Kim Seon Young, Joo Sei Ick, Yi Jongyoun, Kim Eui Chong
Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea.
Korean J Lab Med. 2010 Apr;30(2):160-5. doi: 10.3343/kjlm.2010.30.2.160.
Although the association between Streptococcus bovis endocarditis and colon carcinoma is well known, very few cases of S. bovis infection associated with underlying malignancies have been reported in Korea. The S. bovis group has been recently reclassified and renamed as Streptococcus gallolyticus and Streptococcus infantarius subspecies under a new nomenclature system. We report a case of infective endocarditis with colon cancer caused by S. gallolyticus subsp. gallolyticus (previously named S. bovis biotype I). A 59-yr-old woman presented with a 1-month history of fever. Initial blood cultures were positive for gram-positive cocci, and echocardiography showed vegetation on mitral and aortic valves. Antibiotic treatment for infective endocarditis was started. The infecting strain was a catalase-negative and bile-esculin-positive alpha-hemolytic Streptococcus susceptible to penicillin and vancomycin. The strain was identified as S. gallolyticus subsp. gallolyticus with the use of the Vitek 2 GPI and API 20 Strep systems (bioMérieux, USA). The 16S rDNA sequences of the blood culture isolates showed 100% homology with those of S. gallolyticus subsp. gallolyticus reported in GenBank. The identification of the infecting organism, and the subsequent communication among clinical microbiologists and physicians about the changed nomenclature, led to the detection of colon cancer. The patient recovered after treatment with antibiotics, valve surgery, and operation for colon cancer. This is the first report of biochemical and genetic identification of S. gallolyticus subsp. gallolyticus causing infective endocarditis associated with underlying colon cancer in a Korean patient.
虽然牛链球菌心内膜炎与结肠癌之间的关联已为人熟知，但在韩国，与潜在恶性肿瘤相关的牛链球菌感染病例报道极少。牛链球菌组最近在新的命名系统下被重新分类并更名为解脲链球菌和婴儿链球菌亚种。我们报告一例由解脲链球菌亚种解脲链球菌（以前称为牛链球菌生物型I）引起的伴有结肠癌的感染性心内膜炎病例。一名59岁女性有1个月发热病史。初始血培养革兰氏阳性球菌阳性，超声心动图显示二尖瓣和主动脉瓣有赘生物。开始针对感染性心内膜炎进行抗生素治疗。感染菌株是一种过氧化氢酶阴性、胆汁七叶苷阳性的α溶血性链球菌，对青霉素和万古霉素敏感。使用Vitek 2 GPI和API 20 Strep系统（美国bioMérieux公司）将该菌株鉴定为解脲链球菌亚种解脲链球菌。血培养分离株的16S rDNA序列与GenBank中报道的解脲链球菌亚种解脲链球菌的序列显示100%同源性。感染病原体的鉴定以及随后临床微生物学家和医生之间关于名称变化的沟通，促成了结肠癌的发现。患者经抗生素治疗、瓣膜手术和结肠癌手术后康复。这是韩国首例对引起与潜在结肠癌相关的感染性心内膜炎的解脲链球菌亚种解脲链球菌进行生化和基因鉴定的报告。
