Aortic valve endocarditis in a dog due to Bartonella clarridgeiae

Fleas (Siphonaptera, Latreille, 1825) from Rio Grande do Sul State, Brazil: Species Diversity, Hosts, and One Health Approach

Background: Fleas are ectoparasitic insects with holometabolous development. It has a hematophagous habit with mouthparts adapted to sting and suck its hosts. There are about 3000 species in the world, ∼61 in Brazil, and 19 in Rio Grande do Sul state. The objective of the research is to catalog the diversity of fleas recorded in the state, their respective hosts, and endosymbionts. Materials and Methods: To this end, a search was carried out in the scientific literature, from articles, books, to abstracts submitted to congresses. Results: The 19 species of fleas occurring in Rio Grande do Sul are divided into 7 families and 10 genera. These ectoparasites, in addition to being found in the environment, were associated with 10 different families of hosts in Rio Grande do Sul, and on the endosymbiont, agents found associated with fleas, there were 7 different species. The main agents researched in the state are Rickettsia spp. and Bartonella spp. The relationships between parasites, hosts, environment, and etiological agents present different scenarios, whether anthropized or conserved, but unknown. Sometimes, this overlap, a factor that aggravates the possibility of spillovers, either from cosmopolitan fleas in these conserved areas, or from their endosymbionts. Conclusion: Thus, it is important to characterize the environment so that the complexities of each location are known for the adoption of environmental and public health policies in each case. The challenges are extensive, but necessary in view of the One Health perspective.

Combining deep sequencing and conventional molecular approaches reveals broad diversity and distribution of fleas and Bartonella in rodents and shrews from Arctic and Subarctic ecosystems

BACKGROUND

Bartonella are intracellular bacteria that are transmitted via animal scratches, bites and hematophagous arthropods. Rodents and their associated fleas play a key role in the maintenance of Bartonella worldwide, with > 22 species identified in rodent hosts. No studies have addressed the occurrence and diversity of Bartonella species and vectors for small mammals in Arctic and Subarctic ecosystems, which are increasingly impacted by invasive species and climate change.

METHODS

In this study, we characterized the diversity of rodent fleas using conventional PCR targeting the mitochondrial cytochrome c oxidase II gene (COII) and Bartonella species in rodents and shrews (n = 505) from northern Canada using conventional PCR targeting the ITS (intergenic transcribed spacer) region and gltA (citrate synthase) gene. Metagenomic sequencing of a portion of the gltA gene was completed on a subset of 42 rodents and four rodent flea pools.

RESULTS

Year, total summer precipitation the year prior to sampling, average minimum spring temperature and small mammal species were significant factors in predicting Bartonella positivity. Occurrence based on the ITS region was more than double that of the gltA gene and was 34% (n = 349) in northern red-backed voles, 35% (n = 20) in meadow voles, 37% (n = 68) in deer mice and 31% (n = 59) in shrews. Six species of Bartonella were identified with the ITS region, including B. grahamii, B. elizabethae, B. washoensis, Candidatus B. rudakovii, B. doshiae, B. vinsonii subsp. berkhoffii and subsp. arupensis. In addition, 47% (n = 49/105) of ITS amplicons had < 97% identity to sequences in GenBank, possibly due to a limited reference library or previously unreported species. An additional Bartonella species (B. heixiaziensis) was detected during metagenomic sequencing of the gltA gene in 6/11 rodents that had ITS sequences with < 97% identity in GenBank, highlighting that a limited reference library for the ITS marker likely accounted for low sequence similarity in our specimens. In addition, one flea pool from a northern red-backed vole contained multiple species (B. grahamii and B. heixiaziensis).

CONCLUSION

Our study calls attention to the usefulness of a combined approach to determine the occurrence and diversity of Bartonella communities in hosts and vectors.

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.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

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'.

A Host-Specific Blocking Primer Combined with Optimal DNA Extraction Improves the Detection Capability of a Metabarcoding Protocol for Canine Vector-Borne Bacteria

Bacterial canine vector-borne diseases are responsible for some of the most life-threatening conditions of dogs in the tropics and are typically poorly researched with some presenting a zoonotic risk to cohabiting people. Next-generation sequencing based methodologies have been demonstrated to accurately characterise a diverse range of vector-borne bacteria in dogs, whilst also proving to be more sensitive than conventional PCR techniques. We report two improvements to a previously developed metabarcoding tool that increased the sensitivity and diversity of vector-borne bacteria detected from canine blood. Firstly, we developed and tested a canine-specific blocking primer that prevents cross-reactivity of bacterial primer amplification on abundant canine mitochondrial sequences. Use of our blocking primer increased the number of canine vector-borne infections detected (five more Ehrlichia canis and three more Anaplasma platys infections) and increased the diversity of bacterial sequences found. Secondly, the DNA extraction kit employed can have a significant effect on the bacterial community characterised. Therefore, we compared four different DNA extraction kits finding the Qiagen DNeasy Blood and Tissue Kit to be superior for detection of blood-borne bacteria, identifying nine more A. platys, two more E. canis, one more Mycoplasma haemocanis infection and more putative bacterial pathogens than the lowest performing kit.

