans and dogs, and the zoonosis potential of Candidatus Bartonella merieuxii, emphasize on the need for more studies on 'Candidatus Bartonella merieuxii'.

Bartonella rochalimae, a newly recognized pathogen in dogs

Background

Bartonella spp. comprise a genus of bacteria that frequently cause persistent, often subclinical infection. Although many Bartonella spp. have been implicated in a variety of clinical presentations, Bartonella rochalimae has yet to be documented in association with a clinical presentation other than infectious endocarditis (IE) in dogs.

Objectives

To document a spectrum of clinical presentations accompanied by mild hematological abnormalities in B rochalimae‐infected dogs from the United States.

Animals

Eight dogs with documented B rochalimae infection.

Methods

Retrospective 10‐year study of B rochalimae naturally infected dogs. Clinical and clinicopathologic data, including medical history, CBC, serum biochemistry panel, urinalysis, echocardiogram, and comprehensive vector‐borne disease diagnostic panel results, were reviewed.

Results

Eight dogs were diagnosed with B rochalimae via polymerase chain reaction (PCR) amplification. Five dogs were diagnosed with IE. Three dogs, PCR positive for B rochalimae, were diagnosed with seizures or antibiotic responsive lameness or during routine screening of a military working dog.

Conclusions

This case series provides support for an association between B rochalimae and IE and provides documentation of dogs infected with B rochalimae with other clinical diagnoses.

Prosthetic Valve Endocarditis with Bartonella washoensis in a Human European Patient and Its Detection in Red Squirrels (Sciurus vulgaris)

Members of the genus Bartonella are fastidious Gram-negative facultative intracellular bacteria that are typically transmitted by arthropod vectors. Several Bartonella spp. have been found to cause culture-negative endocarditis in humans. Here, we report the case of a 75-year-old German woman with prosthetic valve endocarditis due to Bartonella washoensis The infecting agent was characterized by sequencing of six housekeeping genes (16S rRNA, ftsZ, gltA, groEL, ribC, and rpoB), applying a multilocus sequence typing (MLST) approach. The 5,097 bp of the concatenated housekeeping gene sequence from the patient were 99.0% identical to a sequence from a B. washoensis strain isolated from a red squirrel (Sciurus vulgaris orientis) from China. A total of 39% (24/62) of red squirrel (S. vulgaris) samples from the Netherlands were positive for the B. washoensis gltA gene variant detected in the patient. This suggests that the red squirrel is the reservoir host for human infection in Europe.

Prevalence of Bartonella sp. in United States military working dogs with infectious endocarditis: a retrospective case-control study

OBJECTIVES

Bartonella infection has been associated with endocarditis in humans, dogs, cats and cattle. In order to evaluate the importance of this pathogen as a possible source of endocarditis in United States military working dogs (MWDs), we performed a retrospective case-control study on 26 dogs with histological diagnosis of culture negative endocarditis (n = 18), endomyocarditis (n = 5) or endocardiosis (n = 3) and 28 control dogs without any histological cardiac lesions.

METHODS

DNA was extracted from paraffin embedded cardiac valves and tissues from case and control dogs and submitted to PCR testing with primers targeting the Bartonella gltA gene. PCR-RFLP using four restriction endonucleases and partial sequencing was then performed to determine the Bartonella species involved.

RESULTS

Nineteen (73%) cases were PCR positive for Bartonella, including B. henselae (8 dogs), B. vinsonii subsp. berkhoffii (6 dogs), B. washoensis (2 dogs) and B. elizabethae (1 dog). Only one control dog was weakly PCR positive for Bartonella. Based on the type of histological diagnosis, 13 (72.2%) dogs with endocarditis, 3 (60%) dogs with endomyocarditis and all 3 dogs with endocardiosis were Bartonella PCR positive.

CONCLUSIONS

Bartonella sp. Infections were correlated with cardiopathies in US military working dogs. Systemic use of insecticides against ectoparasites and regular testing of MWDs for Bartonella infection seem highly appropriate to prevent such life-threatening exposures.

