Biomaterial Database

Oxygen sensitivity of heated cells of Escherichia coli O157:H7. 1998

R Bromberg, and S M George, and m W Peck

Institute of Food Research, Norwich Laboratory, UK.

Following defined heat treatments (55 degrees C for 100 min, 50 degrees C for 5 min, 61 degrees C for l min), a 6 decimal (6-D) reduction was obtained when cells of Escherichia coli O157:H7 were enumerated in aerobic growth medium. Part of this reduction (3-D) was due to thermal inactivation (as determined when cells were enumerated in anaerobic growth medium), and part (3-D) was due to the inability of sub-lethally heat-injured cells of E. coli O157:H7 to grow in the presence of oxygen. When held anaerobically, the injured cells regained their ability to grow in the presence of oxygen. Following heating at 59 degrees C for 5 min, repair took 4 h at 30 degrees C, 48 h at 20 degrees C, 95 h at 10 degrees C, but did not occur in 816 at 5 degrees C. Recovery from sub-lethal heat injury was not influenced by heat shock. These findings are relevant to the safety of minimally-heated foods.

UI	MeSH Term	Description	Entries
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D006361	Heating	The application of heat to raise the temperature of the environment, ambient or local, or the systems for accomplishing this effect. It is distinguished from HEAT, the physical property and principle of physics.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D018869	Heat-Shock Response	A sequence of responses that occur when an organism is exposed to excessive heat. In humans, an increase in skin temperature triggers muscle relaxation, sweating, and vasodilation.	Heat-Shock Reaction,Heat Shock,Heat Shock Stress,Heat Stress,Heat-Stress Reaction,Heat-Stress Response,Heat Shock Reaction,Heat Shock Response,Heat Shock Stresses,Heat Shocks,Heat Stress Reaction,Heat Stress Response,Heat Stresses,Heat-Shock Reactions,Heat-Shock Responses,Heat-Stress Reactions,Heat-Stress Responses,Shock, Heat,Stress, Heat,Stress, Heat Shock
D019453	Escherichia coli O157	A verocytotoxin-producing serogroup belonging to the O subfamily of Escherichia coli which has been shown to cause severe food-borne disease. A strain from this serogroup, serotype H7, which produces SHIGA TOXINS, has been linked to human disease outbreaks resulting from contamination of foods by E. coli O157 from bovine origin.	E coli O157,E coli O157-H7,Escherichia coli O157-H7