The Response ofCampylobacter jejunito Low Temperature Differs from That ofEscherichia coli

Abstract

Human infection with Campylobacter jejuni is often associated with the consumption of foods that have been exposed to both chilling and high temperatures. Despite the public health importance of this pathogen, little is known about the effects of cold exposure on its ability to survive a subsequent heat challenge. This work examined the effect of rapid exposure to chilling, as would occur in poultry processing, on the heat resistance at 56°C of two C. jejuni strains, 11168 and 2097e48, and of Escherichia coli K-12. Unlike E. coli K-12, whose cold-exposed cells showed increased sensitivity to 56°C, such exposure had only a marginal effect on subsequent heat resistance in C. jejuni. This may be explained by the finding that during rapid chilling, unlike E. coli cells, C. jejuni cells are unable to alter their fatty acid composition and do not adapt to cold exposure. However, their unaltered fatty acid composition is more suited to survival when cells are exposed to high temperatures. This hypothesis is supported by the fact that in C. jejuni, the ratio of unsaturated to saturated fatty acids was not significantly different after cold exposure, but it was in E. coli. The low-temperature response of C. jejuni is very different from that of other food-borne pathogens, and this may contribute to its tolerance to further heat stresses.

Antimicrobial Edible Apple Films Inactivate Antibiotic Resistant and Susceptible Campylobacter jejuni Strains on Chicken Breast

“…The presence of cyclic fatty acids in the cell membrane allows Campylobacter spp. to maintain membrane fluidity and integrity without requiring a fatty acid composition change at low temperatures (Hughes and others 2009). Exposure of C. jejuni to cold does not appear to make it more sensitive to subsequent heat shock, which may explain its survival during food processing (Hughes and others 2009).…”

Heat Adaptation and Survival ofCronobacterspp. (FormerlyEnterobacter sakazakii)

“…Many bacteria have been shown to respond to changes in environmental temperature by changes in the fatty acid composition of their membrane lipids (Pond and Langworthy, 1987). A common bacterial response to an external challenge, particularly heat stress, is to increase the concentration of saturated membrane fatty acids to increase the rigidity and, therefore, the thermal resistance of the cell (Hughes et al, 2009). The straight-chain saturated fatty acids are efficiently packed tightly side by side to produce rigid membranes with a low permeability that resist heat stress (Zhang and Rock, 2008).…”

Inactivation ofCampylobacter jejuniby Exposure to High-Intensity 405-nm Visible Light

“…The importance of temperature on growth and survival is well documented (El-Shibiny et al, 2009;Hughes et al, 2009) as is information on factors such as oxygen-related toxicity (Hoffman et al, 1979;Bolton et al, 1984;Juven and Rosenthal, 1985;Verhoeff-Bakkenes et al, 2008;Atack and Kelly, 2009), acidity (Reid et al, 2008), osmolarity (Reezal et al, 1998), and nutritional availability (Klancnik et al, 2009), among others.…”