Bartonella washoensis infection in red squirrels (Sciurus vulgaris) and their ectoparasites in Lithuania

This is the first study to investigate the presence of Bartonella infections in different internal organs of red squirrels and their ectoparasites in Lithuania. A total of 39 roadkill red squirrels were collected. Squirrels were infested with Ixodes ricinus ticks (191) and Ceratophyllus sciurorum fleas (36). The presence of Bartonella spp. was screened using 16 S-23 S rRNA internal transcribed spacer region and bacteria were detected in 38.5 % (15/39) samples of squirrels, 1.0 % (2/191) samples of ticks and 55.5 % (20/36) samples of fleas. The infection rate of different internal organs of squirrels varied from 11.1%-47.4%. The 16 S-23 S rRNA ITS region sequences showed that Bartonella washoensis were detected in squirrels and their ectoparasites. The results from this study support the hypothesis that S. vulgaris and their fleas, C.sciurorum, serve as a major reservoir and a vector, respectively, of zoonotic B. washoensis in Lithuania.

Molecular detection and characterization of Bartonella spp. in pet cats and dogs in Shenzhen, China

Bartonella spp. are emerging vector-borne pathogens distributed worldwide that can infect humans and a wide range of mammals including small companion animals (cats and dogs). An increasing number of studies from the worldwide have reported cat and dog Bartonella infections in recently years. Cats and dogs are the primary reservoir or accidental hosts for Bartonella henselae, the main causal agent of human cat scratch disease. Since pet cat and dog sharing human living environment and have the direct and intimate contact with humans, pet cats and dogs may represent excellent epidemiological sentinels for Bartonella infection in humans. In this study, 475 blood samples were collected from pet cats and dogs in local animal hospitals located at five districts of Shenzhen City, and detected the presence of Bartonella. Bartonella DNA was detected in eight samples collected from pet cats, no positive sample was detected from pet dog samples. Sequence comparison and phylogenetic analysis revealed that the eight sequences of Bartonella identified here shared the highest identity with B. henselae. Given the intimate contact between pet animals and humans, many attentions should be paid to prevent the Bartonella infections originate from pet cats or dogs, although the Bartonella infection rate in pet cats and dogs might be rather low.

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

Companion vector-borne diseases (CVBDs) are an important threat for pet life, but may also have an impact on human health, due to their often zoonotic character. The importance and awareness of CVBDs continuously increased during the last years. However, information on their occurrence is often limited in several parts of the world, which are often especially affected. Latin America (LATAM), a region with large biodiversity, is one of these regions, where information on CVBDs for pet owners, veterinarians, medical doctors and health workers is often obsolete, limited or non-existent. In the present review, a comprehensive literature search for CVBDs in companion animals (dogs and cats) was performed for several countries in Central America (Belize, Caribbean Islands, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico) as well as in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana (British Guyana), Paraguay, Peru, Suriname, Uruguay, Venezuela) regarding the occurrence of the following parasitic and bacterial diseases: babesiosis, heartworm disease, subcutaneous dirofilariosis, hepatozoonosis, leishmaniosis, trypanosomosis, anaplasmosis, bartonellosis, borreliosis, ehrlichiosis, mycoplasmosis and rickettsiosis. An overview on the specific diseases, followed by a short summary on their occurrence per country is given. Additionally, a tabular listing on positive or non-reported occurrence is presented. None of the countries is completely free from CVBDs. The data presented in the review confirm a wide distribution of the CVBDs in focus in LATAM. This wide occurrence and the fact that most of the CVBDs can have a quite severe clinical outcome and their diagnostic as well as therapeutic options in the region are often difficult to access and to afford, demands a strong call for the prevention of pathogen transmission by the use of ectoparasiticidal and anti-feeding products as well as by performing behavioural changes.

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.

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.

ANIMALS

Thirty dogs with naturally occurring blood culture-negative endocarditis were examined from 2010 to 2017 at three veterinary referral hospitals, located in northwest, northeast, and southeast of Spain.

METHODS

It is a retrospective study. Medical records were reviewed to extract relevant data. Frozen or paraffin-embedded cardiac valve tissue and/or ethylenediamine tetraacetic acid blood samples were evaluated by PCR for the presence of Bartonella DNA. Positive results were sequenced to confirm the species.

