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 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 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.

Prediction of chlorine and trihalomethanes concentration profile in bulk drinking water distribution systems from laboratory data

2003 ◽  
Vol 3 (1-2) ◽  
pp. 239-246 ◽  
Author(s):  
G. Kastl ◽  
I. Fisher ◽  
V. Jegatheesan ◽  
J. Chandy ◽  
K. Clarkson
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Laboratory Data ◽  
Water Distribution Systems ◽  
Optimum Level ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Chlorine Decay

Nearly all drinking water distribution systems experience a “natural” reduction of disinfection residuals. The most frequently used disinfectant is chlorine, which can decay due to reactions with organic and inorganic compounds in the water and by liquid/solids reaction with the biofilm, pipe walls and sediments. Usually levels of 0.2-0.5 mg/L of free chlorine are required at the point of consumption to maintain bacteriological safety. Higher concentrations are not desirable as they present the problems of taste and odour and increase formation of disinfection by-products. It is usually a considerable concern for the operators of drinking water distribution systems to manage chlorine residuals at the “optimum level”, considering all these issues. This paper describes how the chlorine profile in a drinking water distribution system can be modelled and optimised on the basis of readily and inexpensively available laboratory data. Methods are presented for deriving the laboratory data, fitting a chlorine decay model of bulk water to the data and applying the model, in conjunction with a simplified hydraulic model, to obtain the chlorine profile in a distribution system at steady flow conditions. Two case studies are used to demonstrate the utility of the technique. Melbourne’s Greenvale-Sydenham distribution system is unfiltered and uses chlorination as its only treatment. The chlorine model developed from laboratory data was applied to the whole system and the chlorine profile was shown to be accurately simulated. Biofilm was not found to critically affect chlorine decay. In the other case study, Sydney Water’s Nepean system was modelled from limited hydraulic data. Chlorine decay and trihalomethane (THM) formation in raw and treated water were measured in a laboratory, and a chlorine decay and THM model was derived on the basis of these data. Simulated chlorine and THM profiles agree well with the measured values available. Various applications of this modelling approach are also briefly discussed.

scholarly journals Whole-Genome Sequences of Four Strains Closely Related to Members of the Mycobacterium chelonae Group, Isolated from Biofilms in a Drinking Water Distribution System Simulator: TABLE 1 

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Vicente Gomez-Alvarez ◽  
Randy P. Revetta
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Draft Genome ◽  
Drinking Water Distribution System ◽  
Genome Sequences ◽  
Mycobacterium Chelonae ◽  
Drinking Water Distribution

We report here the draft genome sequences of four Mycobacterium chelonae strains from biofilms subjected to a “chlorine burn” in a chloraminated drinking water distribution system simulator. These opportunistic pathogens have been detected in hospital and municipal water distribution systems, in which biofilms have been recognized as an important factor for their persistence.

scholarly journals Occurrence of Mycobacteria in Water Treatment Lines and in Water Distribution Systems

2002 ◽  
Vol 68 (11) ◽  
pp. 5318-5325 ◽  
Author(s):  
Corinne Le Dantec ◽  
Jean-Pierre Duguet ◽  
Antoine Montiel ◽  
Nadine Dumoutier ◽  
Sylvie Dubrou ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Sand Filtration ◽  
Mycobacterial Species ◽  
Slow Sand Filtration ◽  
Drinking Water Distribution ◽  
Rapid Sand Filtration

