Cryptosporidium Oocysts and Giardia Cysts on Salad Products Irrigated with Contaminated Water

2010 ◽  
Vol 73 (6) ◽  
pp. 1138-1140 ◽  
Author(s):  
INMACULADA AMORÓS ◽  
JOSÉ L. ALONSO ◽  
GONZALO CUESTA
Keyword(s):  
Water Samples ◽  
Environmental Protection Agency ◽  
Internal Controls ◽  
Protozoan Parasites ◽  
Cryptosporidium Oocysts ◽  
Salad Vegetables ◽  
Texas Red ◽  
Irrigation Waters ◽  
Environmental Protection Agency Method ◽  
Giardia Cysts

A field study in Valencia, Spain, was done to determine the occurrence of Giardia and Cryptosporidium on salad products that are frequently eaten raw, such as lettuces and Chinese cabbage, and in irrigation waters. Four water samples were taken weekly 1 month before harvesting the vegetables. All water samples were analyzed using techniques included in the U.S. Environmental Protection Agency Method 1623. Standard methods for detecting protozoan parasites on salad vegetables are not available. Published techniques for the isolation of parasites from vegetables generally have low and variable recovery efficiencies. In this study, vegetables were analyzed using a recently reported method for detection of Cryptosporidium oocysts and Giardia cysts on salad products. The waters tested were positive for both Cryptosporidium and Giardia. Of 19 salad products studied, we observed Cryptosporidium in 12 samples and Giardia in 10 samples. Recoveries of the Texas Red–stained Cryptosporidium and Giardia, which were used as internal controls, were 24.5% ± 3.5% for Cryptosporidium and 16.7% ± 8.1% for Giardia (n = 8). This study provides data on the occurrence of Cryptosporidium and Giardia in salad products in Spain. The method was useful in the detection of Cryptosporidium oocysts and Giardia cysts on the vegetables tested, and it provides a useful analytical tool for occurrence monitoring.

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.

Detection of Protozoan Parasites and Microsporidia in Irrigation Waters Used for Crop Production

2002 ◽  
Vol 65 (2) ◽  
pp. 378-382 ◽  
Author(s):  
JEANETTE A. THURSTON-ENRIQUEZ ◽  
PAMELA WATT ◽  
SCOT E. DOWD ◽  
RICARDO ENRIQUEZ ◽  
IAN L. PEPPER ◽  
...  
Keyword(s):  
United States ◽  
Crop Production ◽  
The United States ◽  
Central American ◽  
Protozoan Parasites ◽  
Encephalitozoon Intestinalis ◽  
Cryptosporidium Oocysts ◽  
Polymerase Chain ◽  
Irrigation Waters ◽  
Giardia Cysts

The occurrence of human pathogenic parasites in irrigation waters used for food crops traditionally eaten raw was investigated. The polymerase chain reaction was used to detect human pathogenic microsporidia in irrigation waters from the United States and several Central American countries. In addition, the occurrence of both Cryptosporidium oocysts and Giardia cysts was determined by immunofluorescent techniques. Twenty-eight percent of the irrigation water samples tested positive for microsporidia, 60% tested positive for Giardia cysts, and 36% tested positive for Cryptosporidium oocysts. The average concentrations in samples from Central America containing Giardia cysts and Cryptosporidium oocysts were 559 cysts and 227 oocysts per 100 liters. In samples from the United States, averages of 25 Giardia cysts per 100 liters and <19 (average detection limit) Cryptosporidium oocysts per 100 liters were detected. Two of the samples that were positive for microsporidia were sequenced, and subsequent database homology comparisons allowed the presumptive identification of two human pathogenic species, Encephalitozoon intestinalis (94% homology) and Pleistophora spp. (89% homology). The presence of human pathogenic parasites in irrigation waters used in the production of crops traditionally consumed raw suggests that there may be a risk of infection to consumers who come in contact with or eat these products.

scholarly journals Low-cost internal controls for detection of Giardia cysts in water samples

