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Survival and growth characteristics of Escherichia coli O157:H7 in pasteurized and unpasteurized Cheddar cheese whey.
Int J Food Microbiol. 2004 Jul 01; 94(1):1-7.IJ

Abstract

The objective of this study was to determine the survival and growth characteristics of Escherichia coli O157:H7 in whey. A five-strain mixture of E. coli O157:H7 was inoculated into 100 ml of fresh, pasteurized or unpasteurized Cheddar cheese whey (pH 5.5) at 10(5) or 10(2) CFU/ml, and stored at 4, 10 or 15 degrees C. The population of E. coli O157:H7 (on Sorbitol MacConkey agar supplemented with 0.1% 4-methylumbelliferyl-beta-D-glucuronide) and lactic acid bacteria (on All Purpose Tween agar) were determined on days 0, 1, 4, 7, 14, 21 and 28. At all storage temperatures, survival of E. coli O157:H7 was significantly higher (P<0.01) in the pasteurized whey compared to that in the unpasteurized samples. At 10 and 15 degrees C, E. coli O157:H7 in pasteurized whey significantly (P<0.05) increased during the first week of storage, followed by a decrease thereafter. However at the same temperatures, E. coli O157:H7 exhibited a steady decline in the unpasteurized samples from day 0. At 4 degrees C, E. coli O157:H7 did not grow in pasteurized and unpasteurized whey; however, the pathogen persisted longer in pasteurized samples. At all the three storage temperatures, E. coli O157:H7 survived up to day 21 in the pasteurized and unpasteurized whey. The initial load of lactic acid bacteria in the unpasteurized whey samples was approximately 7.0 log10 CFU/ml and, by day 28, greater than 3.0 log10 CFU/ml of lactic acid bacteria survived in unpasteurized whey at all temperatures, with the highest counts recovered at 4 degrees C. Results indicate the potential risk of persistence of E. coli O157:H7 in whey in the event of contamination with this pathogen.

Authors+Show Affiliations

Marek P
Department of Animal Science, Unit-40, University of Connecticut, 3636 Horsebarn Hill Road Extension, Storrs 06269, USA.
Nair MK
No affiliation info available
Hoagland T
No affiliation info available
Venkitanarayanan K
No affiliation info available

MeSH

CheeseColony Count, MicrobialEscherichia coli O157Food MicrobiologyFood PreservationHydrogen-Ion ConcentrationLactobacillusMilk ProteinsTemperatureTime FactorsWhey Proteins

Pub Type(s)

Journal Article

Language

eng

PubMed ID

15172479

Citation

Marek, Patrick, et al. "Survival and Growth Characteristics of Escherichia Coli O157:H7 in Pasteurized and Unpasteurized Cheddar Cheese Whey." International Journal of Food Microbiology, vol. 94, no. 1, 2004, pp. 1-7.
Marek P, Nair MK, Hoagland T, et al. Survival and growth characteristics of Escherichia coli O157:H7 in pasteurized and unpasteurized Cheddar cheese whey. Int J Food Microbiol. 2004;94(1):1-7.
Marek, P., Nair, M. K., Hoagland, T., & Venkitanarayanan, K. (2004). Survival and growth characteristics of Escherichia coli O157:H7 in pasteurized and unpasteurized Cheddar cheese whey. International Journal of Food Microbiology, 94(1), 1-7.
Marek P, et al. Survival and Growth Characteristics of Escherichia Coli O157:H7 in Pasteurized and Unpasteurized Cheddar Cheese Whey. Int J Food Microbiol. 2004 Jul 1;94(1):1-7. PubMed PMID: 15172479.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Survival and growth characteristics of Escherichia coli O157:H7 in pasteurized and unpasteurized Cheddar cheese whey. AU - Marek,Patrick, AU - Nair,Manoj Kumar Mohan, AU - Hoagland,Thomas, AU - Venkitanarayanan,Kumar, PY - 2002/10/28/received PY - 2003/05/01/revised PY - 2003/05/30/accepted PY - 2004/6/3/pubmed PY - 2004/9/10/medline PY - 2004/6/3/entrez SP - 1 EP - 7 JF - International journal of food microbiology JO - Int J Food Microbiol VL - 94 IS - 1 N2 - The objective of this study was to determine the survival and growth characteristics of Escherichia coli O157:H7 in whey. A five-strain mixture of E. coli O157:H7 was inoculated into 100 ml of fresh, pasteurized or unpasteurized Cheddar cheese whey (pH 5.5) at 10(5) or 10(2) CFU/ml, and stored at 4, 10 or 15 degrees C. The population of E. coli O157:H7 (on Sorbitol MacConkey agar supplemented with 0.1% 4-methylumbelliferyl-beta-D-glucuronide) and lactic acid bacteria (on All Purpose Tween agar) were determined on days 0, 1, 4, 7, 14, 21 and 28. At all storage temperatures, survival of E. coli O157:H7 was significantly higher (P<0.01) in the pasteurized whey compared to that in the unpasteurized samples. At 10 and 15 degrees C, E. coli O157:H7 in pasteurized whey significantly (P<0.05) increased during the first week of storage, followed by a decrease thereafter. However at the same temperatures, E. coli O157:H7 exhibited a steady decline in the unpasteurized samples from day 0. At 4 degrees C, E. coli O157:H7 did not grow in pasteurized and unpasteurized whey; however, the pathogen persisted longer in pasteurized samples. At all the three storage temperatures, E. coli O157:H7 survived up to day 21 in the pasteurized and unpasteurized whey. The initial load of lactic acid bacteria in the unpasteurized whey samples was approximately 7.0 log10 CFU/ml and, by day 28, greater than 3.0 log10 CFU/ml of lactic acid bacteria survived in unpasteurized whey at all temperatures, with the highest counts recovered at 4 degrees C. Results indicate the potential risk of persistence of E. coli O157:H7 in whey in the event of contamination with this pathogen. SN - 0168-1605 UR - https://www.unboundmedicine.com/medline/citation/15172479/Survival_and_growth_characteristics_of_Escherichia_coli_O157:H7_in_pasteurized_and_unpasteurized_Cheddar_cheese_whey_ DB - PRIME DP - Unbound Medicine ER -