Brain Abscess Caused by Bifidobacterium spp. in a Previously Healthy Adolescent: A Case Report.

Brain abscesses in children are uncommon but serious conditions. Bifidobacterium species, typically considered commensal organisms of the oral cavity, gastrointestinal tract, and female genital tract, are rarely implicated in invasive infections. We present a case of multiple brain abscesses caused by Bifidobacterium spp. in a previously healthy 11-year-old male, secondary to contiguous spread from chronic left-sided paranasal sinusitis with ethmoid bone erosion. Neuroimaging demonstrated left frontal abscesses with marked perilesional edema, ring enhancement and midline shift, together with opacification of the left maxillary, ethmoid and frontal sinuses. Bifidobacterium spp. was the only organism isolated from both the brain abscess aspirate and the sinus samples. The patient was treated with burr-hole aspiration of the abscesses and same-session endoscopic sinus surgery, followed by six weeks of intravenous crystalline penicillin G. He achieved full clinical recovery without neurological sequelae, with stable residual changes on follow-up MRI. To our knowledge, this is the first detailed case report of a brain abscess caused by Bifidobacterium spp. in a previously healthy pediatric patient. This case highlights the potential of this typically commensal organism to cause serious central nervous system infection via contiguous spread from the paranasal sinuses.