scholarly journals Calcium-Mediated Biophysical Binding ofCryptosporidium parvumOocysts to Surfaces Is Sensitive to Oocyst Age

2019 ◽  
Vol 85 (17) ◽  
Author(s):  
Tooba Sarkhosh ◽  
X. Frank Zhang ◽  
Kristen L. Jellison ◽  
Sabrina S. Jedlicka
Keyword(s):  
Drinking Water ◽  
Carboxylic Acid ◽  
Cryptosporidium Parvum ◽  
Gastrointestinal Disease ◽  
Fate And Transport ◽  
Drinking Water Treatment ◽  
Outer Wall ◽  
Content Type ◽  
Binding Strength ◽  
Binding Forces

ABSTRACTCryptosporidium parvumcauses potentially life-threatening gastrointestinal disease in humans and may not be effectively removed from drinking water via conventional methods. Prior research has shown that environmental biofilms immobilize oocysts from the water column, but the biophysical mechanisms driving this attraction are still under investigation. This study investigates the affinity ofC. parvumoocysts to silanized surfaces. Surfaces were prepared with hydroxyl, amine, and carboxyl moieties. Binding forces between the oocysts and these engineered substrates were analyzed, with and without divalent ions, using atomic force microscopy. Binding forces were measured over several weeks to investigate the influence of age on adhesion.C. parvumoocysts bind most strongly to carboxylic acid functional groups, with rupture forces greater than that required to break noncovalent molecular bonds, regardless of oocyst age. This adhesion is shown to be due to divalent cation bridging mechanisms. In addition, the binding strength increases over a 5-week period as the oocysts age, followed by a decrease in the binding strength, which may be related to structural or biochemical changes in the outer wall-bound glycosylated proteins. This study sheds new light on the biochemical parameters that influenceC. parvumoocyst binding to surfaces. Increased understanding of how age and water chemistry influence the binding strength of oocysts may inform future developments in environmental detection and drinking water treatment, such as with the development of oocyst-specific sensors that allow for more frequent tracking of oocysts in the environment.IMPORTANCEThe mechanisms by which pathogens bind to surfaces are of interest to a wide variety of scientific communities, as these mechanisms drive infectivity, fate, and transport of the pathogenic organisms. This study begins to reveal the mechanism of direct binding ofCryptosporidium parvumto surfaces containing both carboxylic acid and amine moieties, in an attempt to understand how much of the binding ability is due to long-range electrostatic forces versus other mechanisms (specific or nonspecific) of bonding. In addition to improving the scientific understanding of fate and transport of oocysts, an expanded understanding of the binding mechanisms may aid in the development of new tools and sensors designed to detect and track oocysts in waterways. Furthermore, the methods used to examine binding in this study could be translated to other waterborne pathogens of interest.

scholarly journals Molecular Characterization of Human-Pathogenic Microsporidia and Cyclospora cayetanensis Isolated from Various Water Sources in Spain: a Year-Long Longitudinal Study

2012 ◽  
Vol 79 (2) ◽  
pp. 449-459 ◽  
Author(s):  
Ana Luz Galván ◽  
Angela Magnet ◽  
Fernando Izquierdo ◽  
Soledad Fenoy ◽  
Cristina Rueda ◽  
...  
Keyword(s):  
Drinking Water ◽  
Longitudinal Study ◽  
Water Treatment ◽  
Molecular Characterization ◽  
Drinking Water Treatment ◽  
Enterocytozoon Bieneusi ◽  
Content Type ◽  
Cyclospora Cayetanensis ◽  
Water Treatment Plants

