This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bacon, R. T.
Right arrow Articles by Smith, G. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bacon, R. T.
Right arrow Articles by Smith, G. C.
Agricola
Right arrow Articles by Bacon, R. T.
Right arrow Articles by Smith, G. C.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, July 2003, p. 4123-4128, Vol. 69, No. 7
0099-2240/03/$08.00+0     DOI: 10.1128/AEM.69.7.4123-4128.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Thermal Inactivation of Susceptible and Multiantimicrobial-Resistant Salmonella Strains Grown in the Absence or Presence of Glucose

R. T. Bacon,1 J. R. Ransom,1 J. N. Sofos,1* P. A. Kendall,2 K. E. Belk,1 and G. C. Smith1

Center for Red Meat Safety, Department of Animal Sciences, Colorado State University, Ft. Collins, Colorado 80523-1171,1 Department of Food Science and Human Nutrition, Colorado State University, Ft. Collins, Colorado 80523-15712

Received 17 October 2002/ Accepted 28 April 2003

The heat resistance of susceptible and multiantimicrobial-resistant Salmonella strains grown to stationary phase in glucose-free tryptic soy broth supplemented with 0.6% yeast extract (TSBYE-G; nonadapted), in regular (0.25% glucose) TSBYE, or in TSBYE-G with 1.00% added glucose (TSBYE+G; acid adapted) was determined at 55, 57, 59, and 61°C. Cultures were heated in sterile 0.1% buffered peptone water (50 µl) in heat-sealed capillary tubes immersed in a thermostatically controlled circulating-water bath. Decimal reduction times (D values) were calculated from survival curves having r2 values of >0.90 as a means of comparing thermal tolerance among variables. D59°C values increased (P < 0.05) from 0.50 to 0.58 to 0.66 min for TSBYE-G, TSBYE, and TSBYE+G cultures, respectively. D61°C values of antimicrobial-susceptible Salmonella strains increased (P < 0.05) from 0.14 to 0.19 as the glucose concentration increased from 0.00 to 1.00%, respectively, while D61°C values of multiantimicrobial-resistant Salmonella strains did not differ (P > 0.05) between TSBYE-G and TSBYE+G cultures. When averaged across glucose levels and temperatures, there were no differences (P > 0.05) between the D values of susceptible and multiantimicrobial-resistant inocula. Collectively, D values ranged from 4.23 to 5.39, 1.47 to 1.81, 0.50 to 0.66, and 0.16 to 0.20 min for Salmonella strains inactivated at 55, 57, 59, and 61°C, respectively. zD values were 1.20, 1.48, and 1.49°C for Salmonella strains grown in TSBYE+G, TSBYE, and TSBYE-G, respectively, while the corresponding activation energies of inactivation were 497, 493, and 494 kJ/mol. Study results suggested a cross-protective effect of acid adaptation on thermal inactivation but no association between antimicrobial susceptibility and the ability of salmonellae to survive heat stress.

* Corresponding author. Mailing address: Center for Red Meat Safety, Department of Animal Sciences, Colorado State University, Ft. Collins, CO 80523-1171. Phone: (970) 491-7703. Fax: (970) 491-0278. E-mail: John.Sofos{at}colostate.edu.

Applied and Environmental Microbiology, July 2003, p. 4123-4128, Vol. 69, No. 7
0099-2240/03/$08.00+0     DOI: 10.1128/AEM.69.7.4123-4128.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»