Introduction: Chryseobacterium arthrosphaerae is a gram-negative bacteria, known for its intrinsic multidrug resistance, which can lead to treatment difficulties.
Patient concerns: A 56-year-old male had an indwelling external ventricular drainage catheter for 6 months and had been frequently treated with antibiotics for nosocomial infections. He showed cerebrospinal fluid pleocytosis and an abrupt fever during hospitalization.
Diagnosis: He was diagnosed as a ventriculitis caused by Chryseobacterium arthrosphaerae (C arthrosphaerae).
Intervention: Initially, we used ciprofloxacin as the backbone in combination with minocycline (and rifampin). However, fever and pleocytosis persisted, and improvement was slow. We then switched the minocycline and rifampin regiment to trimethoprim/sulfamethoxazole. Following this switch of antibiotics, the patient's pleocytosis rapidly improved, allowing the replacement of his external ventricular drainage catheters. C arthrospharae was no longer growing in cerebrospinal fluid and he was recovered from ventriculitis.
Outcomes: The patient remains alive without any incidence of C arthrosphaerae recurrence.
Conclusion: We propose trimethoprim/sulfamethoxazole alone or in combination with ciprofloxacin to be good candidates for the treatment of ventriculitis by C arthrosphaerae.