Validation of Bartonella henselae Western Immunoblotting for Serodiagnosis of Bartonelloses in Dogs

Bartonella spp. are etiological agents of life-threatening zoonotic diseases in dogs worldwide. Due to the poor sensitivity of immunofluorescent-antibody assays (IFAs), a reliable serodiagnostic test for canine bartonelloses is of clinical importance. The utility of Western blotting (WB) for the serodiagnosis of canine bartonelloses has not been critically investigated. The objective of this study was to characterize WB immunodominant proteins that could be used to confirm a serodiagnosis of bartonelloses. Using agar-grown Bartonella henselae San Antonio type 2 (SA2) whole-cell proteins, sera derived from four dog groups were tested by WB to assess immunodominant protein recognition patterns: group I consisted of 92 serum samples (10 preexposure and 82 postexposure serum samples) from 10 adult beagles experimentally inoculated with Bartonella spp., group II consisted of 36 serum samples from Bartonella PCR-positive naturally infected dogs, group III consisted of 26 serum samples from Bartonella PCR-negative and IFA-negative dogs, and group IV consisted of serum samples from 8 Brucella canis IFA-positive and 10 Rickettsia rickettsii IFA-positive dogs. Following experimental inoculation, 9 (90%) group I dogs were variably seroreactive to one or more of six specific immunodominant proteins (13, 17, 29, 50, 56, and 150 kDa). There was a strong but variable recognition of these proteins among 81% of group II dogs. In contrast, 24/26 group III dogs were not reactive to any immunodominant protein. In this study, the sensitivity and diagnostic accuracy of B. henselae SA2 WB were higher than those of B. henselae SA2 IFA testing. Some B. henselae SA2 immunodominant proteins were recognized by dogs experimentally and naturally infected with Bartonella spp. other than B. henselae Additional research is necessary to more fully define the utility of WB for the serodiagnosis of canine bartonelloses.

Aortic valve endocarditis due to Bartonella clarridgeiae in a dog in Brazil

We report the first documented case of endocarditis associated with Bartonella clarridgeiae in a dog in Latin America. Infective vegetative valvular aortic endocarditis was diagnosed in a 10-year-old male mixed breed dog. The dog presented grade V/VI systolic and diastolic murmur, hyperthermia, and progressive weight loss. Cardiomegaly and presence of diffuse alveolar pattern in the lung fields were observed in the thorax radiography evaluation. Irregular and hyperechogenic structures adhered to the aortic leaflets, causing obstruction of the left ventricular outflow tract and severe aortic insufficiency, were observed in the echocardiography evaluation. A vegetative, whitish, hardened structure measuring 1.0 cm in diameter was observed in aortic semilunar valve at necropsy. Based on a combination of pre-enrichment insect-based medium liquid culture, quantitative real-time and conventional PCR assays based on nuoG and gltA genes, respectively, followed by sequencing and phylogenetic inferences, B. clarridgeiae DNA was detected in the patient's aortic valve lesions. Clinical, echocardiographic, anatomopathologic and molecular features supported the diagnosis of severe aortic vegetative endocarditis possibly caused by B. clarridgeiae in a dog in Brazil.

Bartonella clarridgeiae infection in a patient with aortic root abscess and endocarditis

Introduction.

Bartonella species are increasingly recognized as agents of culture-negative endocarditis. However, to date, almost all human cases have been associated with two members of the genus, Bartonella henselae and Bartonella quintana. B. henselae infections are zoonotic, with domestic cats serving as reservoir hosts for the pathogen. Bartonella clarridgeiae also exploits cats as reservoir hosts, but its zoonotic potential is far less established.

Case presentation.

A 34-year-old male presented with palpitations after a history of aortic incompetence. During surgery for an aortic valve replacement, two vegetations were found on the aortic valve. PCR analysis of the vegetation demonstrated the presence of Bartonella species and so the patient was treated post-operatively with ceftriaxone and doxycycline, making a good recovery. Further PCR-based analysis of the patient’s aortic vegetation confirmed the presence of B. clarridgeiae.

