Colonization by Pseudomonas aeruginosa of dental unit waterlines and its relationship with other bacteria: suggestions for microbiological monitoring

Abstract Pseudomonas aeruginosa is an environmental bacterium, ubiquitous in aquatic habitats and water distribution systems, including dental unit waterlines (DUWLs). We investigated the prevalence of P. aeruginosa in DUWLs from private dental settings. We also analyzed the relationship between P. aeruginosa contamination and the presence of Legionella spp. and total viable count (TVC) in order to suggest a simple and inexpensive protocol to test the quality of water from DUWLs. We detected and quantified P. aeruginosa both by culture and by a PMA (propidium monoazide)-qPCR method. Overall, we detected P. aeruginosa in 17 samples using the PMA-qPCR and in 11 samples using the culture. All culture-positive samples were positive with the PMA-qPCR too, with an agreement between the two methods of 93% and a Cohen's kappa coefficient of κ = 0.747 (good concordance). Comparing results with results of our previous study, we noted that (a) P. aeruginosa was isolated only from DUWLs with high TVC and (b) five out of six Legionella-positive samples were negative for Pseudomonas spp. Our final suggestion is that the cleanliness of DUWLs should be assessed by TVC because it is a good indicator of the presence of pathogens such as Legionella spp. and P. aeruginosa.

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A Head Formulation for the Steady-State Analysis of Water Distribution Systems Using an Explicit and Exact Expression of the Colebrook–White Equation

Water ◽

10.3390/w13091163 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1163

Author(s):

Mengning Qiu ◽

Avi Ostfeld

Keyword(s):

Steady State ◽

Distribution System ◽

Distribution Systems ◽

Water Distribution ◽

Solution Method ◽

Water Distribution System ◽

Academic Research ◽

Exact Expression ◽

Contamination Source

Steady-state demand-driven water distribution system (WDS) solution is the bedrock for much research conducted in the field related to WDSs. WDSs are modeled using the Darcy–Weisbach equation with the Swamee–Jain equation. However, the Swamee–Jain equation approximates the Colebrook–White equation, errors of which are within 1% for ϵ/D∈[10−6,10−2] and Re∈[5000,108]. A formulation is presented for the solution of WDSs using the Colebrook–White equation. The correctness and efficacy of the head formulation have been demonstrated by applying it to six WDSs with the number of pipes ranges from 454 to 157,044 and the number of nodes ranges from 443 to 150,630. The addition of a physically and fundamentally more accurate WDS solution method can improve the quality of the results achieved in both academic research and industrial application, such as contamination source identification, water hammer analysis, WDS network calibration, sensor placement, and least-cost design and operation of WDSs.

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The Water Safety Plan Approach: Application to Small Drinking-Water Systems—Case Studies in Salento (South Italy)

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18084360 ◽

2021 ◽

Vol 18 (8) ◽

pp. 4360

Author(s):

Francesca Serio ◽

Lucia Martella ◽

Giovanni Imbriani ◽

Adele Idolo ◽

Francesco Bagordo ◽

...

Keyword(s):

Drinking Water ◽

Case Studies ◽

Distribution Systems ◽

Water Systems ◽

Water Safety ◽

Quality Of Water ◽

Safety Plan ◽

Water Safety Plan ◽

Drinking Water Systems

Background: The quality of water for human consumption is an objective of fundamental importance for the defense of public health. Since the management of networks involves many problems of control and efficiency of distribution, the Water Safety Plan (WSP) was introduced to address these growing problems. Methods: WSP was applied to three companies in which the water resource assumes central importance: five water kiosks, a third-range vegetable processing company, and a residence and care institution. In drafting the plan, the terms and procedures designed and tested for the management of urban distribution systems were applied to safeguard the resource over time. Results: The case studies demonstrated the reliability of the application of the model even to small drinking-water systems, even though it involved a greater effort in analyzing the incoming water, the local intended use, and the possibilities for managing the containment of the dangers to which it is exposed. This approach demonstrates concrete effectiveness in identifying and mitigating the dangers of altering the quality of water. Conclusions: Thanks to the WSP applied to small drinking-water systems, we can move from management that is focused mainly on verifying the conformity of the finished product to the creation of a global risk assessment and management system that covers the entire water supply chain.

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Rapid Performance Evaluation of Water Supply Services for Strategic Planning

Civil Engineering Journal ◽

10.28991/cej-2019-03091324 ◽

2019 ◽

Vol 5 (5) ◽

pp. 1197-1204 ◽

Cited By ~ 7

Author(s):

Gulfam Shahzad ◽

Rashid Rehan ◽

Muhammad Fahim

Keyword(s):

Strategic Planning ◽

Water Supply ◽

Distribution System ◽

Distribution Systems ◽

Google Earth ◽

System A ◽

Quality Of Water ◽

Interactive Map ◽

Water Supply Services

The assessment of existing water supply services was carried out through selected performance indicators with the aim of using that data in future for strategic planning of urban Mardan. The key performance indictors studied were selected to assess both the quantity and quality of water. The quality of water was assessed by turbidity, pH, and E-coli tests for samples collected at the start, middle, and tail end of the distribution system. The quantity of water supplied was measured by calculating discharges from water tapes at the three selected locations in the distribution system. A total of thirty samples were collected from ten union councils out of fourteen covering urban Mardan. A number of issues are highlighted in the overall water supply infrastructure and short, mid, and long term remedial measures are recommended. The results are presented in the form of an interactive map using Google Earth and VBA based dynamic database. It was found that the overall quality of water is generally acceptable for drinking. However, the presence of bacteria is an issue in many cases which needs to be resolved. A significant decrease in discharge is observed in the distribution systems away from the source due to leakages and illegal connections. A comprehensive overhaul of both management and infrastructure is required for sustainable and satisfactory level of services.

