Survival of Campylobacter jejuni and Escherichia coli in groundwater during prolonged starvation at low temperatures

Aims: To evaluate the survival of Campylobacter jejuni relative to that of Escherichia coli in groundwater microcosms varying in nutrient composition. Methods and Results: Studies were conducted in groundwater and deionized water incubated for up to 470 days at 4°C. Samples were taken for culturable and total cell counts, nutrient and molecular analysis. Die-off in groundwater microcosms was between 2·5 and 13 times faster for C. jejuni than for E. coli. Campylobacter jejuni had the lowest decay rate and longest culturability in microcosms with higher dissolved organic carbon (4 mg l-1). Escherichia coli survival was the greatest when the total dissolved nitrogen (12·0 mg l-1) was high. The transition of C. jejuni to the coccoid stage was independent of culturability. Conclusion: The differences in the duration of survival and response to water nutrient composition between the two organisms suggest that E. coli may be present in the waters much longer and respond to water composition much differently than C. jejuni. Significance and Impact of the Study: The data from these studies would aid in the evaluation of the utility of E. coli as an indicator of C. jejuni. This study also provided new information about the effect of nutrient composition on C. jejuni viability.