25 results on '"Scardala S"'
Search Results
2. A7. SITUAZIONE NAZIONALE: CORPI IDRICI INTERESSATI DA CIANOBATTERI TOSSICI
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Manganelli, M, Viaggiu, E, Buzzi, F, Caviglia, F, Congestri, R, Copetti, D, Angelis, R, Godeas, F, Guzzella, L, Masala, E, Salmaso, N, Scardala, S., BARONE, Rossella, NASELLI FLORES, Luigi, Funari, E, Manganelli, M, Testai, E, Viaggiu, E, Barone, R, Buzzi, F, Caviglia, F, Congestri, R, Copetti, D, Angelis, R, Godeas, F, Guzzella, L, Masala, E, Naselli-Flores, L, Salmaso, N, and Scardala, S
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Valutazione del rischio ,Balneazione ,Tossine biologiche ,Settore BIO/03 - Botanica Ambientale E Applicata ,Bathing water ,Biological toxins ,Risk assessment - Abstract
I cianobatteri sono diffusi in moltissimi ambienti acquatici, dove possono produrre cianotossine con diversi profili tossicologici. Il presente rapporto riporta le linee guida per la gestione delle fioriture di cianobatteri nelle acque di balneazione, elaborate da un gruppo di esperti. La prima parte sintetizza le attuali conoscenze scientifiche su vari aspetti, fra cui la loro presenza nei laghi italiani, le caratteristiche chimiche e tossicologiche delle varie cianotossine, gli effetti osservati sulla salute dell’uomo e la valutazione del rischio. La seconda parte definisce le linee guida per prevenire effetti dannosi per la salute dei bagnanti e gestire il rischio associato alle fioriture. Vengono fornite indicazioni per pianificare attività di monitoraggio ambientale e sorveglianza sanitaria nelle aree a maggiore criticità. Viene inoltre presentato un sistema di reportistica, ambientale e sanitario, anche allo scopo di uniformare le informazioni a livello nazionale. Il rapporto è completato dalle indicazioni tecniche rivolte alle strutture territoriali preposte. Cyanobacteria thrive in many aquatic environments, where they can produce cyanotoxins with different toxicological profiles. This report provides the guidelines for the management of cyanobacterial blooms in bathing water, put together by a group of experts. The first part summarizes the current scientific knowledge on various aspects, including their presence in the Italian lakes, chemical and toxicological characteristics of different cyanotoxins, the observed effects on human health and the risk assessment. The second part defines the guidelines to prevent harmful effects on the health of bathers and manage the risk associated with blooms. It provides recommendations for planning environmental monitoring activities and a health surveillance system in most critical areas. It also introduces an environmental and health reporting system, with the purpose to standardize the information at national level too. The report is supplemented by technical information aimed at territorial authorities in charge.
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- 2014
3. METODI CHIMICI PER L' ANALISI DELLE CIANOTOSSINE NELLE ACQUE DI BALNEAZIONE
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Cerasino S., Bogialli S., Guzzella L., and Scardala S.
