Bacterial Contamination in Cold Water Samples Obtained from Water Dispensers

Furuhata, Katsunori; Ishizaki, Naoto; Fukuyama, Masafumi

doi:10.4265/bio.20.147

Cited by 8 publications

(5 citation statements)

References 11 publications

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“…Several studies have already demonstrated how the drinking water quality could change over time within MWDs [1,20,22,43]. According to these findings, the bacterial contamination found could be attributed to many factors, such as insufficient and inadequate maintenance of the dispenser outlets/nozzles, storage tanks, UV lamps, and manufacturer's materials, in addition to the absence of knowledge about the correct cleaning procedures and routine functionality checks required to maintain MWDs' hygiene and safety.…”

Section: Discussionmentioning

confidence: 99%

“…The temperature is considered a relevant determinant to preserve water quality, since its changes can influence physical, chemical, and biological processes that occur in natural and artificial environments. Specifically, temperature can influence the dynamics of microorganisms promoting biofilm formation, which could be a reservoir of waterborne pathogens, guaranteeing their survival [43,44]. According to Semerjian et al 2020 [1], another risk factor is the MWDs' location, such as placing them in humid environments or in facilities or rooms with poor ventilation.…”

Section: Discussionmentioning

confidence: 99%

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Study of Long-Term Effectiveness of Water Safety Plan Applied to Microfiltered Water Dispensers to Improve Water Quality

Mazzotta

Salaris

Pascale

et al. 2021

Water

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The use of Microfiltered Water Dispensers (MWDs) is increasing in offices, companies, or commercial facilities, as a response to plastic pollution. Despite their widespread use, poor data are available about the water quality and pathogens developed. Starting from a high contamination found in MWDs, a Water Safety Plan (WSP) was implemented on 57 MWDs to improve the water quality. To assess the effectiveness of WSP during the period 2017–2021, the environmental monitoring of heterotrophic plate counts (HPCs) at 36 °C and 22 °C, Enterococcus spp., Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Clostridium perfringens, as prescribed by Italian regulation for drinking water, was conducted. A high level of HPCs at both temperatures was observed, over the regulation limit; contrarily, the pathogenic bacteria were absent. The contamination found was studied with respect to the temperature threshold of 25 °C, suggested by directives. No significant differences were found between samples above and below the threshold, while a significant decrease over the years was observed for HPCs at 36 °C (p = 0.0000000001) and 22 °C (p = 0.000006). The WSP implementation resulted in a 43.09% decrease for HPCs at 36 °C and a 24.26% decrease for HPCs at 22 °C. Moreover, during the SARS-CoV-2 pandemic, the WSP contributed to limit the microbial contamination, preserving the MWDs’ functionality and hygienic conditions and the drinking water quality.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Study of Long-Term Effectiveness of Water Safety Plan Applied to Microfiltered Water Dispensers to Improve Water Quality

Mazzotta

Salaris

Pascale

et al. 2021

Water

View full text Add to dashboard Cite

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“…The OTUs number with increased abundance at the species level is shown in Supplementary Figure 4. Furuhata et al [52] found that Ralstonia sp. was the most dominant bacteria in cold water samples from water dispensers, which also presented in healthy human bodies and widely distributed in the upper respiratory tract, such as the oral cavity, pharynx and trachea.…”

Section: Bacterial Community Structurementioning

confidence: 99%

Impact of indoor heating and overnight stagnation on tap water: Dynamics in water quality, biomass, bio-activity and bacterial community structure

Zhang

Liu²,

Ma³

et al. 2022

Preprint

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The drinking water distribution system is an important link with water supply system and it affects the quality of the drinking water. Indoor pipeline water quality is regulated by physical, hydraulic and biological elements, such as indoor temperature and stagnation. In this study, full-length 16S rRNA gene sequencing and flow cytometry were used to assess the indoor heating and overnight stagnation on the variation in bacterial community structure and the Intact cell count. The results exhibited that the average intact cell count was 6.99 × 104 cells/mL and the low nucleic acid (LNA) bacteria was 4.48 × 104 cells/mL after stagnation. The average concentration of total and intracellular adenosine triphosphate (ATP) was 3.64 × 10-12 gATP/mL and 3.13 × 10-17 gATP/cell in stagnant water, respectively. The growth of LNA cells played a crucial role in increasing ATP. The dominant phylum was Proteobacteria with average abundance of 87.21%, followed by Actinobacteria (8.25%). Pseudomonas sp. and Mycobacterium sp. increased 1.2-fold and 5.8-fold in stagnant water. Structural equation model and redundancy analysis illustrated that temperature, residual chlorine and Fe concentration significantly affected bacterial count and bacterial community. Taking together, these results show responses of drinking water quality to overnight stagnation and indoor heating, and provide scientific basis for drinking water security management.

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“…To our knowledge, several studies have performed on the bacteriological quality of drinking water in household and office building, while there are few studies on WCDs in educational places. [ 6 7 9 10 11 12 ] Regarding the essential of safe drinking water supply for the student, this study aims to investigate the hygienic conditions of WCDs and bacteriological quality of drinking water distributed through WCDs located in a student dormitory at the university campus in Nakhon Si Thammarat, Thailand.…”

Section: Introductionmentioning

confidence: 99%

Bacteriological quality of drinking water and hygienic assessment of water cooler dispensers in higher education institution

Jawjit,

Precha,

Rattanaphan

et al. 2022

Int J Prev Med

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Bacterial Contamination in Cold Water Samples Obtained from Water Dispensers

Cited by 8 publications

References 11 publications

Study of Long-Term Effectiveness of Water Safety Plan Applied to Microfiltered Water Dispensers to Improve Water Quality

Study of Long-Term Effectiveness of Water Safety Plan Applied to Microfiltered Water Dispensers to Improve Water Quality

Impact of indoor heating and overnight stagnation on tap water: Dynamics in water quality, biomass, bio-activity and bacterial community structure

Bacteriological quality of drinking water and hygienic assessment of water cooler dispensers in higher education institution

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