scholarly journals Biofilm and Related Amoebas in an UK Chlorinated Drinking Water System

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3069
Author(s):  
Gonzalo Del Olmo ◽  
Natalia Malinowski ◽  
Geoffrey J. Puzon ◽  
Matthew J. Morgan ◽  
Carolina Calero ◽  
...  
Keyword(s):  
Public Health ◽  
Drinking Water ◽  
Distribution System ◽  
Bacterial Communities ◽  
Distribution Systems ◽  
Water Distribution ◽  
Bulk Water ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
The Uk

Drinking water distribution systems (DWDS) can host pathogenic amoebae, but the role of biofilms in supporting the occurrence of these organisms needs to be fully explored in the UK systems. The presence of amoebae and associated bacteria in biofilms attached to inner pipe surfaces was studied in an experimental full-scale chlorinated distribution system in the UK. Quantitative polymerase change reaction (qPCR) was used to identify and quantify amoebae, whilst the bacterial communities in the biofilms were characterised by sequencing the 16S rRNA gene. Despite the maintenance of a chlorine residual in the network (free chlorine ≥ 0.24 mg/L), several species of amoebae belonging to the genera Acanthamoeba, Vermamoeba, and Naegleria were identified in 30-day-old biofilm samples; however, no amoebae were detected in the water samples analysed. The dominant bacterial communities present in the biofilm samples were Variovorax, Pseudomonas, and Aquabacterium. These results indicate that the biofilm samples contained potential pathogenic amoebae and bacteria, such as Acanthamoeba and Pseudomonas, respectively, which implies a potential public health risk if the biofilms are mobilised into the bulk water. Several of the amoebae identified in this study are able to support the presence of resistant bacteria that can remain viable within these prokaryotic organisms until they reach people’s taps. The identification of the microorganisms associated with the pathogenic amoeba species in biofilms could be used to improve the surveillance of DWDS in order to protect public health.

scholarly journals Ammonia- and Nitrite-Oxidizing Bacterial Communities in a Pilot-Scale Chloraminated Drinking Water Distribution System

2002 ◽  
Vol 68 (1) ◽  
pp. 73-81 ◽  
Author(s):  
John M. Regan ◽  
Gregory W. Harrington ◽  
Daniel R. Noguera
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Rflp Analysis ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Rrna Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Drinking Water Distribution

ABSTRACT Nitrification in drinking water distribution systems is a common operational problem for many utilities that use chloramines for secondary disinfection. The diversity of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in the distribution systems of a pilot-scale chloraminated drinking water treatment system was characterized using terminal restriction fragment length polymorphism (T-RFLP) analysis and 16S rRNA gene (ribosomal DNA [rDNA]) cloning and sequencing. For ammonia oxidizers, 16S rDNA-targeted T-RFLP indicated the presence of Nitrosomonas in each of the distribution systems, with a considerably smaller peak attributable to Nitrosospira-like AOB. Sequences of AOB amplification products aligned within the Nitrosomonas oligotropha cluster and were closely related to N. oligotropha and Nitrosomonas ureae. The nitrite-oxidizing communities were comprised primarily of Nitrospira, although Nitrobacter was detected in some samples. These results suggest a possible selection of AOB related to N. oligotropha and N. ureae in chloraminated systems and demonstrate the presence of NOB, indicating a biological mechanism for nitrite loss that contributes to a reduction in nitrite-associated chloramine decay.

scholarly journals DRINKING WATER QUALITY IN DISTRIBUTION SYSTEMS OF SURFACE AND GROUND WATERWORKS IN FINLAND

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Jenni Meirami Ikonena ◽  
Anna-Maria Hokajärvi ◽  
Jatta Heikkinen ◽  
Tarja Pitkänen ◽  
Robert Ciszek ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Source ◽  
Bulk Water ◽  
Available Phosphorus ◽  
Raw Water ◽  
Drinking Water Distribution Systems

