Proteomics and microscopy tools for the study of antimicrobial resistance and germination mechanisms of bacterial spores

Food Microbiol. 2019 Aug:81:89-96. doi: 10.1016/j.fm.2018.03.006. Epub 2018 Mar 14.

Abstract

Bacterial spores are ubiquitous in nature and can withstand both chemical and physical stresses. Spores can survive food preservation processes and upon outgrowth cause food spoilage as well as safety risks. The heterogeneous germination and outgrowth behavior of isogenic spore populations exacerbates this risk. A major unknown factor of spores is likely to be the inherently heterogeneous spore protein composition. The proteomics methods discussed here help in broadening the knowledge about spore structure and identification of putative target proteins from spores of different spore formers. Approaches to synchronize Bacillus subtilis spore formation, and to analyze spore proteins as well as the physiology of spore germination and outgrowth are also discussed. Live-imaging and fluorescence microscopy techniques discussed here allow analysis, at single cell level, of the 'germinosome', the process of spore germination itself, spore outgrowth and the spore intracellular pH dynamics. For the latter, a recently published improved pHluorin (IpHluorin) under control of the ptsG promoter is applicable. While the data obtained from such tools offers novel insight in the mechanisms of bacterial spore awakening, it may also be used to probe candidate antimicrobial compounds for inhibitory effects on spore germination and strengthen microbial risk assessment.

Keywords: Bacterial spores; Heterogeneity; Live cell imaging; Proteomics; Stress resistance.

Publication types

  • Review

MeSH terms

  • Bacillus subtilis / genetics
  • Bacillus subtilis / growth & development
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Drug Resistance, Bacterial*
  • Food Handling
  • Food Microbiology*
  • Food Preservation
  • Genetic Heterogeneity
  • Hydrogen-Ion Concentration
  • Kinetics
  • Microscopy / methods*
  • Models, Theoretical
  • Phosphoenolpyruvate Sugar Phosphotransferase System / genetics
  • Promoter Regions, Genetic
  • Protein Kinases / genetics
  • Protein Kinases / metabolism
  • Proteomics / methods*
  • Spores, Bacterial / cytology
  • Spores, Bacterial / genetics
  • Spores, Bacterial / growth & development*
  • Spores, Bacterial / metabolism*
  • Stress, Physiological

Substances

  • Bacterial Proteins
  • kinA protein, Bacillus subtilis
  • Protein Kinases
  • Phosphoenolpyruvate Sugar Phosphotransferase System
  • phosphoenolpyruvate-glucose phosphotransferase