SURVIVAL AND GROWTH OF FREEZE‐STRESSED Campylobacter jejuni CELLS IN SELECTIVE MEDIA

Freezing and thawing of Campylobacter jejuni inflicted sublethal injury among survivors. About 95% or more of the survivors lost viability within 2 h of microaerobic incubation at 42°C in brucella broth containing a Campylobacter‐selective antibiotic supplement of vancomycin, trimethoprim, polymyxin B, cephalothin and amphotericin. The remaining viable cells were able to multiply under these incubation conditions. The stressed cells were adversely affected by incubation at 42°C andpolymyxin B. A method consisting of incubating suspected samples microaerobically in brucella broth, supplemented with nutrients (succinate + cysteine) and antibiotics (vancomycin, trimethoprim, cephalothin and amphotericin) at 37°C for the initial 6 h and then adding polymyxin B and shifting the temperature to 42°C up to 24 h could improve detection of C. jejuni from frozen foods.