A Case of Listeria monocytogenes ST-219 Meningo-Encephalitis

Listeriosis is a foodborne disease characterized by high hospitalization and fatality rates, especially in vulnerable groups including elderly subjects, pregnant women, etc. We report on the first case of Listeria monocytogenes ST-219 meningo-encephalitis in a woman aged 83 years. An epidemiological and molecular investigation was performed to detect the source of infection and the virulence factors associated with L. monocytogenes invasiveness in this patient. All environmental- and clinical-associated isolates were found to belong to serotype 4b and ST-219 as well as possessing actA, prfA, hlyA, and rrn virulence genes. Antibiotic susceptibility testing also detected resistance to cotrimoxazole, clindamycin, erythromycin, and oxacillin in these isolates. Conventional and molecular surveillance of listeriosis cases, based on the systematic assessment of spatio-temporal trends, virulence genes, and antimicrobial susceptibility testing patterns, are key to preventing and controlling the emergence and spread of L. monocytogenes strains, including hypervirulent clones.