Effect of temperature and pipe material on biofilm formation and survival of Escherichia coli in used drinking water pipes: a laboratory-based study

2006 ◽  
Vol 54 (3) ◽  
pp. 49-56 ◽  
Author(s):  
J. Silhan ◽  
C.B. Corfitzen ◽  
H.J. Albrechtsen
Keyword(s):  
Drinking Water ◽  
Biofilm Formation ◽  
Water Phase ◽  
Effect Of Temperature ◽  
Plate Count ◽  
Pipe Material ◽  
E Coli ◽  
Water Pipes ◽  
Higher Temperature ◽  
Static Conditions

Segments of used drinking water pipes of galvanised steel (GS), cross-linked polyethylene (PEX), copper pipes (Cu) or new medium-density polyethylene (PE) were investigated for the formation of biofilm and survival of E. coli in biofilm and in the water phase. Pipes were filled with water and incubated at 15 °C or 35 °C under static conditions. Biofilm formation was followed during 32, 40 and 56 (58) d. The most dense biofilm was formed on GS, reaching approximately 4.7×105 CFU/cm2 measured as heterotrophic plate count (HPC), and at the other materials the density reached 3×103 CFU/cm2 on PE and PEX and 5×101 and 5×102 CFU/cm2 on Cu pipes after 58 d at 15 °C. Biofilm HPC values were higher at 35 °C than at 15 °C, with only slightly higher values on the metals, but 100-fold higher on PE and PEX. Adenosine triphosphate (ATP) measurements confirmed the general trends observed by HPC. Higher temperature was seen to be an important factor reducing E. coli survival in the water phase in drinking water pipes. At 15 °C E. coli survived more than 4 d in GS and Cu pipes and 8 d in PE pipes, but was not detected after 48 h at 35 °C. The E. coli survived longer at both temperatures in the glass control bottles than in the drinking water pipes. Despite the obvious biofilm formation, E. coli was not detected in the biofilm at any of the investigated surfaces.

scholarly journals Effect of Temperature, pH and Plasmids on In Vitro Biofilm Formation in Escherichia coli

Acta Naturae ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 129-132 ◽  
Author(s):  
A. Mathlouthi ◽  
E. Pennacchietti ◽  
D. De Biase
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Acid Resistance ◽  
Transcriptional Regulators ◽  
Growth Conditions ◽  
Luria Bertani ◽  
Effect Of Temperature ◽  
E Coli ◽  
Static Conditions

Acid resistance (AR) in Escherichia coli is an important trait that protects this microorganism from the deleterious effect of low-pH environments. Reports on biofilm formation in E. coli K12 showed that the genes participating in AR were differentially expressed. Herein, we investigated the relationship between AR genes, in particular those coding for specific transcriptional regulators, and their biofilm-forming ability at the phenotypic level. The latter was measured in 96-well plates by staining the bacteria attached to the well, following 24-hour growth under static conditions, with crystal violet. The growth conditions were as follows: Luria Bertani (LB) medium at neutral and acidic pH, at 37C or 25C. We observed that the three major transcriptional regulators of the AR genes (gadX, gadE, gadW) only marginally affected biofilm formation in E. coli. However, a striking and novel finding was the different abilities of all the tested E. coli strains to form a biofilm depending on the temperature and pH of the medium: LB, pH 7.4, strongly supported biofilm formation at 25C, with biofilm being hardly detectable at 37C. On the contrary, LB, pH 5.5, best supported biofilm formation at 37C. Moreover, we observed that when E. coli carried a plasmid, the presence of the plasmid itself affected the ability to develop a biofilm, typically by increasing its formation. This phenomenon varies from plasmid to plasmid, depends on growth conditions, and, to the best of our knowledge, remains largely uninvestigated.

scholarly journals The Role of the Motility of Methylobacterium in Bacterial Interactions in Drinking Water

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1386 ◽  
Author(s):  
Erifyli Tsagkari ◽  
William Sloan
Keyword(s):  
Drinking Water ◽  
Biofilm Formation ◽  
Bacterial Motility ◽  
Water Industry ◽  
Water Pipes ◽  
Bacterial Interactions ◽  
Available Energy ◽  
Potential Tool

