Influence of US EPA 1622 method successive steps on the viability of Cryptosporidium oocysts

2000 ◽  
Vol 41 (7) ◽  
pp. 189-196 ◽  
Author(s):  
K. Guyot ◽  
M. F. Gireaudot-Liepmann ◽  
A. Cabon ◽  
I. Riveau-Ricard ◽  
M. Lange ◽  
...  
Keyword(s):  
Water Samples ◽  
Tap Water ◽  
High Recovery ◽  
The Us ◽  
Cryptosporidium Oocysts ◽  
Cartridge Filter ◽  
Us Epa ◽  
Cryptosporidium Parvum Oocysts ◽  
Elution Step

Viable Cryptosporidium parvum oocysts were processed by the US EPA 1622 method to determine if the procedure that requires successive filtration, elutionand centrifugation alters their integrity and viability (determined by in vitro excystation). Oocyst seeded in tap water samples were also used to evaluate recovery efficiencies and impact of the whole procedure on oocyst viability. Filtration through Envirochek Gelman cartridge was found not to damage oocysts. The use of Laureth-12 buffer during the elution step was shown to lead to greater spontaneous oocysts excystation than other phosphate buffers containing between 80 and/or SDS (like the Gelman buffer). However, this drawback was widely balanced against the best efficiency of this buffer to elute oocysts captured by the cartridge filter and therefore against its high recovery efficiency. Thus, in water samples in which the oocyst concentration is expected to be low, it is more advantageous to employ the Laureth-12 buffer for the elution through it can influence viability. Centrifugation speeds (1,000–5,000 g) did not alter oocysts.

scholarly journals Detection of Giardia and Cryptosporidium cysts/oocysts in watersheds and drinking water sources in Brazil urban areas

2009 ◽  
Vol 8 (2) ◽  
pp. 399-404 ◽  
Author(s):  
Maria Tereza Pepe Razzolini ◽  
Thaís Filomena da Silva Santos ◽  
Veridiana Karmann Bastos
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Urban Areas ◽  
Water Sources ◽  
Raw Water ◽  
Protozoan Parasites ◽  
The Us ◽  
Cryptosporidium Oocysts ◽  
Us Epa ◽  
Giardia Cysts

The protozoan parasites Giardia and Cryptosporidium have been described as important waterborne disease pathogens, and are associated with severe gastrointestinal illnesses. The objective of this paper was to investigate the presence of Giardia cysts and Cryptosporidium oocysts in samples from watershed catchments and treated water sources. A total of 25 water samples were collected and examined according to the US EPA—Method 1623, 2005, consisting of 12 from drinking water and 13 from raw water. Positive samples from raw water for Giardia cysts and Cryptosporidium oocysts were 46.1 and 7.6%, respectively. In finished water, positive samples were 41.7% for Giardia cysts and 25.0% for Cryptosporidium oocysts. Concentrations of Giardia cysts found in raw water samples ranged from “not detected” to 3.4 cysts/L, whereas concentrations of Cryptoporidium oocysts ranged from “not detected” to 0.1 oocysts/L. In finished water, Giardia concentrations ranged from “not detected” to 0.06 cysts/L, and Cryptosporidium, from “not detected” to 0.01 oocysts/L. Concentrations of Giardia cysts and Cryptosporidium oocysts were not high in the samples analyzed. Nevertheless, the results of this study highlight the need to monitor these organisms in both raw and drinking water.

Evaluation of different filtration techniques for the concentration of cryptosporidium oocysts from water

1995 ◽  
Vol 31 (5-6) ◽  
pp. 425-429 ◽  
Author(s):  
K. M. Shepherd ◽  
A. P. Wyn-Jones
Keyword(s):  
River Water ◽  
Recovery Rate ◽  
Membrane Filtration ◽  
Tap Water ◽  
High Recovery ◽  
High Recovery Rate ◽  
Cellulose Acetate Membranes ◽  
Cryptosporidium Oocysts ◽  
Cartridge Filter ◽  
Consistent Method

The relative performances of different filter matrices were assessed for the concentration of Cryptosporidium oocysts in water. Cartridge filtration methods were examined and compared with membrane filtration and a flocculation method using seeded tap and river water to determine the most efficient and consistent method of sample concentration. From 10L samples, calcium carbonate flocculation gave the most consistently high recovery rate of Cryptosporidium oocysts (tap water mean 72.9%; river water mean 41.9%), followed by membrane filtration using 1.2μm cellulose acetate membranes (tap water mean 37.8%; river water mean 26.6%). For filtration of larger volumes (>100L) of water the Cuno Microwynd II cartridge filter provided the highest recovery rate of oocysts (tap water mean 13.3%; river water mean 10.8%) when compared with the Vokes cartridge and Balston filters. All recoveries fell dramatically when sucrose flotation techniques were applied.

