scholarly journals A Summer of Cyanobacterial Blooms in Belgian Waterbodies: Microcystin Quantification and Molecular Characterizations

Toxins ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 61
Author(s):  
Wannes Hugo R. Van Hassel ◽  
Mirjana Andjelkovic ◽  
Benoit Durieu ◽  
Viviana Almanza Marroquin ◽  
Julien Masquelier ◽  
...  
Keyword(s):  
Water Samples ◽  
Direct Sequencing ◽  
Amplicon Sequencing ◽  
Cyanobacterial Blooms ◽  
World Health ◽  
Limit Of Quantification ◽  
Guideline Value ◽  
16S Rna ◽  
Mcye Gene ◽  
Health Organization

In the context of increasing occurrences of toxic cyanobacterial blooms worldwide, their monitoring in Belgium is currently performed by regional environmental agencies (in two of three regions) using different protocols and is restricted to some selected recreational ponds and lakes. Therefore, a global assessment based on the comparison of existing datasets is not possible. For this study, 79 water samples from a monitoring of five lakes in Wallonia and occasional blooms in Flanders and Brussels, including a canal, were analyzed. A Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) method allowed to detect and quantify eight microcystin congeners. The mcyE gene was detected using PCR, while dominant cyanobacterial species were identified using 16S RNA amplification and direct sequencing. The cyanobacterial diversity for two water samples was characterized with amplicon sequencing. Microcystins were detected above limit of quantification (LOQ) in 68 water samples, and the World Health Organization (WHO) recommended guideline value for microcystins in recreational water (24 µg L−1) was surpassed in 18 samples. The microcystin concentrations ranged from 0.11 µg L−1 to 2798.81 µg L−1 total microcystin. For 45 samples, the dominance of the genera Microcystis sp., Dolichospermum sp., Aphanizomenon sp., Cyanobium/Synechococcus sp., Planktothrix sp., Romeria sp., Cyanodictyon sp., and Phormidium sp. was shown. Moreover, the mcyE gene was detected in 75.71% of all the water samples.

scholarly journals Noncompetitive Chromogenic Lateral-Flow Immunoassay for Simultaneous Detection of Microcystins and Nodularin

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 79 ◽  
Author(s):  
Sultana Akter ◽  
Teemu Kustila ◽  
Janne Leivo ◽  
Gangatharan Muralitharan ◽  
Markus Vehniäinen ◽  
...  
Keyword(s):  
Water Quality ◽  
Simultaneous Detection ◽  
Antibody Fragment ◽  
Water Quality Monitoring ◽  
Lateral Flow ◽  
Cyanobacterial Blooms ◽  
World Health ◽  
Lateral Flow Immunoassay ◽  
Guideline Value ◽  
Health Organization

Cyanobacterial blooms cause local and global health issues by contaminating surface waters. Microcystins and nodularins are cyclic cyanobacterial peptide toxins comprising numerous natural variants. Most of them are potent hepatotoxins, tumor promoters, and at least microcystin-LR is possibly carcinogenic. In drinking water, the World Health Organization (WHO) recommended the provisional guideline value of 1 µg/L for microcystin-LR. For water used for recreational activity, the guidance values for microcystin concentration varies mostly between 4–25 µg/L in different countries. Current immunoassays or lateral flow strips for microcystin/nodularin are based on indirect competitive method, which are generally more prone to sample interference and sometimes hard to interpret compared to two-site immunoassays. Simple, sensitive, and easy to interpret user-friendly methods for first line screening of microcystin/nodularin near water sources are needed for assessment of water quality and safety. We describe the development of a two-site sandwich format lateral-flow assay for the rapid detection of microcystins and nodularin-R. A unique antibody fragment capable of broadly recognizing immunocomplexes consisting of a capture antibody bound to microcystins/nodularin-R was used to develop the simple lateral flow immunoassay. The assay can visually detect the major hepatotoxins (microcystin-LR, -dmLR, -RR, -dmRR, -YR, -LY, -LF -LW, and nodularin-R) at and below the concentration of 4 µg/L. The signal is directly proportional to the concentration of the respective toxin, and the use of alkaline phosphatase activity offers a cost efficient alternative by eliminating the need of toxin conjugates or other labeling system. The easy to interpret assay has the potential to serve as a microcystins/nodularin screening tool for those involved in water quality monitoring such as municipal authorities, researchers, as well as general public concerned of bathing water quality.

