Differential oxidative damage and expression of stress defence regulons in culturable and non-culturable Escherichia coli cells

Benoit Desnues (1) , Caroline Cuny (2) , Gérald Grégori (3) , Sam Dukan (4) , Hugo Aguilaniu (5) , Thomas Nystrom (6)

1 Laboratoire de Microbiologie Marine
2 EESC-GEM Grenoble Ecole de Management
3 LMGEM - Laboratoire de MicrobiologiE de Géochimie et d'Ecologie Marines
4 LCB - Laboratoire de chimie bactérienne
5 IGFL - Institut de Génomique Fonctionnelle de Lyon
6 Department of Cell and Molecular Biology [Uppsala]

Potentially pathogenic bacteria, such as Escherichia coli and Vibrio cholerae, become non-culturable during stasis. The analysis of such cells has been hampered by difficulties in studying bacterial population heterogeneity. Using in situ detection of protein oxidation in single E. coli cells, and using a density-gradient centrifugation technique to separate culturable and non-culturable cells, we show that the proteins in non-culturable cells show increased and irreversible oxidative damage, which affects various bacterial compartments and proteins. The levels of expression of specific stress regulons are higher in non-culturable cells, confirming increased defects relating to oxidative damage and the occurrence of aberrant, such as by amino-acid misincorporation, proteins. Our data suggest that non-culturable cells are produced due to stochastic deterioration, rather than an adaptive programme, and pinpoint oxidation management as the 'Achilles heel' of these cells.

Domaines: Sciences du Vivant [q-bio]

Benoit Desnues, Caroline Cuny, Gérald Grégori, Sam Dukan, Hugo Aguilaniu, et al.. Differential oxidative damage and expression of stress defence regulons in culturable and non-culturable Escherichia coli cells. EMBO Reports, 2003, 4 (4), pp.400-404. ⟨10.1038/sj.embor.embor799⟩. ⟨hal-02025874⟩