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Gosselin F, Mathieu L, Block JC, Carteret C, Muhr H, Jorand FPA. Assessment of an anti-scale low-frequency electromagnetic field device on drinking water biofilms. Biofouling 2018; 34:1020-1031. [PMID: 30612474 DOI: 10.1080/08927014.2018.1532998] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 10/01/2018] [Accepted: 10/02/2018] [Indexed: 06/09/2023]
Abstract
Low intensity and very low-frequency electromagnetic fields (EMF) used for preventing scaling in water distribution systems were tested for the first time for their potential impact on drinking water biofilms. The assays were carried out in laboratory-scale flow-through reactors that mimic water distribution systems. The drinking water biofilms were not directly exposed to the core of the EMF generator and only subjected to waterborne electromagnetic waves. The density and chlorine susceptibility of nascent or mature biofilms grown under exposure to EMF were evaluated in soft and hard water. This EMF treatment was able to modify CaCO3 crystallization but it did not significantly affect biofilms. Indeed, over all the tested conditions, there was no significant change in cell number, or in the integrity of the cells (membrane, culturability), and no measurable effect of chlorine on the biofilm.
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Affiliation(s)
- F Gosselin
- a CNRS, LCPME , Université de Lorraine , Nancy , France
| | - L Mathieu
- b LCPME , EPHE, PSL Research University , Nancy , France
| | - J-C Block
- a CNRS, LCPME , Université de Lorraine , Nancy , France
| | - C Carteret
- a CNRS, LCPME , Université de Lorraine , Nancy , France
| | - H Muhr
- c CNRS, LRGP , Université de Lorraine , Nancy , France
| | - F P A Jorand
- a CNRS, LCPME , Université de Lorraine , Nancy , France
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2
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Pelleieux S, Mathieu L, Block JC, Gantzer C, Bertrand I. The effect of chlorination and hydrodynamic shear stress on the persistence of bacteriophages associated with drinking water biofilms. J Appl Microbiol 2016; 121:1189-97. [PMID: 27452787 DOI: 10.1111/jam.13243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 11/30/2022]
Abstract
AIMS This work aimed to assess at pilot scale the effect of chlorination and water flushing on 2-month-old drinking water biofilms and, above all, on biofilm-associated F-specific RNA bacteriophages MS2, GA and Qβ. METHODS AND RESULTS Chlorination (4 mg l(-1) ) was applied first with a hydrodynamic shear stress of 1 Pa and second with an increase in hydrodynamic shear stress to 10 Pa. Despite a rapid decrease in the number of biofilm bacteria and associated phages, infectious phages were still detected on surfaces after completion of the 150 min cleaning procedure. The resulting sequence of phage removal was: GA > Qβ ≫ MS2. CONCLUSIONS The effect of chlorine on biofilm bacteria and biofilm-associated phages was limited to the upper layers of the biofilm and was not enhanced by an increase in hydrodynamic shear stress. A smaller decrease was observed for MS2 than for GA or Qβ after completion of the cleaning procedure. SIGNIFICANCE AND IMPACT OF THE STUDY The differences observed between the three phages suggest that the location of the viral particles in the biofilm, which is related to their surface properties, affects the efficiency of chlorine disinfection.
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Affiliation(s)
- S Pelleieux
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France.,LCPME, UMR 7564, Université de Lorraine, Nancy, France
| | - L Mathieu
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France.,EPHE, UL, CNRS, UMR 7564 LCPME, PSL Research University, Nancy, France
| | - J-C Block
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France.,LCPME, UMR 7564, Université de Lorraine, Nancy, France
| | - C Gantzer
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France.,LCPME, UMR 7564, Université de Lorraine, Nancy, France
| | - I Bertrand
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France. .,LCPME, UMR 7564, Université de Lorraine, Nancy, France.
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Mathieu L, Bertrand I, Abe Y, Angel E, Block JC, Skali-Lami S, Francius G. Drinking water biofilm cohesiveness changes under chlorination or hydrodynamic stress. Water Res 2014; 55:175-184. [PMID: 24607313 DOI: 10.1016/j.watres.2014.01.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 12/28/2013] [Accepted: 01/25/2014] [Indexed: 06/03/2023]
Abstract
Attempts at removal of drinking water biofilms rely on various preventive and curative strategies such as nutrient reduction in drinking water, disinfection or water flushing, which have demonstrated limited efficiency. The main reason for these failures is the cohesiveness of the biofilm driven by the physico-chemical properties of its exopolymeric matrix (EPS). Effective cleaning procedures should break up the matrix and/or change the elastic properties of bacterial biofilms. The aim of this study was to evaluate the change in the cohesive strength of two-month-old drinking water biofilms under increasing hydrodynamic shear stress τw (from ∼0.2 to ∼10 Pa) and shock chlorination (applied concentration at T0: 10 mg Cl2/L; 60 min contact time). Biofilm erosion (cell loss per unit surface area) and cohesiveness (changes in the detachment shear stress and cluster volumes measured by atomic force microscopy (AFM)) were studied. When rapidly increasing the hydrodynamic constraint, biofilm removal was found to be dependent on a dual process of erosion and coalescence of the biofilm clusters. Indeed, 56% of the biofilm cells were removed with, concomitantly, a decrease in the number of the 50-300 μm(3) clusters and an increase in the number of the smaller (i.e., <50 μm(3)) and larger (i.e., >600 μm(3)) ones. Moreover, AFM evidenced the strengthening of the biofilm structure along with the doubling of the number of contact points, NC, per cluster volume unit following the hydrodynamic disturbance. This suggests that the compactness of the biofilm exopolymers increases with hydrodynamic stress. Shock chlorination removed cells (-75%) from the biofilm while reducing the volume of biofilm clusters. Oxidation stress resulted in a decrease in the cohesive strength profile of the remaining drinking water biofilms linked to a reduction in the number of contact points within the biofilm network structure in particular for the largest biofilm cluster volumes (>200 μm(3)). Changes in the cohesive strength of drinking water biofilms subsequent to cleaning/disinfection operations call into question the effectiveness of cleaning-in-place procedures. The combined alternating use of oxidation and shear stress sequences needs to be investigated as it could be an important adjunct to improving biofilm removal/reduction procedures.
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Affiliation(s)
- L Mathieu
- Ecole Pratique des Hautes Etudes (EPHE), LCPME, UMR 7564 CNRS - Université de Lorraine, Nancy, France.
| | - I Bertrand
- CNRS and Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Nancy, France
| | - Y Abe
- CNRS and Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Nancy, France
| | - E Angel
- Ecole Pratique des Hautes Etudes (EPHE), LCPME, UMR 7564 CNRS - Université de Lorraine, Nancy, France
| | - J C Block
- CNRS and Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Nancy, France
| | - S Skali-Lami
- CNRS and Université de Lorraine, Laboratoire d'Energétique et de Mécanique Théorique et Appliquée (LEMTA), UMR 7563, Nancy, France
| | - G Francius
- CNRS and Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Nancy, France
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Gosselin F, Madeira LM, Juhna T, Block JC. Drinking water and biofilm disinfection by Fenton-like reaction. Water Res 2013; 47:5631-5638. [PMID: 23866142 DOI: 10.1016/j.watres.2013.06.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 06/17/2013] [Accepted: 06/19/2013] [Indexed: 06/02/2023]
Abstract
A Fenton-like disinfection process was conducted with Fenton's reagent (H2O2) at pH 3 or 5 on autochthonous drinking water biofilms grown on corroded or non-corroded pipe material. The biofilm disinfection by Fenton-like oxidation was limited by the low content of iron and copper in the biomass grown on non-corroded plumbing. It was slightly improved by spiking the distribution system with some additional iron source (soluble iron II or ferrihydrite particles appeared as interesting candidates). However successful in situ disinfection of biofilms was only achieved in fully corroded cast iron pipes using H2O2 and adjusting the pH to 5. These new results provide additional support for the use of Fenton's processes for cleaning drinking water distribution systems contaminated with biological agents or organics.
