Effect of Particles on the Recovery of Cryptosporidium Oocysts from Source Water Samples of Various Turbidities

ABSTRACT Cryptosporidium parvum can be found in both source and drinking water and has been reported to cause serious waterborne outbreaks which threaten public health safety. The U.S. Environmental Protection Agency has developed method 1622 for detection of Cryptosporidium oocysts present in water. Method 1622 involves four key processing steps: filtration, immunomagnetic separation (IMS), fluorescent-antibody (FA) staining, and microscopic evaluation. The individual performance of each of these four steps was evaluated in this study. We found that the levels of recovery of C. parvum oocysts at the IMS-FA and FA staining stages were high, averaging more than 95%. In contrast, the level of recovery declined significantly, to 14.4%, when the filtration step was incorporated with tap water as a spiking medium. This observation suggested that a significant fraction of C. parvum oocysts was lost during the filtration step. When C. parvum oocysts were spiked into reclaimed water, tap water, microfiltration filtrate, and reservoir water, the highest mean level of recovery of (85.0% ± 5.2% [mean ± standard deviation]) was obtained for the relatively turbid reservoir water. Further studies indicated that it was the suspended particles present in the reservoir water that contributed to the enhanced C. parvum oocyst recovery. The levels of C. parvum oocyst recovery from spiked reservoir water with different turbidities indicated that particle size and concentration could affect oocyst recovery. Similar observations were also made when silica particles of different sizes and masses were added to seeded tap water. The optimal particle size was determined to be in the range from 5 to 40 μm, and the corresponding optimal concentration of suspended particles was 1.42 g for 10 liters of tap water.

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Concentration and Detection of Cryptosporidium Oocysts in Surface Water Samples by Method 1622 Using Ultrafiltration and Capsule Filtration

Applied and Environmental Microbiology ◽

10.1128/aem.67.3.1123-1127.2001 ◽

2001 ◽

Vol 67 (3) ◽

pp. 1123-1127 ◽

Cited By ~ 77

Author(s):

Otto D. Simmons ◽

Mark D. Sobsey ◽

Christopher D. Heaney ◽

Frank W. Schaefer ◽

Donna S. Francy

Keyword(s):

Surface Water ◽

Surface Waters ◽

Hollow Fiber ◽

Water Samples ◽

Environmental Protection Agency ◽

Fluorescent Antibody ◽

Immunomagnetic Separation ◽

Recovery Rates ◽

Microscopic Evaluation ◽

Surface Water Samples

ABSTRACT The protozoan parasite Cryptosporidium parvumis known to occur widely in both source and drinking water and has caused waterborne outbreaks of gastroenteritis. To improve monitoring, the U.S. Environmental Protection Agency developed method 1622 for isolation and detection of Cryptosporidium oocysts in water. Method 1622 is performance based and involves filtration, concentration, immunomagnetic separation, fluorescent-antibody staining and 4′,6-diamidino-2-phenylindole (DAPI) counterstaining, and microscopic evaluation. The capsule filter system currently recommended for method 1622 was compared to a hollow-fiber ultrafilter system for primary concentration of C. parvum oocysts in seeded reagent water and untreated surface waters. Samples were otherwise processed according to method 1622. Rates of C. parvumoocyst recovery from seeded 10-liter volumes of reagent water in precision and recovery experiments with filter pairs were 42% (standard deviation [SD], 24%) and 46% (SD, 18%) for hollow-fiber ultrafilters and capsule filters, respectively. Mean oocyst recovery rates in experiments testing both filters on seeded surface water samples were 42% (SD, 27%) and 15% (SD, 12%) for hollow-fiber ultrafilters and capsule filters, respectively. Although C. parvum oocysts were recovered from surface waters by using the approved filter of method 1622, the recovery rates were significantly lower and more variable than those from reagent grade water. In contrast, the disposable hollow-fiber ultrafilter system was compatible with subsequent method 1622 processing steps, and it recovered C. parvum oocysts from seeded surface waters with significantly greater efficiency and reliability than the filter suggested for use in the version of method 1622 tested.

