Fate of Escherichia coli O157:H7 in coleslaw during storage.
An outbreak of Escherichia coli O157:H7 infection associated with the consumption of coleslaw in several units of a restaurant chain prompted a study to determine the fate of the pathogen in two commercial coleslaw preparations (pH 4.3 and 4.5) held at 4, 11, and 21 degrees C for 3 days. At an initial population of 5.3 log10 CFU/g of coleslaw, E. coli O157:H7 did not grow in either coleslaw stored at the three temperatures. Rather, the population of E. coli O157:H7 decreased by 0.1 to 0.5 log10 CFU/g within 3 days. The greatest reduction (0.4 and 0.5 log10 CFU/g) in population occurred at 21 degrees C, whereas only slight decreases (0.1 to 0.2 log10 CFU/g) occurred at 4 and 11 degrees C. A pH of 4.3 to 4.5 of coleslaw had little effect on reducing E. coli O157:H7 populations. Results suggest that the tolerance of E. coli O157:H7 to acid pH, not temperature abuse, is a major factor influencing the pathogen's fate in restaurant-prepared coleslaw.
Wu
F M
FM
Center for Food Safety and Department of Food Science and Technology, University of Georgia, Griffin 30223-1797, USA.
Beuchat
L R
LR
Doyle
M P
MP
Garrett
V
V
Wells
J G
JG
Swaminathan
B
B
D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000254:growth & development*; D005506:Food Contamination / Q000517:prevention & control*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D013997:Time Factors