scholarly journals Temporal and spatial variability of cyanobacterial toxins microcystins in three interconnected freshwater reservoirs

2010 ◽  
Vol 75 (9) ◽  
pp. 1303-1312 ◽  
Author(s):  
Luděk Bláha ◽  
Lucie Bláhová ◽  
Jiří Kohoutek ◽  
Ondřej Adamovský ◽  
Pavel Babica ◽  
...  
Keyword(s):  
Dry Weight ◽  
Cyanobacterial Blooms ◽  
World Health ◽  
Cyanobacterial Toxins ◽  
Toxic Cyanobacteria ◽  
Guideline Value ◽  
High Concentrations ◽  
Health Organization ◽  
Reported Data ◽  
Natural Dynamics

In spite of substantial research on health and the ecological risks associated with cyanobacterial toxins in the past decades, the understanding of the natural dynamics and variability of toxic cyanobacterial blooms is still limited. Herein, the results of long term monitoring 1998-1999 / 2001-2008 of three reservoirs (V?r, Brno and Nov? Ml?ny), where toxic blooms develop annually, are reported. These three reservoirs provide a unique model because they are interconnected by the Svratka River, which allows possible transfer of phytoplankton as well as toxins from one reservoir to another. The frequency of the occurrence and dominance of the major cyanobacterial taxa Microcystis aeruginosa did not change during the investigated period but substantial variability was observed in the composition of other phytoplankton. Although absolute concentrations of the studied toxins (microcystins) differed among the reservoirs, there were apparent parallel trends. For example, during certain years, the microcystin concentrations were systematically elevated in all three studied reservoirs. Furthermore, the concentration profiles in the three sites were also correlated (parallel trends) within individual seasons based on monthly sampling. Microcystin-LR, a variant for which the World Health Organization has recommended a guideline value, formed only about 30-50% of the total microcystins. This is of importance, especially in the V?r reservoir that serves as a drinking water supply. Maxima in the cell-bound microcystins (intracellular; expressed per dry weight biomass) generally preceded the maxima of total microcystins (expressed per volume of water sample). Overall, the maximum concentration in the biomass (all three reservoirs, period 1993-2005) was 6.1 mg g-1 dry weight and the median values were in the range 0.065-2.3 mg g-1 dry weight. These are generally high concentrations in comparison with both Czech Republic and worldwide reported data. The present data revealed substantial variability of both toxic cyanobacteria and their peptide toxins that should be reflected by detailed monitoring programs.

scholarly journals OCORRÊNCIA DO HERBICIDA TEBUTHIURON NA ÁGUA SUBTERRÂNEA DA MICROBACIA DO CÓRREGO ESPRAIADO, RIBEIRÃO PRETO - SP

2001 ◽  
Vol 11 ◽  
Author(s):  
MARCO ANTONIO FERREIRA GOMES ◽  
CLÁUDIO A. SPADOTTO ◽  
VERA LÚCIA LANCHOTTE
Keyword(s):  
Biological Activity ◽  
Low Temperature ◽  
Water Samples ◽  
Critical Level ◽  
World Health ◽  
Contamination Risk ◽  
Soil Mobility ◽  
Drinkable Water ◽  
Health Organization ◽  
Monitoring Area