Blind trials evaluating in vitro infectivity ofCryptosporidiumoocysts using cell culture immunofluorescence

2007 ◽  
Vol 53 (5) ◽  
pp. 656-663 ◽  
Author(s):  
Zia Bukhari ◽  
David M. Holt ◽  
Michael W. Ware ◽  
Frank W. Schaefer
Keyword(s):  
Cell Culture ◽  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Cost Effective ◽  
Protection Agency ◽  
The Us ◽  
Cryptosporidium Parvum Oocysts ◽  
High Degree ◽  
Blind Trials

An optimized cell culture immunofluorescence (IFA) procedure, using the HCT-8 cell line, was evaluated in blind trials to determine the sensitivity and reproducibility of measuring the infectivity of flow-cytometry-prepared inocula of Cryptosporidium parvum oocysts. In separate trials, suspensions consisting of between 0% and 100% viable oocysts were prepared at the US Environmental Protection Agency, shipped to the American Water Laboratory, and analyzed blindly by cell culture IFA. Data indicated the control (100% live) oocyst suspensions yielded statistically similar results to cell culture dose–response curve data developed previously at the American Water Laboratory. For test samples containing oocyst suspensions of unknown infectivity, cell culture IFA analyses indicated a high degree of correlation (r2= 0.89; n = 26) with the values expected by the US Environmental Protection Agency. Cell culture infectivity correlates well with neonatal mouse infectivity assays, and these blind validation trials provide credibility for the cell culture IFA procedure as a cost-effective and expedient alternative to mouse infectivity assays for determining in vitro infectivity of C. parvum oocysts.

scholarly journals Disinfection by-products and extractable organic compounds in South African tap water

2008 ◽  
Vol 4 (1) ◽  
Author(s):  
Carien Nothnagel ◽  
Karsten Kotte ◽  
J J Pienaar ◽  
P G Van Zyl ◽  
J P Beukes
Keyword(s):  
Drinking Water ◽  
South African ◽  
Tap Water ◽  
Target Range ◽  
Preliminary Results ◽  
The Us ◽  
Microbiological Parameters ◽  
Us Epa ◽  
Micro Organisms ◽  
By Products

An important step in urban purification of drinking water is disinfection by e.g. chlorination where potential pathogenic micro-organisms in the water supply are killed. The presence of organic material in natural water leads to the formation of organic by- products during disinfection. Over 500 of these disinfection by-products (DBPs) have been identified and many more are estimated to form during the disinfection step. Several DBPs such as trihalomethanes (THMs), which is carcinogenic, poses serious health risks to the community. There is very few quantitative data available which realizes the actual levels of these compounds present in drinking water. The levels of four THMs present in drinking water were measured. It included chloroform, bromodichloromethane, chlorodibromomethane and bromoform. Although microbiological parameters are considered to get more attention than disinfection by-products, the measurement of the levels of these compounds in South-African drinking water is essential together with establishing minimum acceptable concentration levels. The target range for total trihalomethanes (TTHMs) established by the US EPA at the end of 2003 is 0-0.08ug/mL. The aim of this paper is to create an awareness of the problem as well as presenting preliminary results obtained with the method of analysis. Preliminary results indicate that urgent attention must be given to the regulation and monitoring of DBPs in South African drinking water.

Optimization of the Envirochek capsule method and immunomagnetic separation procedure for the detection of low levels of Cryptosporidium in large drinking water samples

2000 ◽  
Vol 41 (7) ◽  
pp. 111-117 ◽  
Author(s):  
A. Pezzana ◽  
Ph. Vilaginès ◽  
F. Bordet ◽  
D. Coquard ◽  
B. Sarrette ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Magnetic Beads ◽  
Tap Water ◽  
Immunomagnetic Separation ◽  
Sample Volume ◽  
Separation Procedure ◽  
Cryptosporidium Oocysts ◽  
Low Levels ◽  
Drinking Water Samples

The method for concentration of Cryptosporidium oocysts in large drinking water samples using the Envirocheck capsule has been optimized for the detection of low levels of oocysts. Elution from the filter by contact time and vortex agitation gave 68% oocyst recovery. Centrifugation (1,250 g; 30 min; 4°C) improved recovery to 94% without morphological damage of the oocysts. Increasing the ratio of magnetic beads to sample volume in the IMS procedure led to 69% efficiency. In these conditions, the overall recovery of the procedure was 49% as assessed with low oocysts spike doses in 100 litres tap water samples. The methodology described allows the detection of 0.1 oocyst per litre when 100 litres samples are processed.

