Exploring the oxidative stress response mechanism triggered by environmental water samples

Abstract Background Pesticide residue contamination of surface water in agricultural areas can have adverse effects on the ecosystem. We have performed an integrated chemical and bioanalytical profiling of surface water samples from Swedish agricultural areas, aiming to assess toxic activity due to presence of pesticides. A total of 157 water samples were collected from six geographical sites with extensive agricultural activity. The samples were chemically analyzed for 129 commonly used pesticides and transformation products. Furthermore, the toxicity was investigated using in vitro bioassays in the water samples following liquid–liquid extraction. Endpoints included oxidative stress response (Nrf2 activity), estrogen receptor (ER) activity, and aryl hydrocarbon receptor (AhR) activity. The bioassays were performed with a final enrichment factor of 5 for the water samples. All bioassays were conducted at non-cytotoxic conditions. Results A total of 51 pesticides and transformation products were detected in the water samples. Most of the compounds were herbicides, followed by fungicides, insecticides and transformation products. The highest total pesticide concentration in an individual sample was 39 µg/L, and the highest median total concentration at a sample site was 1.1 µg/L. The largest number of pesticides was 31 in a single sample. We found that 3% of the water samples induced oxidative stress response, 23% of the samples activated the estrogen receptor, and 77% of the samples activated the aryl hydrocarbon receptor. Using Spearman correlation coefficients, a statistically significant correlation was observed between AhR and ER activities, and AhR activity was strongly correlated with oxidative stress in samples with a high AhR activity. Statistically significant relationships were observed between bioactivities and individual pesticides, although the relationships are probably not causal, due to the low concentrations of pesticides. Co-occurrence of non-identified chemical pollutants and naturally occurring toxic compounds may be responsible for the induced bioactivities. Conclusions This study demonstrated that integrated chemical analysis and bioanalysis can be performed in water samples following liquid/liquid extraction with a final enrichment factor of 5. AhR and ER activities were induced in water samples from agricultural areas. The activities were presumably not caused by the occurrence of pesticides, but induced by other anthropogenic and natural chemicals.

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

Water Science & Technology ◽

10.2166/wst.1995.0654 ◽

1995 ◽

Vol 31 (5-6) ◽

pp. 435-438 ◽

Cited By ~ 12

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.

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Hollow-fiber ultrafiltration ofCryptosporidium parvumoocysts from a wide variety of 10-L surface water samples

Canadian Journal of Microbiology ◽

10.1139/w02-049 ◽

2002 ◽

Vol 48 (6) ◽

pp. 542-549 ◽

Cited By ~ 36

Author(s):

Ryan C Kuhn ◽

Kevin H Oshima

Keyword(s):

Surface Water ◽

Hollow Fiber ◽

Water Samples ◽

Cost Effective ◽

Environmental Water ◽

Cryptosporidium Oocysts ◽

Cost Effective Alternative ◽

High Turbidity ◽

Surface Water Samples ◽

Better Than

An optimized hollow-fiber ultrafiltration system (50 000 MWCO) was developed to concentrate Cryptosporidium oocysts from 10-L samples of environmental water. Seeded experiments were conducted using a number of surface-water samples from the southwestern U.S.A. and source water from four water districts with histories of poor oocyst recovery. Ultrafiltration produced a mean recovery of 47.9% from 19 water samples (55.3% from 39 individual tests). We also compared oocyst recoveries using the hollow-fiber ultrafiltration system with those using the Envirochek filter. In limited comparison tests, the hollow-fiber ultrafiltration system produced recoveries similar to those of the Envirochek filter (hollow fiber, 74.1% (SD = 2.8); Envirochek, 71.9% (SD = 5.2)) in low-turbidity (3.9 NTU) samples and performed better than the Envirochek filter in high-turbidity (159.0 NTU) samples (hollow fiber, 27.5%; Envirochek, 0.4%). These results indicate that hollow-fiber ultrafiltration can efficiently recover oocysts from a wide variety of surface waters and may be a cost-effective alternative for concentrating Cryptosporidium from water, given the reusable nature of the filter.Key words: Cryptosporidium, ultrafiltration, oocyst.

