Comprehensive characterisation of the attenuated double auxotroph Mycobacterium tuberculosis ?leuD?panCD as an alternative to H37Rv

Mycobacterium tuberculosis research requires access to biosafety level 3 facilities, emphasising the need for mycobacterial model organisms to facilitate our understanding of M. tuberculosis pathogenesis. Previous work demonstrated the use of auxotrophic strains as models for drug-resistant M. tuberculosis and for studying latent tuberculosis, however it is important to understand how well these represent non-attenuated M. tuberculosis. In this study, we determined the suitability of the double auxotrophic M. tuberculosis ?leuD?panCD strain as a model for M. tuberculosis research by comparing it to the widely used M. tuberculosis H37Rv reference strain. We provide comprehensive comparative analyses between these two strains concerning in vitro and intra-macrophage growth, genomic features, response to anti-tuberculosis agents, proteomic response to stress and host immune response. Our results suggest that M. tuberculosis ?leuD?panCD is a suitable and safe alternative for M. tuberculosis research, which can be conducted in a biosafety level 2 laboratory.