Abstract: Francisella tularensis is the bacterial pathogen that causes tularemia in humans and a number of animals. To date, no approved vaccine exists for this widespread and life-threatening disease. The present disclosure provides attenuated Francisella mutants that include functional deletions in one or more of the dsbB, FTT0742, pdpB, fumA, and carB genes. Also provided are immunogenic compositions that include the attenuated bacteria. Methods are provided for treatment using the attenuated Francisella mutants.

Abstract: Francisella tularensis is the bacterial pathogen that causes tularemia in humans and a number of animals. To date, no approved vaccine exists for this widespread and life-threatening disease. The present disclosure provides attenuated Francisella mutants that include functional deletions in one or more of the dsbB, FTT0742, pdpB, fumA, and carB genes. Also provided are immunogenic compositions that include the attenuated bacteria. Methods are provided for treatment using the attenuated Francisella mutants.

Abstract: A transposable element is provided that as a 3? and a 5? end. The transposable element includes a 5? recombining site 5? of a nucleic acid sequence encoding a selectable marker, a 3? recombining site 3? of the nucleic acid sequence encoding a selectable marker, a nucleic acid sequence encoding and MHC epitope 5? to the 5? recombining site or 3? to the 3? recombining site, and an insertion end comprising an inverted repeat sequence sufficient for integration of the transposable element at the 5? and the 3? end of the transposable element. In one embodiment, a transposable element is provided that has a 5? and a 3? end. The transposable element includes a 5? loxP sequence 5? of a nucleic acid encoding a selectable marker, a 3? loxP sequences 3? of a nucleic acid encoding the selectable marker, an MHC epitope 5? to the 5? loxP sequences or 3? of the 3? loxP sequence, an insertion end at the 5? end of the transposable element, and an insertion end at the 3? of the transposable element.