Author, as appears in the article.: Sanchis M; Inza I; Figueras MJ
Department: Ciències Mèdiques Bàsiques
URV's Author/s: Figueras Salvat, María Josefa / Sanchis Talón, Marta
Keywords: Cooling towers (cts) Heterotrophic plate count (hpc) Legionella spp. (lsp)
Abstract: Legionella pneumophila (Lp) colonizes aquatic environments and is a potential pathogen to humans, causing outbreaks of Legionnaire’s disease. It is mainly associated with contaminated cooling towers (CTs). Several regulations, including Spanish legislation (Sl), have introduced the analysis of heterotrophic plate count (HPC) bacteria and Legionella spp. (Lsp) in management plans to prevent and control Legionella outbreaks from CTs. The 2003 Sl for CTs (RD 865/2003) considered that concentrations of HPC bacteria ≤10,000 cfu/mL and of Lsp ≤100 cfu/L are safe; therefore, no action is required, whereas management actions should be implemented above these standards. We have investigated to what extent the proposed standard for HPC bacteria is useful to predict the presence of Lsp in cooling waters. For this, we analyzed Lsp and HPC concentrations, water temperature, and the levels of chlorine in 1376 water samples from 17 CTs. The results showed that in the 1138 water samples negative for Legionella spp. (LN), the HPC geometric mean was significantly lower (83 cfu/mL, p < 0.05) than in the positive Lsp. samples (135 cfu/mL). Of the 238 (17.3%) LP samples, 88.4% (210/238) were associated with values of HPC ≤10,000 cfu/mL and most of them showed HPC concentrations ≤100 (53.7%). In addition, a relatively low percentage of LP (28/238, 11.6%) samples were associated with HPC bacteria concentrations >10,000 cfu/mL, indicating that this standard does not predict the colonization risk for Legionella in the CTs studied. The present study has demonstrated that a threshold concentration ≤100 cfu/mL of HPC bacteria could better predict the higher concentration of Legionella in CTs, which will aid in preventing possible outbreaks.
Thematic Areas: Farmacia General immunology and microbiology Immunology and allergy Immunology and microbiology (all) Immunology and microbiology (miscellaneous) Infectious diseases Microbiology Microbiology (medical) Molecular biology
licence for use: https://creativecommons.org/licenses/by/3.0/es/
Author's mail: mariajose.figueras@urv.cat marta.sanchis@urv.cat
Author identifier: 0000-0002-2268-8980 0000-0001-7251-6792
Record's date: 2023-04-15
Papper version: info:eu-repo/semantics/publishedVersion
Link to the original source: https://www.mdpi.com/2076-0817/12/3/466
Papper original source: Pathogens. 12 (3):
APA: Sanchis M; Inza I; Figueras MJ (2023). Heterotrophic Plate Count Can Predict the Presence of Legionella spp. in Cooling Towers. Pathogens, 12(3), -. DOI: 10.3390/pathogens12030466
Licence document URL: http://repositori.urv.cat/ca/proteccio-de-dades/
Article's DOI: 10.3390/pathogens12030466
Entity: Universitat Rovira i Virgili
Journal publication year: 2023
Publication Type: Journal Publications
Repositori URV