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Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country

BACKGROUND: Culture contamination with environmental bacteria is a major challenge in tuberculosis (TB) laboratories in hot and humid climate zones. We studied the effect of cetylpyridinium chloride (CPC) preservation on culture results and performance of Xpert MTB/RIF. METHODS: Consecutive sputum s...

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Autores principales: Hiza, Hellen, Doulla, Basra, Sasamalo, Mohamed, Hella, Jerry, Kamwela, Lujeko, Mhimbira, Francis, Reither, Klaus, Gagneux, Sebastien, Jugheli, Levan, Fenner, Lukas
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5543576/
https://www.ncbi.nlm.nih.gov/pubmed/28778186
http://dx.doi.org/10.1186/s12879-017-2642-z
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author Hiza, Hellen
Doulla, Basra
Sasamalo, Mohamed
Hella, Jerry
Kamwela, Lujeko
Mhimbira, Francis
Reither, Klaus
Gagneux, Sebastien
Jugheli, Levan
Fenner, Lukas
author_facet Hiza, Hellen
Doulla, Basra
Sasamalo, Mohamed
Hella, Jerry
Kamwela, Lujeko
Mhimbira, Francis
Reither, Klaus
Gagneux, Sebastien
Jugheli, Levan
Fenner, Lukas
author_sort Hiza, Hellen
collection PubMed
description BACKGROUND: Culture contamination with environmental bacteria is a major challenge in tuberculosis (TB) laboratories in hot and humid climate zones. We studied the effect of cetylpyridinium chloride (CPC) preservation on culture results and performance of Xpert MTB/RIF. METHODS: Consecutive sputum samples from microscopy smear-positive TB patients were collected. Two-hundred samples were equally split in two aliquots, one aliquot was treated with CPC and stored at ambient temperature for 7 days. The second aliquot was immediately processed. Samples were decontaminated for 20, 15 or 10 min, and subsequently cultured on Löwenstein-Jensen medium. Furthermore, 50 samples were stored for 7, 14 and 21 days, and 100 CPC-pretreated samples tested by Xpert MTB/RIF. RESULTS: CPC pretreated samples showed a higher culture yield compared to non-treated sputum samples across all decontamination times: 94% vs. 73% at 10 min (p = 0.01), 94% vs. 64% at 15 min (p = 0.004), and 90% vs. 52% at 20 min (p < 0.001). The quantitative culture grading was consistently higher in CPC treated compared to non-CPC treated samples. The proportion of contaminated cultures was lower in CPC pretreated samples across all decontamination times (range 2-6%) compared to non-CPC treated samples (15-16%). For storage times of CPC treated samples of 7, 14, and 21 days, 84, 86, and 84% of the respective cultures were positive. Of 91 CPC treated samples with a positive culture, 90 were also Xpert MTB/RIF positive. CONCLUSIONS: CPC increases culture yield, decreases the proportion of contamination, and does not alter the performance of Xpert MTB/RIF.
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spelling pubmed-55435762017-08-07 Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country Hiza, Hellen Doulla, Basra Sasamalo, Mohamed Hella, Jerry Kamwela, Lujeko Mhimbira, Francis Reither, Klaus Gagneux, Sebastien Jugheli, Levan Fenner, Lukas BMC Infect Dis Research Article BACKGROUND: Culture contamination with environmental bacteria is a major challenge in tuberculosis (TB) laboratories in hot and humid climate zones. We studied the effect of cetylpyridinium chloride (CPC) preservation on culture results and performance of Xpert MTB/RIF. METHODS: Consecutive sputum samples from microscopy smear-positive TB patients were collected. Two-hundred samples were equally split in two aliquots, one aliquot was treated with CPC and stored at ambient temperature for 7 days. The second aliquot was immediately processed. Samples were decontaminated for 20, 15 or 10 min, and subsequently cultured on Löwenstein-Jensen medium. Furthermore, 50 samples were stored for 7, 14 and 21 days, and 100 CPC-pretreated samples tested by Xpert MTB/RIF. RESULTS: CPC pretreated samples showed a higher culture yield compared to non-treated sputum samples across all decontamination times: 94% vs. 73% at 10 min (p = 0.01), 94% vs. 64% at 15 min (p = 0.004), and 90% vs. 52% at 20 min (p < 0.001). The quantitative culture grading was consistently higher in CPC treated compared to non-CPC treated samples. The proportion of contaminated cultures was lower in CPC pretreated samples across all decontamination times (range 2-6%) compared to non-CPC treated samples (15-16%). For storage times of CPC treated samples of 7, 14, and 21 days, 84, 86, and 84% of the respective cultures were positive. Of 91 CPC treated samples with a positive culture, 90 were also Xpert MTB/RIF positive. CONCLUSIONS: CPC increases culture yield, decreases the proportion of contamination, and does not alter the performance of Xpert MTB/RIF. BioMed Central 2017-08-04 /pmc/articles/PMC5543576/ /pubmed/28778186 http://dx.doi.org/10.1186/s12879-017-2642-z Text en © The Author(s). 2017 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Hiza, Hellen
Doulla, Basra
Sasamalo, Mohamed
Hella, Jerry
Kamwela, Lujeko
Mhimbira, Francis
Reither, Klaus
Gagneux, Sebastien
Jugheli, Levan
Fenner, Lukas
Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country
title Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country
title_full Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country
title_fullStr Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country
title_full_unstemmed Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country
title_short Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country
title_sort preservation of sputum samples with cetylpyridinium chloride (cpc) for tuberculosis cultures and xpert mtb/rif in a low-income country
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5543576/
https://www.ncbi.nlm.nih.gov/pubmed/28778186
http://dx.doi.org/10.1186/s12879-017-2642-z
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