show Abstracthide AbstractGenerating a comprehensive inventory of factors important for T3SS gene expression in Pseudomonas aeruginosa strain PAK. Transposon insertion libraries harboring T3SS fluorescent reporter were cultured under inducing conditions for T3SS gene expression and individual cells were sorted into T3SS-Off and T3SS-On populations on FACS. NexGen sequencing of the transposon insertion sites and comparison of the T3SS-Off and T3SS-On populations identified genes and small noncoding RNAs that playing a role in T3SS gene expression.