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

Abstract 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.摘要 本研究报道了拉丁美洲地区首例有记录的犬类克拉丽斯巴尔通体（Bartonella clarridgeiae）相关性心内膜炎病例。研究对一只10岁雄性混种犬确诊为感染性赘生性主动脉瓣心内膜炎。该犬临床表现为V/VI级收缩期与舒张期杂音、高热及进行性体重下降。胸部X线检查可见心脏增大及肺野弥漫性肺泡影。超声心动图检查显示，主动脉瓣叶附着不规则高回声结构，该结构造成左心室流出道梗阻及重度主动脉瓣关闭不全。尸检时在主动脉半月瓣处可见直径1.0cm的赘生、色白且质地坚硬的病变结构。本研究联合使用基于昆虫源性培养基的预富集液体培养、分别以nuoG基因与gltA基因为靶标的实时定量聚合酶链式反应与常规PCR检测，随后开展测序及系统发育推断，最终在患犬的主动脉瓣病变组织中检出克拉丽斯巴尔通体的DNA。临床特征、超声心动图表现、解剖病理结果及分子生物学检测结果均支持，巴西地区一例犬类重度主动脉赘生性心内膜炎可能由克拉丽斯巴尔通体引发。