2019 ◽  
Vol 71 ◽  
pp. 177-179
Author(s):  
Melissa Solano Barquero ◽  
Eric Morales Mora ◽  
Luz Chacón Jiménez ◽  
Erick Cordero Jara ◽  
Liliana Reyes Lizano ◽  
...  
Keyword(s):  
Water Samples ◽  
Low Cost ◽  
Internal Controls ◽  
Giardia Cysts

Occurrence of Cryptosporidium oocysts and Giardia cysts in a conventional water purification plant

2001 ◽  
Vol 43 (12) ◽  
pp. 89-92 ◽  
Author(s):  
A. Hashimoto ◽  
T. Hirata ◽  
S. Kunikane
Keyword(s):  
Water Purification ◽  
Water Samples ◽  
Geometric Mean ◽  
Giardia Cyst ◽  
Raw Water ◽  
Observation Level ◽  
Cryptosporidium Oocysts ◽  
Purification Plant ◽  
Mean Concentration ◽  
Giardia Cysts

A one-year monitoring of Cryptosporidium oocysts and Giardia cysts was conducted at a water purification plant. A total of thirteen 50 L samples of river source water and twenty-six 2,000 L samples of filtered water (treated by coagulation-flocculation, sedimentation and rapid filtration) were concentrated using a hollow fibre ultrafiltration membrane module at a purification plant. Cryptosporidium oocysts were detected in all raw water samples with a geometric mean concentration of 400 oocysts/m3 (range 160-1,500 oocysts/m3). Giardia cysts were detected in 12/13 raw waters (92%) with a geometric mean concentration of 170 cysts/m3 (range 40-580 oocysts/m3). Probability distributions of both Cryptosporidium oocyst and Giardia cyst concentration in raw water were nearly log-normal. In filtered water samples, Cryptosporidium oocysts were detected in 9/26 samples (35%) with a geometric mean concentration of 1.2 oocysts/m3 (range 0.5-8 oocysts/m3) and Giardia cysts in three samples (12%) with 0.8 cysts/m3 (range 0.5-2 oocysts/m3). The estimated removal of Cryptosporidium oocysts and Giardia cysts was, respectively, 2.54 log10 and 2.53 log10 on the basis of geometric means, 3.20 and 3.57 log10 on the basis of 50% observation level and 2.70 and 2.90 log10 on the basis of 90% observation level.

scholarly journals Development of a Method for Detection of Giardia duodenalis Cysts on Lettuce and for Simultaneous Analysis of Salad Products for the Presence of Giardia Cysts and Cryptosporidium Oocysts

2007 ◽  
Vol 73 (22) ◽  
pp. 7388-7391 ◽  
Author(s):  
N. Cook ◽  
R. A. B. Nichols ◽  
N. Wilkinson ◽  
C. A. Paton ◽  
K. Barker ◽  
...  
Keyword(s):  
Internal Control ◽  
Giardia Duodenalis ◽  
Immunomagnetic Separation ◽  
Internal Controls ◽  
Food Sample ◽  
Simultaneous Analysis ◽  
Natural Food ◽  
Cryptosporidium Oocysts ◽  
Natural Foods ◽  
Texas Red

ABSTRACT We report a method for detecting Giardia duodenalis cysts on lettuce, which we subsequently use to examine salad products for the presence of Giardia cysts and Cryptosporidium oocysts. The method is based on four basic steps: extraction of cysts from the foodstuffs, concentration of the extract and separation of the cysts from food materials, staining of the cysts to allow their visualization, and identification of cysts by microscopy. The concentration and separation steps are performed by centrifugation, followed by immunomagnetic separation using proprietary kits. Cyst staining is also performed using proprietary reagents. The method recovered 46.0% ± 19.0% (n = 30) of artificially contaminating cysts in 30 g of lettuce. We tested the method on a variety of commercially available natural foods, which we also seeded with a commercially available internal control, immediately prior to concentration of the extract. Recoveries of the Texas Red-stained Giardia cyst and Cryptosporidium oocyst internal controls were 36.5% ± 14.3% and 36.2% ± 19.7% (n = 20), respectively. One natural food sample of organic watercress, spinach, and rocket salad contained one Giardia cyst 50 g−1 of sample as an indigenous surface contaminant.

