TKT and bacterial infectious disease: Given the need for more noninvasive means of tracking bacterial infection, the objectives of the current study were set to: (i) demonstrate the tk bioengineering potential in three critical pathogens - P. aeruginosa, A. baumannii and B. pseudomallei, that lack the tk gene; (ii) utilize PET imaging to determine the sensitivity of detection at a given bacterial infection site within a reasonable time post-infection and (iii) establish the utility of bioengineered pathogens for developing in vivo therapeutic imaging model(s) for noninvasive evaluation of drug candidates in the host.