Introduction: Listeria monocytogenes is one of the most common causes of bacterial central nervous system infections in adults. It often affects immunicompromised and elderly patients. Even with appropriate antimicrobial treatment, mortality due to Listeria monocytogenes meningoencephalitis is among the highest of all causes of bacterial central nervous system infections.
Case report: We presented a previously healthy, 79-year-old farmer with typical clinical features of meningoencephalitis. The initial treatment with vancomycin and meropenem did not produce any clinical effect. On day six, Listeria monocytogenes was isolated from the cerebrospinal fluid and blood culture and identified by using conventional and automated microbiology methods. Antimicrobial susceptibility testing was performed by E test method. After bacterial isolation and identification, the administration of ampicillin and gentamicin was followed by the complete recovery of our patient.
Conclusion: This case is presented to emphasize the negative outcome of empirical treatment when Listeria monocytogenes is not taken into consideration. Furthermore, the administration of ampicillin and gentamicin combination for treatment should be considered as the best therapeutic option in Listeria monocytogenes meningoencephalitis.