Brucella is a facultative intracellular pathogenic bacterium responsible for brucellosis, a worldwide re-emerging zoonotic disease affecting wildlife and livestock. Brucella can be transmitted to humans via contaminated food or infected aerosol particles, thereby leading to undulant fever followed by chronic devastating multi-organ inflammation if untreated. By RNA-seq analysis of blood of patient cohorts from Spain and Macedonia, the inventors have identified SLAMF1 as a biomarker of the acute phase of Brucella infection in humans. In addition, cytokine analysis led us to define a set of four serum biomarkers (IL-10, IL1RA, CXCL1 and IL-7) for Brucella chronicity. SLAMF1 is an immune cell receptor expressed notably at the surface of dendritic cells (DC), lymphocytes and haematopoietic stem cells and involved in the control of immune responses.
Thus the present invention relates to the detection of Brucella infection and the stratification of the patients (those with acute phase or chronic phase of the infection).