Conclusion.

This report expands the number of Bartonella species associated with endocarditis and provides clear evidence that B. clarridgeiae should be considered a zoonotic pathogen.

Assessment of a metabarcoding approach for the characterisation of vector-borne bacteria in canines from Bangkok, Thailand

BACKGROUND

Globally, bacterial vector-borne disease (VBD) exerts a large toll on dogs in terms of morbidity and mortality but nowhere is this more pronounced than in the tropics. Tropical environments permit a burgeoning diversity and abundance of ectoparasites some of which can transmit an extensive range of infectious agents, including bacteria, amongst others. Although some of these vector-borne bacteria are responsible for both animal and human diseases in the tropics, there is a scarcity of epidemiological investigation into these pathogens' prevalence. The situation is further exacerbated by frequent canine co-infection, complicating symptomatology that regular diagnostic techniques may miss or be unable to fully characterise. Such limitations draw attention to the need to develop screening tools capable of detecting a wide range of pathogens from a host simultaneously.

RESULTS

Here, we detail the employment of a next-generation sequencing (NGS) metabarcoding methodology to screen for the spectrum of bacterial VBD that are infecting semi-domesticated dogs across temple communities in Bangkok, Thailand. Our NGS detection protocol was able to find high levels of Ehrlichia canis, Mycoplasma haemocanis and Anaplasma platys infection rates as well as less common pathogens, such as "Candidatus Mycoplasma haematoparvum", Mycoplasma turicensis and Bartonella spp. We also compared our high-throughput approach to conventional endpoint PCR methods, demonstrating an improved detection ability for some bacterial infections, such as A. platys but a reduced ability to detect Rickettsia.

CONCLUSIONS

Our methodology demonstrated great strength at detecting coinfections of vector-borne bacteria and rare pathogens that are seldom screened for in canines in the tropics, highlighting its advantages over traditional diagnostics to better characterise bacterial pathogens in environments where there is a dearth of research.

Combination of microbiome analysis and serodiagnostics to assess the risk of pathogen transmission by ticks to humans and animals in central Germany

BACKGROUND

Arthropod-borne diseases remain a major health-threat for humans and animals worldwide. To estimate the distribution of pathogenic agents and especially Bartonella spp., we conducted tick microbiome analysis and determination of the infection status of wild animals, pets and pet owners in the state of Hesse, Germany.

RESULTS

In total, 189 engorged ticks collected from 163 animals were tested. Selected ticks were analyzed by next generation sequencing (NGS) and confirmatory PCRs, blood specimens of 48 wild animals were analyzed by PCR to confirm pathogen presence and sera of 54 dogs, one cat and 11 dog owners were analyzed by serology. Bartonella spp. were detected in 9.5% of all ticks and in the blood of 17 roe deer. Further data reveal the presence of the human and animal pathogenic species of genera in the family Spirochaetaceae (including Borrelia miyamotoi and Borrelia garinii), Bartonella spp. (mainly Bartonella schoenbuchensis), Rickettsia helvetica, Francisella tularensis and Anaplasma phagocytophilum in ticks. Co-infections with species of several genera were detected in nine ticks. One dog and five dog owners were seropositive for anti-Bartonella henselae-antibodies and one dog had antibodies against Rickettsia conorii.

CONCLUSIONS

This study provides a snapshot of pathogens circulating in ticks in central Germany. A broad range of tick-borne pathogens are present in ticks, and especially in wild animals, with possible implications for animal and human health. However, a low incidence of Bartonella spp., especially Bartonella henselae, was detected. The high number of various detected pathogens suggests that ticks might serve as an excellent sentinel to detect and monitor zoonotic human pathogens.

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 Potential Risk Factors for Bartonella Infection in Tunisian Stray Dogs

