Nocardia are filamentous-growing Gram-positive soil saprophytes that belong to Actinobacteria. Nocardial infections or nocardiosis are lung infections in most of the cases (60%) and more rarely brain infections. Nocardia cyriacigeorgica strain GUH-2 had cause the death of a patient in the 70's. Studies have shown that its strain had a high pathogenicity and the ability to trigger the development of motor disorders in mice and primates similar to those seen in Parkinson's disease.In order to understand the involvement of this opportunistic pathogen in one of the major neurodegenerative diseases of the 21st century, the genome of the strain N. cyriacigeorgica GUH-2 was sequenced. It allowed the identification of a large number of genes related to virulence, antibiotic resistance and the identification of genomic islands and insertion sequences reflecting a greater plasticity that it was previously described for this bacterial genus. The study of clusters of genes involved in the production of secondary metabolites showed that these molecules could be responsible for the neurodegenerative properties of the strain. N. cyriacigeorgica species is frequently encountered in the clinic without its natural reservoir has been identified to date. The development of genetic markers for detection was carried out to allow the search for the habitat of this species but also to facilitate the diagnosis of nocardiosis.