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Metodi chimici ,acque di balneazione ,cianotossine - Abstract
I metodi chimici per l'analisi delle cianotossine consentono la loro identificazione e la loro quantificazione. A fronte di questi vantaggi, rispe tto ad altri metodi di indagine, i metodi chimici richiedono apparecchiature più sofis ticate e personale adeguatamente formato. La performance di un metodo chimico viene genera lmente espressa in termini di specificità (capacità di riconoscere con certezza le singole tossine), di sensibilità (quantità minima di tossina rilevabile) e robustezza (affida bilità durante l'impiego normale). I metodi chimici più diffusi per analizzare le cianotossine sono quelli che si basano su un cromatografo liquido (LC, Liquid Chromatography ) accoppiato ad un apposito rivelatore. I rivelatori possono essere di due tipologie: basa ti su spettroscopia molecolare (UV-vis, diode- array , fluorimetro), oppure rivelatori di massa (s ingolo o triplo quadrupolo, trappola ionica, TOF Time-of-Flight , ecc.). Quelli basati su spettroscopia molecolare sono più semplici e facili da gestire ma offrono performance infe riori. I rivelatori di massa (MS, Mass Spectrometry ) sono molto più performanti, ma sono molto più sofi sticati e richiedono personale adeguatamente specializzato; inoltre, in commerc io esistono rivelatori di massa con tecnologie e caratteristiche costruttive molto diverse, alcuni più performanti su l lato della specificità, altri sul lato della sensibilità. Nel momento in cui si deve implementare un pr otocollo analitico, occorre quindi valutare a) quale performance si desidera raggiungere e b) quale strumentazione si ha a disposizione, considerando che un metodo LC-UV/diode array/fluorimetro è in generale subito applicabile, e che, invece, un metodo LC-MS molto spesso va prima "adeguato" alla strumentazione disponibile. I metodi chimici di analisi vengono messi a punto in maniera specifica a seconda della struttura e delle caratteristiche chimiche delle molecole in esame; il numero di sostanze che possono essere quantificate dipende dalla disponibilità di standard di riferimento. Gli standard delle cianotossine sul mercato comprendono solo una frazione delle cianotossine conosciute; sebbene questi standard rappresentino le tossine di gran lunga più frequenti, occorre sempre tenere presente che l'analisi chimica non è in gra do di determinare tossine diverse da quelle per cui il metodo è stato sviluppato. In letteratura sono stati descritti diversi met odi per l'analisi delle varie categorie di cianotossine: peptidi (microcistine, nodularine), alcaloidi (anatossine, cilindrospermopsine, saxitossine). A causa della grande eterogeneità nelle proprietà chimiche, non esiste un metodo omnicomprensivo ed efficiente per l'analisi di tu tte le cianotossine (sebbene ci siano alcuni esempi descritti in letteratura), ma ogni categor ia va analizzata con uno specifico metodo che garantisca adeguata specificità, sensibilità e robustezza.
- Published
- 2014
4. Situazione nazionale: corpi idrici interessati da cianobatteri tossici
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Manganelli M., Viaggiu E., Barone R., Buzzi F., Caviglia F., Congestri R., Copetti D., De Angelis R., Godeas F., Guzzella L., Masala E., Naselli-Flores L., Salmaso N., and Scardala S.
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Laghi ,Cianotossine ,cianobatteri tossici ,Settore BIO/07 - ECOLOGIA ,Cianobatteri ,corpi idrici ,Distribuzione - Abstract
Nel primo paragrafo di questo capitolo vengono ri portati alcuni dati relativi alle fioriture di cianobatteri nei bacini italiani, utili per avere un quadro aggiornato della situazione nazionale e per evidenziare eventuali criticità e/o attività di studio o gestione da intraprendere. Sono stati utilizzati sia dati relativi al monitoraggio per la balneazione, pubblicati sui siti web delle varie agenzie regionali, o forniti direttamente da alc uni coautori, sia dati pubblicati nella letteratura scientifica, per evidenziare trend temporali e, a titolo meramente esemplificativo, descrivere situazioni molto complesse e dinamiche nel tempo. Nel secondo paragrafo, per le sole specie res ponsabili della maggior parte delle fioriture in Italia, sono riportate le informazioni sulle basi genetiche e sui fattori ambientali (ove disponibili) che determinano la produzione di tossine. Tali informazioni dovrebbero essere di supporto per avviare eventuali programmi di monitoraggio specifici. Nel terzo paragrafo, infine, viene descritta la distribuzione dei cianobatteri tossici negli altri continenti, per individuare eventuali similitudini o differenze fra ciò che è presente nel nostro territorio e il resto del mondo.
- Published
- 2014
5. Metodi chimici per l’analisi delle cianotossine nelle acque di balneazione
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Cerasino, L., Bogialli, S., Guzzella, L., and Scardala, S.
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Recreational waters ,Cianotossine ,Settore CHIM/01 - CHIMICA ANALITICA ,Algal toxins ,Metodi chimici ,Cyanotoxins ,Chemical methods ,Acque di balneazione ,Tossine algali ,LC-MS - Published
- 2014
6. Carbon and nitrogen removal and enhanced methane production in a microbial electrolysis cell
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Villano M., Scardala S., Aulenta F., and Majone M.
