Identification of M. tuberculosis mutants with altered capacity to seed and initiate an infection in the lung of mice.

(A) We generated a M . tuberculosis transposon mutant library and analyzed the number of TA site containing at least one transposon insertion in the library used to infect mice (corresponding to the inoculum) or after 1 day or 8 days of infection. The values in the table indicate that there is no substantial reduction in the number of different mutants in the library before and after infection. (B) The distribution of insertions in the bacterial populations recovered from each mouse at day 1 or day 8 was analyzed using TnSeq and compared with the distribution in the inoculum using the TRANSIT or ESSENTIAL methods. The figure shows Venn-diagrams of results obtained for each mouse and the two analytical methods. For each day, we retained hits identified in at least three mouse and the two methods. Finally, we retained only the 17 hits identified both at day 1 and day 8 post-infection. (EPS)