Case Report: Listeria monocytogenes meningitis complicated by an acute exacerbation of chronic obstructive pulmonary disease: the key diagnostic role of metagenomic high-throughput sequencing

Background Listeria monocytogenes is an opportunistic foodborne pathogen that causes severe invasive infections, such as meningitis, primarily in immunocompromised individuals, the elderly, and pregnant women. Diagnosis is often challenging due to nonspecific early symptoms. Case description A 67-year-old male with a history of chronic obstructive pulmonary disease (COPD) presented with a 4-day history of persistent high-grade fever and altered mental status. Initial empirical antibiotic therapy (meropenem) proved ineffective.Metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) definitively identified L.monocytogenes . The patient was diagnosed with “Listeria monocytogenes meningitis complicated by an acute exacerbation of chronic obstructive pulmonary disease”. Patients with pathogenic bacterial infections completed a 21-day course of ampicillin and sulbactam sodium and a 14-day course of gentamicin, resulting in a rapid improvement in clinical symptoms and biochemical parameters. Conclusion This case underscores the critical role of mNGS in the aetiological diagnosis of central nervous system infections, especially when conventional methods are inconclusive. It highlights the need for a high index of suspicion for listeriosis in elderly patients with comorbidities presenting with unexplained fever and neurological decline.