Transcriptional profile of Salmonella enterica serovar Typhimurium 4/74 wild-type and mutants using strand-specific RNA-seq

New tools for studying bacterial transcripts at the single nucleotide level offer an unparalleled opportunity to understand the bacterial transcriptome. For the model pathogen Salmonella enterica serovar Typhimurium, it is necessary to identify the regulatory inputs for all RNA transcripts, including small RNAs (sRNAs) and coding genes. Here, we use RNA-seq to define the transcriptomes of mutants lacking 18 global regulatory systems that, among other functions, modulate the expression of the SPI1 and SPI2 Type Three secretion systems in S. Typhimurium strain 4/74. We directly compared the roles of the major regulators of transcription, and reported the effects of the regulatory mutations on expression of sRNAs. We also use this method to describe the impact of the RNA chaperone Hfq upon the steady state levels of 280 sRNA transcripts. Overall design: Transcriptome analysis of S. Typhimurium 4/74 using RNA isolated wild-type and mutants grown under infection-relevant conditions.