title: Induction of an adaptive tolerance response in the foodborne pathogen, Campylobacter jejuni.
abstract: In this study we aimed to determine if Campylobacter had the ability to induce an adaptive tolerance response (ATR) to acid and/or aerobic conditions. Campylobacter jejuni CI 120 was grown to the appropriate phase in Brucella broth under microaerobic conditions. Cells were initially adapted to a mild stress (pH 5.5) for 5 h prior to challenge at pH 4.5, a lethal pH. Survival was examined by determining the numbers of viable cells on Campylobacter blood free selective agar base. Stationary phase cells adapted at pH 5.5 induced an ATR that enabled a 100-fold greater survival compared to an uninduced culture. Aerobic adaptation also protected the cells against acid challenge. The cross protection provided a 500-fold increase in survival when compared to unadapted cells. The incorporation of chloramphenicol during the induction period eliminated the ATR and resulted in death kinetics similar to an uninduced culture. These data suggest that Campylobacter spp. have the ability to induce an ATR to sublethal treatments, which increased their ability to withstand subsequent stresses.
authors.affiliation: Teagasc, Dairy Products Research Centre, Moorepark, Fermoy, Co., Cork, Ireland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Murphy
authors.forename: Cyril
authors.initials: C
authors.lastname: Carroll
authors.forename: Kieran N
authors.initials: KN
authors.lastname: Jordan
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000332:Aerobiosis; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016123:Campylobacter jejuni / Q000187:drug effects* / Q000254:growth & development*; D002701:Chloramphenicol / Q000494:pharmacology; D003470:Culture Media; D005516:Food Microbiology; D006851:Hydrochloric Acid / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D002701:Chloramphenicol; D006851:Hydrochloric Acid