[: update and new challenges].

Mycoplasma pneumoniae is a frequent cause of community acquired pneumonia, especially in children. Discovered by Eaton in the 1940s, it has long been considered as a virus, in part because of its difficult growth in cultures. M. pneumoniae can cause many complications, some of which are severe such as dermatological lesions or affections of the central nervous system. The laboratory diagnosis of M. pneumoniae is difficult, notably because of the fastidious growth conditions, the persistence of IgM antibody after acute infection and the debated existence of asymptomatic carriers. In recent years, the spread of mutants resistant to macrolides caused an additional challenge linked to this pathogen.