ACID HABITUATION IN SALMONELLA-ENTERITIDIS PT4 - IMPACT OF INHIBITION OF PROTEIN-SYNTHESIS

Incubation of Salmonella enteritidis PT4 in media at pH values between 3.0-6.0 resulted in a marked and rapid increase in acid resistance, manifested when cells were subsequently challenged at pH 2.5-2.9. Habituation involves two separate systems, one of which is independent of protein synthesis. The relative importance of the two systems is governed by the pH of the challenge medium. Thus in broth at pH 2.7 or above, inhibition of protein synthesis during habituation did not lessen subsequent acid resistance. At pH values of 2.6 and below, the addition of chloramphenicol during habituation was found to reduce subsequent acid resistance although cells were not as sensitive as control cultures grown at pH 7.0.