ABSTRACTRecent studies suggest the involvement of water in the epidemiology ofCyclospora cayetanensisand some microsporidia. A total of 223 samples from four drinking water treatment plants (DWTPs), seven wastewater treatment plants (WWTPs), and six locations of influence (LI) on four river basins from Madrid, Spain, were analyzed from spring 2008 to winter 2009. Microsporidia were detected in 49% of samples (109/223),Cyclosporaspp. were detected in 9% (20/223), and both parasites were found in 5.4% (12/223) of samples. Human-pathogenic microsporidia were detected, includingEnterocytozoon bieneusi(C, D, and D-like genotypes),Encephalitozoon intestinalis,Encephalitozoon cuniculi(genotypes I and III), andAnncaliia algerae.C. cayetanensiswas identified in 17 of 20 samples. To our knowledge, this is the first study that shows a year-long longitudinal study ofC. cayetanensisin drinking water treatment plants. Additionally, data about the presence and molecular characterization of the human-pathogenic microsporidia in drinking water, wastewater, and locations of influence during 1 year in Spain are shown. It is noteworthy that although the DWTPs and WWTPs studied meet European and national regulations on water sanitary quality, both parasites were found in water samples from these plants, supporting the idea that new and appropriate controls and regulations for drinking water, wastewater, and recreational waters should be proposed to avoid health risks from these pathogens.

scholarly journals Draft Genome Assembly of a Potentially Zoonotic Cryptosporidium parvum Isolate, UKP1

2018 ◽  
Vol 7 (19) ◽  
Author(s):  
John H. E. Nash ◽  
James Robertson ◽  
Kristin Elwin ◽  
Rachel A. Chalmers ◽  
Andrew M. Kropinski ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Gastrointestinal Disease ◽  
Draft Genome ◽  
Small Ruminants ◽  
Protozoan Parasite ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Content Type ◽  
Draft Genome Assembly ◽  
Animal Reservoirs

Cryptosporidium parvum is a zoonotic protozoan parasite that causes food and waterborne gastrointestinal disease and whose major animal reservoirs are cattle and small ruminants. We report here on a draft whole-genome sequence of a zoonotic isolate of C. parvum isolated from a person with cryptosporidiosis.

scholarly journals Comparison of Assays for Sensitive and Reproducible Detection of Cell Culture-Infectious Cryptosporidium parvum and Cryptosporidium hominis in Drinking Water

2011 ◽  
Vol 78 (1) ◽  
pp. 156-162 ◽  
Author(s):  
Anne M. Johnson ◽  
George D. Di Giovanni ◽  
Paul A. Rochelle
Keyword(s):  
Cell Culture ◽  
Drinking Water ◽  
Cryptosporidium Parvum ◽  
False Positives ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Cryptosporidium Hominis ◽  
Content Type ◽  
Detection Assay ◽  
Pcr Targeting

ABSTRACTThis study compared the three most commonly used assays for detectingCryptosporidiumsp. infections in cell culture: immunofluorescent antibody and microscopy assay (IFA), PCR targetingCryptosporidiumsp.-specific DNA, and reverse transcriptase PCR (RT-PCR) targetingCryptosporidiumsp.-specific mRNA. Monolayers of HCT-8 cells, grown in 8-well chamber slides or 96-well plates, were inoculated with a variety of viable and inactivated oocysts to assess assay performance. All assays detected infection with low doses of flow cytometry-enumeratedCryptosporidium parvumoocysts, including infection with one oocyst and three oocysts. All methods also detected infection withCryptosporidium hominis. The RT-PCR assay, IFA, and PCR assay detected infection in 23%, 25%, and 51% of monolayers inoculated with threeC. parvumoocysts and 10%, 9%, and 16% of monolayers inoculated with one oocyst, respectively. The PCR assay was the most sensitive, but it had the highest frequency of false positives with mock-infected cells and inactivated oocysts. IFA was the only infection detection assay that did not produce false positives with mock-infected monolayers. IFA was also the only assay that detected infections in all experiments with spiked oocysts recovered from Envirochek capsules following filtration of 1,000 liters of treated water. Consequently, cell culture with IFA detection is the most appropriate method for routine and sensitive detection of infectiousCryptosporidium parvumandCryptosporidium hominisin drinking water.

scholarly journals Genetic (In)stability of 2,6-Dichlorobenzamide Catabolism in Aminobacter sp. Strain MSH1 Biofilms under Carbon Starvation Conditions

2017 ◽  
Vol 83 (11) ◽  
Author(s):  
Benjamin Horemans ◽  
Bart Raes ◽  
Hannelore Brocatus ◽  
Jeroen T'Syen ◽  
Caroline Rombouts ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Drinking Water Treatment ◽  
Gene Clusters ◽  
Content Type ◽  
Assimilable Organic Carbon ◽  
Water Treatment Plants ◽  
Catabolic Genes ◽  
Starvation Conditions

