The responses to pH and @entity2827 of four strains of @entity5125 isolated from Portuguese cheese, with a @entity2827 concentration of about 2% (w/v) and a pH value from 5.1 to 6.2, were studied. Two isolates from meat and two clinical isolates related to @entity6766 , in which the implicated food product had about 2-3.5% (w/v) @entity2827 , also were studied. The effect of temperature on pH and @entity2827 sensitivity was also determined. The results show that natural isolates vary in response to these stresses and the data were often at variance with previously published data. Strains varied in sensitivity to low pH and to high @entity2827 concentration but the cheese isolates tended to be more resistant. A lower temperature was associated with a decrease in resistance to low pH and to @entity2827 . All strains showed an acid tolerance response induction when grown at pH 5.5 and although the time required for maximum induction of the response varied between strains, 2 h of acid adaptation, at least, was necessary which is longer than previously reported. Some strains showed an osmotolerance response after incubation in 3.5% (w/v) @entity2827 . Osmoadaptation, in addition to inducing an osmotolerance response, also induced cross-protection against acid shock conditions (pH 3.5). The acid tolerance response also induced a cross-protection against osmotic shock conditions (20% (w/v) @entity2827 ). In some cases there was a relationship between the degree of resistance and adaptation, but usually the behaviour of a particular strain was independent of the conditions from which it was isolated.

Stress response of XXXX isolated from cheese and other foods.

@entity2827 :: ('MESH:D012965', 'Chemical') :: ['sodium chloride'] @entity5125 :: ('1639', 'Species') :: ['Listeria monocytogenes'] @entity6766 :: ('MESH:D005517', 'Disease') :: ['food-borne listeriosis']
@entity5125 :: (1639,Species) :: ['Listeria monocytogenes']
