| 1. |
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| 2. |
- Paylar, Berkay, 1990-, et al.
(författare)
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Assessing organism differences in mixed metal sensitivity
- 2023
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 905
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Tidskriftsartikel (refereegranskat)abstract
- Metal contamination of aquatic environments remains a major concern and has received significant attention in recent years. The present study aimed to evaluate the effects of metal mixtures of varying concentrations over time in a lake receiving runoff water from a decommissioned mine. By subjecting several organisms to this water, we aimed to identify the most susceptible species, thus enabling a comprehensive evaluation of the risk posed by different toxins to the biotic environment.We have evaluated the effects of mixed metal exposure on survival and stress gene expression in selected invertebrate and vertebrate model species. Our observations revealed differences in sensitivity among the invertebrate models Caenorhabditis elegans, Daphnia magna, Ceriodaphnia dubia, and Heterocypris incongruens, as well as in the vertebrate model Zebrafish (Danio rerio) and two cell lines; a zebrafish liver cell line (ZFL) and a human hepatocellular carcinoma cell line (HepG2). While the sensitivity shows great variation among the tested species, the expression of metallothionein was consistent with the levels of metals found in the mixed exposure media. Despite differences in acute toxicity, the universal induction of mt1/A and mt2/B genes make them an important biomarker for assessing the environmental risk of metals.
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| 3. |
- Chupani, Latifeh, et al.
(författare)
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Water Hardness Alters the Gene Expression Response and Copper Toxicity in Daphnia magna
- 2022
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Ingår i: Fishes. - : MDPI. - 2410-3888. ; 7:5
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Tidskriftsartikel (refereegranskat)abstract
- The influence of water hardness on copper (Cu) toxicity in Daphnia magna was studied using gene expression analysis. Exposing D. magna to Cu in water with increasing levels of hardness decreased the acute toxicity. Hardness did not affect the predicted Cu complexation. After 24 h, D. magna showed an increased level of genes related to metal homeostasis (mt) following exposure to 25 mu g Cu/L in hard water. Daphnids in soft and medium water responded to 25 mu g Cu/L by upregulation of antioxidant defense and mt genes, revealing oxidative stress as a mechanism of Cu toxicity in D. magna. D. magna exposed to 25 mu g Cu/L in soft water did not survive for 96 h. In contrast, those exposed to 25 mu g Cu/L in medium and hard water survived for 96 h with significantly higher levels of mt genes. The genes related to oxidative damage (heat shock protein and glutathione S-transferase) in these groups did not deviate from control levels, indicating the protective effect of hardness. Metallothionein genes were upregulated at 17 mu g Cu/L at both 24 h and 96 h. The expression of catalase and ferritin increased in this group in soft and hard water at 96 h. The protective effect of hardness (in the tested range) on survival was also observed at a concentration of 25 mu g/L. The results suggest metallothionein (A and B), catalase, and ferritin genes, as potential biomarkers for copper exposure in D. magna regardless of hardness.
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| 4. |
- Elmarghani, Ahmed, 1975-, et al.
(författare)
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Contribution of pharmaceuticals, fecal bacteria and endotoxin to the inflammatory responses to inland waters
- 2014
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 488-489, s. 228-235
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Tidskriftsartikel (refereegranskat)abstract
- The increasing contamination of freshwater with pharmaceuticals, surfactants, pesticides and other organic compounds are of major concern. As these contaminants are detected at trace levels in the environment it is important to determine if they elicit biological responses at the observed levels. In addition to chemical pollutants, there is also a concern for increasing levels of bacteria and other microorganisms in freshwater systems. In an earlier study, we observed the activation of inflammatory systems downstream of a wastewater treatment plant (WWTP) in southern Sweden. We also observed that the water contained unidentified components that were pro-inflammatory and potentiated the immune response in human urinary bladder epithelial cells. In order to determine if these effects were unique for the studied site or represent a common response in Swedish water, we have now performed a study on three WWTPs and their recipient waters in central Sweden. Analysis of immune responses in urinary bladder epithelial cells, monocyte-like cells and blood mononuclear cells confirm that these waters activate the immune system as well as induce pro-inflammatory responses. The results indicate that the cytokine profiles correlate to the endotoxin load of the waters rather than to the levels of pharmaceuticals or culturable bacteria load, suggesting that measurements of endotoxin levels and immune responses would be a valuable addition to the analysis of inland waters.
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| 5. |
- Ericson Jogsten, Ingrid, 1980-, et al.
