Viability and DNA Maintenance in Nonculturable Spiral Campylobacter jejuni Cells after Long-Term Exposure to Low Temperatures

Survival of Campylobacter jejuni at 4 and 20°C was investigated by using cellular integrity, respiratory activity, two-dimensional (2D) protein profile, and intact DNA content as indicators of potential viability of nonculturable cells. Intact DNA content after 116 days, along with cellular integrity and respiring cells, was detected for up to 7 months at 4°C by pulsed-field gel electrophoresis. Most changes in 2D protein profiles involved up- or down-regulation.