Studies on the prevalence of giardia cysts and cryptosporidium oocysts in South African water

1995 ◽  
Vol 31 (5-6) ◽  
pp. 435-438 ◽  
Author(s):  
R. Kfir ◽  
C. Hilner ◽  
M. du Preez ◽  
B. Bateman
Keyword(s):  
Surface Water ◽  
South African ◽  
Water Samples ◽  
Environmental Water ◽  
Treated Effluent ◽  
Effective Removal ◽  
Cryptosporidium Oocysts ◽  
South African Water ◽  
Surface Water Samples ◽  
Giardia Cysts

The levels of Giardia cysts and Cryptosporidium oocysts in 650 environmental water samples were investigated. Cysts and oocysts were found in all types of water tested. The presence of Giardia cysts exceeded Cryptosporidium oocysts both in the number per sample and the number of positive samples. Almost 50% of sewage samples studied contained Giardia cysts and 30% contained both Giardia cysts and Cryptosporidium oocysts. Treatment of sewage resulted in a reduction in the percentage of samples containing cysts and/or oocysts (30% of treated effluent samples were positive for Giardia and 25% had both cysts and oocysts). Higher numbers of Giardia cysts were found in surface water samples than in either sewage or treated effluents (55% of surface water samples were positive). However, the number of cysts isolated per surface water sample was lower on average. Most water purification plants showed effective removal of cysts and oocysts. However, 13% of potable water samples contained protozoan parasites, indicating occasional failure of the purification processes and the need for monitoring final treated water.

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.

scholarly journals Water used to moisten vegetables is a source of Escherichia coli and protozoan parasite contamination at markets in Hanoi, Vietnam

2014 ◽  
Vol 12 (4) ◽  
pp. 896-900 ◽  
Author(s):  
Nguyen Thuy Tram ◽  
Anders Dalsgaard
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Water Samples ◽  
Protozoan Parasite ◽  
Protozoan Parasites ◽  
Safety Hazards ◽  
E Coli ◽  
Cryptosporidium Spp ◽  
Median Concentration ◽  
Cryptosporidium Oocysts

The study was done to assess the level of fecal (Escherichia coli) and protozoan parasite (Cryptosporidium spp. and Giardia spp.) contamination in water used by traders to moisten vegetables at markets in Hanoi, Vietnam. A total of 200 splashing water samples from markets located within eight districts were analyzed for E. coli and Cryptosporidium spp. and Giardia spp. (oo)cysts. Giardia cysts were found in 17 splashing water samples and Cryptosporidium oocysts in nine samples, with median values of 20 cysts ml−1 and 10 oocysts ml−1, respectively. E. coli was found with a median concentration of 636 cfu ml−1 and its occurrence was negatively correlated with the numbers of protozoan parasites. The splashing water was kept in buckets that were rarely cleaned and often used for handwashing. The finding of these pathogens in splashing water is likely to represent real food safety hazards.

scholarly journals Effect of Sample Holding Time on Recovery ofCryptosporidium Oocysts and Giardia Cysts from Water Samples

2000 ◽  
Vol 66 (4) ◽  
pp. 1724-1725 ◽  
Author(s):  
L. J. Robertson ◽  
B. Gjerde
Keyword(s):  
Environmental Protection ◽  
Water Samples ◽  
Environmental Protection Agency ◽  
Holding Time ◽  
Raw Water ◽  
Protection Agency ◽  
Spiking Experiment ◽  
Giardia Cysts

ABSTRACT U.S. Environmental Protection Agency methods for analysis of water for Cryptosporidium and Giardia stipulate maximum sample holding times which are not always practical to comply with. A spiking experiment indicated that holding times of up to 2 weeks had no significant effect on recovery of these parasites from 10-liter samples of raw water in plastic carboys.

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