ABSTRACT Aminobacter sp. strain MSH1 grows on and mineralizes the groundwater micropollutant 2,6-dichlorobenzamide (BAM) and is of interest for BAM removal in drinking water treatment plants (DWTPs). The BAM-catabolic genes in MSH1 are located on plasmid pBAM1, carrying bbdA, which encodes the conversion of BAM to 2,6-dichlorobenzoic acid (2,6-DCBA) (BbdA+ phenotype), and plasmid pBAM2, carrying gene clusters encoding the conversion of 2,6-DCBA to tricarboxylic acid (TCA) cycle intermediates (Dcba+ phenotype). There are indications that MSH1 easily loses its BAM-catabolic phenotype. We obtained evidence that MSH1 rapidly develops a population that lacks the ability to mineralize BAM when grown on nonselective (R2B medium) and semiselective (R2B medium with BAM) media. Lack of mineralization was explained by loss of the Dcba+ phenotype and corresponding genes. The ecological significance of this instability for the use of MSH1 for BAM removal in the oligotrophic environment of DWTPs was explored in lab and pilot systems. A higher incidence of BbdA+ Dcba− MSH1 cells was also observed when MSH1 was grown as a biofilm in flow chambers under C and N starvation conditions due to growth on nonselective residual assimilable organic carbon. Similar observations were made in experiments with a pilot sand filter reactor bioaugmented with MSH1. BAM conversion to 2,6-DCBA was not affected by loss of the DCBA-catabolic genes. Our results show that MSH1 is prone to BAM-catabolic instability under the conditions occurring in a DWTP. While conversion of BAM to 2,6-DCBA remains unaffected, BAM mineralization activity is at risk, and monitoring of metabolites is warranted. IMPORTANCE Bioaugmentation of dedicated biofiltration units with bacterial strains that grow on and mineralize micropollutants was suggested as an alternative for treating micropollutant-contaminated water in drinking water treatment plants (DWTPs). Organic-pollutant-catabolic genes in bacteria are often easily lost, especially under nonselective conditions, which affects the bioaugmentation success. In this study, we provide evidence that Aminobacter sp. strain MSH1, which uses the common groundwater micropollutant 2,6-dichlorobenzamide (BAM) as a C source, shows a high frequency of loss of its BAM-mineralizing phenotype due to the loss of genes that convert 2,6-DCBA to Krebs cycle intermediates when nonselective conditions occur. Moreover, we show that catabolic-gene loss also occurs in the oligotrophic environment of DWTPs, where growth of MSH1 depends mainly on the high fluxes of low concentrations of assimilable organic carbon, and hence show the ecological relevance of catabolic instability for using strain MSH1 for BAM removal in DWTPs.

scholarly journals Trends in Ozonation Disinfection By-Products—Occurrence, Analysis and Toxicity of Carboxylic Acids

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 756
Author(s):  
Rama Pulicharla ◽  
François Proulx ◽  
Sonja Behmel ◽  
Jean-B. Sérodes ◽  
Manuel J. Rodriguez
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Drinking Water Treatment ◽  
Water Sources ◽  
Diverse Range ◽  
Ozone Dose ◽  
Analytical Approaches ◽  
By Products

Ozonation is becoming a common disinfection method for drinking water treatment. This has prompted the investigation of ozonation disinfection by-products (ODBPs) in drinking water. Ozonation generates a diverse range of carbonyl disinfection by-products, including carboxylic acids, aldehydes, ketones and aldo-ketoacids. Among these ODBPs, carboxylic acid by-products (CABPs) are observed in higher concentrations compared to other carbonyl by-products. However, relatively little research has been conducted on CABPs, including their precursors, formation and occurrence, methods of detection and toxicity. This review outlines the occurrence and variability of CABPs in a number of water sources treated and disinfected with ozonation. It considers the effect of ozonation parameters, including ozone dose, temperature and time of ozonation on the formation of CABPs. The review also discusses the various analytical approaches for CABP quantification, as well as their possible toxicity in drinking water.