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Affiliation(s)
- F Gosselin
- Université de Lorraine and CNRS, LCPME, UMR 7564, 405 rue de Vandoeuvre, 54600 Villers-lès-Nancy, France
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Abstract
AIMS The main objective of our study was to assess the persistence of Mycobacterium avium in an oligotrophic environment such as bottled groundwater. METHODS AND RESULTS Filtered groundwater samples were spiked with washed Myco. avium suspension and stored in dark and under static conditions, at 20 degrees C, for 3 months in 500 ml PET bottles. The loss of Myco. avium cultivability was slow in water. On the contrary, after a 3-month storage at 20 degrees C, growth of attached cells was observed and cell adhesiveness to the PET wall increased with time. It could probably be because of the presence of an extracellular matrix. CONCLUSIONS This study has shown the great stability of Myco. avium in bulk water as well as their adhesiveness and their growth on a PET bottle wall in an oligotrophic environment. SIGNIFICANCE AND IMPACT OF THE STUDY Slowly growing mycobacteria are well adapted to oligotrophic environments such as groundwater. As they stick very well to surfaces, they could be used for determining the efficiency of the cleaning of contaminated surfaces.
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Affiliation(s)
- J-A Tatchou-Nyamsi-König
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564 CNRS, Nancy-Université, Vandoeuvre-lès-Nancy, France
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Mathieu L, Bouteleux C, Fass S, Angel E, Block JC. Reversible shift in the alpha-, beta- and gamma-proteobacteria populations of drinking water biofilms during discontinuous chlorination. Water Res 2009; 43:3375-3386. [PMID: 19539973 DOI: 10.1016/j.watres.2009.05.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 04/29/2009] [Accepted: 05/05/2009] [Indexed: 05/27/2023]
Abstract
As disinfection strategies could support a shift of some bacterial populations, the biodiversity of drinking water biofilms depending on the disinfectant concentrations was explored. The effect of different chlorine sequences applied for several weeks (0.1-0.4-0.1 mg Cl(2)L(-1) or vice versa) was tested on the abundance of the alpha-, beta- and gamma-proteobacteria populations, used as indicators of changes in bacterial populations within drinking water biofilms. Using dynamic (industrial pilot) and batch (bench scale) conditions, our work demonstrated the ability of the 3 proteobacteria subclasses to re-organize following discontinuous chlorinations. The beta- and gamma-proteobacteria subclasses were favoured by high free residual chlorine concentrations (0.4 mg Cl(2)L(-1)) while alpha-proteobacteria population was sensitive to this oxidant level. The proteobacteria population shifts within the biofilm exposed to discontinuous chlorination were reversible. The resilience of the biofilm proteobacteria populations exposed to oxidant stress questioned the emergence of bacterial population less sensitive to chlorine.
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Affiliation(s)
- L Mathieu
- Laboratoire d'hydroclimatologie médicale Environnement et Santé, Ecole Pratique des Hautes Etudes, UMR 7564, CNRS-Nancy Université, 15 avenue du Charmois, F-54500 Vandoeuvre-lès-Nancy, France.
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7
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Tatchou-Nyamsi-König JA, Moreau A, Fédérighi M, Block JC. Behaviour of Campylobacter jejuni in experimentally contaminated bottled natural mineral water. J Appl Microbiol 2008; 103:280-8. [PMID: 17650187 DOI: 10.1111/j.1365-2672.2006.03239.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The main objective of the present study was to estimate the survival of microaerophilic Campylobacter jejuni in filtered natural mineral water at 4 degrees C and 25 degrees C. The influence of the presence of biodegradable organic matter was tested, assuming that the bacterial contamination of a bottled natural mineral water could be associated with contamination by organic matter. METHODS AND RESULTS Washed Campylobacter cultures were inoculated in natural mineral water and sterile natural mineral water, and incubated in the dark at 4 degrees C and 25 degrees C. The effect of temperature, the biodegradable organic matter added, incubation atmosphere and autochthonous microflora were tested on the cultivability of Camp. jejuni. CONCLUSIONS The survival of Camp. jejuni in natural mineral water was better at 4 degrees C than at 25 degrees C, and the presence of organic matter led to a deceleration in the loss of cultivability and to the multiplication of Camp. jejuni in natural mineral water. SIGNIFICANCE AND IMPACT OF THE STUDY This study highlighted the fact that, in the event of dual contamination of a bottled natural mineral water (Campylobacter and biodegradable organic matter), the pathogen could survive (and even grow) for a relatively long time, especially at low temperature and in spite of the presence of oxygen.
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Affiliation(s)
- J-A Tatchou-Nyamsi-König
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), Nancy-University, Vandoeuvre-lès-Nancy, France
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8
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Abstract
Several studies have shown that the staining by fluorochromes (DAPI, SYBR Green II, and TOTO-1) of bacteria is altered by chlorination. To evaluate the effect of chlorine (bleach solution) on propidium iodide (PI) staining, we studied Escherichia coli in suspension and biomolecules in solution (DNA, RNA, BSA, palmitic acid, and dextran) first subjected to chlorine and then neutralized by sodium thiosulphate. The suspensions and solutions were subsequently stained with PI. The fluorescence intensity of the PI-stained DNA and RNA in solution dramatically decreased with an increase in the chlorine concentration applied. These results explain the fact that for chlorine concentrations higher than 3 μmol/L Cl2, the E. coli cells were too damaged to be properly stained by PI. In the case of highly chlorinated bacteria, it was impossible to distinguish healthy cells (with a PI-impermeable membrane and undamaged nucleic acids), which were nonfluorescent after PI staining, from cells severely injured by chlorine (with a PI-permeable membrane and damaged nucleic acids) that were also nonfluorescent, as PI penetrated but did not stain chlorinated nucleic acids. Our results suggest that it would be prudent to be cautious in interpreting the results of PI staining, as PI false-negative cells (cells with compromised membranes but not stained by PI because of nucleic acid damage caused by chlorine) are obtained as a result of nucleic acid damage, leading to an underestimation of truly dead bacteria.
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Affiliation(s)
- M-H Phe
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, LCPME UMR 7564 CNRS - Nancy-Université, 15, avenue du Charmois, 54500 Vandoeuvre-lès-Nancy, France
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9
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Abstract
AIMS The aim of this study was to elucidate if the need for iron for Escherichia coli to remain cultivable in a poorly nutritive medium such as the drinking water uses the iron transport system via the siderophores. METHODS AND RESULTS Environmental strains of E. coli (isolated from a drinking water network), referenced strains of E. coli and mutants deficient in TonB, an essential protein for iron(III) acquisition, were incubated for 3 weeks at 25 degrees C, in sterile drinking water with and without lepidocrocite (gamma-FeOOH), an insoluble iron corrosion product. Only cells with a functional iron transport system were able to survive throughout the weeks. CONCLUSIONS The iron transport system via protein TonB plays an essential role on the survival of E. coli in a weakly nutritive medium like drinking water. SIGNIFICANCE AND IMPACTS OF THE STUDY Iron is a key parameter involved in coliform persistence in drinking water distribution systems.
