Exposure to non-acid fresh meat decontamination washing fluids sensitizes Escherichia coli O157:H7 to organic acids.
OBJECTIVE
To investigate whether Escherichia coli O157:H7 maintains acid tolerance in water meat decontamination washing fluids.


RESULTS
A rifampicin-resistant derivative of E. coli O157:H7 strain ATCC 43895 was inoculated (10(5) cfu ml(-1)) in spray-washings from meat sprayed with cold (10 degrees C) or hot (85 degrees C) water, stored at 10 degrees C for up to 14 days, and its acid tolerance was assessed at 2 and 8 days by exposure to broth or new washings adjusted to pH 3.5 or 3.7 with lactic or acetic acid. The pathogen survived in the water washings, but it was outgrown by the natural, Pseudomonas-like flora, and it was sensitized to acid.


CONCLUSIONS
The acid tolerance of E. coli O157:H7 decreases following exposure to non-acid, but otherwise stressful, conditions prevailing in water meat washings at 10 degrees C.


CONCLUSIONS
These findings suggest that the more intense use of water-based technologies should be included in meat decontamination strategies because they may contribute to enhanced meat safety by inducing acid sensitization in E. coli O157:H7.
Samelis
J
J
Center for Red Meat Safety, Department of Animal Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
Sofos
J N
JN
Ikeda
J S
JS
Kendall
P A
PA
Smith
G C
GC
D000818:Animals; D002417:Cattle; D019453:Escherichia coli O157 / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration; D008460:Meat / Q000382:microbiology*; D012449:Safety; D014871:Water Microbiology