scholarly journals Nontuberculous Mycobacteria, Fungi, and Opportunistic Pathogens in Unchlorinated Drinking Water in the Netherlands

2012 ◽  
Vol 79 (3) ◽  
pp. 825-834 ◽  
Author(s):  
Paul W. J. J. van der Wielen ◽  
Dick van der Kooij
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
The Netherlands ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Distribution System ◽  
Nontuberculous Mycobacteria ◽  
Opportunistic Pathogens ◽  
Content Type ◽  
Premise Plumbing

ABSTRACTThe multiplication of opportunistic pathogens in drinking water supplies might pose a threat to public health. In this study, distributed unchlorinated drinking water from eight treatment plants in the Netherlands was sampled and analyzed for fungi, nontuberculous mycobacteria (NTM), and several opportunistic pathogens by using selective quantitative PCR methods. Fungi and NTM were detected in all drinking water samples, whereasLegionella pneumophila,Pseudomonas aeruginosa,Stenotrophomonas maltophilia, andAspergillus fumigatuswere sporadically observed.Mycobacterium aviumcomplex andAcanthamoebaspp. were not detected. Season had no influence on the occurrence of these organisms, except for NTM andS. maltophilia, which were present in higher numbers in the summer. Opportunistic pathogens were more often observed in premise plumbing water samples than in samples from the distribution system. The lowest number of these organisms was observed in the finished water at the plant. Thus, fungi, NTM, and some of the studied opportunistic pathogens can multiply in the distribution and premise plumbing systems. Assimilable organic carbon (AOC) and/or total organic carbon (TOC) had no clear effects on fungal and NTM numbers or onP. aeruginosa- andS. maltophilia-positive samples. However,L. pneumophilawas detected more often in water with AOC concentrations above 10 μg C liter−1than in water with AOC levels below 5 μg C liter−1. Finally, samples that containedL. pneumophila,P. aeruginosa, orS. maltophiliawere more frequently positive for a second opportunistic pathogen, which shows that certain drinking water types and/or sampling locations promote the growth of multiple opportunistic pathogens.

scholarly journals Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 957
Author(s):  
Abraham C. Cullom ◽  
Rebekah L. Martin ◽  
Yang Song ◽  
Krista Williams ◽  
Amanda Williams ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Chemistry ◽  
Legionella Pneumophila ◽  
High Surface ◽  
Metallic Copper ◽  
Health Concern ◽  
Future Research ◽  
Opportunistic Pathogens ◽  
Premise Plumbing ◽  
Pipe Materials

Growth of Legionella pneumophila and other opportunistic pathogens (OPs) in drinking water premise plumbing poses an increasing public health concern. Premise plumbing is constructed of a variety of materials, creating complex environments that vary chemically, microbiologically, spatially, and temporally in a manner likely to influence survival and growth of OPs. Here we systematically review the literature to critically examine the varied effects of common metallic (copper, iron) and plastic (PVC, cross-linked polyethylene (PEX)) pipe materials on factors influencing OP growth in drinking water, including nutrient availability, disinfectant levels, and the composition of the broader microbiome. Plastic pipes can leach organic carbon, but demonstrate a lower disinfectant demand and fewer water chemistry interactions. Iron pipes may provide OPs with nutrients directly or indirectly, exhibiting a high disinfectant demand and potential to form scales with high surface areas suitable for biofilm colonization. While copper pipes are known for their antimicrobial properties, evidence of their efficacy for OP control is inconsistent. Under some circumstances, copper’s interactions with premise plumbing water chemistry and resident microbes can encourage growth of OPs. Plumbing design, configuration, and operation can be manipulated to control such interactions and health outcomes. Influences of pipe materials on OP physiology should also be considered, including the possibility of influencing virulence and antibiotic resistance. In conclusion, all known pipe materials have a potential to either stimulate or inhibit OP growth, depending on the circumstances. This review delineates some of these circumstances and informs future research and guidance towards effective deployment of pipe materials for control of OPs.

scholarly journals Pyrosequence Analysis of thehsp65Genes of Nontuberculous Mycobacterium Communities in Unchlorinated Drinking Water in the Netherlands