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Affiliation(s)
- D Grandjean
- Laboratoire de Chimie Physique et Microbiologie Pour l'Environnement (LCPME), rue de Vandoeuvre, Villers-lès-Nancy, France
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10
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Batté M, Féliers C, Servais P, Gauthier V, Joret JC, Block JC. Coliforms and other microbial indicators occurrence in water and biofilm in full-scale distribution systems. Water Sci Technol 2006; 54:41-8. [PMID: 17037131 DOI: 10.2166/wst.2006.446] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Biofilm and microbial water quality were studied in four middle size full-scale distribution systems (DS) in France serving 5,000-30,000 inhabitants (maximum residence time 23-160h) through three sampling campaigns over 1 year. Three of these DSs were chosen because of a quite high occurrence of bacterial indicators (i.e. total coliforms), the last DS was considered as a reference. Biofilm was studied on cast iron coupons incubated for more than 1 month in devices continuously fed with water from the DS in conditions imitating those met in DS. The devices were located at different points (4-6) along each DS. The abundance of bacteria in biofilm was estimated by heterotrophic plate counts (HPC) after detachment of the biofilm from the support by sonication. Microbiological water quality was estimated in parallel; analysis of total coliforms, E. coli, enterococci and anaerobic sulphide-reducing bacteria spores (ASRB spores) was carried out in biofilm and water. Over the period of the study, 171 water samples and 57 biofilm samples were collected. Over these 171 waters, 19 (11%) were positive for at least one of the measured indicators while two biofilm samples were positive (3.5%). Significant differences were observed in the levels of contamination between the DSs. High residence time in the DS, low disinfectant residual and high temperature increased the risk of indicator occurrence in the water phase. Due to the low number of biofilm samples positive for bacterial indicators, the data collected in the present study did not allow observation of a direct association between biofilm and water contaminations, even if the occurrence of indicators in water appeared on DSs with the highest density of biofilm (HPC).
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Affiliation(s)
- M Batté
- LCPME, UMR 7564 CNRS, Université Henri Poincaré Nancy 1, 15 ave. Du Charmois, F-54500, Vandoeuvre-Lès-Nancy, France
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11
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Conrad A, Cadoret A, Corteel P, Leroy P, Block JC. Adsorption/desorption of linear alkylbenzenesulfonate (LAS) and azoproteins by/from activated sludge flocs. Chemosphere 2006; 62:53-60. [PMID: 15950257 DOI: 10.1016/j.chemosphere.2005.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2004] [Revised: 03/22/2005] [Accepted: 04/06/2005] [Indexed: 05/02/2023]
Abstract
Our study investigated the adsorption/desorption by/from activated sludge flocs, dispersed in river water or in diluted wastewater, of organic compounds (C(11)-LAS, azoalbumin and azocasein) at concentrations relevant to environmental conditions. Activated sludge flocs, used as a model of biological aggregates, are characterized by a very heterogeneous matrix able to sorb the three organic compounds tested at 4 degrees C. The adsorbed amount of C(11)-LAS by activated sludge flocs was higher than that of azocasein or azoalbumin, as shown by the Freundlich parameters (K(ads)=8.6+/-1.7, 1.6+/-0.3 and 0.3+/-0.1 micromol(1-1/n)g(-1)l(1/n) for C(11)-LAS, azocasein and azoalbumin, respectively; n=3 sludges). C(11)-LAS sorption from activated sludge appeared to be partially reversible in river water, while a marked hysteresis phenomenon was observed for azocasein and azoalbumin, implying a low degree of reversibility in their exchange between activated sludge and river water. It has also been displayed that the conductivity variation of bulk water (comprised between 214 and 838 microS cm(-1)) exerted no dramatic effect on the C(11)-LAS desorption from activated sludge flocs, while a little effect of it on azocasein desorption was observed. Thus, biological aggregates as activated sludge flocs can serve as an intermediate carrier for C(11)-LAS, while it represents a sink for proteins.
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Affiliation(s)
- A Conrad
- LCPME, UMR 7564 CNRS-Université Henri Poincaré Nancy 1, Faculté de Pharmacie, Pôle de l'Eau, 15 avenue du Charmois, 54500 Vandoeuvre-lès-Nancy, France
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Dziurla MA, Salhi M, Leroy P, Paul E, Ginestet P, Block JC. Variations of respiratory activity and glutathione in activated sludges exposed to low ozone doses. Water Res 2005; 39:2591-8. [PMID: 15972223 DOI: 10.1016/j.watres.2005.04.049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2004] [Revised: 02/11/2005] [Accepted: 04/24/2005] [Indexed: 05/03/2023]
Abstract
Ozonation is one of the most effective treatments for reducing the production of activated sludges in wastewater treatment plants. However, because microorganisms are present in the form of microcolonies, some bacteria may be exposed to sub-lethal ozone doses that could lead to adaptation and resistance to further exposition to oxidative treatment. This represents a major question as it may limit the effect of the treatment, especially when low ozone doses are applied. The critical ozone dosage, defined as the lowest specific transferred ozone concentration leading to a decrease in the maximum oxygen uptake rate was estimated to range between 0.9 and 13.6mg O(3)g(-1) COD(sludges), according to the sludges tested. The lowest ozone dosage leading to the decrease of GSH and GSHt concentrations could be estimated to be lower than 10mg O(3)g(-1) COD(sludges) for GSH, and close to 10mg O(3)g(-1) COD(sludges) for GSHt. After sludge exposure to low ozone doses, no higher amounts of glutathione were synthesized, suggesting that no development of resistance to ozonation occurred after sludge treatment with low ozone doses.
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Affiliation(s)
- M A Dziurla
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement-LCPME, Unité Mixte de Recherche, UMR 7564 CNRS-Université Henri Poincaré Nancy 1, Pôle de l'eau, 15, avenue du Charmois, 54500 Vandoeuvre-lès-Nancy, France
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13
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Grandjean D, Fass S, Tozza D, Cavard J, Lahoussine V, Saby S, Guilloteau H, Block JC. Coliform culturability in over- versus undersaturated drinking waters. Water Res 2005; 39:1878-86. [PMID: 15899286 DOI: 10.1016/j.watres.2005.03.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Revised: 02/25/2005] [Indexed: 05/02/2023]
Abstract
The culturability of Escherichia coli in undersaturated drinking water with respect to CaCO3 (corrosive water) or in oversaturated water (non-corrosive water) was tested in different reactors: glass flasks (batch, "non-reactive" wall); glass reactors (chemostat, "non-reactive" wall) versus a corroded cast iron Propella reactor (chemostat, "reactive" wall) and a 15-year-old distribution system pilot (chemostat, "reactive" wall with 1% corroded cast iron and 99% cement-lined cast iron). The E. coli in E. coli-spiked drinking water was not able to maintain its culturability and colonize the experimental systems. It appears from our results that the optimal pH for maintaining E. coli culturability was around 8.2 or higher. However, in reactors with a reactive wall (corroded cast iron), the decline in E. coli culturability was slower when the pH was adjusted to 7.9 or 7.7 (i.e. a reactor fed with corrosive water; pH<pHs) than in non-corrosive water (pH 8.64 or 8.24; pH>pHs). We tentatively deduce that corrosion products coming from chemical reactions driven by corrosive waters on the pipe wall improve E. coli culturability.
