Cargando…

Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples

PDX-LIB, Listeria Indicator Broth, was developed as a proprietary sensitive screening test to identify presumptively positive environmental swab samples for Listeria sp. The original formulation, while sensitive, initially proved to exhibit acceptable levels of false positive test results. Paradigm...

Descripción completa

Detalles Bibliográficos
Autores principales: Olstein, Alan D., Feirtag, Joellen M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560446/
https://www.ncbi.nlm.nih.gov/pubmed/31137769
http://dx.doi.org/10.3390/microorganisms7050151
_version_ 1783425971852935168
author Olstein, Alan D.
Feirtag, Joellen M.
author_facet Olstein, Alan D.
Feirtag, Joellen M.
author_sort Olstein, Alan D.
collection PubMed
description PDX-LIB, Listeria Indicator Broth, was developed as a proprietary sensitive screening test to identify presumptively positive environmental swab samples for Listeria sp. The original formulation, while sensitive, initially proved to exhibit acceptable levels of false positive test results. Paradigm Diagnostics has been undertaken to modify the medium formulation to render it more selective while not sacrificing its sensitivity. After identification of a candidate formulation through laboratory studies, a field trial was conducted to validate the test performance parameters, including the true positive frequency and false positive frequency in several different food-processing facilities. Identical swab samples were enriched in both the original medium formulation and the new formulation. Presumptive positive samples were confirmed by plating on selective differential agar and qPCR analysis. The field trial data demonstrate that the new formulation significantly reduces the frequency of false positive samples compared to the original Listeria Indicator Broth formulation, without compromising the sensitivity of the original formulation. The new medium formulation resulted in no false positive samples compared to the 54% increased presumptive positive samples obtained with the original medium formulation.
format Online
Article
Text
id pubmed-6560446
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-65604462019-06-17 Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples Olstein, Alan D. Feirtag, Joellen M. Microorganisms Technical Note PDX-LIB, Listeria Indicator Broth, was developed as a proprietary sensitive screening test to identify presumptively positive environmental swab samples for Listeria sp. The original formulation, while sensitive, initially proved to exhibit acceptable levels of false positive test results. Paradigm Diagnostics has been undertaken to modify the medium formulation to render it more selective while not sacrificing its sensitivity. After identification of a candidate formulation through laboratory studies, a field trial was conducted to validate the test performance parameters, including the true positive frequency and false positive frequency in several different food-processing facilities. Identical swab samples were enriched in both the original medium formulation and the new formulation. Presumptive positive samples were confirmed by plating on selective differential agar and qPCR analysis. The field trial data demonstrate that the new formulation significantly reduces the frequency of false positive samples compared to the original Listeria Indicator Broth formulation, without compromising the sensitivity of the original formulation. The new medium formulation resulted in no false positive samples compared to the 54% increased presumptive positive samples obtained with the original medium formulation. MDPI 2019-05-27 /pmc/articles/PMC6560446/ /pubmed/31137769 http://dx.doi.org/10.3390/microorganisms7050151 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Technical Note
Olstein, Alan D.
Feirtag, Joellen M.
Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples
title Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples
title_full Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples
title_fullStr Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples
title_full_unstemmed Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples
title_short Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples
title_sort improved positive predictive performance of listeria indicator broth: a sensitive environmental screening test to identify presumptively positive swab samples
topic Technical Note
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560446/
https://www.ncbi.nlm.nih.gov/pubmed/31137769
http://dx.doi.org/10.3390/microorganisms7050151
work_keys_str_mv AT olsteinaland improvedpositivepredictiveperformanceoflisteriaindicatorbrothasensitiveenvironmentalscreeningtesttoidentifypresumptivelypositiveswabsamples
AT feirtagjoellenm improvedpositivepredictiveperformanceoflisteriaindicatorbrothasensitiveenvironmentalscreeningtesttoidentifypresumptivelypositiveswabsamples