Survival of clinical and poultry-derived isolates of Campylobacter jejuni at a low temperature (4 degrees C)

Campylobacter jejuni is a leading cause of bacterial gastroenteritis in hum ans, and contamination of poultry has been implicated in illness. The bacte ria are fastidious in terms of their temperature requirements, being unable to grow below ca. 31 degreesC, but have been found to be physiologically a ctive at lower temperatures and to tolerate exposure to low temperatures in a strain-dependent manner. In this study, 19 field isolates of C. jejuni ( 10 of clinical and 9 of poultry origin) were studied for their ability to t olerate prolonged exposure to low temperature (4 degreesC). Although substa ntial variability was found among different strains, clinical isolates tend ed to be significantly more likely to remain viable following cold exposure than poultry-derived strains. In contrast, the relative degree of toleranc e of the bacteria to freezing at -20 degreesC and freeze-thawing was strain specific but independent of strain source (poultry versus clinical) and de gree of cold (4 degreesC) tolerance.