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Affiliation(s)
- D Grandjean
- LCPME, UMR 7564 CNRS-UHP, Faculté de Pharmacie, Pôle de l'Eau, 15 avenue du Charmois, 54500 Vandoeuvre-lès-Nancy, France
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14
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Grandjean D, Jorand F, Yañez C, Appenzeller BMR, Block JC. Influence of lepidocrocite (gamma-FeOOH) on Escherichia coli cultivability in drinking water. Environ Technol 2005; 26:211-217. [PMID: 15791802 DOI: 10.1080/09593332608618577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A washed suspension of the bacteria Escherichia coli, pre-grown on a complex culture medium, was stored in sterilized drinking water for 21 days at 25 degrees C in glass flasks in order to assess the effect of iron corrosion products on the persistenceof the bacteria in drinking water. Four conditions were tested: aerobic with 50 mM lepidocrocite (gamma-FeOOH, an insoluble iron corrosion product), anaerobic with 50 mM lepidocrocite, aerobic without lepidocrocite and anaerobic without lepidocrocite. The survival of E. coli was monitored by their cultivability and their membrane integrity (propidium iodide staining). When the samples were not supplemented with the iron oxide, the cultivability and cell integrity of the bacteria were dramatically altered: from the 10(7) initially added, only 10 CFU ml(-1) remained after 21 days; 90% of the cells exhibited membrane alteration after 2 weeks of storage. In contrast, bacteria with lepidocrocite preserved their cultivability and integrity over the 21 days of storage. In the presence of di-oxygen and without iron oxide, the alteration of cell cultivability was more pronounced than that in anaerobic conditions, suggesting that oxidative stress was part of the phenomenon. When the cells were pre-grown in a growth medium supplemented by a large excess of an easily available form of iron (ferric-citrate), the cells stored a higher amount of iron and persisted one week longer in the iron-free drinking water than cells pre-grown in the standard growth medium. Therefore, in an oligotrophic environment like drinking water, E. coli cells can find the ability to survive a long time through the presence of iron corrosion products. The necessity of controlling the corrosiveness of drinking water for sanitary reasons is therefore emphasized by this study.
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Affiliation(s)
- D Grandjean
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564 CNRS-UHP, Faculté de Pharmacie - Extension Pô le de l'Eau, 15, avenue du Charmois, 54500 Vandoeuvre-lè s-Nancy, France
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15
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Phe MH, Dossot M, Block JC. Chlorination effect on the fluorescence of nucleic acid staining dyes. Water Res 2004; 38:3729-3737. [PMID: 15350425 DOI: 10.1016/j.watres.2004.05.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2003] [Revised: 03/24/2004] [Accepted: 05/28/2004] [Indexed: 05/24/2023]
Abstract
An alternative to culture methods for the control of drinking water disinfection would use fluorescent dyes that could evidence the nucleic acid damages provoked by sodium hypochlorite treatment. The two dyes selected in this study, SYBR Green II RNA gel stain and TOTO-1 iodide, efficiently stain nucleic acids (DNA and RNA) and quite poorly the other biomolecules considered (Bovine serum albumin, palmitic acid and dextrane). After treatment of nucleic acid solutions with increasing amounts of sodium hypochlorite, a decrease of fluorescence intensity is observed for both DNA and RNA stained with either SYBR-II or TOTO-1. However, the two fluorochromes do not lead to the same results, which shows that the two dyes are not bound to nucleic acids in the same way. Contrary to TOTO-1, SYBR-II reveals to be sufficiently sensitive to indicate both DNA or RNA damages as soon as the latter are in contact with hypochlorite even at concentrations of HClO lower than 10 micromol/L. Moreover, SYBR-II offers the opportunity to make quantitative titration of chlorine treated DNA and therefore seems to be the appropriate candidate to control the efficiency of the hypochlorite disinfection process of drinking water samples.
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Affiliation(s)
- M H Phe
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME) UMR 7564 CNRS, Université Henri Poincaré, Pôle de l'Eau-15, avenue du Charmois, F-54500 Vandoeuvre-lès-Nancy, France
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16
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Dziurla MA, Leroy P, Strünkmann GW, Salhi M, Lee DU, Camacho P, Heinz V, Müller JA, Paul E, Ginestet P, Audic JM, Block JC. Measurement of glutathione in activated sludges. Water Res 2004; 38:236-244. [PMID: 14630122 DOI: 10.1016/j.watres.2003.08.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Thermal, electric, mechanical or oxidative stress seem a promising way to reduce the production of excess activated sludge during biological wastewater treatment. However, the adaptation and the resistance of the sludge microbial ecosystem to stress conditions is a major question as it may definitively limit the effect of some treatments. Defence mechanisms developed by aerobic organisms, in particular, in response to oxidative stress involve various antioxidant activities and compounds such as glutathione. An HPLC method was developed for measuring reduced and total glutathione (GSH and GSHt) in perchloric acid sludge extracts. The method was sensitive, highly specific and validated for linearity, precision and recovery. Considering the extraction yield and the oxidation of GSH during extract storage, the measured GSH concentration was estimated to represent 60% of the GSH content from activated sludges. GSHt ranged from 0.32 to 3.34micromolg(-1) volatile solids and the GSH/GSHt ratio ranged from 32% to 91%. Measurements performed on sludges stressed in precise conditions selected to reach a reduction of sludge production showed a decrease of GSH and GSHt concentrations with thermal, mechanical, electric and ozone stress.
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Affiliation(s)
- M A Dziurla
- Laboratoire de Chimie, Physique et Microbiologie pour l'Environnement-LCPME, Unité Mixte de Recherche-UMR 7564, CNRS-Université Henri Poincaré, Nancy 1, Faculté de Pharmacie-Pôle de l'eau, 15, avenue du Charmois, 54500 Vandoeurve-les-Nancy, France
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17
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Fass S, Block JC, Boualam M, Gauthier V, Gatel D, Cavard J, Benabdallah S, Lahoussine V. Release of organic matter in a discontinuously chlorinated drinking water network. Water Res 2003; 37:493-500. [PMID: 12688683 DOI: 10.1016/s0043-1354(02)00362-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The effects of discontinuous chlorination on the characteristics of the water in a pilot drinking water distribution network were investigated. The release or consumption of organic matter (as dissolved organic carbon, DOC) following chlorination and non-chlorination periods were estimated, as were changes in bacterial cell production. In each unchlorinated network 0.3 mg DOCl(-1) was consumed and the average cell production was approximately 1.3 x 10(5) cells ml(-1). In discontinously chlorinated networks (chlorine treatment: 3.3 mg Cl2l(-1), chlorine residual: 0.1 mg Cl2l(-1)) the DOC release (DOCout-DOCin) was between 0.1 and 0.2 mg Cl(-1). Biomass production (cells(out)-cells(in)) during this chlorination period was lower (approximately 2 x 10(4) cells ml(-1)). The delay before DOC was released in chlorinated networks appeared to be less than 24 h, which corresponds to one hydraulic residence time. Likewise, when chlorination was stopped, 24 h or less were required before an efficient DOC removal was resumed. When chlorination was prolonged the observed release of DOC was progressively reduced from 0.2 mg l(-1) to zero, thus after 6 weeks of continuous chlorination the DOCin was equivalent to the DOCout.
