Details

Autor(en) / Beteiligte

• Rajkowski, K.T. (USDA, ARS, Eastern Regional Research Center, Philadelphia, PA.)
• Marmer, B.S

Titel

Growth of Escherichia coli O157:H7 at fluctuating incubation temperatures

Ist Teil von

• Journal of food protection, 1995-12, Vol.58 (12), p.1307-1313

Ort / Verlag

Des Moines, IA: International Association of Milk, Food and Environmental Sanitarians

Erscheinungsjahr

1995

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Temperature abuse of foods is often transitory and little information is available describing the response of the foodborne pathogen, Escherichia coli O157:H7, to nonisothermal and/or fluctuating temperature storage. Growth responses were determined for a mixture of three E. coli O157:H7 strains in brain heart infusion (BHI) broth as a function of temperature (static and fluctuating), initial pH (5, 6, and 7), and NaCl content (0.5, 1, 2, and 3%). Five 6-h "squarewave" fluctuating temperature regimes were used: 4 to 12, 4 to 19, 4 to 28, 8 to 19, and 12 to 28 degrees C and compared with growth at 8, 10, 12, 19, and 28 degrees C. The growth curves obtained from fitting the Gompertz equation for the fluctuating temperatures were compared to those obtained for the static temperatures. Increased NaCl concentration decreased growth temperature both for the fluctuating temperature growth curves and the static growth data. The cells grew or remained viable for up to 21 days underall conditions and fluctuating temperatures. Growth kinetics at fluctuating temperatures more closely approximated the higher temperature than the midpoint temperature of each cyclic range. The results indicate that transitory abuse could lead to more rapid growth than expected of E. coli O157:H7 in foods and that given sufficient time E. coli O157:H7 can grow at as low as 8 degrees C