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Enumeration of Cryptosporidium spp. in Water with U.S. EPA Method 1622

Journal of AOAC International ◽

10.1093/jaoac/83.5.1108 ◽

2000 ◽

Vol 83 (5) ◽

pp. 1108-1114 ◽

Cited By ~ 3

Author(s):

James L Sinclair

Keyword(s):

Environmental Protection Agency ◽

Fluorescent Antibody ◽

Cryptosporidium Oocyst ◽

Immunomagnetic Separation ◽

Dapi Staining ◽

Cell Structures ◽

Cryptosporidium Oocysts ◽

Additional Cell ◽

Sparse Methods ◽

Made In

Abstract The occurrence of Cryptosporidium parvum or other pathogenic Cryptosporidium species in water must be known in order to assess risk and determine the treatment needed to reduce Cryptosporidium oocysts to acceptable levels in finished drinking water. Because Cryptosporidium oocyst occurrence may be sparse, methods must concentrate a large volume of water and correctly identify oocysts in the concentrate. The U.S. Environmental Protection Agency Information Collection Rule (ICR) protozoan method gives low and variable recoveries of Cryptosporidium oocysts, making risk assessment difficult. Therefore, a method giving better oocyst recovery and more consistent results was needed. Method 1622 was developed with existing materials and procedures, and improvements were made in filtration, cleanup, and detection. Absolute porosity filters were used, with cleanup by immunomagnetic separation and detection by direct fluorescent antibody stain with 4′,6-diamidino-2-phenylindole (DAPI) staining for additional cell structures. Both the level and consistency of oocyst recovery were improved compared to recovery with the ICR method.

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Effects of CO<sub>2</sub> on particle size distribution and phytoplankton abundance during a mesocosm bloom experiment (PeECE II)

Biogeosciences ◽

10.5194/bg-5-509-2008 ◽

2008 ◽

Vol 5 (2) ◽

pp. 509-521 ◽

Cited By ~ 85

Author(s):

A. Engel ◽

K. G. Schulz ◽

U. Riebesell ◽

R. Bellerby ◽

B. Delille ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Large Scale ◽

Phytoplankton Community ◽

Co2 Enrichment ◽

Suspended Particles ◽

Phytoplankton Abundance ◽

General Importance ◽

Co2 Treatment

Abstract. The influence of seawater carbon dioxide (CO2) concentration on the size distribution of suspended particles (2–60 μm) and on phytoplankton abundance was investigated during a mesocosm experiment at the large scale facility (LFS) in Bergen, Norway, in the frame of the Pelagic Ecosystem CO2 Enrichment study (PeECE II). In nine outdoor enclosures the partial pressure of CO2 in seawater was modified by an aeration system to simulate past (~190 μatm CO2), present (~370 μatm CO2) and future (~700 μatm CO2) CO2 conditions in triplicates. Due to the initial addition of inorganic nutrients, phytoplankton blooms developed in all mesocosms and were monitored over a period of 19 days. Seawater samples were collected daily for analysing the abundance of suspended particles and phytoplankton with the Coulter Counter and with Flow Cytometry, respectively. During the bloom period, the abundance of small particles (<4 μm) significantly increased at past, and decreased at future CO2 levels. At that time, a direct relationship between the total-surface-to-total-volume ratio of suspended particles and DIC concentration was determined for all mesocosms. Significant changes with respect to the CO2 treatment were also observed in the phytoplankton community structure. While some populations such as diatoms seemed to be insensitive to the CO2 treatment, others like Micromonas spp. increased with CO2, or showed maximum abundance at present day CO2 (i.e. Emiliania huxleyi). The strongest response to CO2 was observed in the abundance of small autotrophic nano-plankton that strongly increased during the bloom in the past CO2 mesocosms. Together, changes in particle size distribution and phytoplankton community indicate a complex interplay between the ability of the cells to physiologically respond to changes in CO2 and size selection. Size of cells is of general importance for a variety of processes in marine systems such as diffusion-limited uptake of substrates, resource allocation, predator-prey interaction, and gravitational settling. The observed changes in particle size distribution are therefore discussed with respect to biogeochemical cycling and ecosystem functioning.

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Effects of Water Particles in the Jinjiang River Estuary on the Physiological and Biochemical Characteristics of Microcystit Flos-Aquae

10.21203/rs.3.rs-557128/v1 ◽

2021 ◽

Author(s):

Yiting Nan ◽

Peiyong Guo ◽

Hui Xing ◽

Sijia Chen ◽

Bo Hu ◽

...

