Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products

Yi Chen, Régis Pouillot, Laurel S. Burall, Errol A. Strain, Jane M. Van Doren, Antonio J. De Jesus, Anna Laasri, Hua Wang, Laila Ali, Aparna Tatavarthy, Guodong Zhang, Lijun Hu, James Day, Ishani Sheth, Jihun Kang, Surasri Sahu, Devayani Srinivasan, Eric Wayne Brown, Mickey Parish, Donald L. ZinkAtin R. Datta, Thomas S. Hammack, Dumitru Macarisin

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

A precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods.

Original languageEnglish (US)
Pages (from-to)15-22
Number of pages8
JournalInternational journal of food microbiology
Volume241
DOIs
StatePublished - Jan 16 2017

Fingerprint

Ice Cream
ice cream
Listeria monocytogenes
Least-Squares Analysis
Agar
probability analysis
Linear Models
sampling
Regression Analysis
Matched-Pair Analysis
least squares
Listeria
Bayes Theorem
agar
Disease Outbreaks
Food
statistical analysis
methodology

All Science Journal Classification (ASJC) codes

  • Food Science
  • Microbiology

Cite this

Chen, Yi ; Pouillot, Régis ; S. Burall, Laurel ; Strain, Errol A. ; Van Doren, Jane M. ; De Jesus, Antonio J. ; Laasri, Anna ; Wang, Hua ; Ali, Laila ; Tatavarthy, Aparna ; Zhang, Guodong ; Hu, Lijun ; Day, James ; Sheth, Ishani ; Kang, Jihun ; Sahu, Surasri ; Srinivasan, Devayani ; Brown, Eric Wayne ; Parish, Mickey ; Zink, Donald L. ; Datta, Atin R. ; Hammack, Thomas S. ; Macarisin, Dumitru. / Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products. In: International journal of food microbiology. 2017 ; Vol. 241. pp. 15-22.
@article{30c516f18a844490a2c3a6a742ec8c64,
title = "Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products",
abstract = "A precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods.",
author = "Yi Chen and R{\'e}gis Pouillot and {S. Burall}, Laurel and Strain, {Errol A.} and {Van Doren}, {Jane M.} and {De Jesus}, {Antonio J.} and Anna Laasri and Hua Wang and Laila Ali and Aparna Tatavarthy and Guodong Zhang and Lijun Hu and James Day and Ishani Sheth and Jihun Kang and Surasri Sahu and Devayani Srinivasan and Brown, {Eric Wayne} and Mickey Parish and Zink, {Donald L.} and Datta, {Atin R.} and Hammack, {Thomas S.} and Dumitru Macarisin",
year = "2017",
month = "1",
day = "16",
doi = "10.1016/j.ijfoodmicro.2016.09.021",
language = "English (US)",
volume = "241",
pages = "15--22",
journal = "International Journal of Food Microbiology",
issn = "0168-1605",
publisher = "Elsevier",

}

Chen, Y, Pouillot, R, S. Burall, L, Strain, EA, Van Doren, JM, De Jesus, AJ, Laasri, A, Wang, H, Ali, L, Tatavarthy, A, Zhang, G, Hu, L, Day, J, Sheth, I, Kang, J, Sahu, S, Srinivasan, D, Brown, EW, Parish, M, Zink, DL, Datta, AR, Hammack, TS & Macarisin, D 2017, 'Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products', International journal of food microbiology, vol. 241, pp. 15-22. https://doi.org/10.1016/j.ijfoodmicro.2016.09.021

Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products. / Chen, Yi; Pouillot, Régis; S. Burall, Laurel; Strain, Errol A.; Van Doren, Jane M.; De Jesus, Antonio J.; Laasri, Anna; Wang, Hua; Ali, Laila; Tatavarthy, Aparna; Zhang, Guodong; Hu, Lijun; Day, James; Sheth, Ishani; Kang, Jihun; Sahu, Surasri; Srinivasan, Devayani; Brown, Eric Wayne; Parish, Mickey; Zink, Donald L.; Datta, Atin R.; Hammack, Thomas S.; Macarisin, Dumitru.

In: International journal of food microbiology, Vol. 241, 16.01.2017, p. 15-22.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products

AU - Chen, Yi

AU - Pouillot, Régis

AU - S. Burall, Laurel

AU - Strain, Errol A.

AU - Van Doren, Jane M.

AU - De Jesus, Antonio J.

AU - Laasri, Anna

AU - Wang, Hua

AU - Ali, Laila

AU - Tatavarthy, Aparna

AU - Zhang, Guodong

AU - Hu, Lijun

AU - Day, James

AU - Sheth, Ishani

AU - Kang, Jihun

AU - Sahu, Surasri

AU - Srinivasan, Devayani

AU - Brown, Eric Wayne

AU - Parish, Mickey

AU - Zink, Donald L.

AU - Datta, Atin R.

AU - Hammack, Thomas S.

AU - Macarisin, Dumitru

PY - 2017/1/16

Y1 - 2017/1/16

N2 - A precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods.

AB - A precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods.

UR - http://www.scopus.com/inward/record.url?scp=84991704756&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84991704756&partnerID=8YFLogxK

U2 - 10.1016/j.ijfoodmicro.2016.09.021

DO - 10.1016/j.ijfoodmicro.2016.09.021

M3 - Article

C2 - 27741432

AN - SCOPUS:84991704756

VL - 241

SP - 15

EP - 22

JO - International Journal of Food Microbiology

JF - International Journal of Food Microbiology

SN - 0168-1605

ER -