2013 ◽  
Vol 79 (19) ◽  
pp. 6160-6166 ◽  
Author(s):  
Paul W. J. J. van der Wielen ◽  
Leo Heijnen ◽  
Dick van der Kooij
Keyword(s):  
Drinking Water ◽  
The Netherlands ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Formation Rate ◽  
Nontuberculous Mycobacterium ◽  
Gene Sequences ◽  
Local Conditions ◽  
Content Type

ABSTRACTStudies have shown that certain opportunistic pathogenic species of nontuberculous mycobacteria (NTM) can be present in distributed drinking water. However, detailed information about NTM population composition in drinking water is lacking. Therefore, NTM communities in unchlorinated drinking water from the distribution system of five treatment plants in the Netherlands were characterized using 454 pyrosequencing of thehsp65gene. Results showed high diversities in unchlorinated drinking water, with up to 28 different NTM operational taxonomic units (OTUs) in a single sample. Each drinking water sample had a unique NTM community, and most (81.1%) OTUs were observed only once. One OTU was observed in 14 of 16 drinking water samples, indicating that this NTM species is well adapted to unchlorinated drinking water conditions. A clear influence of season, source type (groundwater, surface water), easily assimilable organic carbon (AOC) concentration, biofilm formation rate, and active biomass in treated water on the establishment of an NTM community in drinking water was not observed. Apparently, local conditions are more important for the development of a specific NTM community in the drinking water distribution system. A low (4.2%) number ofhsp65gene sequences showed more than 97% similarity to sequences of the opportunistic pathogensM. avium,M. genavense, andM. gordonae. However, most (95.8%) NTMhsp65gene sequences were related to not-yet-described NTM species that have not been linked to disease, indicating that most NTM species in unchlorinated drinking water from distribution systems in the Netherlands have a low public health significance.

scholarly journals Identification of Bacteria in Biofilm and Bulk Water Samples from a Nonchlorinated Model Drinking Water Distribution System: Detection of a Large Nitrite-Oxidizing Population Associated with Nitrospira spp

2005 ◽  
Vol 71 (12) ◽  
pp. 8611-8617 ◽  
Author(s):  
Adam C. Martiny ◽  
Hans-Jørgen Albrechtsen ◽  
Erik Arvin ◽  
Søren Molin
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Water Samples ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Bulk Water ◽  
Drinking Water Distribution System ◽  
Assimilable Organic Carbon ◽  
Drinking Water Distribution

ABSTRACT In a model drinking water distribution system characterized by a low assimilable organic carbon content (<10 μg/liter) and no disinfection, the bacterial community was identified by a phylogenetic analysis of rRNA genes amplified from directly extracted DNA and colonies formed on R2A plates. Biofilms of defined periods of age (14 days to 3 years) and bulk water samples were investigated. Culturable bacteria were associated with Proteobacteria and Bacteriodetes, whereas independently of cultivation, bacteria from 12 phyla were detected in this system. These included Acidobacteria, Nitrospirae, Planctomycetes, and Verrucomicrobia, some of which have never been identified in drinking water previously. A cluster analysis of the population profiles from the individual samples divided biofilms and bulk water samples into separate clusters (P = 0.027). Bacteria associated with Nitrospira moscoviensis were found in all samples and encompassed 39% of the sequenced clones in the bulk water and 25% of the biofilm community. The close association with Nitrospira suggested that a large part of the population had an autotrophic metabolism using nitrite as an electron donor. To test this hypothesis, nitrite was added to biofilm and bulk water samples, and the utilization was monitored during 15 days. A first-order decrease in nitrite concentration was observed for all samples with a rate corresponding to 0.5 × 105 to 2 × 105 nitrifying cells/ml in the bulk water and 3 × 105 cells/cm2 on the pipe surface. The finding of an abundant nitrite-oxidizing microbial population suggests that nitrite is an important substrate in this system, potentially as a result of the low assimilable organic carbon concentration. This finding implies that microbial communities in water distribution systems may control against elevated nitrite concentrations but also contain large indigenous populations that are capable of assisting the depletion of disinfection agents like chloramines.