Physico-chemical and microbiological water quality in the drinking water distribution systems (DWDSs) of five waterworks in Finland with different raw water sources and treatment processes was explored. Water quality was monitored during four seasons with on-line equipment and bulk water samples were analysed in laboratory. Seasonal changes in the water quality were more evident in DWDSs of surface waterworks compared to the ground waterworks and artificially recharging ground waterworks (AGR). Between seasons, temperature changed significantly in every sys-tem but pH and EC changed only in one AGR system. Seasonal change was seen also in the absorbance values of all sys-tems. The concentration of microbially available phosphorus (MAP, μg PO₄-P/l) was the highest in drinking water origi-nating from the waterworks supplying groundwater. Total assimilable organic carbon (AOC, μg AOC-C/l) concentrations were significantly different between the DWDSs other than between the two AGR systems. This study reports differences in the water quality between surface and ground waterworks using a wide set of parameters commonly used for monitor-ing. The results confirm that every distribution system is unique, and the water quality is affected by environmental fac-tors, raw water source, treatment methods and disinfection.

scholarly journals Identification and inactivation of Gordonia, a new chlorine-resistant bacterium isolated from a drinking water distribution system

2020 ◽  
Vol 18 (6) ◽  
pp. 995-1008
Author(s):  
Nannan Lu ◽  
Shaohua Sun ◽  
Fumin Chu ◽  
Mingquan Wang ◽  
Qinghua Zhao ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Radiation Treatment ◽  
Flow Cytometric Analysis ◽  
Resistant Bacterium ◽  
Resistant Bacteria ◽  
Inactivation Kinetics ◽  
Water Safety

Abstract Chlorine-resistant bacteria threaten drinking water safety in water distribution systems. In this study, a novel chlorine-resistant bacterium identified as Gordonia was isolated from the drinking water supply system of Jinan City for the first time. We examined the resistance and inactivation of the isolate by investigating cell survival, changes in cell morphology, and the permeability of cell membranes exposed to chlorine. After 240 min chlorine exposure, the chlorine residual was greater than 0.5 mg L−1 and the final inactivation was about 3 log reduction, which showed that the Gordonia strain had high chlorine tolerance. Flow-cytometric analysis indicated that, following sodium hypochlorite treatments with increasing membrane permeability, culturable cells enter a viable but nonculturable state and then die. We also investigated the inactivation kinetics of Gordonia following chlorine dioxide and ultraviolet radiation treatment. We found that these treatments can effectively inactivate Gordonia, which suggests that they may be used for the regulation of chlorine-resistant microorganisms.

scholarly journals Non-invasive Biofouling Monitoring to Assess Drinking Water Distribution System Performance

2021 ◽  
Vol 12 ◽  
Author(s):  
Frances C. Pick ◽  
Katherine E. Fish ◽  
Stewart Husband ◽  
Joby B. Boxall
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Bulk Water ◽  
Water Supply Systems ◽  
Customer Contact ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Contact Data

Biofilms are endemic in drinking water distribution systems (DWDS), forming on all water and infrastructure interfaces. They can pose risks to water quality and hence consumers. Our understanding of these biofilms is limited, in a large part due to difficulties in sampling them without unacceptable disruption. A novel, non-destructive and non-disruptive biofilm monitoring device (BMD), which includes use of flow cytometry analysis, was developed to assess biofouling rates. Laboratory based experiments established optimal configurations and verified reliable cell enumeration. Deployment at three operational field sites validated assessment of different biofouling rates. These differences in fouling rates were not obvious from bulk water sampling and analysis, but did have a strong correlation with long-term performance data of the associated networks. The device offers the potential to assess DWDS performance in a few months, compared to the number of years required to infer findings from historical customer contact data. Such information is vital to improve the management of our vast, complex and uncertain drinking water supply systems; for example rapidly quantifying the benefits of improvements in water treatment works or changes to maintenance of the network.

scholarly journals Identification of Aminoglycoside Resistance Genes From Bacteria Isolated From Selected Municipal Drinking Water Distribution Systems in Southwestern Nigeria