Bacterial motility is one important factor that affects biofilm formation. In drinking water there are key bacteria in aggregation, whose biology acts to enhance the formation of biofilms. However, it is unclear whether the motility of these key bacteria is an important factor for the interactions between bacteria in drinking water, and, subsequently, in the formation of aggregates, which are precursors to biofilms. Thus, the role of the motility of one of these key bacteria, the Methylobacterium strain DSM 18358, was investigated in the interactions between bacteria in drinking water. The motility of pure Methylobacterium colonies was initially explored; if it was affected by the viscosity of substrate, the temperature, the available energy and the type of substrate. Furthermore, the role of Methylobacterium in the interactions between mixed drinking water bacteria was investigated under the mostly favourable conditions for the motility of Methylobacterium identified before. Overall, the motility of Methylobacterium was found to play a key role in the communication and interactions between bacteria in drinking water. Understanding the role of the motility of key bacteria in drinking water might be useful for the water industry as a potential tool to control the formation of biofilms in drinking water pipes.

The effects of traffic loads on drinking water main failure frequencies in the Netherlands

2016 ◽  
Vol 11 (3) ◽  
pp. 524-530
Author(s):  
A. Moerman ◽  
B. A. Wols ◽  
R. Diemel
Keyword(s):  
Drinking Water ◽  
Asset Management ◽  
Pipe Material ◽  
Regression Analyses ◽  
Pipe Failure ◽  
Water Pipes ◽  
Traffic Loads ◽  
Diameter Pipe ◽  
Water Companies ◽  
External Loads

Understanding pipe failure is essential for effective asset management. Buried drinking water pipes are exposed to several types of external loads, e.g. soil weight, loads due to soil settling differences and traffic loads. The hypothesis that traffic loads positively affects the number of failures was statistically tested. For three out of four studied water companies significant higher failure frequencies than average were found at road crossings. Frequencies equal to average were found for pipes which are installed under other road sections. Frequencies higher than average–but not statistically significant–were found around speed bumps. The results of the multiple regression analyses show that the overall contribution of the parameter ‘road classification’ to pipe failure is small compared to the influence of pipe diameter, pipe material and year of installation.

scholarly journals Control of microbial contamination in drinking water from microfiltering dispensers by dialysis ultrafilters

2016 ◽  
Vol 27 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Luca Bolelli ◽  
Elida Nora Ferri ◽  
Stefano Girotti
Keyword(s):  
Drinking Water ◽  
Flow Rate ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Tap Water ◽  
Plate Count ◽  
Resistant Bacteria ◽  
Contamination Levels ◽  
Selection Of

Abstract Tap water filtering devices are widely employed to improve odor and taste of tap water, or to obtain refrigerated or sparkling drinking water. The presence of disinfectants-resistant bacteria in tap water is responsible of the biofilm formation inside tubes and tanks. The consequent contamination of dispensed water is a well-known hygiene problem because of the quite constant presence of potentially pathogenic bacteria likes P. aeruginosa. In this study, we tested the technical feasibility and effectiveness of the addition to different commercial devices of a packaged polysulphone fibers filter. We aimed to find a simple solution to implement the quality of the delivered water. Water contamination levels were determined in a wide selection of microfiltered water dispensers and we selected among them a representative group of 10 devices, new or in use. The packaged ultrafilter was introduced in about half of them, to monitor, when possible, in parallel the contamination levels and flow rate of a couple of identical units, with and without the filter. The placement of the dialysis filters resulted feasible at different positions along the water circuits of the variously designed filtration units. Delivered water resulted completely free from bacteria when the filter was placed exactly at, or very close to, the outlet in spite of the inner surfaces contamination. This performance was not obtained in presence of a more or less long tract of water circuits downstream the ultrafilter: a significant but not complete reduction of the plate count numbers was observed. The filters worked in continue over the whole study period, ten months, showing exactly the same efficiency. Moreover, the flow rate in presence of the filter was quite unaffected. The addition of this kind of filter to already in use water dispensers was technically easy, and its use can be recommended in all cases a simple but reliable water sanitization is requested.

