Cellular Response of the Amoeba Acanthamoeba castellanii to Chlorine, Chlorine Dioxide, and Monochloramine Treatments

Mogoa, Emerancienne; Bodet, Charles; Morel, Franck; Rodier, Marie‐Hélène; Légube, B.; Héchard, Yann

doi:10.1128/aem.00234-11

Cited by 26 publications

(26 citation statements)

References 26 publications

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“…Previous research has revealed that cocultures of the pathogenic Burkholderia species Burkholderia pseudomallei with the ubiquitous freshwater amoeba Acanthamoeba astronyxis greatly enhances the survival of B. pseudomallei in the presence of monochloramine, with 100 times more monochloramine required to maintain disinfectant efficacy when the amoeba was present (29). This is due to the ability of Acanthamoeba cysts to resist common disinfectants, such as monochloramine and chlorine, and their ability to bear phagocytosis-resistant bacteria within, thus protecting the bacteria from water treatments (30). While these particular species may not have been present in these systems, it may be the case that similar interkingdom interactions can occur for other Burkholderiales species.…”

Section: Discussionmentioning

confidence: 99%

Using Amplicon Sequencing To Characterize and Monitor Bacterial Diversity in Drinking Water Distribution Systems

Shaw

Monis

Weyrich

et al. 2015

Appl Environ Microbiol

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b Drinking water assessments use a variety of microbial, physical, and chemical indicators to evaluate water treatment efficiency and product water quality. However, these indicators do not allow the complex biological communities, which can adversely impact the performance of drinking water distribution systems (DWDSs), to be characterized. Entire bacterial communities can be studied quickly and inexpensively using targeted metagenomic amplicon sequencing. Here, amplicon sequencing of the 16S rRNA gene region was performed alongside traditional water quality measures to assess the health, quality, and efficiency of two distinct, full-scale DWDSs: (i) a linear DWDS supplied with unfiltered water subjected to basic disinfection before distribution and (ii) a complex, branching DWDS treated by a four-stage water treatment plant (WTP) prior to disinfection and distribution. In both DWDSs bacterial communities differed significantly after disinfection, demonstrating the effectiveness of both treatment regimes. However, bacterial repopulation occurred further along in the DWDSs, and some end-user samples were more similar to the source water than to the postdisinfection water. Three sample locations appeared to be nitrified, displaying elevated nitrate levels and decreased ammonia levels, and nitrifying bacterial species, such as Nitrospira, were detected. Burkholderiales were abundant in samples containing large amounts of monochloramine, indicating resistance to disinfection. Genera known to contain pathogenic and fecal-associated species were also identified in several locations. From this study, we conclude that metagenomic amplicon sequencing is an informative method to support current compliance-based methods and can be used to reveal bacterial community interactions with the chemical and physical properties of DWDSs.T ransmission of pathogens via contaminated water is a significant cause of illness worldwide. It has been estimated that one-third of gastrointestinal illnesses are caused by contaminated drinking water (1), and 4% of all deaths worldwide are due to polluted drinking water and poor sanitation (2). In developed nations water quality assessments and treatment facilities have been introduced to reduce microbial contamination, resulting in a significant reduction in drinking water-related illnesses and deaths. Water treatment commonly involves the reduction of organics and other contaminants via coagulation and sedimentation, separation of any remaining solids via filtration, and finally disinfection via chemical oxidants or ultraviolet (UV) radiation. The addition of chemical oxidants such as chlorine and monochloramine is the most common method of drinking water disinfection (3). The level of treatment required varies from system to system, with some drinking water distribution systems (DWDSs) receiving only one or two levels of treatment, while others require multiple treatments to create water suitable for end use.Currently, most drinking water quality assessments do not directly taxonomically ide...