scholarly journals Modifications to United States Environmental Protection Agency Methods 1622 and 1623 for Detection of Cryptosporidium Oocysts and Giardia Cysts in Water

2003 ◽  
Vol 69 (1) ◽  
pp. 267-274 ◽  
Author(s):  
Randi M. McCuin ◽  
Jennifer L. Clancy
Keyword(s):  
Environmental Protection ◽  
Water Samples ◽  
Environmental Protection Agency ◽  
Tap Water ◽  
Sample Collection ◽  
Protection Agency ◽  
Cryptosporidium Oocysts ◽  
The Mean ◽  
Epa Methods ◽  
Made In

ABSTRACT Collaborative and in-house laboratory trials were conducted to evaluate Cryptosporidium oocyst and Giardia cyst recoveries from source and finished-water samples by utilizing the Filta-Max system and U.S. Environmental Protection Agency (EPA) methods 1622 and 1623. Collaborative trials with the Filta-Max system were conducted in accordance with manufacturer protocols for sample collection and processing. The mean oocyst recovery from seeded, filtered tap water was 48.4% ± 11.8%, while the mean cyst recovery was 57.1% ± 10.9%. Recovery percentages from raw source water samples ranged from 19.5 to 54.5% for oocysts and from 46.7 to 70.0% for cysts. When modifications were made in the elution and concentration steps to streamline the Filta-Max procedure, the mean percentages of recovery from filtered tap water were 40.2% ± 16.3% for oocysts and 49.4% ± 12.3% for cysts by the modified procedures, while matrix spike oocyst recovery percentages ranged from 2.1 to 36.5% and cyst recovery percentages ranged from 22.7 to 68.3%. Blinded matrix spike samples were analyzed quarterly as part of voluntary participation in the U.S. EPA protozoan performance evaluation program. A total of 15 blind samples were analyzed by using the Filta-Max system. The mean oocyst recovery percentages was 50.2% ± 13.8%, while the mean cyst recovery percentages was 41.2% ± 9.9%. As part of the quality assurance objectives of methods 1622 and 1623, reagent water samples were seeded with a predetermined number of Cryptosporidium oocysts and Giardia cysts. Mean recovery percentages of 45.4% ± 11.1% and 61.3% ± 3.8% were obtained for Cryptosporidium oocysts and Giardia cysts, respectively. These studies demonstrated that the Filta-Max system meets the acceptance criteria described in U.S. EPA methods 1622 and 1623.

Studies evaluating the applicability of utilising the same concentration techniques for the detection of protozoan parasites and viruses in water

1995 ◽  
Vol 31 (5-6) ◽  
pp. 417-423 ◽  
Author(s):  
R. Kfir ◽  
C. Hilner ◽  
M. du Preez ◽  
B. Bateman
Keyword(s):  
Water Samples ◽  
Tap Water ◽  
Cost Effective ◽  
Environmental Water ◽  
Similar Efficacy ◽  
Sample Volume ◽  
Water Recovery ◽  
Protozoan Parasites ◽  
Cartridge Filter ◽  
Giardia Muris

In this study concentration techniques regularly used for viral detection, i.e. flat-bed ultrafiltration and Filterite cartridge filtration, were evaluated for their efficacies in the recovery of protozoan parasites from water. Recovery of cysts was studied using tap water seeded with Giardia muris cysts and compared to methods designed for the detection of protozoan parasites. Recovery of cysts utilizing 1.2µm membrane filters was 11.1% (4.5-23%) compared to 11.6% (2.7-25.5%) with ultrafiltration (pore size 46-50 Å, with a molecular cut off of 50 000 daltons). Comparison of these methods for the isolation of Giardia cysts and Cryptosporidium oocysts from environmental water samples also indicated a similar efficacy. The recovery of cysts from 1001 of seeded samples using a Cuno wynd cartridge filter was 12.2% (1.6-46%) compared to 13.4% (5-24.2%) using a Filterite cartridge filter. Although the results indicated similar recovery efficacies for these two methods, use of Filterite resulted in a more consistent recovery rate. This study also indicated that the use of cartridge filters for the processing of large volume water samples (1001) showed a slightly better recovery efficacy than the flat-bed filtration technique which limits sample volume to about 101. This study shows that concentration techniques utilised for the isolation of enteric viruses can also be applied for the detection of protozoan parasites from water. This procedure allows for co-analysis of both viruses and protozoan parasites and provides a more rapid and cost-effective evaluation of water quality.

