Rifampin monotherapy for multidrug-resistant Chryseobacterium indologenes meningitis unresponsive to trimethoprim-sulfamethoxazole: a case report and review of the literature.

Multidrug-resistant (MDR) Chryseobacterium indologenes is an emerging pathogen causing challenging central nervous system (CNS) infections, for which there are no standardized treatment guidelines. A systematic review of the literature indicates that such infections are extremely rare. Although trimethoprim-sulfamethoxazole (TMP-SMX) is the most frequently reported first-line therapy, its clinical efficacy is not universal, posing a significant therapeutic challenge. We present the case of a 25-year-old postpartum woman who developed MDR C. indologenes meningitis and a brain abscess after undergoing a neurosurgical procedure. The infection did not respond to initial treatment with meropenem or a subsequent course of the first-line agent TMP-SMX. Based on antimicrobial susceptibility testing, therapy was switched to rifampin monotherapy, which led to rapid clinical and microbiological recovery. The patient completed a 24-day course of rifampin and remained recurrence-free during a 20-month follow-up. This is the first report of successful rifampin monotherapy for an MDR C. indologenes CNS infection in a patient unresponsive to TMP-SMX. When considered alongside existing literature, these findings highlight the essential role of susceptibility testing and establish rifampin as an important salvage therapy for this life-threatening infection, particularly when recommended first-line treatments fail.