RESULTS

Polymerase chain reaction was positive for eight out of 30 dogs included (26.6%). Bartonella rochalimae, Bartonella vinsonii subsp. berkhoffii, and Bartonella koehlerae were detected in valve tissue or blood.

CONCLUSIONS

Bartonella could be an important cause of blood culture-negative infectious endocarditis in dogs from Spain. The outcome for those dogs affected with Bartonella spp. was grave. Prompt empirical treatment with amoxicillin-clavulanate plus fluoroquinolones could be of value in cases of blood culture-negative endocarditis.

Prevalence and Seasonality of Fleas Associated With California Ground Squirrels and the Potential Risk of Tularemia in an Outdoor Non-Human Primate Research Facility

Ectoparasites at primate research centers may be difficult to control, e.g. without exposing non-human primates (NHPs) to toxicants, but their impact on NHP health is poorly understood. In 2010, there was an epizootic of tularemia at the California National Primate Research Center (CNPRC) in Yolo County, California that resulted in 20 confirmed and suspect clinical cases in outdoors housed rhesus macaques (Macaca mulatta [Zimmermann]) and a 53% seroprevalence in the southern section of the colony. We studied ectoparasite burdens at the CNPRC in order to understand possible conditions at the time of the epizootic and provide data for the management of ectoparasites for the future. In 2015, we recorded 52 California ground squirrel (Otospermophilus beecheyi [Richardson]) burrow systems in the southern colony and collected 560 fleas. The largest number of fleas (n = 184) was collected in October and the most common species were Hoplopsyllus anomalus (Baker) (n = 331), Oropsylla montana (Baker) (n = 158), Echidnophaga gallinacea (Westwood) (n = 60), and Ctenocephalides felis (Bouché) (n = 11), all of which are opportunistically anthropophilic. Free, non-host-associated fleas included 12 H. anomalus, 9 C. felis, 6 O. Montana, and 1 E. gallinacea. We collected 1 H. anomalus from a rhesus macaque. Our results suggest a high potential for the rapid spread of zoonotic infectious diseases via flea transmission in primate facilities with ground squirrels and that flea control measures should be given a high priority.

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

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

Distribution and Diversity of Bartonella washoensis Strains in Ground Squirrels from California and Their Potential Link to Human Cases

We investigated the prevalence of Bartonella washoensis in California ground squirrels (Otospermophilus beecheyi) and their fleas from parks and campgrounds located in seven counties of California. Ninety-seven of 140 (69.3%) ground squirrels were culture positive and the infection prevalence by location ranged from 25% to 100%. In fleas, 60 of 194 (30.9%) Oropsylla montana were found to harbor Bartonella spp. when screened using citrate synthase (gltA) specific primers, whereas Bartonella DNA was not found in two other flea species, Hoplopsyllus anomalus (n = 86) and Echidnophaga gallinacea (n = 6). The prevalence of B. washoensis in O. montana by location ranged from 0% to 58.8%. A majority of the gltA sequences (92.0%) recovered from ground squirrels and fleas were closely related (similarity 99.4-100%) to one of two previously described strains isolated from human patients, B. washoensis NVH1 (myocarditis case in Nevada) and B. washoensis 08S-0475 (meningitis case in California). The results from this study support the supposition that O. beecheyi and the flea, O. montana, serve as a vertebrate reservoir and a vector, respectively, of zoonotic B. washoensis in California.

Pathology of Bartonella Endocarditis in Six Dogs

In a 5-year retrospective study of dogs presenting to the Veterinary Medical Teaching Hospital at the University of California, Davis, there were 31 histologic diagnoses of valvular endocarditis. By polymerase chain reaction (PCR) amplification of embedded valvular tissue, Bartonella organisms were exclusively associated with 6 out of 31 cases (19%). Confirmed Bartonella cases involved the aortic valve alone (five out of six) or in combination with the mitral valve (one of six). Microscopic features of Bartonella endocarditis were compared with valves from non -Bartonella endocarditis and with valvular change unrelated to infectious agents (endocardiosis). Features of Bartonella endocarditis included a combination of fibrosis, mineralization, endothelial proliferation, and neovascularization with variable inflammation. None of these features is specific; however, the combination is distinct both from endocarditis caused by culturable bacteria and from endocardiosis. Ultrastructural analyses revealed both extracellular and intraendothelial bacteria. Clinical history, serology, and PCR are currently necessary to establish an etiologic diagnosis of Bartonella endocarditis.

