title: Global transcriptome and mutagenic analyses of the acid tolerance response of Salmonella enterica serovar Typhimurium.
abstract: Salmonella enterica serovar Typhimurium (S. Typhimurium) is one of the leading causative agents of food-borne bacterial gastroenteritis. Swift invasion through the intestinal tract and successful establishment in systemic organs are associated with the adaptability of S. Typhimurium to different stress environments. Low-pH stress serves as one of the first lines of defense in mammalian hosts, which S. Typhimurium must efficiently overcome to establish an infection. Therefore, a better understanding of the molecular mechanisms underlying the adaptability of S. Typhimurium to acid stress is highly relevant. In this study, we have performed a transcriptome analysis of S. Typhimurium under the acid tolerance response (ATR) and found a large number of genes (∼47%) to be differentially expressed (more than 1.5-fold or less than -1.5-fold; P < 0.01). Functional annotation revealed differentially expressed genes to be associated with regulation, metabolism, transport and binding, pathogenesis, and motility. Additionally, our knockout analysis of a subset of differentially regulated genes facilitated the identification of proteins that contribute to S. Typhimurium ATR and virulence. Mutants lacking genes encoding the K(+) binding and transport protein KdpA, hypothetical protein YciG, the flagellar hook cap protein FlgD, and the nitrate reductase subunit NarZ were significantly deficient in their ATRs and displayed varied in vitro virulence characteristics. This study offers greater insight into the transcriptome changes of S. Typhimurium under the ATR and provides a framework for further research on the subject.
authors.affiliation: School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India.
authors.forename: Daniel
authors.initials: D
authors.lastname: Ryan
authors.affiliation: Institute of Medical Microbiology, German Centre of Infection Research, Site Giessen-Marburg-Langen, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Niladri Bhusan
authors.initials: NB
authors.lastname: Pati
authors.affiliation: School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India.
authors.forename: Urmesh K
authors.initials: UK
authors.lastname: Ojha
authors.affiliation: School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India.
authors.forename: Chandrashekhar
authors.initials: C
authors.lastname: Padhi
authors.affiliation: School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Ray
authors.affiliation: School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India.
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Jaiswal
authors.affiliation: School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India.
authors.forename: Gajinder P
authors.initials: GP
authors.lastname: Singh
authors.affiliation: Institute of Medical Microbiology, German Centre of Infection Research, Site Giessen-Marburg-Langen, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Gopala K
authors.initials: GK
authors.lastname: Mannala
authors.affiliation: Institute of Medical Microbiology, German Centre of Infection Research, Site Giessen-Marburg-Langen, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Tilman
authors.initials: T
authors.lastname: Schultze
authors.affiliation: Institute of Medical Microbiology, German Centre of Infection Research, Site Giessen-Marburg-Langen, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Trinad
authors.initials: T
authors.lastname: Chakraborty
authors.affiliation: School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India msuar@kiitbiotech.ac.in.
authors.forename: Mrutyunjay
authors.initials: M
authors.lastname: Suar
mesh_terms: D000143:Acids / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006863:Hydrogen-Ion Concentration; D009154:Mutation; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism; D017423:Sequence Analysis, RNA; D059467:Transcriptome; D014774:Virulence
chemical_list: D000143:Acids