Methods: The low transformation efficiency ofC. trachomatis necessitated the design of a self-replicating vector carrying the transposon mutagenesis cassette (i.e. the Himar-1 transposon containing the beta lactamase gene as well as a hyperactive transposase gene under inducible control of thetet promoter system with the addition of a riboswitch).Chlamydia transformed with this vector (pSW2-RiboA-C9Q) were induced at 24 hours post-infection. This evidence concerns the gene LACTB and infection.