Diagnosis of Listeria monocytogenes Meningitis Using the FilmArray Meningitis/Encephalitis Panel in a Patient With Prior Antibiotic Exposure: A Case Report.

Bacterial meningitis is a medical emergency with high mortality rates and a significant risk of complications. Conventional diagnostic methods, such as Gram staining, sometimes fail to identify the causative pathogen, and cultures take time to yield results. The FilmArray meningitis/encephalitis (ME) Panel, a molecular diagnostic tool, identifies 14 pathogens in approximately one hour. We report a case of Listeria monocytogenes meningitis in a 79-year-old man, diagnosed using the FilmArray ME Panel after antibiotic exposure. The diagnosis was made on day seven, three days after admission, using a cerebrospinal fluid sample that had been stored due to the unavailability of the test over the weekend. Despite negative cultures, the panel facilitated diagnosis and effective treatment with ampicillin and gentamicin, leading to full recovery without sequelae. This case highlights the utility of the FilmArray ME Panel in challenging diagnostic scenarios and underscores the importance of ensuring its availability during after-hours and weekends to facilitate timely care in critical conditions.