scholarly journals Prevalence of Legionella spp. and Escherichia coli in the drinking water distribution system of Wrocław (Poland)

2020 ◽  
Vol 20 (3) ◽  
pp. 1083-1090
Author(s):  
M. Wolf-Baca ◽  
A. Siedlecka
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Potential Threat ◽  
E Coli ◽  
Drinking Water Distribution

Abstract Drinking water should be free from bacterial pathogens that threaten human health. The most recognised waterborne opportunistic pathogens, dwelling in tap water, are Legionella pneumophila and Escherichia coli. Drinking water samples were tested for the presence of Legionella spp., L. pneumophila, and E. coli in overall sample microbiomes using a quantitative real-time polymerase chain reaction (qPCR) approach. The results indicate a rather low contribution of Legionella spp. in total bacteria in the tested samples, but L. pneumophila was not detected in any sample. E. coli was detected in only one sample, but at a very low level. The qacEΔ1 gene, conferring resistance to quaternary ammonium compounds, was also not detected in any sample. The results point to generally sufficient quality of drinking water, although the presence of Legionella spp. in tap water samples suggests proliferation of these bacteria in heating units, causing a potential threat to consumer health.

scholarly journals Biofilm Composition and Threshold Concentration for Growth of Legionella pneumophila on Surfaces Exposed to Flowing Warm Tap Water without Disinfectant

2017 ◽  
Vol 83 (5) ◽  
Author(s):  
Dick van der Kooij ◽  
Geo L. Bakker ◽  
Ronald Italiaander ◽  
Harm R. Veenendaal ◽  
Bart A. Wullings
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Carbon ◽  
Legionella Pneumophila ◽  
Tap Water ◽  
Threshold Concentration ◽  
Plate Count ◽  
Water Quality Criteria ◽  
Content Type ◽  
Hydraulic Conditions

ABSTRACT Legionella pneumophila in potable water installations poses a potential health risk, but quantitative information about its replication in biofilms in relation to water quality is scarce. Therefore, biofilm formation on the surfaces of glass and chlorinated polyvinyl chloride (CPVC) in contact with tap water at 34 to 39°C was investigated under controlled hydraulic conditions in a model system inoculated with biofilm-grown L. pneumophila. The biofilm on glass (average steady-state concentration, 23 ± 9 pg ATP cm−2) exposed to treated aerobic groundwater (0.3 mg C liter−1; 1 μg assimilable organic carbon [AOC] liter−1) did not support growth of the organism, which also disappeared from the biofilm on CPVC (49 ± 9 pg ATP cm−2) after initial growth. L. pneumophila attained a level of 4.3 log CFU cm−2 in the biofilms on glass (1,055 ± 225 pg ATP cm−2) and CPVC (2,755 ± 460 pg ATP cm−2) exposed to treated anaerobic groundwater (7.9 mg C liter−1; 10 μg AOC liter−1). An elevated biofilm concentration and growth of L. pneumophila were also observed with tap water from the laboratory. The Betaproteobacteria Piscinibacter and Methyloversatilis and amoeba-resisting Alphaproteobacteria predominated in the clones and isolates retrieved from the biofilms. In the biofilms, the Legionella colony count correlated significantly with the total cell count (TCC), heterotrophic plate count, ATP concentration, and presence of Vermamoeba vermiformis. This amoeba was rarely detected at biofilm concentrations of <100 pg ATP cm−2. A threshold concentration of approximately 50 pg ATP cm−2 (TCC = 1 × 106 to 2 × 106 cells cm−2) was derived for growth of L. pneumophila in biofilms. IMPORTANCE Legionella pneumophila is the etiologic agent in more than 10,000 cases of Legionnaires' disease that are reported annually worldwide and in most of the drinking water-associated disease outbreaks reported in the United States. The organism proliferates in biofilms on surfaces exposed to warm water in engineered freshwater installations. An investigation with a test system supplied with different types of warm drinking water without disinfectant under controlled hydraulic conditions showed that treated aerobic groundwater (0.3 mg liter−1 of organic carbon) induced a low biofilm concentration that supported no or very limited growth of L. pneumophila. Elevated biofilm concentrations and L. pneumophila colony counts were observed on surfaces exposed to two types of extensively treated groundwater, containing 1.8 and 7.9 mg C liter−1 and complying with the microbial water quality criteria during distribution. Control measures in warm tap water installations are therefore essential for preventing growth of L. pneumophila.