Bartonellae are blood-borne and vector-transmitted pathogens, some are zoonotic, which have been reported in several Mediterranean countries. Transmission from dogs to humans is suspected, but has not been clearly demonstrated. Our objectives were to determine the seroprevalence of Bartonella henselae, Bartonella vinsonii subsp. berkhoffii, Bartonella clarridgeiae, and Bartonella bovis (as a proxy for Candidatus Bartonella merieuxii) in stray dogs from Tunisia, identify the Bartonella species infecting the dogs and evaluate potential risk factors for canine infection. Blood samples were collected between January and November 2013 from 149 dogs in 10 Tunisian governorates covering several climatic zones. Dog-specific and geographic variables were analyzed as potential risk factors for Bartonella spp. seropositivity and PCR-positivity. DNA was extracted from the blood of all dogs and tested by PCR for Bartonella, targeting the ftsZ and rpoB genes. Partial sequencing was performed on PCR-positive dogs. Twenty-nine dogs (19.5%, 95% confidence interval: 14-27.4) were seropositive for one or more Bartonella species, including 17 (11.4%) for B. vinsonii subsp. berkhoffii, 14 (9.4%) for B. henselae, 13 (8.4%) for B. clarridgeiae, and 7 (4.7%) for B. bovis. Statistical analysis revealed a few potential risk factors, mainly dog's age and breed, latitude and average winter temperature. Twenty-two (14.8%) dogs, including 8 of the 29 seropositive dogs, were PCR-positive for Bartonella based on the ftsZ gene, with 18 (81.8%) of these 22 dogs also positive for the rpoB gene. Partial sequencing showed that all PCR-positive dogs were infected with Candidatus B. merieuxii. Dogs from arid regions and regions with cold average winter temperatures were less likely to be PCR-positive than dogs from other climatic zones. The widespread presence of Bartonella spp. infection in Tunisian dogs suggests a role for stray dogs as potential reservoirs of Bartonella species in Tunisia.

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.

Infective endocarditis in 13 cats

INTRODUCTION

To describe the clinical presentation, clinicopathological abnormalities and outcomes of a series of cats diagnosed with infective endocarditis (IE) at two tertiary care referral institutions.

ANIMALS

Thirteen client-owned cats presenting to the cardiology or emergency services of tertiary referral institutions with a diagnosis of endocarditis based on the modified Duke criteria.

MATERIALS AND METHODS

Retrospective case series. Medical records were reviewed to extract relevant data. In addition, cases that had cardiac tissue available were evaluated by polymerase chain reaction for the presence of Bartonella DNA.

RESULTS

Prevalence of feline IE was 0.007%. Cats with endocarditis tended to be older (median age: 9 years, range: 2-12 years) and no sex or breed was overrepresented. Commonly encountered clinical signs included respiratory distress (n = 5) and locomotor abnormalities of varying severity (n = 5). Echocardiographic examination detected valvular lesions consistent with endocarditis on the aortic (n = 8) or mitral (n = 5) valves. Nine cats were diagnosed with congestive heart failure at the time of endocarditis diagnosis. Overall, prognosis was grave with a median survival time of 31 days.

CONCLUSIONS

In contrast to dogs, cats with IE typically present with clinical signs consistent with cardiac decompensation and locomotor abnormalities suggestive of either thromboembolic disease or inflammatory arthritis. Given the advanced state of disease when diagnosis typically occurs, prognosis is grave.

Bartonella spp. - a chance to establish One Health concepts in veterinary and human medicine

Infectious diseases remain a remarkable health threat for humans and animals. In the past, the epidemiology, etiology and pathology of infectious agents affecting humans and animals have mostly been investigated in separate studies. However, it is evident, that combined approaches are needed to understand geographical distribution, transmission and infection biology of “zoonotic agents”. The genus Bartonella represents a congenial example of the synergistic benefits that can arise from such combined approaches: Bartonella spp. infect a broad variety of animals, are linked with a constantly increasing number of human diseases and are transmitted via arthropod vectors. As a result, the genus Bartonella is predestined to play a pivotal role in establishing a One Health concept combining veterinary and human medicine.

Bartonella clarridgeiae bacteremia detected in an asymptomatic blood donor

Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.

Bartonella clarridgeiae and Bartonella vinsonii subsp. berkhoffii exposure in captive wild canids in Brazil

SUMMARY Wild canids are potential hosts for numerous species of Bartonella, yet little research has been done to quantify their infection rates in South America. We sought to investigate Bartonella seroprevalence in captive wild canids from 19 zoos in São Paulo and Mato Grosso states, Brazil. Blood samples were collected from 97 wild canids belonging to four different native species and three European wolves (Canis lupus). Indirect immunofluorescent antibody testing was performed to detect the presence of B. henselae, B. vinsonii subsp. berkhoffii, B. clarridgeiae, and B. rochalimae. Overall, Bartonella antibodies were detected in 11 of the canids, including five (12·8%) of 39 crab-eating foxes (Cerdocyon thous), three (11·1%) of 27 bush dogs (Speothos venaticus), two (8·7%) of 23 maned wolves (Chrysocyon brachyurus) and one (12·5%) of eight hoary foxes (Lycalopex vetulus), with titres ranging from 1:64 to 1:512. Knowing that many species of canids make excellent reservoir hosts for Bartonella, and that there is zoonotic potential for all Bartonella spp. tested for, it will be important to conduct further research in non-captive wild canids to gain an accurate understanding of Bartonella infection in free-ranging wild canids in South America.

