Genetic Susceptibility and Biomarkers in Listeriosis

Listeriosis is a rare, severe foodborne infection caused by the bacterium Listeria monocytogenes (Lm). It manifests as septicemia, central nervous system (CNS) infection and maternal-fetal (MF) infection. Its associated overall mortality is very high, above of 30%. A better knowledge on the factors involved in its occurrence and in clinical manifestations is therefore needed to improve outcome. A number of frequent acquired risk factors for listeriosis have been identified, such as pregnancy, diabetes, cancer, HIV infection, and immunosuppressive therapies. However, no genetic study on host susceptibility to listeriosis in humans has been performed so far, in the absence of prospective collection of patients' samples. Also, listeriosis diagnosis is based on Lm culture from clinical samples. This method lacks sensitivity, and the contribution of biomarkers to listeriosis diagnosis and prognosis has not been evaluated. The Multicentric Observational NAtional Analysis of Listeriosis and Listeria (MONALISA), is the first national case-control prospective study on listeriosis. It is implemented since 2009 and enrolls all culture-proven cases declared to the NRCL: and collects for each patient clinical and biological data and biological samples. Controls with comparable background and presentation are also included. 818 cases have been included (427 S, 252 CNS and 107 MN) over 3.5 years, along with 456 controls. The aim of the study is to identify human genetic susceptibility factors to listeriosis, biomarkers to improve its diagnosis and prognosis (survival or death), and thereby help improve management of patients with listeriosis. Samples from the completed cohort will be analyzed : SNPs genotyping and exam sequencing; biomarkers a identification in serum and plasma of patients and controls by simultaneous multi-analyte and metabolomic profiling.