title: Stress response and virulence of heat-stressed Campylobacter jejuni.
abstract: Thermotolerant Campylobacter spp. frequently cause bacterial gastroenteritis in humans commonly infected through the consumption of undercooked poultry meat. We examined Campylobacter jejuni heat-stress responses in vitro after exposure to 48°C and 55°C. The in vivo modulation of its pathogenicity was also investigated using BALB/c mice intravenously infected with stressed C. jejuni. Regardless of the bacterial growth phase, the culturability and viability of C. jejuni in vitro was reduced after exposure to 55°C. This correlated with the altered protein profile and decreased virulence properties observed in vivo. Heat stress at 48°C elicited the transition to more resistant bacterial forms, independent of morphological changes or the appearance of shorter spiral and coccoid cells. This treatment did not cause marked changes in bacterial virulence properties in vivo. These results indicated that the characteristics and pathogenicity of C. jejuni in response to heat stress are temperature dependent. Further studies on the responses of C. jejuni to stresses used during food processing, as well as the modulation of its virulence, are important for a better understanding of its contamination and infective cycle, and will, thus, contribute to improved safety in the food production chain.
authors.affiliation: Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana.
authors.forename: Anja
authors.initials: A
authors.lastname: Klančnik
authors.forename: Darinka
authors.initials: D
authors.lastname: Vučković
authors.forename: Polona
authors.initials: P
authors.lastname: Jamnik
authors.forename: Maja
authors.initials: M
authors.lastname: Abram
authors.forename: Sonja Smole
authors.initials: SS
authors.lastname: Možina
mesh_terms: D000818:Animals; D002169:Campylobacter Infections / Q000382:microbiology / Q000473:pathology; D016123:Campylobacter jejuni / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology* / Q000528:radiation effects*; D004195:Disease Models, Animal; D006358:Hot Temperature; D008807:Mice, Inbred BALB C; D050296:Microbial Viability / Q000528:radiation effects; D013312:Stress, Physiological; D014774:Virulence / Q000528:radiation effects