(författare)
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Microbial binding of perfluoroalkyl substances (PFASs)
- 2018
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Ingår i: INEF 2018. ; , s. 33-34
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Per- and polyfluorinated alkyl substances (PFASs) are environmental pollutants of global concern due to their persistence and widespread occurrence in humans, wildlife and the environment. These compounds have been extensively used in various commercial and industrial applications since the mid-1900. In 2009, perfluorooctane sulfonic acid (PFOS) was added to the Stockholm convention to protect humans and wildlife from harmful effects. In Sweden, severe PFAS contamination in drinking water has resulted in elevated blood PFAS concentrations in residents living in contaminated areas.The present study evaluated microbial binding of PFASs was tested. The binding capacity was assessed in both live and dead Escherichia coli for various PFOS concentrations. The binding capacity of dead cells was higher (286-3324 μg/g of bacterial pellet) compared to live E. coli cells, showing a 5 – 7 fold lower binding capacity (38-675 μg/g of bacterial pellet). For PFOS, the affinity of branched isomers was similar to that of linear compounds. . Furthermore, other species of bacteria were tested for binding capacity of various mixtures of PFASs from both technical products and contaminated environmental waters, including Pseudomonas nitroreducens and Acidovorax delafieldii. After treatment, bacteria pellets were extracted and analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). Preliminary results indicate preferential binding for PFOS, the contaminant present in the highest concentration in both contaminated environmental water and spiked water of the sum of eleven PFASs recommended for analysis by the Swedish Food agency.This study gives increased knowledge of microbial binding of perfluoroalkyl substances giving insight on PFAS transport in the environment and at different trophic levels. The phenomenon of microbial binding of PFASs could also be used to establish a more cost effective remediation of PFAS contaminated waters. Further, it could lead to increased understanding of toxicological effects of PFASs related to the gut microbiota.
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| 6. |
- Fagerström, Anna, 1980-, et al.
(författare)
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Comparative distribution of extended-spectrum beta-lactamase-producing Escherichia coli from urine infections and environmental waters
- 2019
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Ingår i: PLOS ONE. - : PLOS. - 1932-6203. ; 14:11
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Tidskriftsartikel (refereegranskat)abstract
- Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli have been reported in natural environments, and may be released through wastewater. In this study, the genetic relationship between ESBL-producing E. coli collected from patient urine samples (n = 45, both hospitalized patients and out-patients) and from environmental water (n = 82, from five locations), during the same time period, was investigated. Three independent water samples were collected from the municipal wastewater treatment plant, both incoming water and treated effluent water; the receiving river and lake; and a bird sanctuary near the lake, on two different occasions. The water was filtered and cultured on selective chromID ESBL agar plates in order to detect and isolate ESBL-producing E. coli. Illumina whole genome sequencing was performed on all bacterial isolates (n = 127). Phylogenetic group B2 was more common among the clinical isolates than the environmental isolates (44.4% vs. 17.1%, p < 0.01) due to a significantly higher prevalence of sequence type (ST) 131 (33.3% vs. 13.4%, p < 0.01). ST131 was, however, one of the most prevalent STs among the environmental isolates. There was no significant difference in diversity between the clinical isolates (DI 0.872 (0.790-0.953)) and the environmental isolates (DI 0.947 (0.920-0.969)). The distribution of ESBL genes was similar: blaCTX-M-15 dominated, followed by blaCTX-M-14 and blaCTX-M-27 in both the clinical (60.0%, 8.9%, and 6.7%) and the environmental isolates (62.2%, 12.2%, and 8.5%). Core genome multi-locus sequence typing showed that five environmental isolates, from incoming wastewater, treated wastewater, Svartån river and Hjälmaren lake, were indistinguishable or closely related (≤10 allele differences) to clinical isolates. Isolates of ST131, serotype O25:H4 and fimtype H30, from the environment were as closely related to the clinical isolates as the isolates from different patients were. This study confirms that ESBL-producing E. coli are common in the aquatic environment even in low-endemic regions and suggests that wastewater discharge is an important route for the release of ESBL-producing E. coli into the aquatic environment.
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| 7. |
- Gemeda, S.T., et al.
(författare)
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Diarrheagenic toxins in stool correlate to drinking water from improved water sources in Ethiopia
- 2022
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Ingår i: Environmental Challenges. - : Elsevier. - 2667-0100. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Escherichia coli toxins are the most common types found in association with disease in E. coli bacteria. They are found in nearly all pathogenic E. coli bacteria either released from the bacteria or E. coli cell or both transmitted via the orofecal route. The present study evaluated the relationship between E. coli toxins detected in ‘improved’ drinking water sources and toxins found in stool samples from individuals with diarrhea that consumed the water. Improved water is defined as the water source, by the nature of their construction or through active intervention, are protected from external contamination, particularly with fecal matter. A correlation between toxins in the water with toxins in the stools suggests that contaminated drinking water is a potential infection source. Stool samples were collected from people with diarrhea (248 stool samples) and their drinking water at their home (248 water samples). Only diarrhea patients that reported use of improved drinking water sources as per the definition of the WHO/UNICEF Joint Monitoring Programme were included in the study. E. coli isolates were analysed for 5 major toxins (enteroaggregative E. coli heat-stable enterotoxin 1 (EAST1), heat-stable enterotoxin a (Sta); shiga-like toxin 1 (Stx1), shiga-like toxin 2 (Stx2), and heat-liable enterotoxin (LT)) using a multiplex polymerase chain reaction (mPCR). Descriptive statistics, Chi-square (χ2) test, Fisher's exact, logistic regression, and bivariate Pearson correlation coefficients were used to examine the association and correlation of toxins in the drinking water with those in the stool samples. Of the 248 households, 24% had positive results in both water and stool samples, 63% [Confidence Interval (CI): 55–67%] had positive results in water samples only and 46% [CI: 37- 49%] were found to be positive for toxins in stool samples only. EAST1 was the most frequently detected from the 5 toxins evaluated, with 33% in the water and 38% in the stool. ESAT1, Stx1, and LT toxins were the most commonly found contaminants in water from improved water sources. The prevalence of toxins in household water samples was higher than that obtained from yard connections (51%) and piped systems connected to public stands (42%), compared to the other types of water sources. Both a positive correlation (P < 0.05; r = 0.412) and statistically significant association (P=0.0001) was found between the toxins in the water and toxins in the stool. EAST1 in the stool was significantly correlated with overall toxins in water (r = 0.378) and increased the probability of the occurrence of EAST1 in water (odds ratio (OR)=4.96, 95% CI, 2.81–8.74; P=0.000). E. coli toxins have been found to be effective biomarkers for detecting possible drinking water contamination in households with diarrhea. Long-term planning for the protection and/or treatment of stored household drinking water to ensure toxins free water at the point of use are required.
