Aortic Valve Endocarditis in a Dog Due toBartonella clarridgeiae

Abstract

We report the first documented case of endocarditis associated with Bartonella clarridgeiae in any species. B. clarridgeiae was identified as a possible etiological agent of human cat scratch disease. Infective vegetative valvular aortic endocarditis was diagnosed in a 2.5-year-old male neutered boxer. Historically, the dog had been diagnosed with a systolic murmur at 16 months of age and underwent balloon valvuloplasty for severe valvular aortic stenosis. Six months later, the dog was brought to a veterinary hospital with an acute third-degree atrioventricular block and was diagnosed with infective endocarditis. (1,5,8,19,20,45,49).At present, only two Bartonella species have been identified to cause clinical diseases in dogs. B. vinsonii subsp. berkhoffii has been shown to cause endocarditis, arrhythmia, and myocarditis (6, 9, 31), as well as granulomatous lymphadenitis and granulomatous rhinitis (40), and B. henselae was recently associated with a case of peliosis hepatis (27). During an active investigation of canine endocarditis cases, we cultured a fastidious, gram-negative organism that we identified to be B. clarridgeiae from the blood of a dog with an aortic endocarditis. We describe the clinicopathologic and histopathologic features as well as the microbiologic and genotypic identification of the organism isolated from the dog's blood and detected by molecular methods in the infected aortic valve. MATERIALS AND METHODSStrain sources. The type strains of B. vinsonii subsp. berkhoffii (ATCC 51672) and B. clarridgeiae (ATCC 51734) were obtained from the American Type Culture Collection (Rockville, Md.). Isolate B. henselae strain U4 was obtained from our culture collection at the University of California, Davis (UC Davis). Isolate UCD-dog1 was cultured from the blood of the dog described in this report.Clinical samples. Blood (6 ml) was collected aseptically from the dog's external jugular vein and both lateral saphenous veins at the time of acute thirddegree atrioventricular (AV) block, infectious endocarditis, and just prior to death. Blood samples were submitted for aerobic and aero-anaerobic cultures, as well as for specific Bartonella isolation on fresh blood agar (5% defibrinated rabbit blood) (16). Serum was submitted for determination of Bartonella antibody titers and for detection of several tick-borne pathogens (Ehrlichia spp., Borrelia burgdorferi) and of Coxiella burnetii, a known agent of endocarditis in humans and animals.Similarly, on 22 June 2000, blood (0.5 to 2 ml) was collected aseptically from the external jugular vein of three cats from the household of origin for Bartonella culture and serology. A serum sample was also obtained from the dog's owner for possible detection of Bartonella antibodies.Tissue samples. Fragments of the aortic and pulmonic valves were frozen for PCR and electron microscopic examination and fixed in 10% buffered formalin for histology. After 24 h, formalin-fixed tissues were embedded in paraffin, sectioned, and stained with hematoxylin and eosin or silver (Wa...

Factors associated with the rapid emergence of zoonotic Bartonella infections

“…berkhoffii has also been isolated from clinically healthy dogs, which may be long-term carriers of the bacterium [132]. Dogs can be infected by several other zoonotic Bartonella species, including B. clarridgeiae isolated from the blood of a dog with endocarditis [48] and detected by PCR in a dog with hepatic lymphocytic hepatitis [91]. B. henselae DNA has been detected in a dog with peliosis hepatis [124] and more recently in a dog with granulomatous hepatopathy [91].…”

“…berkhoffii was identified in a human case of endocarditis [200]. This subspecies appears to be the most common Bartonella species/subspecies causing endocarditis in dogs [25]; however, other Bartonella species, including B. clarridgeiae, B. washoensis have been identified in canine endocarditis cases [48,50,154]. Overall, the prevalence of B. vinsonii subsp.…”

Canine bartonellosis: serological and molecular prevalence in Brazil and evidence of co-infection withBartonella henselaeandBartonella vinsoniisubsp.berkhoffii

“…berkhoffii (hereafter B. v. berkhoffii) DNA was detected in aortic valves of six dogs with vegetative endocarditis, based upon independent studies [9,14,32]; B. elizabethae DNA was detected in a dog with weight loss and sudden death [37]; B. henselae DNA was sequenced from a dog with peliosis hepatis and from a dog with granulomatous hepatitis [22]; and B. washoensis was isolated from a dog with mitral valve endocarditis [15]. A potentially new species closely related to B. clarridgeiae (proposed name B. rochalimaea) has been isolated from three dogs and from 22 gray foxes in California [32] 1 .…”

Molecular Evidence of Bartonella Infection in Domestic Dogs from Algeria, North Africa, by Polymerase Chain Reaction (PCR)

“…2 However, B. clarridgeiae was isolated from the blood and amplified and sequenced from the heart valve of a dog with aortic endocarditis. 15 Bartonella clarridgeiae has also been isolated from dogs from Gabon. 16 Bartonella elizabethae was isolated for the first time in 1986 from the blood of a human patient with endocarditis.…”

“…Bartonella clarridgeiae was associated with endocartitis and lymphocytic hepatitis in a few sick dogs, 15,22 and B. elizabethae has also been detected in dogs with various clinical abnormalities including lethargy, anemia, and weight loss. 18 In this study, two dogs infected with Bartonella were healthy on physical examination.…”