Low-shear modeled microgravity: a global environmental regulatory signal affecting bacterial gene expression, physiology, and pathogenesis.
Bacteria inhabit an impressive variety of ecological niches and must adapt constantly to changing environmental conditions. While numerous environmental signals have been examined for their effect on bacteria, the effects of mechanical forces such as shear stress and gravity have only been investigated to a limited extent. However, several important studies have demonstrated a key role for the environmental signals of low shear and/or microgravity in the regulation of bacterial gene expression, physiology, and pathogenesis [Chem. Rec. 1 (2001) 333; Appl. Microbiol. Biotechnol. 54 (2000) 33; Appl. Environ. Microbiol. 63 (1997) 4090; J. Ind. Microbiol. 18 (1997) 22; Curr. Microbiol. 34(4) (1997) 199; Appl. Microbiol. Biotechnol. 56(3-4) (2001) 384; Infect Immun. 68(6) (2000) 3147; Cell 109(7) (2002) 913; Appl. Environ. Microbiol. 68(11) (2002) 5408; Proc. Natl. Acad. Sci. U. S. A. 99(21) (2002) 13807]. The response of bacteria to these environmental signals, which are similar to those encountered during prokaryotic life cycles, may provide insight into bacterial adaptations to physiologically relevant conditions. This review focuses on the current and potential future research trends aimed at understanding the effect of the mechanical forces of low shear and microgravity analogues on different bacterial parameters. In addition, this review also discusses the use of microgravity technology to generate physiologically relevant human tissue models for research in bacterial pathogenesis.
Nickerson
Cheryl A
CA
Program in Molecular Pathogenesis and Immunity, Department of Microbiology and Immunology, SL 38, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA. cnicker@tulane.edu
Ott
C Mark
CM
Wilson
James W
JW
Ramamurthy
Rajee
R
LeBlanc
Carly L
CL
Höner zu Bentrup
Kerstin
K
Hammond
Timothy
T
Pierson
Duane L
DL
D001419:Bacteria / Q000254:growth & development* / Q000472:pathogenicity*; D001424:Bacterial Infections / Q000382:microbiology / Q000503:physiopathology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008954:Models, Biological; D013314:Stress, Mechanical; D014774:Virulence; D018474:Weightlessness Simulation
D001426:Bacterial Proteins