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Affiliation(s)
- S Fass
- NANCIE, 149 rue Gabriel Péri, BP 290, F-54515 Vandaeuvre-lès-Nancy, France
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18
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Martín-Cereceda M, Jorand F, Guinea A, Block JC. Characterization of extracellular polymeric substances in rotating biological contractors and activated sludge flocs. Environ Technol 2001; 22:951-959. [PMID: 11561952 DOI: 10.1080/09593332208618231] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Extracellular polymeric substances (EPS) from biofilms of a rotating biological contactor (RBC) system and from activated sludge flocs were extracted using ultrasound and a cation exchange resin. In both wastewater treatment systems, the EPS matrix was mainly constituted of proteins, humic-like substances and polysaccharides, although other components--DNA and uronic-like substances--were also present. The composition of the biofilm EPS was different in the succesive RBC wastewater treatment stages: protein had its highest concentration in the first RBC unit, while humic substances and polysaccharides in the third RBC. Significant differences between biofilm and sludge floc EPS were also reported. The amount of proteins was 3.5 times higher for RBC biofilms than for sludge flocs, and quantities of humic substances and polysaccharides extracted from biofilms were twice as high than in sludges. Moreover, biofilm exopolymers were two times more hydrophobic than those of sludge flocs. Implications of wastewater chemistry and microbial growth strategies into EPS composition and properties are suggested.
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Affiliation(s)
- M Martín-Cereceda
- Departamento de Microbiología III. Facultad de Biología, Universidad Complutense de Madrid, Spain
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19
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Block JC. Comments on "Development of an improved synthetic sludge: a possible surrogate for studying activated sludge dewatering characteristics". Banu Ormeci and P. Aarne Vesilind (2000) Wat. Res. 34, 1069-1078. Water Res 2001; 35:1363-1366. [PMID: 11268860 DOI: 10.1016/s0043-1354(00)00383-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- J C Block
- LCPE-UMR University of Nancy-CNRS 7564, 54000 Nancy, France
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20
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Appenzeller BM, Batté M, Mathieu L, Block JC, Lahoussine V, Cavard J, Gatel D. Effect of adding phosphate to drinking water on bacterial growth in slightly and highly corroded pipes. Water Res 2001; 35:1100-1105. [PMID: 11235877 DOI: 10.1016/s0043-1354(00)00337-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effect of phosphate addition in drinking water was tested under static conditions as batch tests and under dynamic conditions using continuously fed reactors. Phosphate supplements in batch tests from 0.1 to 2 mg P-PO4 L(-1) did not show any relationship between bacterial growth and phosphate concentration. Dynamic tests in slightly corroded reactor (stainless steel) treated at 1 mg P-PO4 L(-1) showed only a moderate improvement in the growth of microorganisms. On the contrary, phosphate treatment applied to the highly corroded reactor (unlined cast iron) led to an immediate, drastic drop in iron oxide release and bacterial production. Phosphate uptake by the reactor wall was less than 14% with the stainless-steel reactor and 70-90% with the corroded cast iron reactor. Moreover, about 5% of the phosphate associated to corroded iron pipe walls was released for 20 days after the end of treatment.
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Affiliation(s)
- B M Appenzeller
- LCPE, UMR Université-CNRS 7564, Faculté de Pharmacie, P le de l'eau, Vandoeuvre, France
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21
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Abstract
The organic matter of wastewater was fractionated into settleable (i.e., particulate) and non-settleable (i.e., colloidal + soluble) fractions by settling followed by 0.22 micron filtration. Particulate, colloidal and soluble proportions were found to be relatively constant (45, 31 and 24% of the total COD, respectively). Transfer of soluble fraction always occurred from the wastewater to the activated sludge flocs, whereas bidirectional transfer occurred for the colloidal fraction. The transfer of soluble and colloidal matter reached a steady state after 40 min-mixing and 20 min-mixing, respectively. Desorption of a part of the colloidal organic matter pre-sorbed on the activated sludge flocs was evidenced. The biosorption capacity of activated sludge was around 40-100 mgCODg-1TSS. The biosorbable fraction of wastewater represented on average 45% of the non-settleable fraction.
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Affiliation(s)
- A Guellil
- LCPE, UMR Université Henri Poincaré-CNRS 7564, 15 avenue du Charmois, 54500, Vandoeuvre les Nancy, France
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22
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Guellil A, Boualam M, Quiquampoix H, Ginestet P, Audic JM, Block JC. Hydrolysis of wastewater colloidal organic matter by extracellular enzymes extracted from activated sludge flocs. Water Sci Technol 2001; 43:33-40. [PMID: 11381970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Enzymatic activities associated with the exopolymeric substances (EPSs) extracted from activated sludges were tested for their ability to hydrolyse the organic colloidal fraction of wastewater. Bacteria extracted with EPS and concentrated by wastewater microfiltration were inhibited with NaN3 or KCN. The protein hydrolysis mainly resulted from the enzymatic activity of EPS, whereas the glycolytic activity was mainly present in the organic colloidal fraction of the wastewater.
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Affiliation(s)
- A Guellil
- LSE/LCPE, UMR 7564 Université Henri Poincaré-CNRS, 15 avenue du Charmois, F-54500 Vandoeuvrelès-Nancy, France
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23
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Abstract
Bacteria isolated from biofilms of water distribution pipes and colonized catheters from hospitalized patients were studied for their haemagglutination ability, expression of lectins and hydrophobicity. Higher haemagglutination ability of clinical strains for human red blood cells was demonstrated, which could be an expression of their adaptation to the human ecosystem. Environmental strains had higher hydrophobicity, possibly related to adaptation to a low nutritive ecosystem. Expression of lectins was relatively low and comparable in both bacterial populations, but carbohydrate specificities were very different, possibly related to a different implication of these structures in the two ecosystems.
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Affiliation(s)
- J C Fiorina
- LCPE-UMR, Faculté de Pharmacie-Pôle de l'Eau, Vandoeuvre, France
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24
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Saby S, Leroy P, Block JC. Escherichia coli resistance to chlorine and glutathione synthesis in response to oxygenation and starvation. Appl Environ Microbiol 1999; 65:5600-3. [PMID: 10584025 PMCID: PMC91765 DOI: 10.1128/aem.65.12.5600-5603.1999] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/1999] [Accepted: 09/13/1999] [Indexed: 11/20/2022] Open
Abstract
Reduced glutathione (GSH) levels and resistance to chlorine were measured for two isogenic Escherichia coli strains stressed by oxygenation and/or starvation. The E. coli mutant deficient in GSH was not more sensitive to the oxidant than its parent strain when the bacteria were cultured with a low oxygenation rate. Starvation or oxygenation increased the resistance of the parent strain to chlorine, while the resistance of the deficient strain remained unchanged.
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Affiliation(s)
- S Saby
- LCPE-LSE, UMR Université CNRS 7564, France
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25
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Abstract
Bacteria in drinking water, attached or not attached to goethite particles, were disinfected with chlorine. No additional protection was provided to the bacteria by their attachment to particles, and the limited efficiency of inactivation by chlorine was attributed to the presence of bacterial aggregates in both types of suspension.