Multi-stage assessment of biofilm growth by drinking water bacteria on polymeric pipe materials

2020 ◽  
Author(s):  
Olga Sójka ◽  
Patrick van Rijn ◽  
Henny van der Mei ◽  
Maria Cristina Gagliano
Keyword(s):  
Drinking Water ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Pipe Material ◽  
Bacterial Strains ◽  
Drinking Water Contamination ◽  
Multi Stage ◽  
Biofilm Development ◽  
Pipe Materials ◽  
Mechanical Cleaning

<p><strong>Introduction</strong></p> <p>The presence of biofilms in drinking water distribution systems (DWDS) leads to a number of issues, i.e. secondary (biological) drinking water contamination, pipe damage and increased flow resistance. Among other operational factors, the selection of pipe material plays an important role in biofilm development. Up to now, the studies that have investigated this correlation provide contradictory results in terms of which material might be the most advantageous in the DWDS biofilm control strategy. Hence, to understand the influence of pipe material on biofilm formation, we focused on developing a standardized methodology that allows a multi-stage assessment of biofilm development on real pipe materials.</p> <p><strong>Results</strong></p> <p>Development of the methodology consisted of three steps: 1) material coupon sterilization, 2) biofilm cultivation and 3) biofilm analysis, using  transparent polyvinyl chloride (PVC) as a study material. For the coupon sterilization, methods utilizing immersion in different disinfectant solutions with and without pre-cleaning by rubbing the coupons in a surfactant solution. The results showed that mechanical cleaning before washing  is crucial and without it, reproducible sterilization was difficult to achieve. Biofilm formation on the PVC coupons was performed in a 6-well plate assay (24, 48 and 72 h; under agitation) using DWDS biofilm strains (<em>Sphingomonas spp</em>. and <em>Pseudomonas extremorientalis</em>) and <em>Pseudomonas aeruginosa</em> as a positive control. Bacterial fitness and ability to secrete EPS and form biofilms on the PVC surfaces were tested by monitoring optical density (OD600 nm), chemical oxygen demand (COD) and protein concentration. The formed biofilm and the morphology of attached bacteria were visualized using crystal violet staining (that allow qualitative (bright field microscopy) and quantitative (OD at 570 nm) evaluation), by scanning electron microscopy (SEM) and DNA staining (4′,6-diamidino-2-phenylindole; DAPI) with fluorescence microscopy. Combination of those techniques gave a complete overview of patterns involved in biofilm development by selected drinking water bacterial strains in presence of a PVC surface. The developed methodology was also applied  for the analysis of bacterial growth on real-grade pipe materials, such as PVC and polyethylene (PE), to understand their role in biofilm formation.</p> <p><strong>Conclusions</strong></p> <p>Implementation of various analytical and microscopic techniques is important in understanding mechanisms behind biofilm development in DWDS and the influence of pipe material in the process. The proposed approach allows the observation of biofilm formation in time, but also of the typical bacterial morphology of attached cells. In this study it was shown that to obtain reproducible results, it is crucial to select an appropriate sterilization technique and the influence of mechanical cleaning cannot be ignored in preparation of polymeric surfaces.</p>

scholarly journals Poloxamer 338 Affects Cell Adhesion and Biofilm Formation in Escherichia coli: Potential Applications in the Management of Catheter-Associated Urinary Tract Infections

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 885
Author(s):  
Mariarita Stirpe ◽  
Benedetta Brugnoli ◽  
Gianfranco Donelli ◽  
Iolanda Francolini ◽  
Claudia Vuotto
Keyword(s):  
Escherichia Coli ◽  
Cell Adhesion ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Biofilm Formation ◽  
Attenuated Total Reflection ◽  
Water Contact ◽  
E Coli ◽  
Static Conditions ◽  
Tract Infections