Pretendeu-se mostrar que o herbicida Tebuthiuron, selecionado entre outros usados na cultura de cana-de-açúcar, oferece risco de contaminação para a água subterrânea em função de suas características físico-químicas, principalmente, quando aplicado em áreas de recarga direta de aqüíferos consideradas de alta vulnerabilidade natural. Assim, efetuou-se monitoramento do referido herbicida no período compreendido entre 1995 e 1999, coletando amostras de água de poço semi-artesiano, com 53 metros de profundidade, localizado na microbacia do Córrego Espraiado, município de Ribeirão Preto/SP, Brasil, no qual tem sido freqüente o uso do produto em questão. Para efeito de testemunha da amostra de água foi considerado um poço semi-artesiano de profundidade semelhante, localizado cerca de três quilômetros de distância do poço objeto de monitoramento. Os resultados obtidos mostraram que o Tebuthiuron está presente em todas as amostras analisadas, embora em concentrações abaixo do nível crítico para padrão de potabilidade, conforme os limites mais restritivos estabelecidos pela Organização Mundial de Saúde (para os pesticidas em uso é de 0,1 µg/L por pesticida e de 0,5 µg/L para pesticidas totais). Mesmo com os baixos valores de concentração encontrados fica evidente que o Tebuthiuron está atingindo a água subterrânea podendo aumentar sua concentração pela existência de condições ambientais favoráveis à preservação da molécula em profundidade (tais como baixa temperatura, baixa atividade biológica e ausência de luz). Caso o nível crítico seja atingido, o risco de contaminação poderia ser minimizado por meio da substituição do Tebuthiuron por outro herbicida com menor mobilidade no perfil do solo. OCCURRENCE OF THE HERBICIDE TEBUTHIURON IN GROUNDWATER OF ESPRAIADO CATCHMENT RIBEIRAO PRETO - SP (BRASIL) Abstract The herbicide Tebuthiuron, selected among others utilized in sugar-cane crop, shows groundwater contamination risk due to its physicochemical properties, mainly, when applied in direct recharge areas of aquifers considered of high natural vulnerability. In this context, the monitoring of this herbicide in the period of 1995 through 1999 was realized, by collecting water samples of aquifers 53 m depht, located in Espraiado catchment, Ribeirao Preto/SP (Brazil) in which the product has been extensively used. For blank assays it was utilized water samples collected similarly 3 Km away from the monitoring area. The results obtained showed that Tebuthiuron is present in all analyzed samples. Although in lower concentrations of the critical level for drinkable water, following the restrictive limits established by World Health Organization (for pesticides in use is 0,1 µg/L by pesticide and of 0,5 µg/L for total pesticides). Even if the low concentration values found it is evident that the Tebuthiuron affects the groundwater, and could enhance its concentration by favorable ambiental conditions for molecule preservation in deep water (such as low temperature, low biological activity and absence of light). The present scenary reflects contamination risk in case of reaching the critical level, which could only be minimized by the substitution of Thebuthiuron for other herbicide with lower soil mobility.

scholarly journals Programme for Harmonization to the International Scale in Latin America for BCR-ABL1 quantification in CML patients: findings and recommendations

2020 ◽  
Vol 58 (12) ◽  
pp. 2025-2035
Author(s):  
María Sol Ruiz ◽  
María Belén Sánchez ◽  
Yuly Masiel Vera Contreras ◽  
Evangelina Agrielo ◽  
Marta Alonso ◽  
...  
Keyword(s):  
Latin America ◽  
Myeloid Leukemia ◽  
World Health ◽  
Molecular Response ◽  
Limit Of Quantification ◽  
International Scale ◽  
Deep Molecular Response ◽  
Health Organization ◽  
First Time

AbstractObjectivesThe quantitation of BCR-ABL1 mRNA is mandatory for chronic myeloid leukemia (CML) patients, and RT-qPCR is the most extensively used method in testing laboratories worldwide. Nevertheless, substantial variation in RT-qPCR results makes inter-laboratory comparability hard. To facilitate inter-laboratory comparative assessment, an international scale (IS) for BCR-ABL1 was proposed.MethodsThe laboratory-specific conversion factor (CF) to the IS can be derived from the World Health Organization (WHO) genetic reference panel; however, this material is limited to the manufacturers to produce and calibrate secondary reference reagents. Therefore, we developed secondary reference calibrators, as lyophilized cellular material, aligned to the IS. Our purpose was both to re-evaluate the CF in 18 previously harmonized laboratories and to propagate the IS to new laboratories.ResultsOur field trial including 30 laboratories across Latin America showed that, after correction of raw BCR-ABL1/ABL1 ratios using CF, the relative mean bias was significantly reduced. We also performed a follow-up of participating laboratories by annually revalidating the process; our results support the need for continuous revalidation of CFs. All participating laboratories also received a calibrator to determine the limit of quantification (LOQ); 90% of them could reproducibly detect BCR-ABL1, indicating that these laboratories can report a consistent deep molecular response. In addition, aiming to investigate the variability of BCR-ABL1 measurements across different RNA inputs, we calculated PCR efficiency for each individual assay by using different amounts of RNA.ConclusionsIn conclusion, for the first time in Latin America, we have successfully organized a harmonization platform for BCR-ABL1 measurement that could be of immediate clinical benefit for monitoring the molecular response of patients in low-resource regions.