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Affiliation(s)
- V Gauthier
- Laboratoire Santé-Environnement, LCPE, UMR Université-CNRS, 54000 Nancy, France
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26
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Sibille I, Sime-Ngando T, Mathieu L, Block JC. Protozoan bacterivory and Escherichia coli survival in drinking water distribution systems. Appl Environ Microbiol 1998; 64:197-202. [PMID: 9435076 PMCID: PMC124693 DOI: 10.1128/aem.64.1.197-202.1998] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The development of bacterial communities in drinking water distribution systems leads to a food chain which supports the growth of macroorganisms incompatible with water quality requirements and esthetics. Nevertheless, very few studies have examined the microbial communities in drinking water distribution systems and their trophic relationships. This study was done to quantify the microbial communities (especially bacteria and protozoa) and obtain direct and indirect proof of protozoan feeding on bacteria in two distribution networks, one of GAC water (i.e., water filtered on granular activated carbon) and the other of nanofiltered water. The nanofiltered water-supplied network contained no organisms larger than bacteria, either in the water phase (on average, 5 x 10(7) bacterial cells liter-1) or in the biofilm (on average, 7 x 10(6) bacterial cells cm-2). No protozoa were detected in the whole nanofiltered water-supplied network (water plus biofilm). In contrast, the GAC water-supplied network contained bacteria (on average, 3 x 10(8) cells liter-1 in water and 4 x 10(7) cells cm-2 in biofilm) and protozoa (on average, 10(5) cells liter-1 in water and 10(3) cells cm-2 in biofilm). The water contained mostly flagellates (93%), ciliates (1.8%), thecamoebae (1.6%), and naked amoebae (1.1%). The biofilm had only ciliates (52%) and thecamoebae (48%). Only the ciliates at the solid-liquid interface of the GAC water-supplied network had a measurable grazing activity in laboratory test (estimated at 2 bacteria per ciliate per h). Protozoan ingestion of bacteria was indirectly shown by adding Escherichia coli to the experimental distribution systems. Unexpectedly, E. coli was lost from the GAC water-supplied network more rapidly than from the nanofiltered water-supplied network, perhaps because of the grazing activity of protozoa in GAC water but not in nanofiltered water. Thus, the GAC water-supplied network contained a functional ecosystem with well-established and structured microbial communities, while the nanofiltered water-supplied system did not. The presence of protozoa in drinking water distribution systems must not be neglected because these populations may regulate the autochthonous and allochthonous bacterial populations.
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Affiliation(s)
- I Sibille
- Laboratoire d'Hygiène et de Recherche en Santé Publique, GIP Stelor Vandoeuvre-Lès-Nancy, France
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27
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Lebaron P, Bauda P, Lett MC, Duval-Iflah Y, Simonet P, Jacq E, Frank N, Roux B, Baleux B, Faurie G, Hubert JC, Normand P, Prieur D, Schmitt S, Block JC. Recombinant plasmid mobilization between E. coli strains in seven sterile microcosms. Can J Microbiol 1997; 43:534-40. [PMID: 9226873 DOI: 10.1139/m97-076] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Transfer by mobilization of a pBR derivative recombinant plasmid lacking transfer functions (oriT+, tra-, mob-) from one E. coli K12 strain to another was investigated in seven sterile microcosms corresponding to different environments. These microcosms were chosen as representative of environments that genetically engineered microorganisms (GEMOs) encounter after accidental release, namely attached biomass in aquatic environments (biofilm), soil, seawater, freshwater, wastewater, mouse gut, and mussel gut, GEMOs survived in the same way as the host strains in all microcosms. Recombinant DNA mobilization occurred in the mouse gut, in sterile soil, and in biofilm. The plasmid transfer rates principally reflected the environmental conditions encountered in each microcosm.
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Affiliation(s)
- P Lebaron
- Observatoire océanologique, Unité de recherche associée, Centre national de la recherche scientifique 2071, Banyuls-sur-mer, France.
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28
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Saby S, Sibille I, Mathieu L, Paquin JL, Block JC. Influence of water chlorination on the counting of bacteria with DAPI (4',6-diamidino-2-phenylindole). Appl Environ Microbiol 1997; 63:1564-9. [PMID: 9097452 PMCID: PMC168449 DOI: 10.1128/aem.63.4.1564-1569.1997] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Counting bacteria in drinking water samples by the epifluorescence technique after 4',6-diamidino-2-phenylindole (DAPI) staining is complicated by the fact that bacterial fluorescence varies with exposure of the cells to sodium hypochlorite. An Escherichia coli laboratory-grown suspension treated with sodium hypochlorite (5 to 15 mg of chlorine liter-1) for 90 min was highly fluorescent after DAPI staining probably due to cell membrane permeation and better and DAPI diffusion. At chlorine concentrations greater than 25 mg liter-1, DAPI-stained bacteria had only a low fluorescence. Stronger chlorine doses altered the DNA structure, preventing the DAPI from complexing with the DNA. When calf thymus DNA was exposed to sodium hypochlorite (from 15 to 50 mg of chlorine liter-1 for 90 min), the DNA lost the ability to complex with DAPI. Exposure to monochloramine did not have a similar effect. Treatment of drinking water with sodium hypochlorite (about 0.5 mg of chlorine liter-1) caused a significant increase in the percentage of poorly fluorescent bacteria, from 5% in unchlorinated waters (40 samples), to 35 to 39% in chlorinated waters (40 samples). The presence of the poorly fluorescent bacteria could explain the underestimation of the real number of bacteria after DAPI staining. Microscopic counting of both poorly and highly fluorescent bacteria is essential under these conditions to obtain the total number of bacteria. A similar effect of chlorination on acridine orange-stained bacteria was observed in treated drinking waters. The presence of the poorly fluorescent bacteria after DAPI staining could be interpreted as a sign of dead cells.
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Affiliation(s)
- S Saby
- GIP Stelor/Laboratoire d'Hygiène et de Recherche en Santé Publique, Vandoeuvre les Nancy, France
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29
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Osswald P, Baveye P, Block JC. Bacterial influence on partitioning rate during the biodegradation of styrene in a biphasic aqueous-organic system. Biodegradation 1996; 7:297-302. [PMID: 8987888 DOI: 10.1007/bf00115743] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The degradation by a consortium of slightly-halophile marine bacteria of styrene initially dissolved in silicone oil was monitored in batch reactors stirred at 75, 125 and 500 rpm, respectively. In the 75 and 125 rpm cases, the styrene biodegradation rate was higher than the rate of spontaneous partitioning of styrene from the oil to the water, determined under abiotic conditions. Abiotic transfer tests carried out after biodegradation runs revealed that bacterial activity had resulted in a significant increase in the rate of styrene partitioning between the two liquid phases. Even though bacterial adsorption was noticeable at the oil-water interface, this effect appeared to be due to the release by the bacteria of chemicals in the aqueous phase. Similarity with observations made with Triton X-100 suggested that the chemicals released may have been biosurfactants or solubilizing agents.