Bartonella spp. exposure in northern and southern sea otters in Alaska and California

Since 2002, an increased number of northern sea otters (Enhydra lutris kenyoni) from southcentral Alaska have been reported to be dying due to endocarditis and/or septicemia with infection by Streptococcus infantarius subsp. coli. Bartonella spp. DNA was also detected in northern sea otters as part of mortality investigations during this unusual mortality event (UME) in Kachemak Bay, Alaska. To evaluate the extent of exposure to Bartonella spp. in sea otters, sera collected from necropsied and live-captured northern sea otters, as well as necropsied southern sea otters (Enhydra lutris nereis) unaffected by the UME, were analyzed using an immunofluorescent antibody assay. Antibodies against Bartonella spp. were detected in sera from 50% of necropsied and 34% of presumed healthy, live-captured northern sea otters and in 16% of necropsied southern sea otters. The majority of sea otters with reactive sera were seropositive for B. washoensis, with antibody titers ranging from 1:64 to 1:256. Bartonella spp. antibodies were especially common in adult northern sea otters, both free-living (49%) and necropsied (62%). Adult stranded northern sea otters that died from infectious causes, such as opportunistic bacterial infections, were 27 times more likely to be Bartonella seropositive than adult stranded northern sea otters that died from noninfectious causes (p<0.001; 95% confidence interval 2.62-269.4). Because Bartonella spp. antibodies were detected in necropsied northern sea otters from southcentral (44%) and southwestern (86%) stocks of Alaska, as well as in necropsied southern sea otters (16%) in southcentral California, we concluded that Bartonella spp. exposure is widely distributed among sea otter populations in the Eastern Pacific, providing context for investigating future disease outbreaks and monitoring of Bartonella infections for sea otter management and conservation.

Experimental infection of dogs with various Bartonella species or subspecies isolated from their natural reservoir

Dogs can be infected by a wide variety of Bartonella species. However, limited data is available on experimental infection of dogs with Bartonella strains isolated from domestic animals or wildlife. We report the inoculation of six dogs with Bartonella henselae (feline strain 94022, 16S rRNA type II) in three sets of two dogs, each receiving a different inoculum dose), four dogs inoculated with B. vinsonii subsp. berkhoffii type I (ATCC strain, one mongrel dog) or type II (coyote strain, two beagles and one mongrel) and B. rochalimae (coyote strain, two beagles). None of the dogs inoculated with B. henselae became bacteremic, as detected by classical blood culture. However, several dogs developed severe necrotic lesions at the inoculation site and all six dogs seroconverted within one to two weeks. All dogs inoculated with the B. v. berkhoffii and B. rochalimae strains became bacteremic at levels comparable to previous experimental infections with either a dog isolate or a human isolate. Our data support that dogs are likely accidental hosts for B. henselae, just like humans, and are efficient reservoirs for both B. v. berkhoffii and B. rochalimae.

Bartonella and Bartonella infections in China: from the clinic to the laboratory

The current status of Bartonella studies in mainland China is reviewed including both laboratory and ecological data and limited clinical data. Detection and isolation of Bartonella species from arthropods, pets and small wild animals is commonplace; this includes a variety of known and emerging Bartonella pathogens. In contrast, the medical literature analyzed from 1980 to 2010 consists of 31 reports of only of cat scratch disease (CSD). Most cases are from the East and South-Eastern provinces, the most populated areas with best access to medical care. Disease typically is described as febrile illness with symptoms traditionally reported for CSD elsewhere in the world. Clinical observations and anamnesis are the primary bases for diagnosis, since specialized serologic and molecular diagnosis is not widely available. Seroprevalence of healthy populations determined using Bartonella henselae antigen varies from 9.6 to 19.6%. The apparent discordance postulated between possible environmental exposure to diverse Bartonella agents and restricted B. henselae case etiologies suggests a need to determine whether other Bartonella species may also be etiologic agents of human illness and emphasizes the importance of applying modern diagnostic tools widely in clinical practice in mainland China.