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Effect of Boron on the Groundwater Quality in Altai Region

UNIVERSITY NEWS. NORTH-CAUCASIAN REGION. NATURAL SCIENCES SERIES ◽

10.18522/1026-2237-2021-2-42-48 ◽

2021 ◽

pp. 42-48

Author(s):

Gennady Ya. Baryshnikov ◽

Svetlana S. Slazhneva ◽

Nina B. Maximovа ◽

Petr V. Sotnikov

Keyword(s):

Groundwater Quality ◽

Water Distribution ◽

Maximum Permissible Concentration ◽

Human Consumption ◽

Altai Region ◽

High Incidence ◽

General Complex ◽

High Concentrations ◽

The Relationship

Boron (В) is widely spread in surface and ground waters. The article deals with the problem of drinking groundwater quality. Groundwater is the only source of water supply, in the most districts of the Altai Region. This suggests that the quality of groundwater is of great importance for the population of the region. Drinking water should be suitable for human consumption and for all household purposes. The main attention is focused on identifying the area of distribution B containing waters with the content exceeding the maximum permissible concentration (MPC). The relationship between В and dry residue (MCO) is analyzed. Crucial factors responsible for high В concentration have been identified. The general complex research of presence, distribution and sources of В inflow into groundwaters of the Altai Region are defined in the article. The relationship between the В content and the high incidence of people living in areas with a high В content has been revealed. It was found that high concentrations of В (more than 0.5 mg/l) correspond to the zone of brackish water distribution, which occupies almost the entire territory of the steppe Altai - Kulundinsko-Barnaul artesian basin. Their distribution coincides geographically with the distribution of В.

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Building a Methodology for Assessing Service Quality under Intermittent Domestic Water Supply

Water ◽

10.3390/w10091164 ◽

2018 ◽

Vol 10 (9) ◽

pp. 1164 ◽

Cited By ~ 3

Author(s):

Assia Mokssit ◽

Bernard de Gouvello ◽

Aurélie Chazerain ◽

François Figuères ◽

Bruno Tassin

Keyword(s):

Drinking Water ◽

Water Supply ◽

Water Distribution ◽

Water System ◽

Evaluation Framework ◽

Domestic Water ◽

Water Service ◽

Quality Of Water ◽

History Of

This document proposes a methodology for assessing the quality of water distribution service in the context of intermittent supply, based on a comparison of joint results from literature reviews and feedback from drinking water operators who had managed these networks, with standards for defining the quality of drinking water service. The paper begins by reviewing and proposing an analysis of the definition and characterization of intermittent water supply (IWS), highlighting some important findings. The diversity of approaches used to address the issue and the difficulty of defining a precise and detailed history of water supply in the affected systems broadens the spectrum of intermittency characterization and the problems it raises. The underlined results are then used to structure an evaluation framework for the water service and to develop improvement paths defined in the intermittent networks. The resulting framework highlights the means available to water stakeholders to assess their operational and management performance in achieving the improvement objectives defined by the environmental and socio-economic contexts in which the network operates. Practical examples of intermittent system management are collected from water system operators and presented for illustration purposes (Jeddah, Algiers, Port-au-Prince, Amman, Cartagena, Barranquilla, Mexico, Cancun, Saltillo, Mumbai, Delhi, Coimbatore …).

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Minimum Night Flow Analysis and Application of the Fixed and Variable Area Discharges Model for Characterizing Leakage in the Gorino Ferrarese (FE-Italy) District

Environmental Sciences Proceedings ◽

10.3390/environsciproc2020002008 ◽

2020 ◽

Vol 2 (1) ◽

pp. 8

Author(s):

Irene Marzola ◽

Stefano Alvisi ◽

Marco Franchini

Keyword(s):

Time Series ◽

Distribution Systems ◽

Water Distribution ◽

Flow Analysis ◽

Water Utilities ◽

Smart Meters ◽

Minimum Night Flow ◽

Major Interest ◽

The Relationship ◽

District Metered Area

Leakage in water distribution systems is an important issue and of major interest for water utilities. In this study, the Minimum Night Flow (MNF) method to quantify the amount of water lost and the equations representing the relationship between pressure and leakage in power and FAVAD (Fixed and Variable Area Discharge) forms were applied to a District Metered Area (DMA) located in Gorino Ferrarese (FE, Italy) equipped with smart meters. The analysis carried out by exploiting the collected time series of user water consumption, DMA inflow, and pressure highlighted that: (a) the MNF method can lead to significant inaccuracy in leakage estimation in the presence of users with irregular consumptions, when based on literature values, and (b) the estimation of the parameters of the power and FAVAD equation is highly affected by the number and types of observed data used.