2020 ◽  
Vol 41 (S1) ◽  
pp. s255-s255
Author(s):  
Ayodele T. Adesoji ◽  
Adeniyi A. Ogunjobi
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Southwestern Nigeria ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

Background: Multidrug-resistant bacteria can lead to treatment failure, resulting in infectious diseases being transferred through nonpotable water. Aminoglycosides are an important class of antibiotics that are abused in Nigeria. Few studies have investigated aminoglycoside-modifying genes (AMGs) that are likely responsible for resistance in Nigeria bacteria isolates. Therefore, we aimed to characterize AMGs from isolates in drinking water distribution systems (DWDS) in southwestern Nigeria. Methods: Multidrug-resistant bacteria (n = 181) that had been previously characterized by 16S rDNA sequencing and that were positive for resistance to at least 1 aminoglycoside antibiotic were selected from 6 treated and untreated water distribution systems. Strains were PCR genotyped for 3 AMGs: aph(3)c, ant(3)b and aph(6)-1dd. Results: Of 181 MDR bacteria tested, 69 (38.12%) were positive for at least 1 of the AMGs. The most common was ant(3)c (27.6%), followed by aph(3")c (18.23%). Both aph(3)c and ant(3")b were found in 7.73% of tested isolates, ant(3)b was most commonly found in Alcaligenes spp (50%). Furthermore, aph(3")c was most commonly detected in Proteus spp (50%). Other genera positive for AMGs included Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter, and Serratia. Conclusions: High occurrence of ant(3)c and aph(3)c among these bacteria call for urgent attention among public health workers because these genes can be easily disseminated to consumers if present on mobile genetic elements like plasmids, integrons, and transposons.Funding: NoneDisclosures: None

Control of biofilm growth in drinking water distribution system by biodegradable carbon and disinfectant residuals

2006 ◽  
Vol 6 (2) ◽  
pp. 147-151 ◽  
Author(s):  
X.-J. Zhang ◽  
W. Lu
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Free Water ◽  
Planktonic Cell ◽  
Biofilm Growth ◽  
Bacteria Growth ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

Biofilm growth in drinking water distribution systems was studied in an annular reactor system which was designed to model the hydraulic conditions in water mains. Experiments were performed with chlorine-free water as well as with different disinfectant (chlorine or chloramine) residuals and different AOC concentrations added to the reactor influent to examine the effect of disinfectant residuals and AOC concentrations on biofilm accumulation and planktonic cell numbers. The dynamic parameters of bacteria growth were calculated in water with different disinfectant (chlorine or chloramine) and the results indicated that monochloramine may be more effective than free chlorine for control of biofilm accumulation.

scholarly journals Water quality event detection and customer complaint clustering analysis in distribution systems

2012 ◽  
Vol 12 (5) ◽  
pp. 580-587 ◽  
Author(s):  
Stephen Mounce ◽  
John Machell ◽  
Joby Boxall
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Source ◽  
Water Quality Monitoring ◽  
Water Utility ◽  
Drinking Water Distribution ◽  
Historic Data

Safe, clean drinking water is a foundation of society and water quality monitoring can contribute to ensuring this. A case study application of the CANARY software to historic data from a UK drinking water distribution system is described. Sensitivity studies explored appropriate choice of algorithmic parameter settings for a baseline site, performance was evaluated with artificial events and the system then transferred to all sites. Results are presented for analysis of nine water quality sensors measuring six parameters and deployed in three connected district meter areas (DMAs), fed from a single water source (service reservoir), for a 1 year period and evaluated using comprehensive water utility records with 86% of event clusters successfully correlated to causes (spatially limited to DMA level). False negatives, defined by temporal clusters of water quality complaints in the pilot area not corresponding to detections, were only approximately 25%. It was demonstrated that the software could be configured and applied retrospectively (with potential for future near real time application) to detect various water quality event types (with a wider remit than contamination alone) for further interpretation.

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