scholarly journals PREVALENCE OF CRYPTOSPORIDIUM OOCYSTS IN THE WATER OF AL-DEHAB AL-ABYAD VILLAGE IN BAGHDAD- IRAO

2002 ◽  
Vol 26 (1) ◽  
pp. 44-55
Author(s):  
R. H. Rahif ◽  
B. A. W. Al-Gylani
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Municipal Water Supply ◽  
Municipal Water ◽  
Cryptosporidium Oocysts ◽  
Cartridge Filter ◽  
Water Tanks

Detection of oocysts of Cryptosporidium in water of Al-Dehab AL-Abyad village was carried, from January to December 2001, through examination of 240 different water samples, using millipore cartridge filter and an alternative Iraqi filters. The oocysts were revealed in 73 samples in rate of 30.41%, all water samples collected from ponds revealed oocysts, in 29.16 % of water tanks and 22.91% of sewage samples. Oocysts were not found in the water samples from municipal water supply. Statistical differences (P<0.05) in the presence of oocysts in the different samples were revealed. The alternative tissue filter was efficient for isolation of oocysts in comparison with the imported filters. Differences were found in the measurement and shape of isolated Cryptosporidium oocysts, and they were ranged from round (4.3 * 3.9 - 5 x 4.2 Mm) to oval (7.4 *5.5-8 x 6 mm) and they were also varied in the number according to the samples.

scholarly journals The Microscopic Detection and Identification of Acanthamoeba Spp. In Water Samples Following Enrichment by in Vitro-Cultivation Under Two Distinct Temperature Conditions.

2021 ◽  
Author(s):  
Sakhi Elmahdi ◽  
MOUMNI MOSTAFA ◽  
Radid Horia ◽  
ARAHOU MOHAMED ◽  
FEKHAOUI MOHAMED
Keyword(s):  
Water Samples ◽  
Tap Water ◽  
In Vitro Cultivation ◽  
Temperature Conditions ◽  
Microscopic Detection ◽  
Detection And Identification ◽  
Standard Culture ◽  
Public Bath ◽  
Distinct Temperature

Abstract Acanthamoeba is a genus of free-living amoeba commonly found in environmental sources such as water, soil and air, and can infect humans. There is a significant challenge in the detection and identification of members of this genus in water samples. In order attempt to overcome this challenge, we investigated using in vitro culture, under distinct temperature conditions, to grow and enrich amoeba prior to detection and identification. Aliquots of 150 water samples, collected from Rabat (30 from each river, fountain, sea, public bath and tap water), were individually inoculated into standard culture medium non-nutritive agar and incubated for two weeks at 25 °C and 30 °C under otherwise standard conditions. PCR was used to confirm the presence of Acanthamoeba DNA in positive samples. The findings showed that Acanthamoeba grew more rapidly at 30 °C than 25 °C, allowing improved microscopic detection and identification at the former temperature. This investigation shows clearly that the diagnostic sensitivity of an in vitro based culture system is temperature-dependent.

Development of ATP assay as a surrogate indicator of viability of Cryptosporidium parvum oocysts

2000 ◽  
Vol 41 (7) ◽  
pp. 181-188 ◽  
Author(s):  
I. Somiya ◽  
S. Fujii ◽  
N. Kishimoto ◽  
R-H. Kim
Keyword(s):  
Linear Relationship ◽  
Cryptosporidium Parvum ◽  
Simple Procedure ◽  
Ozone Treatment ◽  
Atp Assay ◽  
Cryptosporidium Oocysts ◽  
Batch Condition ◽  
Cryptosporidium Parvum Oocysts ◽  
Permeability Assay

Adenosine Triphosphate (ATP) determination was applied to evaluate viability of Cryptosporidium oocysts. Three pretreatment methods, such as incubation in acidified Hanks balanced salt solution (HBSS), excystation and sonication were investigated for ATP extraction from oocysts. Incubation in acidified HBSS was insufficient to extract ATP from oocysts, but a linear relationship between the number of oocysts and the concentration of ATP extracted was observed in the test of excystation and sonication treatments. Sonicationtreatment was able to extract ATP from oocysts more rapidly and precisely than excystation treatment. ATP amount per oocyst by sonication treatment (ATPs) was evaluated to be 2.9×10–8 μg on average, andits detection limit was 500 oocysts/100 μl. Ozone treatment experiments were conducted in batch condition to evaluate differences among ATP concentrations extracted, in vitro excystation and DAPI/PI permeability assays. ATPs assay was observed to have a linear relationship with DAPI/PI permeability assay (R2=0.98). As a result, ATP assay is applicable as a surrogate indicator of the viability of C. parvum, and is superior to in vitro excystation and DAPI/PI permeability assay, because of its rapid, accurate and simple procedure.

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