In this study researchers studied chronic infection by Mycobacterium Abscessus in C57Bl/6NCr mice: mice were monitored for body weight, mortality and lungs were processed for microbiological analysis, inflammatory response and histological evaluation.
The results demonstrated that Mycobacterium Abscessus modified agar beads preparation from the standard protocol was able to establish a chronic infection in mice C57Bl/6NCr up to 75 days with MA sspp abscessus, bolleti and massiliense, with a low rate of clearance. The analysis of the bacterial load in the total lung showed a high and stable number of colony forming unit during the course of infection with minimal systemic spread and stable inflammatory response in broncoalveolar lavage fluid (BALF) up to 75 days of infection. Lung histopathological analysis revealed granulomatomatous response with lymphocytes and macrophage aggregation that are disseminated in the lung during the course of MA infection. Through extension project FFC#20/2017, six MA strains, belonging to the three sspp and isolated both from chronic symptomatic and asymptomatic CF patients, will be tested in murine model of chronic lung infection. The availability of a murine model for MA chronic infection will allow the identification of strains causing severe pulmonary disease and to evaluate in vivo novel antimycobacterial protocols.