A Rare Bacteremia in a Patient With Osteomyelitis and Sacral Ulcer: A Case Report of Tissierella praeacuta and Parvimonas micra.

and are anaerobic bacteria rarely encountered in clinical practice, making their identification in bacteremia significant. These organisms are typically found in the human gut and oral flora and are generally considered low-virulence. However, in patients with compromised immunity or significant comorbidities, they can lead to severe infections, including bacteremia. Osteomyelitis, particularly when associated with chronic sacral ulcers, can increase the risk of secondary infections, complicating patient outcomes. We present the case of an 86-year-old male patient with a complex medical history, including atrial fibrillation, congestive heart failure, and chronic obstructive pulmonary disease, who developed bacteremia caused by and . The patient was admitted with a severely infected stage IV sacral ulcer, which had progressed rapidly and was accompanied by systemic signs of sepsis. Despite broad-spectrum antibiotic therapy and surgical debridement, the patient's condition worsened, leading to the identification of rare pathogens in blood cultures. Subsequent management included adjusting antimicrobial therapy and aggressive wound care, ultimately stabilizing the patient's condition. This case highlights the significance of recognizing and accurately diagnosing rare anaerobic bacteremia in patients with chronic ulcers and osteomyelitis. The involvement of and , typically low-virulence organisms, in such severe infections underscores the need for thorough microbiological evaluation and a multidisciplinary approach to treatment. Early identification and appropriate management are crucial in preventing adverse outcomes in complex cases such as this.