ACID ADAPTATION OF ESCHERICHIA-COLI O157-H7 INCREASES SURVIVAL IN ACIDIC FOODS

Escherichia coli O157:H7 aas adapted to acid by culturing for one to two doublings at pH 5.0. Acid adapted cells had an increased resistance to lactic acid, survived better than nonadapted cells during a sausage fermentation, and showed enhanced survival in shredded dry salami (pH 5.0) and apple cider (pH 3.4). Acid adaptation is important for the survival of E. coli O157:H7 in acidic foods and should be considered a prerequisite for inocula used in food challenge studies.