Variation in Resistance to High Hydrostatic Pressure andrpoS Heterogeneity in Natural Isolates ofEscherichia coli O157:H7

ABSTRACT Several natural isolates of Escherichia coliO157:H7 have previously been shown to exhibit stationary-phase-dependent variation in their resistance to inactivation by high hydrostatic pressure. In this report we demonstrate that loss of the stationary-phase-inducible sigma factor RpoS resulted in decreased resistance to pressure inE. coli O157:H7 and in a commensal strain. Furthermore, variation in the RpoS activity of the natural isolates of O157:H7 correlated with the pressure resistance of those strains. Heterogeneity was noted in the rpoS alleles of the natural isolates that may explain the differences in RpoS activity. These results are consistent with a role for rpoS in mediating resistance to high hydrostatic pressure in E. coliO157:H7.

[1]  D. Hoover,et al.  Minimally processed fruits and vegetables : Reducing microbial load by nonthermal physical treatments , 1997 .

[2]  D. Knorr,et al.  Biological effects of high hydrostatic pressure on food microorganisms , 1989 .

[3]  J. Sambrook,et al.  Molecular Cloning: A Laboratory Manual , 2001 .

[4]  J. Smelt,et al.  Recent advances in the microbiology of high pressure processing , 1998 .

[5]  S. Clarke,et al.  RpoS- and OxyR-independent induction of HPI catalase at stationary phase in Escherichia coli and identification of rpoS mutations in common laboratory strains , 1997, Journal of bacteriology.

[6]  C. Buchrieser,et al.  rpoS regulation of acid, heat, and salt tolerance in Escherichia coli O157:H7 , 1996, Applied and environmental microbiology.

[7]  K. Bernaerts,et al.  Protective effect of calcium on inactivation of Escherichia coli by high hydrostatic pressure , 1998, Journal of applied microbiology.

[8]  M. Wiedmann,et al.  Characterization of rpoS alleles in Escherichia coli O157:H7 and in other E. coli serotypes , 1999, Journal of applied microbiology.

[9]  R. Kolter,et al.  Prolonged Stationary-Phase Incubation Selects forlrp Mutations in Escherichia coliK-12 , 2000, Journal of bacteriology.

[10]  N. W. Davis,et al.  Genome sequence of enterohaemorrhagic Escherichia coli O157:H7 , 2001, Nature.

[11]  E. Allen-Vercoe,et al.  The variant rpoS allele of S. enteritidis strain 27655R does not affect virulence in a chick model nor constitutive curliation but does generate a cold-sensitive phenotype. , 1998, FEMS microbiology letters.

[12]  C. Michiels,et al.  Escherichia coli mutants resistant to inactivation by high hydrostatic pressure , 1997, Applied and environmental microbiology.

[13]  H. Schellhorn,et al.  Identification of Conserved, RpoS-Dependent Stationary-Phase Genes of Escherichia coli , 1998, Journal of Bacteriology.

[14]  R. Pagán,et al.  Relationship between Membrane Damage and Cell Death in Pressure-Treated Escherichia coli Cells: Differences between Exponential- and Stationary-Phase Cells and Variation among Strains , 2000, Applied and Environmental Microbiology.

[15]  J. Claude Cheftel,et al.  Review : High-pressure, microbial inactivation and food preservation , 1995 .

[16]  T. Robinson,et al.  Variation in Resistance of Natural Isolates ofEscherichia coli O157 to High Hydrostatic Pressure, Mild Heat, and Other Stresses , 1999, Applied and Environmental Microbiology.

[17]  R. Hengge-aronis,et al.  Identification of transcriptional start sites and the role of ppGpp in the expression of rpoS, the structural gene for the sigma S subunit of RNA polymerase in Escherichia coli , 1995, Journal of bacteriology.

[18]  A. Eisenstark,et al.  DNA base sequence variability in katF (putative sigma factor) gene of Escherichia coli. , 1992, Nucleic acids research.

[19]  F. Neidhardt,et al.  Escherichia Coli and Salmonella: Typhimurium Cellular and Molecular Biology , 1987 .

[20]  P. Small,et al.  Characterization of the acid resistance phenotype and rpoS alleles of shiga-like toxin-producing Escherichia coli , 1996, Infection and immunity.

[21]  Dietrich Knorr,et al.  Effects of high-hydrostatic-pressure processes on food safety and quality , 1993 .

[22]  K. Krogfelt,et al.  rpoS Gene Function Is a Disadvantage forEscherichia coli BJ4 during Competitive Colonization of the Mouse Large Intestine , 2000, Infection and Immunity.

[23]  R. Simpson,et al.  Sensitivity of Vegetative Pathogens to High Hydrostatic Pressure Treatment in Phosphate-Buffered Saline and Foods. , 1995, Journal of food protection.

[24]  T. Whittam,et al.  Gene Conservation and Loss in themutS-rpoS Genomic Region of PathogenicEscherichia coli , 2000, Journal of bacteriology.

[25]  D A Siegele,et al.  Microbial competition: Escherichia coli mutants that take over stationary phase cultures. , 1993, Science.

[26]  A. Campbell,et al.  Bioluminescence and chemiluminescence : fundamentals and applied aspects : proceedings of the 8th International Symposium on Bioluminescence and Chemiluminescence, Cambridge, September 1994 , 1994 .

[27]  J. Foster,et al.  An altered rpoS allele contributes to the avirulence of Salmonella typhimurium LT2 , 1997, Infection and immunity.

[28]  T. Humphrey,et al.  Invasiveness in chickens, stress resistance and RpoS status of wild-type Salmonella enterica subsp. enterica serovar typhimurium definitive type 104 and serovar enteritidis phage type 4 strains. , 2000, Microbiology.