title: Flow cytometry to assess biochemical pathways in heat-stressed Cronobacter spp. (formerly Enterobacter sakazakii).
abstract: OBJECTIVE
  Using a flow cytometry (FC)-based approach in combination with four selected fluorescent probes, the biochemical pathway activated following the adaptation of Cronobacter spp. to lethal heat stress was investigated. This approach assessed the physiological changes induced in four strains of Cronobacter spp.
  
  
  RESULTS
  Using the commercially available live/dead viability assessment fluorescence probes, live, injured or dead bacterial cells were studied. Cellular respiration and membrane potential were evaluated using the dye-labelled probe 3,3'-dihexylocarbocyanine iodide, metabolic activity was evaluated using a fluorescein diacetate (FDA) probe, intracellular pH changes were measured using a carboxy-fluorescein diacetate succinimidyl ester probe, and reactive oxygen species were measured using a hydroethidine fluorescent probe. Adaptation to lethal heat stress induced physiological changes that potentially improve the survival of Cronobacter spp.
  
  
  CONCLUSIONS
  These data showed that in situ assessment of physiological behaviour of lethally stressed cells using multiparameter FC is a useful, rapid and sensitive tool to study and assess the viability and physiological state of Cronobacter cells.
  
  
  CONCLUSIONS
  This study shows that FC is a valuable tool in the study of physiological aspects of increased survival because of sublethal adaptation to heat.
authors.affiliation: Teagasc, Food Research Centre, Moorepark, Fermoy, Cork, Ireland.
authors.forename: B
authors.initials: B
authors.lastname: Arku
authors.forename: S
authors.initials: S
authors.lastname: Fanning
authors.forename: K
authors.initials: K
authors.lastname: Jordan
mesh_terms: D000222:Adaptation, Physiological; D044083:Cronobacter sakazakii / Q000378:metabolism / Q000502:physiology*; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008564:Membrane Potentials; D050296:Microbial Viability; D017382:Reactive Oxygen Species / Q000032:analysis; D013312:Stress, Physiological
chemical_list: D005456:Fluorescent Dyes; D017382:Reactive Oxygen Species