How an Antimicrobial Stewardship Team Treated a Nocardia farcinica-Associated Brain Abscess: A Case Report.

ABSTRACT

Nocardia species, which are ubiquitous in the environment, form lesions primarily in immunocompromised patients via oral or cutaneous infection. Some of these Nocardia species, such as N. farcinica, also infect the central nervous system via hematogenous dissemination, which rarely results in brain abscesses. Notably, N. farcinica is resistant to numerous antimicrobial drugs used in empirical therapy, necessitating the intervention of an infectious disease specialist. To date, no case of antimicrobial stewardship teams (ASTs) playing a central role in community hospitals without an infectious disease specialist has been reported. Here, we describe a case of N. farcinica-associated brain abscess in a small-to-medium-sized hospital with no infectious disease department or specialist, in which the AST assisted in the identification of the causative organism and in selecting appropriate therapeutic agents, ultimately leading to a cure. The patient was an 88-year-old man with a high fever. He had been taking prednisolone (10-15 mg/day) for approximately 1 year for pemphigoid. Considering the possibility of fever owing to bacteremia of cutaneous origin, ampicillin/sulbactam antimicrobial therapy at 6 g/day was initiated. A subsequent close examination led to the diagnosis of a brain abscess. Emergency abscess drainage was performed by a neurosurgeon, and postoperative antimicrobial combination therapy comprising ceftriaxone (4 g/day), vancomycin (2 g/day), and metronidazole (1,500 mg/day) was commenced. The AST suspected Nocardia infection earlier, but further testing was difficult to perform at this facility. Therefore, by requesting assistance from Nagoya University Hospital, we performed early bacterial identification by mass spectrometry and appropriate antimicrobial susceptibility testing by a custom panel on day 11. The patient was non-responsive to all the previously used antibiotics at the time of admission. On day 13 after admission, the patient was successfully treated with trimethoprim-sulfamethoxazole (TMP-SMX) and imipenem/cilastatin sodium, and the patient was cured. The AST can be as effective as an infectious disease specialist when a strong working relationship is established between the team and clinicians. Further, the activities of the AST can improve patient survival via active medical support in collaboration with attending physicians.