Keyword(s):

Particle Size ◽

Particulate Matter ◽

Protein Content ◽

Suspended Particulate Matter ◽

Soluble Protein ◽

Suspended Particles ◽

Dose Effect ◽

Soluble Protein Content ◽

Sod Activity ◽

Suspended Particulate

Abstract The effects of different concentrations (100,150,200,250 mg/L) and different particle sizes (0–75µm, 75–120µm, 120–150µm, 150–500µm) on soluble protein content, SOD and CAT activity, MDA content, chlorophyll a content and photosynthetic parameters of Microcystis flos-aquae were studied, the mechanism of the effect of suspended particulate matter on the physiology and biochemistry of Microcystis flos-aquae was discussed. The results showed that the soluble protein content of Microcystis flos-aquae did not change obviously after being stressed by suspended particles of different concentration/diameter. The SOD activity of Microcystis flos-aquae increased at first and then decreased with the increase of the concentration of suspended particulate matter. The SOD activity of Microcystis flos-aquae reached 28.03 U/mL when the concentration of suspended particulate matter was 100 mg/L. The CAT activity of Microcystis flos-aquae increased with the increase of the concentration of suspended particles, and reached the maximum value of 12.45 U/mgprot in the concentration group of 250 mg/L, showing a certain dose-effect. The effect of small particle size on SOD, CAT and MDA of Microcystis flos-aquae was more significant than that of large particle size. The larger the concentration and the smaller the particle size, the stronger the attenuation of light and the lower the content of chlorophyll a. Both Fv/Fm and Fv/F0 of Microcystis flos-aquae increased at first and then decreased under different concentration/size of suspended particles. The relative electron transfer rate gradually returned to the normal level with the passage of time. There was no significant difference in α value between treatment group and control group, ETRmax and Ik decreased.

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Detection and Discrimination of Cryptosporidium parvum and C. hominis in Water Samples by Immunomagnetic Separation-PCR

Applied and Environmental Microbiology ◽

10.1128/aem.71.2.898-903.2005 ◽

2005 ◽

Vol 71 (2) ◽

pp. 898-903 ◽

Cited By ~ 15

Author(s):

Yoshitsugu Ochiai ◽

Chieko Takada ◽

Mitsugu Hosaka

Keyword(s):

Cryptosporidium Parvum ◽

Water Samples ◽

Nested Pcr ◽

Fragment Length Polymorphism ◽

Detection Method ◽

Fluorescent Antibody ◽

Immunomagnetic Separation ◽

Antibody Assay ◽

Pcr Products ◽

Genetic Detection

ABSTRACT Cryptosporidium parvum and C. hominis have been the cause of large and serious outbreaks of waterborne cryptosporidiosis. A specific and sensitive recovery-detection method is required for control of this pathogen in drinking water. In the present study, nested PCR-restriction fragment length polymorphism (RFLP), which targets the divergent Cpgp40/15 gene, was developed. This nested PCR detected only the gene derived from C. parvum and C. hominis strains, and RFLP was able to discriminate between the PCR products from C. parvum and C. hominis. To evaluate the sensitivity of nested PCR, C. parvum oocysts inoculated in water samples of two different turbidities were recovered by immunomagnetic separation (IMS) and detected by nested PCR and fluorescent antibody assay (FA). Genetic detection by nested PCR and oocyst number confirmed by FA were compared, and the results suggested that detection by nested PCR depends on the confirmed oocyst number and that nested PCR in combination with IMS has the ability to detect a single oocyst in a water sample. We applied an agitation procedure with river water solids to which oocysts were added to evaluate the recovery and detection by the procedure in environmental samples and found some decrease in the rate of detection by IMS.

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Determination of N-Nitrosamines by Gas Chromatography Coupled to Quadrupole–Time-of-Flight Mass Spectrometry in Water Samples

Separations ◽

10.3390/separations7010003 ◽

2020 ◽

Vol 7 (1) ◽

pp. 3 ◽

Cited By ~ 3

Author(s):

Benigno José Sieira ◽

Inmaculada Carpinteiro ◽

Rosario Rodil ◽

José Benito Quintana ◽

Rafael Cela

Keyword(s):

