Listeriosis is a rare, mainly food-borne disease caused by listeria monocytogenes is triggered. In healthy adults, the infection is usually asymptomatic or with a very mild clinical picture. In newborns, pregnant women, elderly persons or patients with severe underlying diseases, infection can lead to very severe courses, which can even be fatal in up to 30 % of cases.

The National Reference Center for Listeriosis is responsible for the cultivation of human isolates and, in close cooperation with the National Reference Laboratory for Listeria, for the clarification of epidemiological questions.

The National Reference Center for Listeriosis is located in our Public Health Business Unit.

• Cultural pathogen detection from clinical examination materials (blood, cerebrospinal fluid, pus, punctates or, in the case of newborns, swabs from the navel, ear or meconium) by means of direct cultivation on solid and liquid selective culture media;
• Identification of isolates by biochemical methods and MALDI-TOF;
• Antibiogram (agar diffusion test or determination of minimum inhibitory concentration by E-test);
• PCR for Listeria monocytogenes;
• Participation in European round robin tests;
• Maintenance of a reference strain collection;
• Consultation on questions of diagnostics, epidemiology, therapy, measures and prevention;
• Reporting

As a rule, the routine tests mentioned above are sufficient for a reliable answer to all clinical-diagnostic and epidemiological questions. PCR from cerebrospinal fluid can be used if cultural pathogen detection is unsuccessful after antibiotic pretreatment. Serological tests are difficult to interpret because cross-reactions in healthy individuals and lack of antibody detection despite infection are frequent, especially with the Widal test. Therefore, we recommend serological testing only in individual cases (e.g., suspected rhombencephalitis) if direct pathogen detection is not possible.

Investigations of isolates from food and environmental samples are performed at the National Reference Laboratory for Listeria.

According to Section 1 of the Epidemic Act 1950, Listeria must be reported as a causative agent of bacterial food poisoning or as a causative agent of invasive bacterial diseases (sepsis, meningoencephalitis). In connection with pregnancy, in a case (mother or newborn in the first month of life) that meets the laboratory criteria, only the mother must be reported.

Submissions should always include information on the origin of the isolates as well as the necessary patient data, clinical and epidemiological data. Please use the appropriate submission form. Fresh cultures in transport medium with appropriate reference to medical diagnostic examination material are best suited for shipping the strains.