Abstract：
We describe a case of brucellosis in a man in his 20s, who presented to the emergency department with a 1-month history of fevers, dry cough and knee pain. Blood cultures were positive after 55 hours and Ochrobactrum daejeonense was identified on matrix-assisted laser desorption/ionisation time of flight (MALDI-TOF) mass spectrometry. Ochrobactrum spp are Gram-negative organisms that are phylogenetically related to Brucella spp but commercially available MALDI-TOF libraries cannot distinguish between the two genera. Further positive blood cultures for O. daejeonense combined with characteristic growth patterns for Brucella spp led to targeted questioning of the patient regarding potential exposure risks, which revealed a history of consumption of unpasteurised camel milk in the Middle East 3 months earlier. Treatment of brucellosis was initiated and subsequent whole genome sequencing identified the blood culture isolate as Brucella melitensis confirming the diagnosis of brucellosis. This case highlights the challenges in the diagnosis of brucellosis in low-incidence settings.
摘要：
我们描述了一个20多岁的男人的布鲁氏菌病病例，他带着一个月的发烧史被送到急诊科，干咳和膝盖疼痛。55小时后，血液培养呈阳性，并且在基质辅助激光解吸/电离飞行时间（MALDI-TOF）质谱上鉴定了大黄杆菌。苍白杆菌属是与布鲁氏菌属相关的革兰氏阴性生物，但市售的MALDI-TOF文库无法区分这两个属。进一步的阳性血液培养与布鲁氏菌属的特征性生长模式相结合，导致患者有针对性地询问潜在的暴露风险，这揭示了3个月前在中东消费未经巴氏杀菌的骆驼奶的历史。开始布鲁氏菌病的治疗，随后的全基因组测序将血液培养分离物鉴定为布鲁氏菌，证实了布鲁氏菌病的诊断。该病例凸显了在低发病率环境中诊断布鲁氏菌病的挑战。