Mass Spectrometry ◽

Environmental Protection Agency ◽

Ion Trap ◽

Solid Phase ◽

Classical Method ◽

Tap Water ◽

Time Of Flight ◽

The United States ◽

Mass Analyzer

An analytical method based on high-resolution quadrupole–time-of-flight (QToF) mass spectrometry has been developed as an alternative to the classical method, using a low-resolution ion trap (IT) analyzer to reduce interferences in N-nitrosamines determination. Extraction of the targeted compounds was performed by solid-phase extraction (SPE) following the United States Environmental Protection Agency (USEPA) -521 method. First, both electron impact (EI) and positive chemical ionization (PCI) using methane as ionization gas were compared, along with IT and QToF detection. Then, parameters such as limits of detection (LOD) and quantification (LOQ), linearity, and repeatability were assessed. The results showed that the QToF mass analyzer combined with PCI was the best system for the determination of the N-nitrosamines, with instrumental LOD and LOQ in the ranges of 0.2–4 and 0.6–11 ng mL−1, respectively, which translated into method LOD and LOQ in the ranges of 0.2–1.3 and 0.6–3.9 ng L−1, respectively. The analysis of real samples showed the presence of 6 of the N-nitrosamines in influent, effluent, and tap water. N-nitrosodimethylamine (NDMA) was quantified in all the analyzed samples at concentrations between 1 and 27 ng L−1. Moreover, four additional nitrosamines were found in tap and wastewater samples.

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Characteristic study of ionic species in nano, ultrafine, fine and coarse particle size mode at a traffic sampling site

Toxicology and Industrial Health ◽

10.1191/0748233706th241oa ◽

2006 ◽

Vol 22 (1) ◽

pp. 27-37 ◽

Cited By ~ 7

Author(s):

Guor-Cheng Fang ◽

Yuh-Shen Wu ◽

Shih-Yo Chang ◽

Jui-Yeh Rau ◽

Shih-Han Huang ◽

...

Keyword(s):

Particle Size ◽

Sampling Site ◽

Principal Component ◽

Ionic Species ◽

Suspended Particles ◽

Winter Period ◽

Average Mass ◽

Mass Size ◽

Pollutant Source ◽

Central Taiwan

A micro-orifice uniform deposit impactor (MOUDI) and a nano-MOUDI were used to measure the atmospheric coarse (PM2.5-10), fine (PM2.5), ultrafine (PM0.056 - 1) and nano (< 0.056 μm) particle concentrations at a traffic sampling site in central Taiwan during the winter period from November 2004 to January 2005. Meanwhile, concentrations of major ionic species (Cl-, NO3−, SO42−, NH4+, Na+, K+, Ca2+ and Mg2+) were also extracted from various particle size modes (nano, ultrafine, fine and coarse) and analysed by ion chromatography (DIONEX-100). The mass size distribution of ambient suspended particles exhibited two modes. The size ranges of the particles at these two particle size modes were between 1.0 and 1.8 mm and 3.2 and 5.6 mm, respectively. The average mass media aerodynamic diameter (MMAD) of suspended particles was 0.99 mm in this study. In addition, statistical methods, such as correlation coefficient and principal component analysis, were also used to identify the possible pollutant source for various particles size modes (nano, ultrafine, fine and coarse) during the winter months at a traffic sampling site in central Taiwan

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Observations of the Particle Size Distribution and Concentration in a Coastal System using an In Situ Laser Analyzer

Marine Technology Society Journal ◽

10.4031/002533202787914304 ◽

2002 ◽

Vol 36 (1) ◽

pp. 59-69 ◽

Cited By ~ 11

Author(s):

Teresa Serra ◽

Xavier Casamitjana ◽

Jordi Colomer ◽

Timothy C. Granata

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Water Column ◽

Size Distribution ◽

Posidonia Oceanica ◽

High Energy ◽

Suspended Particles ◽

Energy Conditions ◽

Coastal System

An in situ laser particle size analyzer (LISST-100, Sequoia Scientific, Inc.) has been used to study the particle size distribution and concentration of biological and non biological particles in the water column of a Mediterranean coastal system. Two field campaigns have been carried out during low and high energy conditions of the flow, caused by the passage of a storm front. For the low energy period, the water column remained stratified, whereas for the high energetic period the water column was warmer and well mixed. The first study dealt with the distribution of particles near the bottom of the coastal area. Here, two regions were taken into account. The first region was a sea-grass meadow of Posidonia oceanica and the second region was a barren sand area. The second study dealt with the determination of the vertical distribution of suspended particles in the whole water column of the system. The results showed a decrease in the vertical concentration of suspended particles in the water column with the passage of the storm front, which was associated with advection of warm water mass rather than by vertical mixing. In contrast, vertical resuspension determined the fate of suspended particles at the bottom of the water column and an increase of their concentration was found.

