Abstract Details

Title Identification of Pathogens in Culture-negative Central Nervous System Ventriculitis and Abscesses Using CSF Metagenomic Sequencing: A Multicenter Case Series

Topic Infectious Disease

Presentation(s) S22 - Neuroinfectious Disease: Basic Sciences (2:36 PM-2:48 PM)

Poster/Presentation
Number 009

Objective NA

Background Culture-negative ventriculitis and brain abscesses pose diagnostic challenges, particularly after antimicrobial pre-treatment. Metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) enables comprehensive, rapid pathogen detection and can identify clinically significant bacteria missed by conventional testing. We describe multicenter experience with CSF mNGS for suspected CNS infection, emphasizing diagnostic and clinical utility.

Design/Methods We conducted a retrospective multicenter case series of patients with ventriculitis or brain abscess and negative or low-yield conventional microbiologic testing. Clinical data, neuroimaging, and microbiologic results were obtained via chart review. Cases were included if mNGS identified a clinically relevant pathogen not detected by standard testing.

CSF mNGS was performed using the Delve Detect assay (Delve Bio). One mL of CSF underwent whole-cell lysis, nucleic acid extraction, and barcoded DNA/RNA library preparation, sequenced to >10 million reads per library. Bioinformatic analysis included human read removal, quality filtering, and alignment to a curated microbial database.

Results

Four adult patients presented with subacute neurologic decline and imaging consistent with ventriculitis and/or abscess. All received empiric antimicrobials before lumbar puncture and had negative culture and multiplex PCR results.

- Streptococcus intermedius: Detected in two patients with intraventricular debris and ring-enhancing lesions; Gram-positive cocci seen on Gram stain; mNGS confirmation enabled directed therapy recovery.
- Enterococcus faecalis: Detected in a patient with ventriculitis and E. faecalis bacteremia one month earlier; conventional testing negative except for broth-only growth; plasma mNGS negative. The mNGS result suggested an ongoing nidus and informed continued management.
- Fusobacterium nucleatum: Identified in a patient with ventriculitis and multiple small abscesses, with silicosis and cavitary lung lesions, supporting an anaerobic source and directing antimicrobials.

All patients survived and improved with organism-directed therapy.

Conclusions CSF mNGS identified bacterial pathogens in four cases of culture-negative ventriculitis and brain abscess, directly impacting management. Additional cases under institutional review will be included in the final analysis.

Authors/Disclosures
Sudeb Dalai, MD, PhD PRESENTER	Dr. Dalai has received personal compensation for serving as an employee of Delve Bio.
Jose F. Camargo (University of Miami Miller School of Medicine)	No disclosure on file
Anthony Leung (Cleveland Clinic Akron General)	No disclosure on file
Khushbu Patel, MD	Dr. Patel has nothing to disclose.
Aakash D. Patil	Mr. Patil has nothing to disclose.
Steven M. Phillips, DO (University of Nebraska Medical Center)	Dr. Phillips has nothing to disclose.
Mohammed Raja, MD	Dr. Raja has nothing to disclose.
Raghav Tirupathi (WellSpan Chambersburg Hospital)	No disclosure on file
Steve Miller, MD, PhD (Delve Bio)	Dr. Miller has received personal compensation for serving as an employee of Delve Bio.

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