Objective:

To evaluate the diagnostic utility of metagenomic next-generation sequencing (mNGS) for diagnosing CNS infections caused by Listeria monocytogenes in patients with decompensated cirrhosis.

Approach:

• Case Presentation: A 62-year-old male with a 7-year history of cirrhosis presented with fever, headache, and loss of consciousness. He was diagnosed with Listeria encephalitis using mNGS after conventional CSF cultures were negative.
• Diagnostic Method: mNGS was employed to analyze cerebrospinal fluid (CSF) samples, detecting Listeria monocytogenes sequences within 16 hours.

Key Findings:

• Conventional CSF cultures were negative despite the presence of Listeria monocytogenes detected by mNGS.
• mNGS provided rapid and unbiased diagnostic results.

Interpretation:

Cirrhosis-associated immune dysfunction can obscure typical CSF diagnostic markers, making mNGS a valuable tool for early diagnosis of CNS infections.

Limitations:

• The study is based on a single case, limiting generalizability.
• Low absolute biomass in CSF samples may affect the specificity of mNGS results.
• Potential biases inherent in a single case study.

Conclusion:

mNGS is effective in diagnosing CNS infections in immunocompromised patients, facilitating timely and targeted therapy.