ABSTRACT The frequency of recovery of atypical mycobacteria was estimated in two treatment plants providing drinking water to Paris, France, at some intermediate stages of treatment. The two plants use two different filtration processes, rapid and slow sand filtration. Our results suggest that slow sand filtration is more efficient for removing mycobacteria than rapid sand filtration. In addition, our results show that mycobacteria can colonize and grow on granular activated carbon and are able to enter distribution systems. We also investigated the frequency of recovery of mycobacteria in the water distribution system of Paris (outside buildings). The mycobacterial species isolated from the Paris drinking water distribution system are different from those isolated from the water leaving the treatment plants. Saprophytic mycobacteria (present in 41.3% of positive samples), potentially pathogenic mycobacteria (16.3%), and unidentifiable mycobacteria (54.8%) were isolated from 12 sites within the Paris water distribution system. Mycobacterium gordonae was preferentially recovered from treated surface water, whereas Mycobacterium nonchromogenicum was preferentially recovered from groundwater. No significant correlations were found among the presence of mycobacteria, the origin of water, and water temperature.

scholarly journals Hydraulic optimization of the physical parameters of a drinking water distribution system

2021 ◽  
Vol 2139 (1) ◽  
pp. 012013
Author(s):  
C A Bonilla-Granados ◽  
N J Cely-Calixto ◽  
G A Carrillo Soto
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Hydraulic Modeling ◽  
Physical Parameters ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

Abstract Drinking-water distribution systems are generally designed with methodologies based on trial-and-error tests, which generate feasible results. However, these trials are not the most economical and reliable solution since they do not consider the optimization of the network. For the present work, the hydraulic model of the drinking water distribution network of San José de Cúcuta, Colombia, was optimized by applying the concept of resilience rate and minimum cost. The development of the work consisted of the hydraulic modeling of the physical components of the network in EPANET software, as well as the application of calculations of the connectivity coefficient and the unitary power of each section. With the data obtained from the modeling and calculations, the physical parameters were optimized, and the cost-benefit ratio was estimated. It was found that the current drinking water distribution system does not have a power surplus to overcome a system failure. The optimization increased the total energy surplus of the network (261%) and the resilience rate (585%). Also, the connectivity coefficient was improved with an average value of 0.95. The hydraulic optimization methodology applied resulted in a network resilient to system failures.

Spatial variation of loose deposit characteristics in a 40 km long operational drinking water distribution system

2019 ◽  
Vol 5 (10) ◽  
pp. 1689-1698
Author(s):  
Xu Ma ◽  
Guiwei Li ◽  
Ying Yu ◽  
Ruya Chen ◽  
Yao Zhang ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Eastern China ◽  
Drinking Water Distribution Systems ◽  
System P ◽  
Loose Deposit ◽  
Drinking Water Distribution

Discoloration problems have occurred in drinking water distribution systems continuously for several years in a rural area of eastern China.

scholarly journals A biochemical multi-species quality model of a drinking water distribution system for simulation and design

2013 ◽  
Vol 23 (3) ◽  
pp. 571-585 ◽  
Author(s):  
Krzysztof Arminski ◽  
Tomasz Zubowicz ◽  
Mietek A. Brdys
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Heterotrophic Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Large Set ◽  
Monitoring And Control ◽  
Quality Model ◽  
Drinking Water Distribution

Abstract Drinking Water Distribution Systems (DWDSs) play a key role in sustainable development of modern society. They are classified as critical infrastructure systems. This imposes a large set of highly demanding requirements on the DWDS operation and requires dedicated algorithms for on-line monitoring and control to tackle related problems. Requirements on DWDS availability restrict the usability of the real plant in the design phase. Thus, a proper model is crucial. Within this paper a DWDS multi-species quality model for simulation and design is derived. The model is composed of multiple highly inter-connected modules which are introduced to represent chemical and biological species and (above all) their interactions. The chemical part includes the processes of chloramine decay with additional bromine catalysis and reaction with nitrogen compounds. The biological part consists of both heterotrophic and chemo-autotrophic bacteria species. The heterotrophic bacteria are assumed to consume assimilable organic carbon. Autotrophs are ammonia oxidizing bacteria and nitrite oxidizing bacteria species which are responsible for nitrification processes. Moreover, Disinfection By-Products (DBPs) are also considered. Two numerical examples illustrate the derived model’s behaviour in normal and disturbance operational states.

Sign in / Sign up

Export Citation Format

Share Document