scholarly journals Diversity and Antibiotic Resistance Patterns of Sphingomonadaceae Isolates from Drinking Water

2011 ◽  
Vol 77 (16) ◽  
pp. 5697-5706 ◽  
Author(s):  
Ivone Vaz-Moreira ◽  
Olga C. Nunes ◽  
Célia M. Manaia
Keyword(s):  
Drinking Water ◽  
Antibiotic Resistance ◽  
Gene Sequence ◽  
Tap Water ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Rrna Gene ◽  
Content Type ◽  
Resistance Patterns ◽  
Antibiotic Resistance Patterns

ABSTRACTSphingomonadaceae(n= 86) were isolated from a drinking water treatment plant (n= 6), tap water (n= 55), cup fillers for dental chairs (n= 21), and a water demineralization filter (n= 4). The bacterial isolates were identified based on analysis of the 16S rRNA gene sequence, and intraspecies variation was assessed on the basis ofatpDgene sequence analysis. The isolates were identified as members of the generaSphingomonas(n= 27),Sphingobium(n= 28),Novosphingobium(n= 12),Sphingopyxis(n= 7), andBlastomonas(n= 12). The patterns of susceptibility to five classes of antibiotics were analyzed and compared for the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance prevalence values were observed in members of the generaSphingomonasandSphingobiumand for beta-lactams, ciprofloxacin, and cotrimoxazole. In tap water and in water from dental chairs, antibiotic resistance was more prevalent than in the other samples, mainly due to the predominance of isolates of the generaSphingomonasandSphingobium. These two genera presented distinct patterns of association with antibiotic resistance, suggesting different paths of resistance development. Antibiotic resistance patterns were often related to the species rather than to the site or strain, suggesting the importance of vertical resistance transmission in these bacteria. This is the first study demonstrating that members of the familySphingomonadaceaeare potential reservoirs of antibiotic resistance in drinking water.

DISINFEKSI UNTUK PROSES PENGOLAHAN AIR MINUM

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Nusa Idaman Said
Keyword(s):  
Drinking Water ◽  
Water Purification ◽  
Distribution System ◽  
Residual Effect ◽  
Drinking Water Treatment ◽  
Disinfection Byproducts ◽  
Water Disinfection ◽  
Pathogenic Microorganisms ◽  
Microbiological Contamination ◽  
Disinfection Process

Water disinfection means the removal, deactivation or killing of pathogenic microorganisms. Microorganisms are destroyed or deactivated, resulting in termination of growth and reproduction. When microorganisms are not removed from drinking water, drinking water usage will cause people to fall ill. Chemical inactivation of microbiological contamination in natural or untreated water is usually one of the final steps to reduce pathogenic microorganisms in drinking water. Combinations of water purification steps (oxidation, coagulation, settling, disinfection, and filtration) cause (drinking) water to be safe after production. As an extra measure many countries apply a second disinfection step at the end of the water purification process, in order to protect the water from microbiological contamination in the water distribution system. Usually one uses a different kind of disinfectant from the one earlier in the process, during this disinfection process. The secondary disinfection makes sure that bacteria will not multiply in the water during distribution. This paper describes several technique of disinfection process for drinking water treatment. Disinfection can be attained by means of physical or chemical disinfectants. The agents also remove organic contaminants from water, which serve as nutrients or shelters for microorganisms. Disinfectants should not only kill microorganisms. Disinfectants must also have a residual effect, which means that they remain active in the water after disinfection. For chemical disinfection of water the following disinfectants can be used such as Chlorine (Cl2),  Hypo chlorite (OCl-), Chloramines, Chlorine dioxide (ClO2), Ozone (O3), Hydrogen peroxide etch. For physical disinfection of water the following disinfectants can be used is Ultraviolet light (UV). Every technique has its specific advantages and and disadvantages its own application area sucs as environmentally friendly, disinfection byproducts, effectivity, investment, operational costs etc. Kata Kunci : Disinfeksi, bakteria, virus, air minum, khlor, hip khlorit, khloramine, khlor dioksida, ozon, UV.

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