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Determination of Regularly Distributed Plant Protectants in Raw and Drinking Waters, Using a Multiresidue Method with Cyclodextrin-Modified Micellar Electrokinetic Chromatography

Journal of AOAC International ◽

10.1093/jaoac/82.6.1510 ◽

1999 ◽

Vol 82 (6) ◽

pp. 1510-1522 ◽

Cited By ~ 3

Author(s):

Hanno Stutz ◽

Hans Malissa

Keyword(s):

Environmental Protection Agency ◽

Micellar Electrokinetic Chromatography ◽

Solid Phase ◽

Tap Water ◽

Sodium Dodecyl ◽

Electrokinetic Chromatography ◽

The European Union ◽

Multiresidue Method ◽

Drinking Waters ◽

Wide Range

Abstract Eighteen plant protectant compounds were separated and determined by cyclodextrin-modified micellar electrokinetic chromatography (MEKC) in a multiclass/multiresidue method. The pesticides included are those dispersed in the greatest amounts today over agricultural acreage, and they represent 8 different classes of compounds (azoles, benzoic acids, chloroacetanilides, phenoxy acids, phenylureas, sulfonylureas, thiocarbamates, and triazines) covering a wide range of chemical reactivities and physicochemical properties. A 500 mL sample of tap water is preconcentrated by solid-phase extraction (SPE) with 300 mg combined polystyrene-divinylbenzene and methacrylate macroporous resins. Trapped analytes are eluted collectively with diethyl ether. Concentration and solvent change yield 250 μL of an acetone “concentrate,” which is further worked up and concentrated 1:10 to produce the MEKC injection solution containing 10 mmol/L sodium dodecyl sulfate (SDS) surfactant. For MEKC,2 phosphate/SDS buffer systems were designed, each allowing complete separation of all pesticides in a single run. Sensitivity was enhanced by a self-etched bubble cell and an injection procedure which employs stacking at reversed polarity. The ability of MEKC to determine plant protectants in raw and drinking waters at the 0.1 μg/L level, as demanded by the guidelines of the European Union, was demonstrated with spiked tap waters. Recoveries were between 75 and 110%, and limits of quantification, evaluated as method detection limits according to guidelines of the U.S. Environmental Protection Agency, ranged between 0.03 and 0.10 μg/L. The precisions of the relative migration times were all below 0.5%.

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Microorganism levels in spray from warm-water bidet toilet seats: factors affecting total viable and heterotrophic plate counts, and examination of the fluctuations and origins of Pseudomonas aeruginosa

Journal of Water and Health ◽

10.2166/wh.2017.137 ◽

2017 ◽

Vol 16 (3) ◽

pp. 346-358

Author(s):

Toru Iyo ◽

Keiko Asakura ◽

Makiko Nakano ◽

Kazuyuki Omae

Keyword(s):

Pseudomonas Aeruginosa ◽

Tap Water ◽

Viable Count ◽

Warm Water ◽

Water Heater ◽

Reservoir Water ◽

Advantages And Disadvantages ◽

On Demand ◽

Plate Counts ◽

Heterotrophic Plate Counts

Abstract The objectives of this study were to conduct an appropriate microbial evaluation of warm-water bidet toilet seats. Health-related advantages and disadvantages have been associated with using warm-water bidet toilet seats, which are classified according to the tank type, including tanks equipped with reservoir water heaters and on-demand tankless systems equipped with an instantaneous water heater. However, related bacterial research is sparse. Here, we performed a long-term survey of the behavior of microorganisms (i.e., the total viable count (TVC), heterotrophic plate counts (HPCs), and Pseudomonas aeruginosa count) in a university campus. We also examined the differences between the tank and on-demand types, and the origins of P. aeruginosa. A low TVC (≤1/mL) in the spray waters from both on-demand and tank-type warm-water bidet toilet seats showed low bacterial contamination, although there was an increase in HPC, i.e., growth of biofilms, inside in the warm-water bidet toilet seats. When P. aeruginosa was detected in spray water over an extended duration, the P. aeruginosa origin was considered as either from feces or tap water. Collectively our findings demonstrate that hygienic safety of warm-water bidet toilet seats is being maintained overall.

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