T26248G-transversion mutation in exon7 of the putative methyltransferase Nsun7 gene causes a change in protein folding associated with reduced sperm motility in asthenospermic men

2015 ◽  
Vol 27 (3) ◽  
pp. 471 ◽  
Author(s):  
Nahid Khosronezhad ◽  
Abasalt Hosseinzadeh Colagar ◽  
Syed Golam Ali Jorsarayi
Keyword(s):  
Protein Folding ◽  
Sperm Motility ◽  
Protein Function ◽  
Direct Sequencing ◽  
Protein Structures ◽  
Single Strand Conformation Polymorphism ◽  
Extraction Methods ◽  
World Health ◽  
Transversion Mutation ◽  
Health Organization

The NOP2/Sun domain family, member 7 (Nsun7) gene, which encodes putative methyltransferase Nsun7, has a role in sperm motility in mice. In humans, this gene is located on chromosome 4 with 12 exons. The aim of the present study was to investigate mutations of exon 7 in the normospermic and asthenospermic men. Semen samples were collected from the Fatemezahra IVF centre (Babol, Iran) and analysed on the basis of World Health Organization (WHO) guidelines using general phenol–chloroform DNA extraction methods. Exon 7 was amplified using Sun7-F and Sun7-R primers. Bands on samples from asthenospermic men that exhibited different patterns of movement on single-strand conformation polymorphism gels compared with normal samples were identified and subjected to sequencing for further identification of possible mutations. Direct sequencing of polymerase chain reaction (PCR) products, along with their analysis, confirmed C26232T-transition and T26248G-transversion mutations in asthenospermic men. Comparison of normal and mutant protein structures of Nsun7 indicated that the amino acid serine was converted to alanine, the structure of the helix, coil and strand was changed, and the protein folding and ligand binding sites were changed in samples from asthenospermic men with a transversion mutation in exon 7, indicating impairment of protein function. Because Nsun7 gene products have a role in sperm motility, if an impairment occurs in exon 7 of this gene, it may lead to infertility. The transversion mutation in exon 7 of the Nsun7 gene can be used as an infertility marker in asthenospermic men.

scholarly journals Physico-chemical quality of drinking water in the Njoro sub-county in Kenya

2018 ◽  
Vol 8 (3) ◽  
pp. 497-507
Author(s):  
Philip Ruciaka Kirianki ◽  
Edward Muchiri ◽  
Natasha Potgieter
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Water Source ◽  
World Health ◽  
Water Shortages ◽  
Storage Container ◽  
Standard Assessment ◽  
Physico Chemical ◽  
Study Support ◽  
Health Organization

Abstract Njoro sub-county in Kenya suffers from constant water shortages causing the residents to rely on both improved and unimproved water sources in the area. The households in the sub-county also use different household storage containers to store drinking water in times when water is not readily available. This study was therefore undertaken to assess selective physico-chemical parameters of water used by the population for drinking purposes using standard assessment methods. A total of 372 water source samples and 162 storage container water samples were tested over a period of three months. Turbidity (0.70–273.85 NTU), iron (0.7–2.10 mg/L), fluoride (0.15–4.01 mg/L), manganese (0.01–0.37 mg/L), and nitrate (0.09–27.90 mg/L) levels in water samples were generally higher than the Kenya Bureau of Standards (KEBS) and/or the World Health Organization (WHO) water quality recommendations for safe drinkable water. The results from this study support the need for continuous monitoring and treating drinking water at the points of collection and of consumption to minimize the long-term health effects on communities consuming this water.

scholarly journals Assessment of Some Heavy Metals in Drinking Water Samples of Tunceli, Turkey

2011 ◽  
Vol 8 (1) ◽  
pp. 276-280 ◽  
Author(s):  
Olcay Kaplan ◽  
Nuran Cikcikoglu Yildirim ◽  
Numan Yildirim ◽  
Nilgun Tayhan
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Water Samples ◽  
World Health ◽  
Environment Protection ◽  
Protection Agency ◽  
Supply Networks ◽  
Health Organization ◽  
The City ◽  
Drinking Water Samples

