Severe sepsis caused by Parvimonas micra identified using 16S ribosomal RNA gene sequencing following patient death

An 83-year-old man visited an orthopedic hospital for his lower back pain. A compression fracture was noted in his second lumbar vertebra. He had taken pain medication for approximately five weeks, but the pain had worsened and he was unable to walk by himself. He was transferred to our hospital and diagnosed with lumbar spondylodiscitis, an iliopsoas abscess, gas gangrene of his left lower limb, and left massive pleural effusion. He was admitted to the intensive care unit. We drained the abscess and pleural effusion, provided continuous hemodiafiltration under ventilator control, and administered intravenous antibiotics. However, he died from sepsis and multiple organ failure three days following admission. Several days after his death, gram-positive cocci were identified in blood culture, pus from the abscess, and pleural exudate; although the causative organism could not be identified. Two weeks subsequent to his death, 16S ribosomal RNA gene sequencing identified Parvimonas micra in specimens taken from his body. Keywords: Anaerobic infection, Gas gangrene, Iliopsoas abscess, Parvimonas micra, Spondylodisciti