Ecological diversity of Bartonella species infection among dogs and their owner in Virginia

Bartonella species comprise a genus of gram-negative, fastidious, intracellular bacteria that have been implicated in association with an increasing spectrum of disease manifestations in dogs and human patients. In this study, chronic canine and human disease, for which causation was not diagnostically defined, were reported by the breeder of a kennel of Doberman pinschers. In addition to other diagnostic tests, serology, polymerase chain reaction, and enrichment blood culture were used to assess the prevalence of Bartonella sp. infection in the dogs and their owner. From five dogs, Bartonella vinsonii subsp. berkhoffii genotype I, multiple Bartonella henselae strains, and a species most similar to Candidatus B. volans, a rodent-associated Bartonella sp., were amplified and sequenced from biopsy tissues, cerebrospinal fluid, or blood enrichment cultures. The owner was bacteremic with B. vinsonii subsp. berkhoffii genotype I, the same subsp. and genotype detected in one of her dogs. These results further emphasize the ecological complexity of Bartonella sp. transmission in nature.

Bartonella infection: treatment and drug resistance

Bartonella species, which belong to the α-2 subgroup of Proteobacteria, are fastidious Gram-negative bacteria that are highly adapted to their mammalian host reservoirs. Bartonella species are responsible for different clinical conditions affecting humans, including Carrion's disease, cat scratch disease, trench fever, bacillary angiomatosis, endocarditis and peliosis hepatis. While some of these diseases can resolve spontaneously without treatment, in other cases, the disease is fatal without antibiotic treatment. In this article, we discuss the antibiotic susceptibility patterns of Bartonella species, detected using several methods. We also provide an overview of Bartonella infection in humans and animals and discuss the antibiotic treatment recommendations for the different infections, treatment failure and the molecular mechanism of antibiotic resistance in these bacteria.

Enrichment culture and molecular identification of diverse Bartonella species in stray dogs

Using pre-enrichment culture in Bartonella alpha-Proteobacteria growth medium (BAPGM) followed by PCR amplification and DNA sequence identification that targeted a fragment of the citrate synthase gene (gltA), we provide evidence of common bartonella infections and diverse Bartonella species in the blood of stray dogs from Bangkok and Khon Kaen, Thailand. The overall prevalence of all Bartonella species was 31.3% (60/192), with 27.9% (31/111) and 35.8% (29/81) in the stray dogs from Bangkok and Khon Kaen, respectively. Phylogenetic analyzes of gltA identified eight species/genotypes of Bartonella in the blood of stray dogs, including B. vinsonii subsp. arupensis, B. elizabethae, B. grahamii, B. quintana, B. taylorii, and three novel genotypes (BK1, KK1 and KK2) possibly representing unique species with ≤ 90.2% similarities to any of the known Bartonella species B. vinsonii subsp. arupensis was the only species detected in dogs from both sites, B. quintana and BK1 were found in the dogs from Bangkok, B. elizabethae, B. taylorii, KK1 and KK2 were found in the dogs from Khon Kaen. We conclude that stray dogs in Thailand are frequently infected with Bartonella species that vary with geographic region. As some Bartonella species detected in the present study are considered pathogenic for humans, stray dogs in Thailand may serve as possible reservoirs for Bartonella causing human illnesses. Further work is needed to determine the role of those newly discovered Bartonella genotypes/species in human and veterinary medicine.

Detection and genetic diversity of Bartonella vinsonii subsp. berkhoffii strains isolated from dogs in Ankara, Turkey

Bartonella vinsonii subsp. berkhoffii has been identified as an important pathogen in dogs and is an emerging pathogen in people with zoonotic potential. This study aimed to isolate Bartonella spp. in 250 blood samples collected from dogs in the province of Ankara, Turkey, between October 2006 and March 2007. The typing of the 23 isolates was carried out by PCR for citrate synthase (gltA) and the 16S-23S intergenic transcribed spacer (ITS). The prevalence of bacteremia was 9.2% in 250 samples. Among 170 shelter dogs, 21 (12.4%) were bacteremic for B. vinsonii subsp. berkhoffii, while the B. vinsonii subsp. berkhoffii bacteremia rate was 5% (2/40) for the stray dogs. B. vinsonii subsp. berkhoffii was not isolated from the pet dogs. The prevalence of bacteremia was found to be 25.5% (13/51) in shelter dogs aged less than one year old. All of the isolates were identified as B.vinsonii subsp. berkhoffii genotype III. In some isolates, MseI digest for gltA was found to be different from the American and European strains due to a single nucleotide change.

