SHM Converge Scientific Abstract ePoster Gallery-Next-Gen Sequencing Uncovers Mysterious Culture-Negative Brain Infection in an Immunocompetent

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This case report describes an immunocompetent 55-year-old woman with no clear risk factors for unusual infection who was found to have 12 ring-enhancing brain lesions consistent with abscesses during evaluation for a pituitary macroadenoma. Initial extensive infectious and autoimmune workup, including blood cultures, CSF studies, fungal and respiratory testing, and echocardiography, was negative. Standard cultures from the brain biopsy also failed to identify an organism.<br /><br />Because routine testing was unrevealing, next-generation sequencing (NGS) of 16S ribosomal RNA from the brain biopsy was performed and identified Streptococcus dysgalactiae as the causative pathogen. This finding guided more precise antibiotic management. The patient was treated empirically with ceftriaxone, metronidazole, and vancomycin, then completed 8 weeks of IV antibiotics followed by oral levofloxacin, with radiographic improvement and eventual resolution of the lesions. In addition, a colovesical fistula was discovered on CT imaging and surgically resected, suggesting a likely hematogenous source of infection.<br /><br />The report highlights that brain abscess diagnosis can be challenging because cultures are often negative, and NGS can be critical when conventional methods fail. It also emphasizes that prompt diagnosis, surgical intervention, and targeted antibiotics are essential for treating S. dysgalactiae brain abscesses, even in patients without immunosuppression.

Asset Subtitle

Colton A. Blinka

Meta Tag

Author List Christopher Tran, Colton A. Blinka, Kanapa Korsawad, Sergio A. Vallejo

Category Clinical Vignettes

Concept Next-Generation Sequencing

Concept Cerebral Abscess

Concept Culture-Negative Infection

Concept 16S rRNA sequencing

Concept Multiple Brain Abscesses

Distinguished Non-Finalist

Presenter Organization The University of Texas Health Science Center at San Antonio

Presenting Author Colton A. Blinka

Track Adult

Keywords

brain abscess

Streptococcus dysgalactiae

next-generation sequencing

16S ribosomal RNA

ring-enhancing lesions

immunocompetent patient

pituitary macroadenoma

colovesical fistula

antibiotic therapy

culture-negative infection

Next-Generation Sequencing

Cerebral Abscess

Culture-Negative Infection

16S rRNA sequencing

Multiple Brain Abscesses