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Affiliation(s)
- P Osswald
- Laboratoire Santé Environnement, Faculté des Sciences Pharmaceutiques et Biologiques, Université Henri Poincaré, Nancy, France
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30
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Abstract
Reducing the time for biodegradability tests to 28 days poses a problem when the inoculum contains few biodegraders, as a biodegradable xenobiotic must give a positive result within this time. The influence of initial concentration (X0, number of cells liter-1) on the lag time (hours) of para-nitrophenol biodegradability tests was examined using different concentrations of adapted Pseudomonas putida with para-nitrophenol as the sole carbon and energy source. Lag time decreased as bacterial density increased according to the expression y = 63.5 - 5.7(log10X0). The addition of river water to the P. putida concentrations shortened the lag time-bacterial density relationship and lag time filled the expression y = 52.4 - 5.1(log10X0). The addition of river water also increased the rate of para-nitrophenol biodegradation from 1.29 mgC (liters x hr)-1 to 2.11 mgC (liters x hr)-1. An examination of the effect of the initial adapted P. putida density, expressed as total cell, cultivable bacteria, or biodegraders, was also made on the para-nitrophenol biodegradability test outcome. The model-related cell density and the probability of test response give very similar k constants (kT = 0.56 x 10(-3) liter total cells-1; kv = 0.11 x 10(-3) liter CFU-1, kMPN = 0.16 x 10(-3) liter MPN-1). Comparisons with nonadapted natural mixed culture (activated sludge, river water) indicate that the biodegradability test responses were the same as with adapted cells when the nonadapted cell concentrations were at least 5 x 10(10) total cells liter-1. As this high cell concentration led to carbon contamination, adapting mixed inocula before the test to increase the number of biodegraders appears to be the best solution. Before biodegradability tests, cell density can be adjusted using techniques which are not specific to biodegraders, and only 10(5) total adapted cells liter-1 are needed for a 99.9% chance of a positive response in para-nitrophenol biodegradability tests.
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Affiliation(s)
- G Thouand
- Laboratoire Santé et Environnement, Faculté des Sciences Pharmaceutiques et Biologiques, Nancy, France
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31
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Osswald P, Courtes R, Bauda P, Block JC, Bryers JD, Sunde E. Xenobiotic biodegradation test using attached bacteria in synthetic seawater. Ecotoxicol Environ Saf 1995; 31:211-217. [PMID: 7498058 DOI: 10.1006/eesa.1995.1065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The aerobic biodegradability of aniline, used as reference chemical, has been performed in synthetic seawater with attached biomass in a continuously fed reactor (biofilm chemostat reactor, BCR). Marine bacteria inocula came from local marine fish aquarium filters to limit the geographic and seasonal variations in quality. A pretreatment of these inocula combining 5-microns filtration and centrifugation was used to concentrate bacteria and remove organic carbon contamination of the test. The performances of the BCR were tested in comparison with simple shake flask tests. Among the different variables tested, the ratio S0/X0 (initial concentration of xenobiotic to initial density of the inoculum), the presence of dissolved oxygen, and the hydraulic residence time appear to be the key parameters controlling the length of the biodegradation process. On the other hand, the addition of a cosubstrate (easily biodegradable compound) does not provide advantages. Thus, marine biofilm chemostat reactors with a high density of attached bacteria (around 10(7) cells cm-2) and fed with synthetic seawater plus nitrogen provide good tools for screening biodegradability of chemicals in the marine environment.
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Affiliation(s)
- P Osswald
- Laboratoire Santé Environnement, Faculté de Pharmacie, Nancy, France
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32
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Thouand G, Friant P, Bois F, Cartier A, Maul A, Block JC. Bacterial inoculum density and probability of para-nitrophenol biodegradability test response. Ecotoxicol Environ Saf 1995; 30:274-282. [PMID: 7541341 DOI: 10.1006/eesa.1995.1031] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
This study has been carried out to establish a model linking probability of positive response in para-nitrophenol biodegradability test to controlled variables of the test (suspended solids, SS; total bacteria, AODC; cultivable bacteria, CFU; specific biodegraders, MPN). Series of dilution of 11 raw inocula (6 activated sludges, 5 river waters) were tested. They reveal very dispersed values of biomass measured as SS, AODC, and CFU and quite comparable values of specific biodegraders for each category of inoculum (river or sludge). The proposed model fits well the empirical distribution of the experimental frequency of positive results versus inoculum density for each controlled variable. The constants k of the model, representing the fraction of biodegraders for each inoculum, were tested by the likelihood ratio test and were proven to be different from one another according to the biomass descriptor and the origin of the inoculum. The probabilistic model, in the case of para-nitrophenol biodegradation, indicates that standardized official tests (closed bottle, AFNOR, Sturm, and MITI I) are seldom optimal under those conditions. It allows the determination of which inoculum concentration can lead to a high probability (e.g., 99.9%) of observing paranitrophenol biodegradation by raw inocula.
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Affiliation(s)
- G Thouand
- Laboratoire Santé et Environnement, Faculté des Sciences Pharmaceutiques et Biologiques, Nancy, France
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33
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Schellhas KP, Wilkes CH, Omlie MR, Peterson CM, Johnson SD, Keck RJ, Block JC, Fritts HM, Heithoff KB. The diagnosis of temporomandibular joint disease: two-compartment arthrography and MR. AJR Am J Roentgenol 1988; 151:341-50. [PMID: 3260725 DOI: 10.2214/ajr.151.2.341] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The reliability and accuracy of two-compartment temporomandibular joint (TMJ) arthrography was compared with MR imaging on the basis of an analysis of surgical findings obtained from joints that had been studied preoperatively with arthrography or MR or, in some cases, both procedures. Seven hundred forty-three consecutive TMJ arthrograms were successfully obtained in a total of 443 patients by using a single 27-gauge needle and a two-compartment technique in each joint. There was a 100% correlation with surgical findings in 218 radiologically abnormal joints operated on within 90 days of arthrography with respect to the presence or degree of meniscus displacement and normal or abnormal disk morphology and function. In 604 patients 1052 TMJs were studied with high-field-strength surface-coil MR. Surgical findings were available for correlation in 170 of the joints studied. Forty-three joints were studied with both two-compartment arthrography and MR. Eight operated joints had been imaged successfully with both two-compartment arthrography and MR. Both methods of evaluation provided highly reliable and accurate information regarding meniscus position and shape. Arthrography was superior to MR in detecting capsular adhesions and the presence or absence of perforation of the disk or meniscus attachments. Simple meniscectomy (with or without insertion of a temporary Silastic TMJ implant) was the most frequently performed surgical procedure in the series, followed by meniscus repositioning procedures. Joint effusions, failed TMJ implants, and avascular necrosis were demonstrated best with MR. Soft-tissue lesions, including intrinsic degeneration of the meniscus, anomalous muscle development, muscle atrophy, tendinitis, and injuries such as contusions and hematomas, were demonstrated only with MR. Partial-flip-angle GRASS (gradient-recalled acquisition in the steady state) techniques permit both fast scanning and study of functional joint dynamic. Joint fluid may appear as high signal intensity on GRASS images because of T2*-weighting. We recommend MR as the procedure of choice for diagnosis of uncomplicated internal derangements of the TMJ. Two-compartment arthrography with videofluoroscopy is an important ancillary procedure that should be performed whenever capsular adhesions or perforations are suspected and not demonstrated with MR and whenever MR is inconclusive.
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Affiliation(s)
- K P Schellhas
- Center for Diagnostic Imaging, St. Louis Park, MN 55416
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Schellhas KP, Wilkes CH, Omlie MR, Block JC, Larsen JW, Idelkope BI. Temporomandibular joint imaging. Practical application of available technology. Arch Otolaryngol Head Neck Surg 1987; 113:744-8. [PMID: 3580155 DOI: 10.1001/archotol.1987.01860070058016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Clinical afflictions of the temporomandibular joint (TMJ) are common, but TMJ afflictions remain one of the most poorly understood and controversial areas of clinical practice. Theories of TMJ pathophysiology, diagnosis, treatment, and patient disposition abound. Many afflicted patients have undergone expensive, protracted, and fruitless therapeutic endeavors, many of which are without scientific basis, causing many health insurers to exclude evaluation and treatment of TMJ disorders from coverage. Medical imaging has a central role in establishing a correct diagnosis. Available imaging procedures include roentgenography, arthrography, videofluoroscopy, magnetic resonance imaging, and computed tomography.
