Cargando…
Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems
Water safety and management programs (WSMP) utilize field measurements to evaluate control limits and monitor water quality parameters including Legionella presence. This monitoring is important to verify that the plan is being implemented properly. However, once it has been determined when and how...
Autores principales: | , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2020
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7696883/ https://www.ncbi.nlm.nih.gov/pubmed/33187132 http://dx.doi.org/10.3390/microorganisms8111770 |
_version_ | 1783615506160287744 |
---|---|
author | Hirsh, Marisa B. Baron, Julianne L. Mietzner, Sue M. Rihs, John D. Yassin, Mohamed H. Stout, Janet E. |
author_facet | Hirsh, Marisa B. Baron, Julianne L. Mietzner, Sue M. Rihs, John D. Yassin, Mohamed H. Stout, Janet E. |
author_sort | Hirsh, Marisa B. |
collection | PubMed |
description | Water safety and management programs (WSMP) utilize field measurements to evaluate control limits and monitor water quality parameters including Legionella presence. This monitoring is important to verify that the plan is being implemented properly. However, once it has been determined when and how to sample for Legionella, it is important to choose appropriate collection and processing methods. We sought to compare processing immediate and flushed samples, filtration of different volumes collected, and sample hold times. Hot water samples were collected immediately and after a 2-min flush. These samples were plated directly and after filtration of either 100 mL, 200 mL, or 1 L. Additionally, unflushed samples were collected and processed immediately and after 1, 24, and 48 h of hold time. We found that flushed samples had significant reductions in Legionella counts compared to immediate samples. Processing 100 mL of that immediate sample both directly and after filter concentration yielded the highest concentration and percent sample positivity, respectively. We also show that there was no difference in culture values from time 0 compared to hold times of 1 h and 24 h. At 48 h, there were slightly fewer Legionella recovered than at time 0. However, Legionella counts were so variable based on sampling location and date that this hold time effect was minimal. The interpretation of Legionella culture results depends on the sample collection and processing methods used, as these can have a huge impact on the success of sampling and the validation of control measures. |
format | Online Article Text |
id | pubmed-7696883 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-76968832020-11-29 Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems Hirsh, Marisa B. Baron, Julianne L. Mietzner, Sue M. Rihs, John D. Yassin, Mohamed H. Stout, Janet E. Microorganisms Article Water safety and management programs (WSMP) utilize field measurements to evaluate control limits and monitor water quality parameters including Legionella presence. This monitoring is important to verify that the plan is being implemented properly. However, once it has been determined when and how to sample for Legionella, it is important to choose appropriate collection and processing methods. We sought to compare processing immediate and flushed samples, filtration of different volumes collected, and sample hold times. Hot water samples were collected immediately and after a 2-min flush. These samples were plated directly and after filtration of either 100 mL, 200 mL, or 1 L. Additionally, unflushed samples were collected and processed immediately and after 1, 24, and 48 h of hold time. We found that flushed samples had significant reductions in Legionella counts compared to immediate samples. Processing 100 mL of that immediate sample both directly and after filter concentration yielded the highest concentration and percent sample positivity, respectively. We also show that there was no difference in culture values from time 0 compared to hold times of 1 h and 24 h. At 48 h, there were slightly fewer Legionella recovered than at time 0. However, Legionella counts were so variable based on sampling location and date that this hold time effect was minimal. The interpretation of Legionella culture results depends on the sample collection and processing methods used, as these can have a huge impact on the success of sampling and the validation of control measures. MDPI 2020-11-11 /pmc/articles/PMC7696883/ /pubmed/33187132 http://dx.doi.org/10.3390/microorganisms8111770 Text en © 2020 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 | Article Hirsh, Marisa B. Baron, Julianne L. Mietzner, Sue M. Rihs, John D. Yassin, Mohamed H. Stout, Janet E. Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems |
title | Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems |
title_full | Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems |
title_fullStr | Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems |
title_full_unstemmed | Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems |
title_short | Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems |
title_sort | evaluation of recommended water sample collection methods and the impact of holding time on legionella recovery and variability from healthcare building water systems |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7696883/ https://www.ncbi.nlm.nih.gov/pubmed/33187132 http://dx.doi.org/10.3390/microorganisms8111770 |
work_keys_str_mv | AT hirshmarisab evaluationofrecommendedwatersamplecollectionmethodsandtheimpactofholdingtimeonlegionellarecoveryandvariabilityfromhealthcarebuildingwatersystems AT baronjuliannel evaluationofrecommendedwatersamplecollectionmethodsandtheimpactofholdingtimeonlegionellarecoveryandvariabilityfromhealthcarebuildingwatersystems AT mietznersuem evaluationofrecommendedwatersamplecollectionmethodsandtheimpactofholdingtimeonlegionellarecoveryandvariabilityfromhealthcarebuildingwatersystems AT rihsjohnd evaluationofrecommendedwatersamplecollectionmethodsandtheimpactofholdingtimeonlegionellarecoveryandvariabilityfromhealthcarebuildingwatersystems AT yassinmohamedh evaluationofrecommendedwatersamplecollectionmethodsandtheimpactofholdingtimeonlegionellarecoveryandvariabilityfromhealthcarebuildingwatersystems AT stoutjanete evaluationofrecommendedwatersamplecollectionmethodsandtheimpactofholdingtimeonlegionellarecoveryandvariabilityfromhealthcarebuildingwatersystems |