Poloxamers are nontoxic, amphiphilic copolymers used in different formulations. Due to its surfactant properties, Poloxamer 338 (P388) is herein proposed as a strategy to avoid biofilm formation often causing recalcitrant catheter-associated urinary tract infections (CAUTI). The aim is to evaluate the ability of P388 coatings to affect the adhesion of Ec5FSL and Ec9FSL Escherichia coli strains on silicone urinary catheters. Attenuated total reflection infrared spectroscopy, atomic force microscopy, and static water contact angle measurement were employed to characterize the P388-coated silicone catheter in terms of amount of P388 layered, coating thickness, homogeneity, and hydrophilicity. In static conditions, the antifouling power of P388 was defined by comparing the E. coli cells adherent on a hydrophilic P388-adsorbed catheter segment with those on an uncoated one. A P388-coated catheter, having a homogeneous coverage of 35 nm in thickness, reduced of 0.83 log10 and 0.51 log10 the biofilm of Ec5FSL and Ec9FSL, respectively. In dynamic conditions, the percentage of cell adhesion on P388-adsorbed silicone channels was investigated by a microfluidic system, simulating the in vivo conditions of catheterized patients. As a result, both E. coli isolates were undetected. The strong and stable antifouling property against E. coli biofilm lead us to consider P388 as a promising anti-biofilm agent for CAUTIs control.

scholarly journals Survival, Biofilm Formation, and Growth Potential of Environmental and Enteric Escherichia coli Strains in Drinking Water Microcosms

2016 ◽  
Vol 82 (17) ◽  
pp. 5320-5331 ◽  
Author(s):  
Cathy L. Abberton ◽  
Ludmila Bereschenko ◽  
Paul W. J. J. van der Wielen ◽  
Cindy J. Smith
Keyword(s):  
Escherichia Coli ◽  
Shear Stress ◽  
Drinking Water ◽  
Biofilm Formation ◽  
Pipe Wall ◽  
Health Concern ◽  
Wall Material ◽  
Content Type ◽  
E Coli ◽  
Contamination Events

ABSTRACTEscherichia coliis the most commonly used indicator for fecal contamination in drinking water distribution systems (WDS). The assumption is thatE. colibacteria are of enteric origin and cannot persist for long outside their host and therefore act as indicators of recent contamination events. This study investigates the fate ofE. coliin drinking water, specifically addressing survival, biofilm formation under shear stress, and regrowth in a series of laboratory-controlled experiments. We show the extended persistence of threeE. colistrains (two enteric isolates and one soil isolate) in sterile and nonsterile drinking water microcosms at 8 and 17°C, withT90(time taken for a reduction in cell number of 1 log10unit) values ranging from 17.4 ± 1.8 to 149 ± 67.7 days, using standard plate counts and a series of (reverse transcription-)quantitative PCR [(RT-)Q-PCR] assays targeting 16S rRNA,tuf,uidA, androdAgenes and transcripts. Furthermore, each strain was capable of attaching to a surface and replicating to form biofilm in the presence of nutrients under a range of shear stress values (0.6, 2.0, and 4.4 dynes [dyn] cm−2; BioFlux system; Fluxion); however, cell numbers did not increase when drinking water flowed over the biofilm (P> 0.05 byttest). Finally,E. coliregrowth within drinking water microcosms containing polyethylene PE-100 pipe wall material was not observed in the biofilm or water phase using a combination of culturing and Q-PCR methods forE. coli. The results of this work highlight that whenE. colienters drinking water it has the potential to survive and attach to surfaces but that regrowth within drinking water or biofilm is unlikely.IMPORTANCEThe provision of clean, safe drinking water is fundamental to society. WDS deliver water to consumers via a vast network of pipes. E. coliis used as an indicator organism for recent contamination events based on the premise that it cannot survive for long outside its host. A key public health concern therefore arises around the fate ofE. colion entering a WDS; its survival, ability to form a biofilm, and potential for regrowth. In particular, ifE. colibacteria have the ability to incorporate and regrow within the pipe wall biofilm of a WDS, they could reinoculate the water at a later stage. This study sheds light on the fate of environmental and enteric strains ofE. coliin drinking water showing extended survival, the potential for biofilm formation under shear stress, and importantly, that regrowth in the presence of an indigenous microbial community is unlikely.

scholarly journals Insulin Regulation of Escherichia coli Abiotic Biofilm Formation: Effect of Nutrients and Growth Conditions

