Changes in Ultrastructure and Fourier Transform Infrared Spectrum of Salmonella enterica Serovar Typhimurium Cells after Exposure to Stress Conditions
- 15 November 2010
- journal article
- Published by American Society for Microbiology in Applied and Environmental Microbiology
- Vol. 76 (22), 7598-7607
- https://doi.org/10.1128/aem.00312-10
Abstract
The effect of exposure to acid (pH 2.5), alkaline (pH 11.0), heat (55°C), and oxidative (40 mM H 2 O 2 ) lethal conditions on the ultrastructure and global chemical composition of Salmonella enterica serovar Typhimurium CECT 443 cells was studied using transmission electron microscopy and Fourier transform infrared spectroscopy (FT-IR) combined with multivariate statistical methods (hierarchical cluster analysis and factor analysis). Infrared spectra exhibited marked differences in the five spectral regions for all conditions tested compared to those of nontreated control cells, which suggests the existence of a complex bacterial stress response in which modifications in a wide variety of cellular compounds are involved. The visible spectral changes observed in all of the spectral regions, together with ultrastructural changes observed by transmission electron microscopy and data obtained from membrane integrity tests, indicate the existence of membrane damage or alterations in membrane composition after heat, acid, alkaline, and oxidative treatments. Results obtained in this study indicate the potential of FT-IR spectroscopy to discriminate between intact and injured bacterial cells and between treatment technologies, and they show the adequacy of this technique to study the molecular aspects of bacterial stress response.Keywords
This publication has 32 references indexed in Scilit:
- Changes in Fourier transform infrared spectra of Salmonella enterica serovars Typhimurium and Enteritidis after adaptation to stressful growth conditionsInternational Journal of Food Microbiology, 2010
- Arginine and lysine decarboxylases and the Acid Tolerance Response of Salmonella TyphimuriumInternational Journal of Food Microbiology, 2010
- A Comparative Study of Thermal and Acid Inactivation Kinetics in Fruit Juices ofSalmonella entericaSerovar Typhimurium andSalmonella entericaSerovar Senftenberg Grown at Acidic ConditionsFoodborne Pathogens & Disease, 2009
- Comparison of acids on the induction of an Acid Tolerance Response in Salmonellatyphimurium, consequences for food safetyMeat Science, 2009
- Modifications in membrane fatty acid composition of Salmonella typhimurium in response to growth conditions and their effect on heat resistanceInternational Journal of Food Microbiology, 2008
- Detection of Sublethal Thermal Injury in Salmonella enterica Serotype Typhimurium and Listeria monocytogenes Using Fourier Transform Infrared (FT‐IR) Spectroscopy (4000 to 600 cm−1)Journal of Food Science, 2008
- Rapid identification of coagulase-negative staphylococci by Fourier transform infrared spectroscopyJournal of Microbiological Methods, 2007
- Effect of selective growth media on the differentiation of Salmonella enterica serovars by Fourier-Transform Mid-Infrared SpectroscopyJournal of Microbiological Methods, 2007
- Fourier transform infrared spectroscopy, detection and identification of Escherichia coli O157:H7 and Alicyclobacillus strains in apple juiceInternational Journal of Food Microbiology, 2006
- Treatment ofSalmonella entericaSerovar Enteritidis with a Sublethal Concentration of Trisodium Phosphate or Alkaline pH Induces ThermotoleranceApplied and Environmental Microbiology, 2004