A Francisella tularensis Schu S4 purine auxotroph is highly attenuated in mice but offers limited protection against homologous intranasal challenge.
Pechous RD, McCarthy TR, Mohapatra NP, Soni S, Penoske RM, Salzman NH, Frank DW, Gunn JS, Zahrt TC. A Francisella tularensis Schu S4 purine auxotroph is highly attenuated in mice but offers limited protection against homologous intranasal challenge. PLoS One. 2008 Jun 25; 3(6):e2487.