Rapid detection of Listeria monocytogenes rhombencephalitis in an immunocompetent patient by multiplexed PCR.

A 46-year-old previously healthy man presented with 1 week of headache, nausea, vomiting and dizziness. He was found to have cranial nerve deficits, his cerebrospinal fluid (CSF) demonstrated a lymphocytic pleocytosis and brain MRI suggested rhombencephalitis. Although Gram stains and cultures of his CSF did not identify a pathogen, Listeria monocytogenes DNA was detected by the FilmArray Meningitis/Encephalitis panel within 2 hours of performing a lumbar puncture. He was treated with ampicillin and gentamicin and had a near-complete recovery. This case highlights the importance of recognising L. monocytogenes infection as a cause of acute cranial nerve impairment with MRI findings suggestive of brainstem encephalitis. It also highlights the frequently atypical CSF profile and low yield of culture in L. monocytogenes rhombencephalitis and the value of multiplex PCR testing of CSF to rapidly identify this pathogen and permit targeted therapy. © BMJ Publishing Group Limited 2018. No commercial re-use. See rights and permissions. Published by BMJ.