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.

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.

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.

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.

Feline bartonellosis

Bartonella infection is common among domestic cats, but the role of Bartonella species as feline pathogens requires further study. Most Bartonella species that infect cats are zoonotic. Cats are the mammalian reservoir and vector for Bartonella henselae, an important zoonotic agent. Cat fleas transmit Bartonella among cats, and cats with fleas are an important source of human B henselae infections. New information about Bartonella as feline pathogens has recently been published, and this article summarizes much of that information. Issues surrounding diagnosis and treatment of feline Bartonella infections are described, and prevention of zoonotic transmission of Bartonella is discussed.

Infective endocarditis in dogs: diagnosis and therapy

Infective endocarditis (IE) is a bacterial disease that commonly occurs in dogs. Difficulty in diagnosis and underreporting of IE in dogs contribute to the reported low prevalence rate of the disease. The mitral and aortic valves are the worst affected by IE. Common causative microbial agents include Staphylococcus spp, Streptococcus spp, Escherichia coli, and Bartonella spp. Congestive heart failure, immune-mediated disease, and thromboembolism are the major complications of IE. Diagnosis of IE by echocardiography and long-term treatment with broad-spectrum antibiotics may contribute to the timely detection and treatment of the disease.

Molecular evidence of Bartonella infection in domestic dogs from Algeria, North Africa, by polymerase chain reaction (PCR)

Bartonella species are being recognized as important bacterial human and canine pathogens, and are associated with multiple arthropod vectors. Bartonella DNA extracted from blood samples was obtained from domestic dogs in Algiers, Algeria. Polymerase chain reaction (PCR) and DNA sequence analyses of the ftsZ gene and the 16S-23S intergenic spacer region (ITS) were performed. Three Bartonella species: Bartonella vinsonii subsp. berkhoffii, Bartonella clarridgeiae, and Bartonells elizabethae were detected infecting Algerian dogs. To our knowledge, this study is the first report of detection by PCR amplification of Bartonella in dogs in North Africa.

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.

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.

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.

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.

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.

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.

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.

Gray foxes (Urocyon cinereoargenteus) as a potential reservoir of a Bartonella clarridgeiae-like bacterium and domestic dogs as part of a sentinel system for surveillance of zoonotic arthropod-borne pathogens in northern California

Two species of Bartonella, a novel Bartonella clarridgeiae-like bacterium and B. vinsonii subsp. berkhoffii, were isolated from rural dogs and gray foxes in northern California. A novel B. clarridgeiae-like species was isolated from 3 (1.7%) of 182 dogs and 22 (42%) of 53 gray foxes, while B. vinsonii subsp. berkhoffii was isolated from 1 dog (0.5%) and 5 gray foxes (9.4%). PCR and DNA sequence analyses of the citrate synthase (gltA) gene and the 16S-23S intergenic spacer region suggested that strains infecting dogs and gray foxes were identical. Fifty-four dogs (29%) and 48 gray foxes (89%) had reciprocal titers of antibodies against Bartonella spp. of > or =64. The high prevalence of bacteremia and seroreactivity to Bartonella spp. in gray foxes suggests that they may act as a reservoir species for the B. clarridgeiae-like species in this region. Domestic dogs were also tested for other arthropod-borne infectious agents. Fifty-one dogs (28%) were positive for Dirofilaria immitis antigen, seventy-four (40%) were seroreactive to Anaplasma phagocytophilum, and five (2.7%) were seropositive for Yersinia pestis. Fourteen dogs (7.6%) were PCR positive for A. phagocytophilum. Polytomous logistic regression models were used to assess the association of Bartonella antibody titer categories with potential risk factors and the presence of other vector-borne agents in domestic dogs. Older dogs were more likely to be seroreactive to Bartonella spp. There was no association between the exposure of dogs to Bartonella and the exposure of dogs to A. phagocytophilum in this study.

Cat scratch disease from a domestic dog

Cat scratch disease (CSD), caused by Bartonella henselae, is a zoonosis and characterized by self-limited lymphadenopathy. It is transmitted commonly by scratch or bite from cats or kitten. We report an unusual case of CSD caused by a domestic dog scratch that we believe is the first report in Taiwan. A 23-year-old healthy woman developed cervical lymphadenopathy, mild fever, headache, and malaise 3 days after dog scratch. Her symptoms improved after azithromycin treatment. Serology proved B. henselae infection. The owners of a domestic dog might be at risk of "cat" scratch disease.

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.