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1349
Author(s):  
Nina Patel ◽  
Jeremy C. Curtis ◽  
Balbina J. Plotkin
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Fold Increase ◽  
Growth Conditions ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
E Coli ◽  
Biofilm Production ◽  
Mueller Hinton ◽  
Static Conditions

Escherichia coli plays an important role in biofilm formation across a wide array of disease and ecological settings. Insulin can function as an adjuvant in the regulation of biofilm levels. The modulation of insulin-regulated biofilm formation by environmental conditions has not been previously described. In the present study, the effects that various environmental growth conditions and nutrients have on insulin-modulated levels of biofilm production were measured. Micropipette tips were incubated with E. coli ATCC® 25922™ in a Mueller Hinton broth (MH), or a yeast nitrogen base with 1% peptone (YNBP), which was supplemented with glucose, lactose, galactose and/or insulin (Humulin®-R). The incubation conditions included a shaking or static culture, at 23 °C or 37 °C. After incubation, the biofilm production was calculated per CFU. At 23 °C, the presence of insulin increased biofilm formation. The amount of biofilm formation was highest in glucose > galactose >> lactose, while the biofilm levels decreased in shaking cultures, except for galactose (3-fold increase; 0.1% galactose and 20 μU insulin). At 37 °C, regardless of condition, there was more biofilm formation/CFU under static conditions in YNBP than in MH, except for the MH containing galactose. E. coli biofilm formation is influenced by aeration, temperature, and insulin concentration in combination with the available sugars.

scholarly journals Bacteriological Quality of Drinking Water in Mardan, Khyber Pakhtunkhwa, Pakistan

2015 ◽  
Vol 21 ◽  
pp. 1-6
Author(s):  
Javid Ali ◽  
Said Hassan ◽  
Dr Ziaurahman ◽  
Inayat Ur Rahman ◽  
Sadhair Abbas ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Fecal Coliforms ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Khyber Pakhtunkhwa ◽  
E Coli ◽  
Micro Organisms

The present study was aimed to isolate and identify micro-organisms load of drinking water of Mardan city, Khyber Pakhtunkhwa Pakistan. A total of 27 samples of drinking water were collected from different locations of the study area. Total Plate Count was determined by pour plate method, while total coliforms, total fecal coliforms and E. coli were determined by multiple tube fermentation method. Of the total collected samples, 17 (62.96%) samples were contaminated with either one or more than one type of microorganisms. The results of most probable number test showed that 13 (48.15%) samples were unsatisfactory. It was concluded that the water should be treated before consumption for drinking purpose. Regular assessment of the water quality is recommended as regular monitoring of the water quality for improvement not only prevents disease and hazards but also checks the water resources from becoming further polluted. ECOPRINT 21: 1-6, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11897

Biofilms and bacteriological water quality in a domestic installation model simulating daily drinking water consumption

2012 ◽  
Vol 12 (6) ◽  
pp. 720-726 ◽  
Author(s):  
Z. G. Tsvetanova ◽  
D. N. Dimitrov
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Temperature ◽  
Water Consumption ◽  
Bacterial Density ◽  
Plate Count ◽  
Hydrodynamic Characteristics ◽  
Pipe Material ◽  
Drinking Water Supply System ◽  
Pipe Materials

The biofilm formation potential of a drinking water supply system is related to the chemical, microbiological and hydrodynamic characteristics of water, and to the pipe materials in contact with water flow. The goals of this study were: to determine the biofilm dynamics in a model of four drinking water installations, to simulate daily household water consumption; to compare the biofilms developed on different polymer pipe materials and their influence on bacteriological water quality. The results demonstrated that bacterial density of biofilms depended on pipe material type and was influenced by water temperature. The biofilms on polyvinylchloride chlorinated and polyethylene materials had higher bacterial density than biofilms on polypropylene (PP) brands. The effect of the materials, and respectively the biofilms, on drinking water quality was stronger in the overnight stagnation periods, especially during the initial weeks of model operation, than in periods of water consumption. Heterotrophic plate count (HPC) in stagnant or in flowing waters and water temperature followed a similar curve pattern, demonstrating significant seasonal variations. In summer, the HPC values of stagnant waters were raised up to seven times higher than in winter and those of the outlet waters (during the consumption periods) were raised up to four times.

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