The drinking water quality is associated with the conditions of the water supply networks, the pollution and the contamination of groundwater with pollutants of both anthropogenic and natural origin. In this study, water samples were taken from four different waterworks in Tunceli, Turkey and heavy metals concentrations (As, Cu, Cd, Cr, Pb, Ni and Hg) were measured. Four sampling sites were pre-defined in different locations of the city. The obtained results showed that, the heavy metals concentrations in water samples did not exceed the values of WHO (World Health Organization), EC (Europe Community), EPA (Environment Protection Agency) and TSE-266 (Turkish Standard) guidelines.

scholarly journals A Sensitive Near-Infrared Fluorescent Probe for Detecting Heavy Metal Ag+ in Water Samples

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 247 ◽  
Author(s):  
Yawen Zhang ◽  
Aiying Ye ◽  
Yuewei Yao ◽  
Cheng Yao
Keyword(s):  
Fluorescent Probe ◽  
Water Samples ◽  
Near Infrared ◽  
Color Change ◽  
World Health ◽  
Naked Eye ◽  
Real Water Samples ◽  
Frequent Use ◽  
The World ◽  
Health Organization

Silver is a common catalyst in industrial production, and the frequent use of Ag+ can cause water pollution. Thus, the detection of Ag+ in the environment is necessary to determine the level of pollution from silver. In this work, we designed a new, highly selective near-infrared (NIR) fluorescent probe QCy to detect Ag+. The probe exhibits “turn-off” fluorescence quenching responses at 760 nm towards Ag+ over other relevant cations, with outstanding sensitivity and a low detection limit (0.03 µM), which is considerably lower than the standard of the World Health Organization (WHO) for drinking water (0.9 µM). Meanwhile, QCy showed a very good linearity at a low concentration of Ag+ with a ‘naked eye’ visible color change of solution from blue to red. The probe has been applied successfully for the detection of Ag+ in real water samples.

scholarly journals IMPACTS OF DUMPSITE ON SOIL AND GROUNDWATER QUALITY: A CASE STUDY OF ERINFUN COMMUNITY, ADO EKITI, SOUTHWESTERN NIGERIA

2021 ◽  
Vol 5 (2) ◽  
pp. 112-116
Author(s):  
F., F. Akinola ◽  
M., O. Lasisi ◽  
B., S. Awe
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Sample ◽  
Biochemical Oxygen Demand ◽  
Water Samples ◽  
Physicochemical Parameters ◽  
Oxygen Demand ◽  
Soil Samples ◽  
World Health ◽  
Health Organization

Groundwater pollution has increased as a result of poor waste disposal practices in developing countries. The purpose of this study was to determine the levels of physicochemical parameters and heavy metal concentrations in order to investigate the impact of dumpsites on groundwater and soil quality in Erinfun community. Four (4) water samples were collected hand dug well and four (4) soil samples designated Ss1 to Ss4 were collected at distances of 10, 20, 30 and 40 m, respectively, away from the waste dumpsite. Physicochemical parameters and traces such as odour, colour, taste and temperature, as well as Biochemical Oxygen Demand, Chemical Oxygen Demand, Dissolve Oxygen, Total Dissolve Solid, pH, and chloride were measured in collected water samples. Collected soil samples were also analyzed for heavy metals such as Magnesium, Zinc, Iron, Chromium, and Lead. All the physical parameters of the water samples analysed were found not to be within the acceptable limit of World Health Organization and Nigerian Standard of Drinking Water Quality standards. The chemical constituents tested were within the acceptable limit of World Health Organization and Nigerian Standard of Drinking Water Quality except for the Biochemical Oxygen Demand, Chemical Oxygen Demand and Dissolve Oxygen of water samples 1 and 2, respectively. The concentration of trace metals in water sample test were within health limit except for Magnesium and Iron which has the highest concentrations in water sample 1 at 10 m away from dumpsite (61.00 mg/l and 0.46 mg/l). Consequently, open dumpsites are discouraged, and constructed standard landfills with appropriate monitoring guidelines are recommended.

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