Novel approaches to monitor bacterial gene expression in infected tissue and host

Elucidating the complex and dynamic host-microbe interactions during infect ion requires, among other things, detailed knowledge of microbial gene expr ession in vivo. Recently, advances in fluorescence and bioluminescence dete ction techniques, as well as recombinase-based in vivo expression technolog y, have rendered monitoring virulence gene expression in vivo a feasible ta sk. These techniques have been adapted by several laboratories to study the spatial and temporal patterns of virulence gene expression by organisms su ch as Salmonella typhimurium, Listeria monocytogenes, Yersinia entercolitic a and Vibrio cholerae during infection of tissue culture or animal models o f infection.