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Schellhas KP, Wilkes CH, Heithoff KB, Omlie MR, Block JC. Temporomandibular joint: diagnosis of internal derangements using magnetic resonance imaging. Minn Med 1986; 69:516-9. [PMID: 3762516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Abstract
A study has been carried out on the Moselle River by means of a microtechnique based on the most-probable-number method for fecal coliform enumeration. This microtechnique, in which each serial dilution of a sample is inoculated into all 96 wells of a microplate, was compared with the standard membrane filter method. It showed a marked overestimation of about 14% due, probably, to the lack of absolute specificity of the method. The high precision of the microtechnique (13%, in terms of the coefficient of variation for log most probable number) and its relative independence from the influence of bacterial density allowed the use of analysis of variance to investigate the effects of spatial and temporal bacterial heterogeneity on the estimation of coliforms. Variability among replicate samples, subsamples, handling, and analytical errors were considered as the major sources of variation in bacterial titration. Variances associated with individual components of the sampling procedure were isolated, and optimal replications of each step were determined. Temporal variation was shown to be more influential than the other three components (most probable number, subsample, sample to sample), which were approximately equal in effect. However, the incidence of sample-to-sample variability (16%, in terms of the coefficient of variation for log most probable number) caused by spatial heterogeneity of bacterial populations in the Moselle River is shown and emphasized. Consequently, we recommend that replicate samples be taken on each occasion when conducting a sampling program for a stream pollution survey.
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Abstract
A study of pollutant flows was carried out at a wastewater treatment plant in Nancy, France, which used activated-sludge treatment. To carry out observation of hourly flow variation, a sampling strategy needs to be defined. A comparison between two methods of sampling was conducted: dip samples every 2 h over a period of 24 h and one 24-h composite sample were taken from raw and treated wastewater and then analyzed for enteroviruses, fecal coliforms, chemical oxygen demand, biochemical oxygen demand, and suspended solids. The results showed that the hourly variations of these pollutants in the effluents are in good agreement with expectations based upon the customers' usage and the characteristics of the wastewater network. Significant correlations were found between all tested parameters and enteroviruses in raw wastewater. After biological treatment, no correlation remained in treated wastewater between viruses and other parameters. As for the two sampling methods, a rather good representation of the daily load was given by the composite mode of sampling as concerns physicochemical and microbiological parameters. Biological treatment removed an average of 83% of viruses.
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Schwartzbrod J, Block JC, Collomb J. Surface water Salmonellae: serotypes and antibiotic resistance. Arch Roum Pathol Exp Microbiol 1983; 42:179-89. [PMID: 6673696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Abstract
A single, simple method for recovering enteroviruses from several different kinds of food, such as ground beef, fish, oysters, and mussels, has been improved. First, sample contamination technique was studied. It appears that virus adsorption occurs at food pH and varies according to the kind of food and the food-virus exchange surface. Second, virus recovery was evaluated. According to the experimental results obtained, we propose the following method. Samples are submerged in 100 ml of demineralized water adjusted to pH 9 with a conductivity of 8,000 mg of NaCl per liter. Then, viruses are concentrated by ultrafiltration or by ultracentrifugation. This method was efficient for virus recovery from the four kinds of food, even in cases of very low contamination.
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Joret JC, Block JC. [Survival of enteric viruses adsorbed on glass microfibers during postal transport]. Can J Microbiol 1981; 27:246-8. [PMID: 6260323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The survival of enteric viruses (poliovirus type 1, Mahoney strain, and indigenous viruses of waste waters) has been studied after adsorption of the viruses (pH 3.5) on glass microfiber filters. After postal transport, the presence of the viruses was checked on the filters being soaked in a 3% beef extract solution (pH 7.5) either frozen or without protection against heat. Viruses were recovered at a rate of 59 to 65%. For qualitative studies, postal shipment of samples adsorbed on fiberglass may allow extension of a control system for enteroviruses in water.
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Block JC, Waite DE, Dehner LP, Leonard AS, Ogle RG, Gatto DJ. Pigmented neuroectodermal tumor of infancy. An example of rarely expressed malignant behavior. Oral Surg Oral Med Oral Pathol 1980; 49:279-85. [PMID: 6244526 DOI: 10.1016/0030-4220(80)90133-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A 4-month-old patient presented with a melanotic neuroectodermal tumor. The tumor continued to progress and recur following each surgical intervention and the patient died at the age of 38 months, 36 months following discovery of the tumor. This article describes the clinical and pathologic features of the disease. At autopsy, the tumor resembled that of a neuroblastoma.
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Rolland D, Block JC. Simultaneous concentration of Salmonella and enterovirus from surface water by using micro-fiber glass filters. Appl Environ Microbiol 1980; 39:659-61. [PMID: 6247975 PMCID: PMC291393 DOI: 10.1128/aem.39.3.659-661.1980] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A method using micro-fiber glass filters (8-micrometers porosity) at pH 3.5 was successfully used for simultaneous concentration of Salmonella and enterovirus from Meurthe River samples, collected 8 km south of Nancy, France. A concentration of 10-liter samples was indispensable and permitted recovery of several enterovirus and Salmonella serotypes in concentrations of 1.3 most probable number of cytopathogenic units per liter and 18 bacteria per liter, respectively.
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Abstract
A method is described for the concentration of Salmonella from water. As is done with enterovirus, Salmonella bacteria were concentrated from water in two steps: by pH 3.5 adsorption on and pH 9.5 elution from 8-micron porosity micro-fiber glass filter tubes. This method worked in less than 30 min, and Salmonella typhimurium was inactivated only slightly in spite of rapid pH variations (pH 3.5 to 9.5). It was demonstrated that the retention by the filters stems from two phenomena: a low retention in the micro-fiber glass labyrinth for small filtered volumes, and a high retention by adsorption at pH 3.5 for any filtered volume (experiments done with 15- and 80-liter samples). Addition in tap water of trivalent ions like Al3+ did not increase Salmonella adsorption. In most of the trials, Salmonella recovery varied from 42 to 93%. Preliminary field investigations indicate that enterovirus and Salmonella may both be concentrated from the same water sample by this procedure.
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Block JC, Joret JC, Hartemann P, Schwartzbrod L, Dixneuf P. [Evaluation of the alginat membrane filter method for the Enterovirus concentration in water (author's transl)]. Zentralbl Bakteriol Orig B 1977; 165:471-7. [PMID: 205063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
It is bound to use a concentration method for the research of enteroviruses in water. One of the concentration methods, the filtration on alginat membranes, avoids the problem of the virus elution from the filter, then the membrane is soluble in a sodium citrat buffer. This method was studied with different types of water (synthetic water, tap water and wastewater). -The recovery efficiency of Poliovirus I in clear waters (synthetic water and tap water) was poor, unsatisfying reproducible; the results are better for small virus concentrations. This efficiency may be slowly enhanced by the addition to the sample of aluminium chlorid at a final concentration of 5.10(-4) M. -The technical problems (brittleness of the membranes, slow filtrations speed, small sample volume), soon noticeable with clear waters, are more important in the case of trouble waters. Meanwhile the use of this filtration method gives better results for the recovery of Poliovirus I in wastewaters than the direct inoculation to cells cultures.
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