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Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation
The primary platform used for pyrazinamide (PZA) susceptibility testing of Mycobacterium tuberculosis is the MGIT culture system (Becton Dickinson). Since false-resistant results have been associated with the use of this system, we conducted a multicenter evaluation to determine the effect of using...
Autores principales: | , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Hindawi
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5698819/ https://www.ncbi.nlm.nih.gov/pubmed/29250443 http://dx.doi.org/10.1155/2017/3748163 |
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author | Morlock, Glenn P. Tyrrell, Frances C. Baynham, Dorothy Escuyer, Vincent E. Green, Nicole Kim, Youngmi Longley-Olson, Patricia A. Parrish, Nicole Pennington, Courtney Tan, Desmond Austin, Brett Posey, James E. |
author_facet | Morlock, Glenn P. Tyrrell, Frances C. Baynham, Dorothy Escuyer, Vincent E. Green, Nicole Kim, Youngmi Longley-Olson, Patricia A. Parrish, Nicole Pennington, Courtney Tan, Desmond Austin, Brett Posey, James E. |
author_sort | Morlock, Glenn P. |
collection | PubMed |
description | The primary platform used for pyrazinamide (PZA) susceptibility testing of Mycobacterium tuberculosis is the MGIT culture system (Becton Dickinson). Since false-resistant results have been associated with the use of this system, we conducted a multicenter evaluation to determine the effect of using a reduced cell density inoculum on the rate of false resistance. Two reduced inoculum densities were compared with that prescribed by the manufacturer (designated as “BD” method). The reduced inoculum methods (designated as “A” and “C”) were identical to the manufacturer's protocol in all aspects with the exception of the cell density of the inoculum. Twenty genetically and phenotypically characterized M. tuberculosis isolates were tested in duplicate by ten independent laboratories using the three inoculum methods. False-resistant results declined from 21.1% using the standard “BD” method to 5.7% using the intermediate (“A”) inoculum and further declined to 2.8% using the most dilute (“C”) inoculum method. The percentages of the resistant results that were false-resistant declined from 55.2% for the “BD” test to 28.8% and 16.0% for the “A” and “C” tests, respectively. These results represent compelling evidence that the occurrence of false-resistant MGIT PZA susceptibility test results can be mitigated through the use of reduced inoculum densities. |
format | Online Article Text |
id | pubmed-5698819 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Hindawi |
record_format | MEDLINE/PubMed |
spelling | pubmed-56988192017-12-17 Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation Morlock, Glenn P. Tyrrell, Frances C. Baynham, Dorothy Escuyer, Vincent E. Green, Nicole Kim, Youngmi Longley-Olson, Patricia A. Parrish, Nicole Pennington, Courtney Tan, Desmond Austin, Brett Posey, James E. Tuberc Res Treat Research Article The primary platform used for pyrazinamide (PZA) susceptibility testing of Mycobacterium tuberculosis is the MGIT culture system (Becton Dickinson). Since false-resistant results have been associated with the use of this system, we conducted a multicenter evaluation to determine the effect of using a reduced cell density inoculum on the rate of false resistance. Two reduced inoculum densities were compared with that prescribed by the manufacturer (designated as “BD” method). The reduced inoculum methods (designated as “A” and “C”) were identical to the manufacturer's protocol in all aspects with the exception of the cell density of the inoculum. Twenty genetically and phenotypically characterized M. tuberculosis isolates were tested in duplicate by ten independent laboratories using the three inoculum methods. False-resistant results declined from 21.1% using the standard “BD” method to 5.7% using the intermediate (“A”) inoculum and further declined to 2.8% using the most dilute (“C”) inoculum method. The percentages of the resistant results that were false-resistant declined from 55.2% for the “BD” test to 28.8% and 16.0% for the “A” and “C” tests, respectively. These results represent compelling evidence that the occurrence of false-resistant MGIT PZA susceptibility test results can be mitigated through the use of reduced inoculum densities. Hindawi 2017 2017-11-08 /pmc/articles/PMC5698819/ /pubmed/29250443 http://dx.doi.org/10.1155/2017/3748163 Text en Copyright © 2017 Glenn P. Morlock et al. https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Article Morlock, Glenn P. Tyrrell, Frances C. Baynham, Dorothy Escuyer, Vincent E. Green, Nicole Kim, Youngmi Longley-Olson, Patricia A. Parrish, Nicole Pennington, Courtney Tan, Desmond Austin, Brett Posey, James E. Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation |
title | Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation |
title_full | Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation |
title_fullStr | Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation |
title_full_unstemmed | Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation |
title_short | Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation |
title_sort | using reduced inoculum densities of mycobacterium tuberculosis in mgit pyrazinamide susceptibility testing to prevent false-resistant results and improve accuracy: a multicenter evaluation |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5698819/ https://www.ncbi.nlm.nih.gov/pubmed/29250443 http://dx.doi.org/10.1155/2017/3748163 |
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