Meningitis due to a "Bartonella washoensis"-like human pathogen

We report the second human case of infection caused by an organism identified as the proposed Bartonella species, "B. washoensis." The organism was isolated from a blood sample from a patient presenting with meningitis and early sepsis. Oropsylla montana fleas were implicated as the vector for disease transmission in this case.

Prevalence of Bartonella infection in cats and dogs in a metropolitan area, Thailand

The prevalence of Bartonella infection was studied in 312 cats and 350 dogs in the Bangkok metropolitan areas, Thailand, between June 2001 and February 2003. Bartonella was isolated from 47 (16.3%) of 288 stray cats, but from none of the 24 pet cats studied. Of the 47 Bartonella-positive cats, 45 animals were infected with only B. henselae, one was infected with only B. clarridgeiae, and one with both B. henselae and B. clarridgeiae. 16S rRNA typing showed that 40 cats were infected with B. henselae type I, four with B. henselae type II, and one with both B. henselae types I and II. These results indicated that B. henselae, especially type I, was prevalent in stray cats that constituted a large Bartonella reservoir in Bangkok. B. clarridgeiae was isolated for the first time in Asia from one of 350 dogs.

A confusing case of canine vector-borne disease: clinical signs and progression in a dog co-infected with Ehrlichia canis and Bartonella vinsonii ssp. berkhoffii

Bartonella spp. are important pathogens in human and veterinary medicine, and bartonellosis is considered as an emerging zoonosis that is being reported with increasing frequency. Of 22 known species and subspecies of Bartonella, seven have been isolated from dogs, causing disease manifestations similar to those seen in human beings. The wide variety of clinical signs and the possible chronic progression of disease manifestations are illustrated in the case of an infected Labrador retriever. Here, the authors discuss the seemingly diverse spectrum of disease manifestations, the co-infections of Bartonella spp. with other vector-borne pathogens (mainly Ehrlichia spp. or Babesia spp.) and the difficulties in microbiological confirmation of an active Bartonella infection, all of which make the disease pathogenesis and clinical diagnosis more problematic.

Molecular documentation of Bartonella infection in dogs in Greece and Italy

This study reports the occurrence of "Bartonella rochalimae" in Europe and the presence of Bartonella vinsonii subsp. berkhoffii genotypes II and III in dogs in southern Italy and provides DNA sequencing evidence of a potentially new Bartonella sp. infecting dogs in Greece and Italy.

Infective endocarditis in a dog and the phylogenetic relationship of the associated "Bartonella rochalimae" strain with isolates from dogs, gray foxes, and a human

The first case of canine endocarditis caused by "Bartonella rochalimae" is reported. By PCR-restriction fragment length polymorphism, sequence, and phylogenetic analyses, Bartonella isolates from a dog with endocarditis, 22 gray foxes, and three dogs, described as B. clarridgeiae like, were confirmed to belong to the new species "B. rochalimae," suggesting canids as the natural reservoir.

Vector transmission of Bartonella species with emphasis on the potential for tick transmission

Bartonella species are gram-negative bacteria that infect erythrocytes, endothelial cells and macrophages, often leading to persistent blood-borne infections. Because of the ability of various Bartonella species to reside within erythrocytes of a diverse number of animal hosts, there is substantial opportunity for the potential uptake of these blood-borne bacteria by a variety of arthropod vectors that feed on animals and people. Five Bartonella species are transmitted by lice, fleas or sandflies. However, Bartonella DNA has been detected or Bartonella spp. have been cultured from numerous other arthropods. This review discusses Bartonella transmission by sandflies, lice and fleas, the potential for transmission by other vectors, and data supporting transmission by ticks. Polymerase chain reaction (PCR) or culture methods have been used to detect Bartonella in ticks, either questing or host-attached, throughout the world. Case studies and serological or molecular surveys involving humans, cats and canines provide indirect evidence supporting transmission of Bartonella species by ticks. Of potential clinical relevance, many studies have proposed co-transmission of Bartonella with other known tick-borne pathogens. Currently, critically important experimental transmission studies have not been performed for Bartonella transmission by many potential arthropod vectors, including ticks.