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Most Oxidative Stress Response In Water Samples Comes From Unknown Chemicals: The Need For Effect-Based Water Quality Trigger Values

Environmental Science & Technology ◽

10.1021/es304793h ◽

2013 ◽

Vol 47 (13) ◽

pp. 7002-7011 ◽

Cited By ~ 123

Author(s):

Beate I. Escher ◽

Charlotte van Daele ◽

Mriga Dutt ◽

Janet Y. M. Tang ◽

Rolf Altenburger

Keyword(s):

Oxidative Stress ◽

Water Quality ◽

Stress Response ◽

Water Samples ◽

Oxidative Stress Response

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NRF2-regulated cell cycle arrest at early stage of oxidative stress response mechanism

PLoS ONE ◽

10.1371/journal.pone.0207949 ◽

2018 ◽

Vol 13 (11) ◽

pp. e0207949 ◽

Cited By ~ 2

Author(s):

Margita Márton ◽

Nikolett Tihanyi ◽

Pál Gyulavári ◽

Gábor Bánhegyi ◽

Orsolya Kapuy

Keyword(s):

Oxidative Stress ◽

Cell Cycle ◽

Stress Response ◽

Cell Cycle Arrest ◽

Early Stage ◽

Oxidative Stress Response ◽

Response Mechanism ◽

Cycle Arrest

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Dead-End Ultrafiltration and DNA-Based Methods for Detection of Cyclospora cayetanensis in Agricultural Water

Applied and Environmental Microbiology ◽

10.1128/aem.01595-20 ◽

2020 ◽

Vol 86 (23) ◽

Author(s):

Mauricio Durigan ◽

Helen R. Murphy ◽

Alexandre J. da Silva

Keyword(s):

Surface Water ◽

Water Samples ◽

Protozoan Parasite ◽

Environmental Water ◽

Agricultural Water ◽

Content Type ◽

Cyclospora Cayetanensis ◽

Dead End ◽

Low Levels ◽

Surface Water Samples

ABSTRACT Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne diarrheal illness outbreaks worldwide. Most of these outbreaks are associated with the consumption of fresh produce. Sensitive and specific methods to detect C. cayetanensis in agricultural water are needed to identify the parasite in agricultural water used to irrigate crops that have been implicated in outbreaks. In this study, a method to detect C. cayetanensis in water by combining dead-end ultrafiltration (DEUF) with sensitive and specific molecular detection was developed and evaluated. Triplicates of 10-liter agricultural water samples were seeded with 200, 100, 25, 12, and 6 C. cayetanensis oocysts. Surface water samples were also collected in the Mid-Atlantic region. All water samples were processed by DEUF and backflushed from the ultrafilters. DNA was extracted from concentrated samples and analyzed by quantitative PCR (qPCR) targeting the C. cayetanensis 18S rRNA gene. All water samples seeded with 12, 25, 100, and 200 oocysts were positive, and all unseeded samples were negative. Samples seeded with 6 oocysts had a detection rate of 66.6% (8/12). The method was also able to detect C. cayetanensis isolates in surface water samples from different locations of the Chesapeake and Ohio Canal (C&O Canal) in Maryland. This approach could consistently detect C. cayetanensis DNA in 10-liter agricultural water samples contaminated with low levels of oocysts, equivalent to the levels that may be found in naturally incurred environmental water sources. Our data demonstrate the robustness of the method as a useful tool to detect C. cayetanensis from environmental sources. IMPORTANCE Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne outbreaks of diarrheal illness worldwide. These foodborne outbreaks associated with the consumption of fresh produce and agricultural water could play a role in the contamination process. In this study, a method to detect C. cayetanensis in agricultural water by combining a robust filtration system with sensitive and specific molecular detection was developed and validated by the FDA. The results showed that this approach could consistently detect low levels of C. cayetanensis contamination in 10 liters of agricultural water, corresponding to the levels that may be found in naturally occurring environmental water sources. The method was also able to detect C. cayetanensis in surface water samples from a specific location in the Mid-Atlantic region. Our data demonstrate the robustness of the method to detect C. cayetanensis in agricultural water samples, which could be very useful to identify environmental sources of contamination.

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