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Effect of growth and recovery temperatures on pressure resistance of Listeria monocytogenes.
Int J Food Microbiol. 2010 Jan 01; 136(3):359-63.IJ

Abstract

Experimental conditions can affect the outcome of bacterial stress-tolerance assays. Growth conditions that optimize microbial recovery should be established to help evaluate the effectiveness of treatment conditions for food safety. The objectives of this study were to determine the effects of growth and recovery temperatures on pressure resistance of early stationary-phase Listeria monocytogenes in milk. The tested conditions were the following: (1) L. monocytogenes was grown at various temperatures (10, 15, 20, 25, 30, 35, 40 and 43 degrees C), suspended in ultra-high temperature (UHT) -processed whole milk, pressure-treated at 400 MPa for 2 min at 21 degrees C and recovered on Tryptic Soy Agar supplemented with 0.6% yeast extract (TSAYE) at 35 degrees C; (2) L. monocytogenes was grown at 35 and 43 degrees C, pressure treated in milk (400 and 500 MPa, respectively, for 2 min at 21 degrees C) and recovered on TSAYE at various temperatures (4, 10, 15, 20, 25, 30, 35 and 40 degrees C); (3) L. monocytogenes originally grown at 35 degrees C, was pressure treated in milk (400 or 450 MPa for 2 min at 21 degrees C), and recovered on TSAYE at 10 degrees C for various time intervals (1, 2, 3, 6, 9 and 12 days) then at 35 degrees C for 5 days. There was no significant difference (P>0.05) in pressure-resistance of L. monocytogenes grown at 10 to 25 degrees C with approximately 6.5-log CFU/ml population reductions. At growth temperatures greater than 25 degrees C, pressure resistance increased with less than 1-log CFU/ml reduction observed for L. monocytogenes originally grown at 43 degrees C. After pressure treatment, regardless of growth temperature and pressure treatment, the greatest recovery of L. monocytogenes was within the 4 to 20 degrees C range; maximum recovery at 10 degrees C required approximately 24 days. The time for comparable post-pressure treatment recovery could be reduced by incubation at 10 degrees C for at least 2 days followed by incubation at 35 degrees C for 5 days. The findings of the present study indicate that growth and recovery temperatures affect the pressure resistance of L. monocytogenes and should, therefore, be taken into account when assessing the adequacy of inactivation treatments.

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Publisher Full Text (DOI)

Authors+Show Affiliations

Shearer AE
University of Delaware, Department of Animal and Food Sciences, Newark, DE 19716, USA.
Neetoo HS
No affiliation info available
Chen H
No affiliation info available

MeSH

AnimalsCattleColony Count, MicrobialConsumer Product SafetyFood ContaminationFood HandlingFood MicrobiologyHumansHydrostatic PressureListeria monocytogenesMilkTemperature

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19931930

Citation

Shearer, Adrienne E H., et al. "Effect of Growth and Recovery Temperatures On Pressure Resistance of Listeria Monocytogenes." International Journal of Food Microbiology, vol. 136, no. 3, 2010, pp. 359-63.
Shearer AE, Neetoo HS, Chen H. Effect of growth and recovery temperatures on pressure resistance of Listeria monocytogenes. Int J Food Microbiol. 2010;136(3):359-63.
Shearer, A. E., Neetoo, H. S., & Chen, H. (2010). Effect of growth and recovery temperatures on pressure resistance of Listeria monocytogenes. International Journal of Food Microbiology, 136(3), 359-63. https://doi.org/10.1016/j.ijfoodmicro.2009.10.034
Shearer AE, Neetoo HS, Chen H. Effect of Growth and Recovery Temperatures On Pressure Resistance of Listeria Monocytogenes. Int J Food Microbiol. 2010 Jan 1;136(3):359-63. PubMed PMID: 19931930.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effect of growth and recovery temperatures on pressure resistance of Listeria monocytogenes. AU - Shearer,Adrienne E H, AU - Neetoo,Hudaa S, AU - Chen,Haiqiang, Y1 - 2009/11/05/ PY - 2009/5/27/received PY - 2009/10/23/revised PY - 2009/10/31/accepted PY - 2009/11/26/entrez PY - 2009/11/26/pubmed PY - 2010/3/10/medline SP - 359 EP - 63 JF - International journal of food microbiology JO - Int J Food Microbiol VL - 136 IS - 3 N2 - Experimental conditions can affect the outcome of bacterial stress-tolerance assays. Growth conditions that optimize microbial recovery should be established to help evaluate the effectiveness of treatment conditions for food safety. The objectives of this study were to determine the effects of growth and recovery temperatures on pressure resistance of early stationary-phase Listeria monocytogenes in milk. The tested conditions were the following: (1) L. monocytogenes was grown at various temperatures (10, 15, 20, 25, 30, 35, 40 and 43 degrees C), suspended in ultra-high temperature (UHT) -processed whole milk, pressure-treated at 400 MPa for 2 min at 21 degrees C and recovered on Tryptic Soy Agar supplemented with 0.6% yeast extract (TSAYE) at 35 degrees C; (2) L. monocytogenes was grown at 35 and 43 degrees C, pressure treated in milk (400 and 500 MPa, respectively, for 2 min at 21 degrees C) and recovered on TSAYE at various temperatures (4, 10, 15, 20, 25, 30, 35 and 40 degrees C); (3) L. monocytogenes originally grown at 35 degrees C, was pressure treated in milk (400 or 450 MPa for 2 min at 21 degrees C), and recovered on TSAYE at 10 degrees C for various time intervals (1, 2, 3, 6, 9 and 12 days) then at 35 degrees C for 5 days. There was no significant difference (P>0.05) in pressure-resistance of L. monocytogenes grown at 10 to 25 degrees C with approximately 6.5-log CFU/ml population reductions. At growth temperatures greater than 25 degrees C, pressure resistance increased with less than 1-log CFU/ml reduction observed for L. monocytogenes originally grown at 43 degrees C. After pressure treatment, regardless of growth temperature and pressure treatment, the greatest recovery of L. monocytogenes was within the 4 to 20 degrees C range; maximum recovery at 10 degrees C required approximately 24 days. The time for comparable post-pressure treatment recovery could be reduced by incubation at 10 degrees C for at least 2 days followed by incubation at 35 degrees C for 5 days. The findings of the present study indicate that growth and recovery temperatures affect the pressure resistance of L. monocytogenes and should, therefore, be taken into account when assessing the adequacy of inactivation treatments. SN - 1879-3460 UR - https://www.unboundmedicine.com/medline/citation/19931930/Effect_of_growth_and_recovery_temperatures_on_pressure_resistance_of_Listeria_monocytogenes_ DB - PRIME DP - Unbound Medicine ER -