Minimization of the Disinfection by-Product Precursors in Treated Waters Exposed to Ozone and Chlorine

2014 ◽  
Vol 884-885 ◽  
pp. 91-95
Author(s):  
Shang Chao Yue ◽  
Le Jun Zhao ◽  
Xiu Duo Wang ◽  
Qi Shan Wang ◽  
Feng Hua He
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Supply ◽  
River Water ◽  
Water Samples ◽  
Full Scale ◽  
Ultraviolet Absorbance ◽  
Treatment Processes ◽  
Removal Efficiencies

The objectives of this study were to investigate impact of preoxidation on disinfection by-product (DBP) precursors in drinking water via two different preoxidation methods. The full-scale study was conducted on surface river water in a water supply plant in Tianjin, China. Two treatment trains were performed, with prechlorination and preozonation as preoxidation methods, respectively. The water samples were collected on different stages along the treatment processes and analyzed by following organic parameters: dissolved organic carbon (DOC), UV254 and specific ultraviolet absorbance (SUVA). The results indicated that Train 2 with preozonation was more effective to reduce DBP precursors. Preozonation possessed an excellent ability in the removal of UV254 and SUVA, the removal efficiencies were 25.14% and 18.77%, respectively, comparing to the removal rates of 6.66% and 5.64% during prechlorination, separately.

Investigation of opportunistic pathogens in municipal drinking water under different supply and treatment regimes

2004 ◽  
Vol 50 (1) ◽  
pp. 83-90 ◽  
Author(s):  
M. Pryor ◽  
S. Springthorpe ◽  
S. Riffard ◽  
T. Brooks ◽  
Y. Huo ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Microbiological Quality ◽  
Opportunistic Pathogens ◽  
Treatment Regimes ◽  
Point Of Use ◽  
Deep Wells ◽  
Before And After ◽  
Legionella Species ◽  
Biofilm Bacteria

Changing regulations to lower disinfectant byproducts in drinking water is forcing utilities to switch disinfection from chlorine to monochloramine. It is generally unknown whether this will impact positively or negatively on the microbiological quality of drinking water. A utility in Florida, using water with relatively high organic carbon levels from deep wells in several wellfields, made the decision to change its disinfection regime from chlorine to chloramine in order to meet the new regulations. To assess the impacts of such a change on the microbiology of its water supplies, it undertook a number of studies before and after the change. In particular, the presence of the opportunistic pathogens Legionella and Mycobacterium, and also the composition of drinking-water biofilms, were examined. A preliminary synthesis and summary of these results are presented here. Legionella species were widely distributed in source waters and in the distribution system when chlorine was the disinfectant. In some samples they seemed to be among the dominant biofilm bacteria. Following the change to monochloramine, legionellae were not detected in the distribution system during several months of survey; however, they remained detectable at point of use, although with less species diversity. A variety of mycobacteria (21 types) were widely distributed in the distribution system when chlorine was the disinfectant, but these seemed to increase in dominance after chloramination was instituted. At point of use, only four species of mycobacteria were detected. Other changes occurring with chloramination included (a) an altered biofilm composition, (b) increased numbers of total coliforms and heterotrophs and (c) nitrification of water storage tanks. The results suggested that consideration should be given to the microbiological effects of changing disinfection regimes in drinking-water and distribution system biofilms.

