Division of Infection Control and Prevention, Osaka University, 2-15 Yamadaoka, Suita-Shi, Osaka, 565-0871, Japan.
Division of Fostering Required Medical Human Resources, Center for Infectious Disease Education and Research (CiDER), Osaka University, Osaka, Japan.
BMC Infect Dis. 2024 Jul 15;24(1):699. doi: 10.1186/s12879-024-09606-4.
Ruthenibacterium lactatiformans, a Gram-stain-negative, rod-shaped, obligate anaerobic bacterium of the Oscillospiraceae family, has not been previously reported in human infections. This study reports the first case of bacteraemia and potential vertebral osteomyelitis caused by Ruthenibacterium lactatiformans.
An 82-year-old man with a history of diabetes, chronic renal failure, and prior spinal surgery for spondylolisthesis and spinal stenosis presented with fever and lower back pain. Magnetic resonance imaging revealed multiple vertebral osteomyelitis lesions. Initial blood cultures identified methicillin-resistant Staphylococcus aureus (MRSA), which prompted vancomycin treatment. However, repeated blood cultures not only confirmed persistent MRSA, but also detected Gram-negative bacilli (GNB). Despite surgical removal of the spinal hardware and antimicrobial therapy, the patient's osteomyelitis worsened, necessitating transfer for further management. Subsequent analysis using 16S rRNA gene sequencing identified the GNB as Ruthenibacterium lactatiformans.
This is the first documented instance of human infection with Ruthenibacterium lactatiformans, signifying its pathogenic potential in vertebral osteomyelitis. The involvement of anaerobic bacteria and the possibility of polymicrobial infections complicate the diagnosis and treatment of vertebral osteomyelitis. This report underscores the need for caution when identifying the causative organism and selecting an appropriate treatment.
鲁氏盐杆菌是阿克曼氏菌科的革兰氏阴性、杆状、专性厌氧菌，以前从未在人类感染中报道过。本研究报告了首例由鲁氏盐杆菌引起的菌血症和潜在的脊椎骨髓炎。
一名 82 岁男性，有糖尿病、慢性肾衰竭和先前因脊椎滑脱和脊椎狭窄而行脊柱手术的病史，出现发热和腰痛。磁共振成像显示多个脊椎骨髓炎病变。初始血培养鉴定出耐甲氧西林金黄色葡萄球菌（MRSA），促使使用万古霉素治疗。然而，重复的血培养不仅证实了持续存在的 MRSA，还检测到革兰氏阴性杆菌（GNB）。尽管进行了脊柱内固定去除术和抗菌治疗，患者的骨髓炎仍恶化，需要转院进一步治疗。随后使用 16S rRNA 基因测序分析鉴定出 GNB 为鲁氏盐杆菌。
这是首例有记录的人类感染鲁氏盐杆菌的病例，表明其在脊椎骨髓炎中有致病潜力。厌氧菌的参与和可能的混合感染使脊椎骨髓炎的诊断和治疗变得复杂。本报告强调在确定病原体和选择适当治疗时需谨慎。