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Kinetic aspects of biofilm formation on surfaces exposed to drinking water

Water Science & Technology ◽

10.2166/wst.1995.0264 ◽

1995 ◽

Vol 32 (8) ◽

pp. 61-65 ◽

Cited By ~ 7

Author(s):

D. van der Kooij ◽

H. S. Vrouwenvelder ◽

H. R. Veenendaal

Keyword(s):

Drinking Water ◽

Biofilm Formation ◽

Distribution Systems ◽

Water Distribution ◽

Formation Rate ◽

Water Distribution Systems ◽

Acetate Concentration ◽

Drinking Water Distribution Systems ◽

Drinking Water Distribution ◽

The Relationship

Biofilm formation in drinking water distribution systems should be limited to prevent the multiplication of undesirable bacteria and other organisms. Certain types of drinking water with an AOC concentration below 10 μg of acetate-C eq/l can support the growth of Aeromonas. Therefore, the effect of acetate at a concentration of 10 μg of C/l on the biofilm formation rate (BFR) of drinking water with a low AOC concentration (3.2 μg C/l) was determined. Drinking water without acetate had a BFR of 3.9 pg ATP/cm2.day, whereas a BFR value of 362 pg ATP/cm2.day was found with acetate added. These data indicate that a low acetate concentration strongly affects biofilm formation, and that only a small fraction of AOC is available for biofilm formation. Aeromonads did not multiply in the biofilm despite their ability to grow at a concentration of 10 μg of acetate-C/l. Further investigations are needed to elucidate the relationship between substrate concentration and biofilm formation in drinking water distribution systems and the growth of undesirable bacteria in these biofilms.

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Rapid and Sensitive Enumeration of Viable Diluted Cells of Members of the Family Enterobacteriaceae in Freshwater and Drinking Water

Applied and Environmental Microbiology ◽

10.1128/aem.68.10.5057-5063.2002 ◽

2002 ◽

Vol 68 (10) ◽

pp. 5057-5063 ◽

Cited By ~ 48

Author(s):

Julia Baudart ◽

Josée Coallier ◽

Patrick Laurent ◽

Michèle Prévost

Keyword(s):

Drinking Water ◽

Membrane Filtration ◽

Laser Scanning ◽

Distribution Systems ◽

Water Distribution ◽

Direct Detection ◽

Water Quality Assessment ◽

Viable Count ◽

Specificity And Sensitivity ◽

The Family

ABSTRACT Water quality assessment involves the specific, sensitive, and rapid detection of bacterial indicators and pathogens in water samples, including viable but nonculturable (VBNC) cells. This work evaluates the specificity and sensitivity of a new method which combines a fluorescent in situ hybridization (FISH) approach with a physiological assay (direct viable count [DVC]) for the direct enumeration, at the single-cell level, of highly diluted viable cells of members of the family Enterobacteriaceae in freshwater and drinking water after membrane filtration. The approach (DVC-FISH) uses a new direct detection device, the laser scanning cytometer (Scan RDI). Combining the DVC-FISH method on a membrane with Scan RDI detection makes it possible to detect as few as one targeted cell in approximately 108 nontargeted cells spread over the membrane. The ability of this new approach to detect and enumerate VBNC enterobacterial cells in freshwater and drinking water distribution systems was investigated and is discussed.

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Microbiological and physico- chemical assessment of the sacred river Alaknanda, India

International Journal of Agricultural Invention ◽

10.46492/ijai/2016.1.1.18 ◽

2016 ◽

Vol 1 (01) ◽

pp. 102-107

Author(s):

Nidhi Sharma ◽

R. C. Sharma

Keyword(s):

Water Quality ◽

Monsoon Season ◽

Winter Season ◽

Viable Count ◽

Chemical Methods ◽

Quality Of Water ◽

Physico Chemical ◽

Autumn And Winter ◽

Habitat Environment

The Alaknanda River is one of the main rivers of Alaknanda sub- system which bubbles out from Alkapuri Glacier. Water quality of the sacred river Alaknanda was evaluated by microbiological and physico- chemical methods. The sampling was undertaken from various sites of lower stretches, including Rudraprayag (530 m a.s.l.), Srinagar (560 m a.s.l.) and Deoprayag upstream (457 m a.s.l.) on the river Alaknanda. A perusal of the data revealed that total viable count (CFU.ml-1) was recorded minimum (25,850 CFU.ml-1) in winter season and then it increased during summer (45,730 CFU.ml-1) and attained peak (56,110 CFU.ml-1) during monsoon season, when the maximum degradation in the water quality was observed. Due to the onset of autumn and winter seasons, the quality of water improved substantially and the density of the bacteria decreased (32,120 CFU.ml-1) significantly during autumn from the monsoon season. It is revealed that the myriad of physico- chemical environmental variables and nutrient load from various sources in the habitat environment are responsible for density and diversity in the sacred river Alakanda.

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