Canine Bacterial Endocarditis: A Review

Bacterial endocarditis is a disease of primarily middle-aged to older, large-breed dogs that is associated with high morbidity and mortality. It presents many challenges with respect to diagnosis and effective treatment. This paper reviews the pathogenesis, clinical presentation, progression, methods of diagnosis, and treatment of bacterial endocarditis in dogs. Methods for proper diagnosis, including echocardiographic findings and blood culture techniques, and recommendations for effective antimicrobial therapy are also provided.

Bartonella vinsonii subsp. berkhoffii endocarditis in a dog from Saskatchewan

A dog referred for lameness was diagnosed with culture-negative endocarditis. Antibodies to Bartonella spp. were detected. Antibiotic treatment resulted in transient clinical improvement, but the dog developed cardiac failure and was euthanized. Bartonella vinsonii subsp. berkhoffii genotype IV was identified within the aortic heart valve lesions by PCR amplification and DNA sequencing.

Canine bartonellosis: serological and molecular prevalence in Brazil and evidence of co-infection with Bartonella henselae and Bartonella vinsonii subsp. berkhoffii

The purpose of this study was to determine the serological and molecular prevalence of Bartonella spp. infection in a sick dog population from Brazil. At the São Paulo State University Veterinary Teaching Hospital in Botucatu, 198 consecutive dogs with clinicopathological abnormalities consistent with tick-borne infections were sampled. Antibodies to Bartonella henselae and Bartonella vinsonii subsp. berkhoffii were detected in 2.0% (4/197) and 1.5% (3/197) of the dogs, respectively. Using 16S-23S rRNA intergenic transcribed spacer (ITS) primers, Bartonella DNA was amplified from only 1/198 blood samples. Bartonella seroreactive and/or PCR positive blood samples (n=8) were inoculated into a liquid pre-enrichment growth medium (BAPGM) and subsequently sub-inoculated onto BAPGM/blood-agar plates. PCR targeting the ITS region, pap31 and rpoB genes amplified B. henselae from the blood and/or isolates of the PCR positive dog (ITS: DQ346666; pap31 gene: DQ351240; rpoB: EF196806). B. henselae and B. vinsonii subsp. berkhoffii (pap31: DQ906160; rpoB: EF196805) co-infection was found in one of the B. vinsonii subsp. berkhoffii seroreactive dogs. We conclude that dogs in this study population were infrequently exposed to or infected with a Bartonella species. The B. henselae and B. vinsonii subsp. berkhoffii strains identified in this study are genetically similar to strains isolated from septicemic cats, dogs, coyotes and human beings from other parts of the world. To our knowledge, these isolates provide the first Brazilian DNA sequences from these Bartonella species and the first evidence of Bartonella co-infection in dogs.

Bartonella quintana endocarditis in dogs

TOC summary line: PCR and sequencing provide the first evidence that B. quintana can be pathogenic in dogs.

We provide the first evidence that Bartonella quintana can infect dogs and cause typical signs of endocarditis. Using PCR and sequencing, we identified B. quintana in the blood of a dog from the United States with aortic valve endocarditis and probably also in the mitral valve of a dog from New Zealand with endocarditis.

Detection ofBartonella henselaeDNA in two dogs with pyogranulomatous lymphadenitis

CASE DESCRIPTION

1 dog evaluated because of inappetence and lameness of the left hind limb of 1 day's duration and 1 dog evaluated because of inappetence, fever, and lymphadenopathy of 2 weeks' duration.

CLINICAL FINDINGS

Histologic examination of excisional biopsy specimens from lymph nodes revealed pyogranulomatous lymphadenitis in both dogs. Quantitative real-time PCR assays detected Bartonella henselae DNA in blood samples and affected lymph node specimens from both dogs. Antibodies against B. henselae were not detected via immunofluorescent antibody testing during active disease in either dog.

