Mycobacteria identified as M. abscessus (MA) are very frequently isolated from CF patients. Subspecies (sspp) identification is not routinely performed, and their role in the deterioration of lung function is unclear. Transmissibility of selected MA clones among CF patients has been postulated by recent studies. The researchers investigated the prevalence of MA sspp and the transmissibility of clones between CF patients; further, they aimed to establish the clinical significance of sspp/clones of MA in CF patients and to investigate the antibiotic resistance profiles of the MA sspp/clones. The data obtained from the project could impact the management of MA infected patients at different levels: protocol of isolation in infected patients, decision to treat based on sspp identification, informed therapeutic regimen based on fast detect.