Sensory aspects of drinking water in contact with epoxy lined copper pipe

2007 ◽  
Vol 55 (5) ◽  
pp. 161-168 ◽  
Author(s):  
T.H. Heim ◽  
A.M. Dietrich
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Compounds ◽  
Sensory Analysis ◽  
Water Samples ◽  
Distribution System ◽  
Distribution Systems ◽  
Free Chlorine ◽  
Copper Pipe

Pipe relining via in situ epoxy lining is used to remediate corroded plumbing or distribution systems. This investigation examined the effects on odour, TOC, THM formation and disinfectant demand in water exposed to epoxy-lined copper pipes used for home plumbing. The study was conducted in accordance with the Utility Quick Test, a migration/leaching method for utilities to conduct sensory analysis of materials in contact with drinking water. The test was performed using water with no disinfectant and levels of chlorine and monochloramines representative of those found in the distribution system. Panelists repeatedly and consistently described a “plastic/adhesive/putty” odour in the water from the pipes. The odour intensity remained relatively constant for each of two subsequent flushes. Water samples stored in the epoxy-lined pipes showed a significant increase in the leaching of organic compounds (as TOC), and this TOC was demonstrated to react with free chlorine to form trichloromethane. Water stored in the pipes also showed a marked increase in disinfectant demand relative to the water stored in glass control flasks. A study conducted at a full scale installation at an apartment demonstrated that after installation and regular use, the epoxy lining did not yield detectable differences in water quality.

Characterization of NOM in a drinking water treatment process train with no disinfectant residual

2009 ◽  
Vol 9 (4) ◽  
pp. 379-386 ◽  
Author(s):  
S. A. Baghoth ◽  
M. Dignum ◽  
A. Grefte ◽  
J. Kroesbergen ◽  
G. L. Amy
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Distribution System ◽  
Chemical Properties ◽  
Drinking Water Treatment ◽  
Building Blocks ◽  
Fluorescence Excitation ◽  
Water Treatment Process ◽  
Water Treatment Plants

For drinking water treatment plants that do not use disinfectant residual in the distribution system, it is important to limit availability of easily biodegradable natural organic matter (NOM) fractions which could enhance bacterial regrowth in the distribution system. This can be achieved by optimising the removal of those fractions of interest during treatment; however, this requires a better understanding of the physical and chemical properties of these NOM components. Fluorescence excitation-emission matrix (EEM) and liquid chromatography with online organic carbon detection (LC-OCD) were used to characterize NOM in water samples from one of the two water treatment plants serving Amsterdam, The Netherlands. No disinfectant residual is applied in the distribution system. Fluorescence EEM and LC-OCD were used to track NOM fractions. Whereas fluorescence EEM shows the reduction of humic-like as well as protein-like fluorescence signatures, LC-OCD was able to quantify the changes in dissolved organic carbon (DOC) concentrations of five NOM fractions: humic substances, building blocks (hydrolysates of humics), biopolymers, low molecular weight acids and neutrals.

scholarly journals Application of model fitting technique to enhance bacterial regrowth potential (BRP) measurement for drinking water supply monitoring

2021 ◽  
Author(s):  
Wenjin Xue ◽  
Christopher W. K. Chow ◽  
John van Leeuwen
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water Samples ◽  
Distribution System ◽  
Distribution Systems ◽  
Tap Water ◽  
Treatment Plant ◽  
Drinking Water Supply ◽  
Water Supply Systems ◽  
Bacterial Regrowth

Abstract The bacterial regrowth potential (BRP) method was utilised to indirectly measure the assimilable organic carbon (AOC) as an indicator for the assessment of the microbial regrowth potential in drinking water distribution systems. A model using various microbial growth parameters was developed in order to standardise the experimental interpretation for BRP measurement. This study used 82 experimental BRP data sets of water samples collected from the water treatment plant to locations (customer taps) in the distribution system. The data were used to model the BRP process (growth curve) by a data fitting procedure and to obtain a best-fitted equation. Statistical assessments and model validation for evaluating the equation obtained by fitting these 82 sets of data were conducted, and the results show average R2 values were 0.987 for treated water samples (collected at the plant prior to chlorination) and 0.983 for tap water (collected at the customer taps). The F values obtained from the F-test are all exceeded their corresponding F critical values, and the results from the t-test also showed a good outcome. These results indicate this model would be successfully applied in modelling BRP in drinking water supply systems.

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