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| 8. |
- Gemeda, Shibabaw Tadesse, et al.
(författare)
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Enterotoxins as a molecular marker of water quality
- 2022
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Ingår i: Water practice and technology. - : IWA Publishing. - 1751-231X. ; 17:2, s. 623-636
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Tidskriftsartikel (refereegranskat)abstract
- Safety of improved water supplies using enterotoxins as a molecular marker is evaluated. Water samples were collected from 248 households and tested for enterotoxins using polymerase chain reaction (PCR). The relationships between the presence of at least one enterotoxin and independent variables were investigated using Chi-square (chi 2), Fisher's exact test and binary logistic regression. Some 156 enterotoxin biomarkers were detected, 39% of samples had at least one, and 17% had multiple varieties. EAST1 was detected in the highest proportion of samples 33% and Sta in the lowest 2%. Shallow groundwater sources yielded 18% less enterotoxins than water from piped systems, a statistically significant result (P=0.031). A lower proportion of enterotoxins was detected in relation to those who did not know and use cloth filters than those with knowledge of them, and the negative association is statistically significant (P=0.017). It was shown that water samples in which TC colonies were detected were more likely to contain enterotoxins than those without (P=0.001). It is concluded that enterotoxin molecular markers can be used to monitor water safety.
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| 9. |
- Goswami, Manish, 1978-, et al.
(författare)
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Development of Escherichia coli-based gene expression profiling of sewage sludge leachates
- 2018
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Ingår i: Journal of Applied Microbiology. - : Blackwell Publishing. - 1364-5072 .- 1365-2672. ; 125:5, s. 1502-1517
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: The impact of municipal waste on pathogenic microorganisms released into the environment is a public health concern. The present study aims to evaluate the effects of sewage sludge and antibiotic contaminants on stress response, virulence and antibiotic resistance in a pathogenic Escherichia coli.METHODS AND RESULTS: The effects of sewage sludge leachates on uropathogenic E. coli CFT073 were determined by monitoring the expression of 45 genes associated with antibiotic/metal resistance, stress response and virulence using RT-qPCR. The E. coli gene expression was validated using sub-inhibitory concentrations of tetracycline and ciprofloxacin. E. coli exposed to sewage sludge or sewage sludge-fly ash leachates altered the expression of 5 antibiotic and metal resistance, 3 stress response and 2 virulence associated genes. When antibiotics were combined with sludge or sludge-fly ash the antibiotic-associated gene expression was altered.CONCLUSIONS: E. coli treated with two sludge leachates had distinct gene expression patterns that were altered when the sludge leachates were combined with tetracycline, although to a lesser extent with ciprofloxacin.SIGNIFICANCE AND IMPACT OF STUDY: The E. coli multigene expression analysis is a potential new tool for assessing the effects of pollutants on pathogenic microbes in environmental waters for improved risk assessment.
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| 10. |
- Goswami, Manish, et al.
(författare)
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Involvement of Antibiotic Efflux Machinery in Glutathione-Mediated Decreased Ciprofloxacin Activity in Escherichia coli
- 2016
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Ingår i: Antimicrobial Agents and Chemotherapy. - Washington, USA : American Society for Microbiology. - 0066-4804 .- 1098-6596. ; 60:7, s. 4369-4374
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Tidskriftsartikel (refereegranskat)abstract
- We have analyzed the contribution of different efflux components to glutathione-mediated abrogation of ciprofloxacin's activity in Escherichia coli and the underlying potential mechanism(s) behind this phenomenon. The results indicated that glutathione increased the total active efflux, thereby partially contributing to glutathione-mediated neutralization of ciprofloxacin's antibacterial action in E. coli However, the role of glutathione-mediated increased efflux becomes evident in the absence of a functional TolC-AcrAB efflux pump.
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