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Section: Discussionmentioning

confidence: 99%

Using Amplicon Sequencing To Characterize and Monitor Bacterial Diversity in Drinking Water Distribution Systems

Shaw

Monis

Weyrich

et al. 2015

Appl Environ Microbiol

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“…Theculturemedium was eliminated and bacteria were fixedw ith 3% glutaraldehyde in phosphate buffer (0.1 m,p H7 .4). Thes amples for the transmission electron microscopy( TEM)a nd the scanninge lectron microscopy (SEM)o bservations wereprepared according to previously described protocols [43] [44].…”

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confidence: 99%

Activity of Six Essential Oils Extracted from Tunisian Plants against Legionella pneumophila

Chaftar

Girardot

Nathalie

et al. 2015

Chemistry & Biodiversity

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The aim of this study was to investigate the composition of six essential oils extracted from Tunisian plants, i.e., Artemisia herba-alba Asso, Citrus sinensis (L.) Osbeck, Juniperus phoenicea L., Rosmarinus officinalis L., Ruta graveolens L., and Thymus vulgaris L., and to evaluate their activity against Legionella pneumophila (microdilution assays). Eight Legionella pneumophila strains were studied, including the two well-known serogroup 1 Lens and Paris strains as controls and six environmental strains isolated from Tunisian spas belonging to serogroups 1, 4, 5, 6, and 8. The essential oils were generally active against L. pneumophila. The activities of the A. herba-alba, C. sinensis, and R. officinalis essential oils were strain-dependent, whereas those of the J. phoenicea and T. vulgaris oils, showing the highest anti-Legionella activities, with minimum inhibitory concentrations (MICs) lower than 0.03 and lower than or equal to 0.07 mg/ml, respectively, were independent of the strains' serogroup. Moreover, the microorganisms treated with T. vulgaris essential oil were shorter, swollen, and less electron-dense compared to the untreated controls. Isoborneol (20.91%), (1S)-α-pinene (18.30%) β-phellandrene (8.08%), α-campholenal (7.91%), and α-phellandrene (7.58%) were the major components isolated from the J. phoenicea oil, while carvacrol (88.50%) was the main compound of the T. vulgaris oil, followed by p-cymene (7.86%). This study highlighted the potential interest of some essential oils extracted from Tunisian plants as biocides to prevent the Legionella risk.

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“…In case of unfavourable growth conditions, such as starvation or desiccation, these protists can exhibit a resistant form, termed cysts. The cyst structure helps the amoebae to survive various disinfection treatments [1], [2], [3]. Thus, amoebae may bypass all the barriers present in drinking water treatment plants [4] and may reach the water distribution system, where they may colonize biofilms and sediments.…”

Section: Introductionmentioning

confidence: 99%

Prevalence and diversity of Chlamydiales and other amoeba-resisting bacteria in domestic drinking water systems

Lienard

Croxatto

Gervaix

et al. 2017

New Microbes and New Infections

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A growing number of human infections incriminate environmental bacteria that have evolved virulent mechanisms to resist amoebae and use them as a replicative niche. These bacteria are designated amoeba-resisting bacteria (ARB). Despite the isolation of these ARB in various human clinical samples, the possible source of infection remains undetermined in most cases. However, it is known that the ARB Legionella pneumophila, for instance, causes a respiratory infection in susceptible hosts after inhalation of contaminated water aerosols from various sources. The Chlamydiales order contains many ARB, such as Parachlamydia acanthamoebae or Simkania negevensis, previously implicated in human respiratory infections with no identified contamination sources. We thus investigated whether domestic water systems are a potential source of transmission of these Chlamydiales to humans by using amoebal culture and molecular methods. Other important ARB such as mycobacteria and Legionella were also investigated, as were their possible amoebal hosts. This work reports for the first time a very high prevalence and diversity of Chlamydiales in drinking water, being detected in 35 (72.9%) of 48 investigated domestic water systems, with members of the Parachlamydiaceae family being dominantly detected. Furthermore, various Legionella and mycobacteria species were also recovered, some species of which are known to be causal agents of human infections.

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Cellular Response of the Amoeba Acanthamoeba castellanii to Chlorine, Chlorine Dioxide, and Monochloramine Treatments

Cited by 26 publications

References 26 publications

Using Amplicon Sequencing To Characterize and Monitor Bacterial Diversity in Drinking Water Distribution Systems

Using Amplicon Sequencing To Characterize and Monitor Bacterial Diversity in Drinking Water Distribution Systems

Activity of Six Essential Oils Extracted from Tunisian Plants against Legionella pneumophila

Prevalence and diversity of Chlamydiales and other amoeba-resisting bacteria in domestic drinking water systems

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