Cross-protection phenomenon in Escherichia coli strains harbouring cytotoxic necrotizing factors and cytolethal distending toxins.
Micro-organisms which are subjected to non-lethal stress can exhibit significantly greater resistance when both the same or an unrelated stress is subsequently reapplied. This latter phenomenon is termed 'cross-protection'. In experiments using three strains of Escherichia coli harbouring cytotoxic necrotizing factor 1 and/or cytolethal distending toxin all three exhibited significantly greater (P < 0.05) resistance to salt (20% w/v) or heat (56 degrees C for up to 75 min) when prestressed with lactic acid (pH 4). This work indicates that the cross-protection phenomenon should be taken into account when devising food process operations designed to minimize the risk posed by these pathogens.
Rowe
M T
MT
Food Microbiology, Food Science Department, The Queen's University of Belfast, Belfast, Northern Ireland. Michael.Rowe@dardni.gov.uk
Kirk
R B
RB
D001427:Bacterial Toxins / Q000096:biosynthesis*; D003603:Cytotoxins / Q000096:biosynthesis*; D004926:Escherichia coli / Q000472:pathogenicity* / Q000502:physiology*; D029968:Escherichia coli Proteins; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D012965:Sodium Chloride / Q000494:pharmacology; D014774:Virulence
D001427:Bacterial Toxins; D003603:Cytotoxins; D029968:Escherichia coli Proteins; C067044:cytolethal distending toxin; C060296:cytotoxic necrotizing factor type 1; D012965:Sodium Chloride