Breitschwerdt Edward B, Maggi Ricardo G, Robert Mozayeni B, Hegarty Barbara C, Bradley Julie M, Mascarelli Patricia E
Intracellular Pathogens Research Laboratory and the Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
Parasit Vectors. 2010 Aug 24;3:76. doi: 10.1186/1756-3305-3-76.
Cats appear to be the primary reservoir host for Bartonella koehlerae, an alpha Proteobacteria that is most likely transmitted among cat populations by fleas (Ctenocephalides felis). Bartonella koehlerae has caused endocarditis in a dog and in one human patient from Israel, but other clinically relevant reports involving this bacterium are lacking. Despite publication of numerous, worldwide epidemiological studies designed to determine the prevalence of Bartonella spp. bacteremia in cats, B. koehlerae has never been isolated using conventional blood agar plates. To date, successful isolation of B. koehlerae from cats and from the one human endocarditis patient has consistently required the use of chocolate agar plates.
In this study, Bartonella koehlerae bacteremia was documented in eight immunocompetent patients by PCR amplification and DNA sequencing, either prior to or after enrichment blood culture using Bartonella alpha Proteobacteria growth medium. Presenting symptoms most often included fatigue, insomnia, joint pain, headache, memory loss, and muscle pain. Four patients were also infected with Bartonella vinsonii subsp. berkhoffii genotype II. After molecular documentation of B. koehlerae infection in these patients, a serological test was developed and serum samples were tested retrospectively. Bartonella koehlerae antibodies were not detected (titers < 1:16) in 30 healthy human control sera, whereas five of eight patient samples had B. koehlerae antibody titers of 1:64 or greater.
Although biased by a study population consisting of individuals with extensive arthropod and animal exposure, the results of this study suggest that B. koehlerae bacteremia is more common in immunocompetent people than has been previously suspected. Future studies should more thoroughly define modes of transmission and risk factors for acquiring infection with B. koehlerae. In addition, studies are needed to determine if B. koehlerae is a cause or cofactor in the development of arthritis, peripheral neuropathies or tachyarrhythmias in patients.
猫似乎是科氏巴尔通体的主要储存宿主，科氏巴尔通体是一种α变形菌，很可能通过跳蚤（猫栉首蚤）在猫群中传播。科氏巴尔通体已在一只狗和一名来自以色列的人类患者中引起心内膜炎，但缺乏涉及这种细菌的其他临床相关报告。尽管发表了许多旨在确定猫中巴尔通体菌血症患病率的全球流行病学研究，但从未使用传统血琼脂平板分离出科氏巴尔通体。迄今为止，要从猫和那名人类心内膜炎患者中成功分离出科氏巴尔通体，始终需要使用巧克力琼脂平板。
在本研究中，通过PCR扩增和DNA测序，在8名免疫功能正常的患者中记录到了科氏巴尔通体菌血症，这些患者在使用巴尔通体α变形菌生长培养基进行富集血培养之前或之后。出现的症状最常见的包括疲劳、失眠、关节疼痛、头痛、记忆力减退和肌肉疼痛。4名患者还感染了文森巴尔通体伯克霍夫亚种基因型II。在对这些患者进行科氏巴尔通体感染的分子记录后，开发了一种血清学检测方法，并对血清样本进行了回顾性检测。30份健康人对照血清中未检测到科氏巴尔通体抗体（滴度<1:16），而8份患者样本中有5份的科氏巴尔通体抗体滴度为1:64或更高。
尽管本研究人群偏向于有大量节肢动物和动物接触史的个体，但该研究结果表明，科氏巴尔通体菌血症在免疫功能正常的人群中比之前怀疑的更为常见。未来的研究应更全面地确定传播方式和感染科氏巴尔通体的危险因素。此外，还需要进行研究以确定科氏巴尔通体是否是患者关节炎、周围神经病变或快速性心律失常发生的原因或辅助因素。