TREATMENT AND OUTCOME

1 dog recovered after 6 weeks of treatment with doxycycline (5 mg/kg [2.3 mg/lb], p.o., q 12 h), whereas the other dog recovered after receiving a combination of azithromycin (14.5 mg/kg [6.6 mg/lb], p.o., q 24 h for 21 days), doxycycline (17.3 mg/kg [7.9 mg/lb], p.o., q 24 h for 4 weeks), and immunosuppressive corticosteroid (prednisone [3 mg/kg {1.4 mg/lb}, p.o., q 24 h], tapered by decreasing the daily dose by 25% every 2 weeks) treatment.

CLINICAL RELEVANCE

B. henselae is implicated as a possible cause or a cofactor in the development of pyogranulomatous lymphadenitis in dogs. In dogs with pyogranulomatous lymphadenitis, immunofluorescent assays may not detect antibodies against B. henselae. Molecular testing, including PCR assay of affected tissues, may provide an alternative diagnostic method for detection of B. henselae DNA in pyogranulomatous lymph nodes.

Rodent-AssociatedBartonellain Saskatchewan, Canada

Six species of wild rodents were sampled at 10 sites in 2002 and 2003 to determine the prevalence of Bartonella infections in rodent communities near Saskatoon, Saskatchewan, Canada. Isolates were characterized genotypically and compared with isolates found at other locations. Of 104 wild rodents examined, 57% were infected with Bartonella and prevalence within species varied from 49% for Richardson's ground squirrels (Spermophilus richardsonii) to 90% for Franklin's ground squirrels (S. franklinii). Infected rodents were found at all sites. Sequencing of a 379-bp portion of the citrate synthase gene was performed on 54 isolates and revealed 13 distinct genotypes, eight of which had not been described previously. The most common genotype detected in red-backed voles (Clethrionomys gapperi) was 99.1% similar to B. grahamii, a known human pathogen. Two of 10 Franklin's ground squirrels were concurrently infected with multiple Bartonella genotypes. All genotypes, with the exception of one detected in both Franklin's and thirteen-lined ground squirrels (S. tridecemlineatus), were found in only one host, and all genotypes from each species, with the exception of genotypes detected in red-backed voles, clustered together within the same relatedness group, suggesting that at least some Bartonella genotypes are specific to some rodent hosts.

Seroprevalence of antibodies against Bartonella species and evaluation of risk factors and clinical signs associated with seropositivity in dogs

OBJECTIVE

To determine the seroprevalence of antibodies against Bartonella spp in a population of sick dogs from northern California and identify potential risk factors and clinical signs associated with seropositivity.

SAMPLE POPULATION

Sera from 3,417 dogs.

PROCEDURE

Via an ELISA, sera were analyzed for antibodies against Bartonella vinsonii subsp berkhoffii, Bartonella clarridgeiae, and Bartonella henselae; test results were used to classify dogs as seropositive (mean optical density value > or = 0.350 for B henselae or > or = 0.300 for B clarridgeiae or B vinsonii subsp berkhoffi) or seronegative. Overall, 305 dogs (102 seropositive and 203 seronegative dogs) were included in a matched case-control study.

RESULTS

102 of 3,417 (2.99%) dogs were seropositive for > or = 1 species of Bartonella. Of these, 36 (35.3%) had antibodies against B henselae only, 34 (33.3%) had antibodies against B clarridgeiae only, 2 (2.0%) had antibodies against B vinsonii subsp berkhoffii only, and 30 (29.4%) had antibodies against a combination of those antigens. Compared with seronegative dogs, seropositive dogs were more likely to be herding dogs and to be female, whereas toy dogs were less likely to be seropositive. Seropositive dogs were also more likely to be lame or have arthritis-related lameness, nasal discharge or epistaxis, or splenomegaly.

CONCLUSIONS AND CLINICAL RELEVANCE

Only a small percentage of dogs from which serum samples were obtained had antibodies against Bartonella spp. Breed appeared to be an important risk factor for seropositivity. Bartonella infection should be considered in dogs with clinical signs of lameness, arthritis-related lameness, nasal discharge or epistaxis, or splenomegaly.