Isolation of Bartonella washoensis from a Dog with Mitral Valve Endocarditis

Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
Journal of Clinical Microbiology (Impact Factor: 3.99). 12/2003; 41(11):5327-32. DOI: 10.1128/JCM.41.11.5327-5332.2003
Source: PubMed


We report the first documented case of Bartonella washoensis bacteremia in a dog with mitral valve endocarditis. B. washoensis was isolated in 1995 from a human patient with cardiac disease. The main reservoir species appears to be ground squirrels (Spermophilus beecheyi) in the western United States. Based on echocardiographic findings, a diagnosis of infective vegetative valvular mitral endocarditis was made in a spayed 12-year-old female Doberman pinscher. A year prior to presentation, the referring veterinarian had detected a heart murmur, which led to progressive dyspnea and a diagnosis of congestive heart failure the week before examination. One month after initial presentation, symptoms worsened. An emergency therapy for congestive heart failure was unsuccessfully implemented, and necropsy evaluation of the dog was not permitted. Indirect immunofluorescence tests showed that the dog was strongly seropositive (titer of 1:4,096) for several Bartonella antigens (B. vinsonii subsp. berkhoffii, B. clarridgeiae, and B. henselae), highly suggestive of Bartonella endocarditis. Standard aerobic and aerobic-anaerobic cultures were negative. However, a specific blood culture for Bartonella isolation grew a fastidious, gram-negative organism 7 days after being plated. Phenotypic and genotypic characterizations of the isolate, including partial sequencing of the citrate synthase (gltA), groEL, and 16S rRNA genes, indicated that this organism was identical to B. washoensis. The dog was seronegative for all tick-borne pathogens tested (Anaplasma phagocytophilum, Ehrlichia canis, and Rickettsia rickettsii), but the sample was highly positive for B. washoensis (titer of 1:8,192) and, according to indirect immunofluorescent-antibody assay, weakly positive for phase II Coxiella burnetii infection.

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    • "This result was not surprising given that serological cross-reactivity of these three Bartonella spp. and others has been previously reported in sera from Bartonella-infected humans and animals (Maurin et al. 2002, Chomel et al. 2003, Tsuneoka et al. 2004, Boulouis et al. 2005). In contrast to samples from sea otter carcasses, the majority of the sera from presumably healthy, live-captured northern sea otters showed exclusive reactivity against B. washoensis (86%; 12/14 B. washoensis–positive samples). "
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    ABSTRACT: Abstract 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.
    Vector Borne and Zoonotic Diseases 12/2014; 14(12):831-7. DOI:10.1089/vbz.2014.1612 · 2.30 Impact Factor
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    • "The partial DNA sequences of the 16S rRNA, gltA, and groEL genes of B. washoensis strains obtained from ground squirrels were identical to those from the human patient, suggesting that the organism is zoonotic and the ground squirrels are the natural reservoirs of the pathogen in western USA (Kosoy et al., 2003). In the same year, B. washoensis was isolated from a dog with mitral valve vegetative endocarditis and the sequences of several genes of the strains were identical to those of B. washoensis from the human and the California ground squirrels (Chomel et al., 2003). Thus, B. washoensis is suggested to be able to infect several species of mammals. "
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    ABSTRACT: To clarify phylogenetic relationships and genetic diversity among Bartonella washoensis strains obtained from squirrels, multi-locus sequence analysis (MLSA) with the 16S rRNA, ftsZ, gltA, groEL, ribC, and rpoB genes was applied for 20 strains of B. washoensis isolated from five genera of squirrels (Tamias, Tamiasciurus, Glaucomys, Sciurus, and Spermophilus) within the family Sciuridae. Sequence similarities in the concatenated sequences of B. washoensis strains from squirrels of different genera ranged from 94.7% (Sciurus vs. Spermophilus) to 98.4% (Tamiasciurus vs. Glaucomys). Phylogenetic trees based on the concatenated sequences revealed that B. washoensis strains formed five distinct clades and each clade correlated with the genus of squirrel from which the strains were originally obtained. The discrimination was supported by 100% bootstrap values and posterior probabilities, respectively. These results suggest that B. washoensis strains may have co-speciated with their squirrel hosts and provide new insights into the application of the MLSA to identify sources of B. washoensis infection with accuracy.
    Veterinary Microbiology 08/2010; 148(1):60-5. DOI:10.1016/j.vetmic.2010.08.007 · 2.51 Impact Factor
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    • "Subsequently, this pathogen has also been associated with cardiac arrhythmias, myocarditis, granulomatous rhinitis, anterior uveitis and chorioditis [1,3-6]. Other Bartonella species which have also been associated with pathology and clinical signs in dogs, including endocarditis, hepatic disease and sudden death are: B. henselae [7-11], B. clarridgeiae [9,12], B. washoensis [13], B. elizabethae [14] and B. quintana [15]. The first and the last, B. henselae and B. quintana, were also detected in the blood or lymph nodes of healthy dogs and dogs suffering from lymphoma [8]. "
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    ABSTRACT: ABSTRACT : 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.
    Parasites & Vectors 02/2009; 2 Suppl 1(Suppl 1):S3. DOI:10.1186/1756-3305-2-S1-S3 · 3.43 Impact Factor
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