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Anaerobic digestion ,Ammonium recovery ,Methane bioproduction ,Biocathode ,Microbial electrolysis cell - Abstract
The anode of a two-chamber methane-producing microbial electrolysis cell (MEC) was poised at +0.200 V vs. the standard hydrogen electrode (SHE) and continuously fed (1.08 gCOD/L d) with acetate in anaerobic mineral medium. A gas mixture (carbon dioxide 30 vol.% in N2) was continuously added to the cathode for both pH control and carbonate supply. At the anode, 94% of the influent acetate was removed, mostly through anaerobic oxidation (91% coulombic efficiency); the resulting electric current was mainly recovered as methane (79% cathode capture efficiency). Low biomass growth was observed at the anode and ammonium was transferred through the cationic membrane and concentrated at the cathode. These findings suggest that the MEC can be used for the treatment of low-strength wastewater, with good energy efficiency and low sludge production.
- Published
- 2013
7. The survival and toxicity of cyanobacteria at intestinal physiological conditions: any possibility to colonize the host? An hypothesis for ALS
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Testai, E., Stefanelli, M., Vichi, S., Scardala, S., Stipa, G., Manganelli, M., and Funari, E.
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- 2010
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8. Metodi chimici per la rivelazione delle cianotossine
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Scardala, S, Bogialli, Sara, and DI CORCIA, A.
- Published
- 2008
9. Ostreopsis ovata algal blooms affecting human health in Genova, Italy, 2005 and 2006
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Brescianini, C, primary, Grillo, C, additional, Melchiorre, N, additional, Bertolotto, R, additional, Ferrari, A, additional, Vivaldi, B, additional, Icardi, G, additional, Gramaccioni, L, additional, Funari, E, additional, and Scardala, S, additional
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- 2006
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10. Co-Occurrence of Taste and Odor Compounds and Cyanotoxins in Cyanobacterial Blooms: Emerging Risks to Human Health?
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Manganelli M, Testai E, Tazart Z, Scardala S, and Codd GA
- Abstract
Cyanobacteria commonly form large blooms in waterbodies; they can produce cyanotoxins, with toxic effects on humans and animals, and volatile compounds, causing bad tastes and odors (T&O) at naturally occurring low concentrations. Notwithstanding the large amount of literature on either cyanotoxins or T&O, no review has focused on them at the same time. The present review critically evaluates the recent literature on cyanotoxins and T&O compounds (geosmin, 2-methylisoborneol, β-ionone and β-cyclocitral) to identify research gaps on harmful exposure of humans and animals to both metabolite classes. T&O and cyanotoxins production can be due to the same or common to different cyanobacterial species/strains, with the additional possibility of T&O production by non-cyanobacterial species. The few environmental studies on the co-occurrence of these two groups of metabolites are not sufficient to understand if and how they can co-vary, or influence each other, perhaps stimulating cyanotoxin production. Therefore, T&Os cannot reliably serve as early warning surrogates for cyanotoxins. The scarce data on T&O toxicity seem to indicate a low health risk (but the inhalation of β-cyclocitral deserves more study). However, no data are available on the effects of combined exposure to mixtures of cyanotoxins and T&O compounds and to combinations of T&O compounds; therefore, whether the co-occurrence of cyanotoxins and T&O compounds is a health issue remains an open question., Competing Interests: The authors declare no conflicts of interest.
- Published
- 2023
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11. Remediation Strategies to Control Toxic Cyanobacterial Blooms: Effects of Macrophyte Aqueous Extracts on Microcystis aeruginosa (Growth, Toxin Production and Oxidative Stress Response) and on Bacterial Ectoenzymatic Activities.
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Tazart Z, Manganelli M, Scardala S, Buratti FM, Nigro Di Gregorio F, Douma M, Mouhri K, Testai E, and Loudiki M
- Abstract
Increasing toxic cyanobacterial blooms in freshwater demand environmentally friendly solutions to control their growth and toxicity, especially in arid countries, where most drinking water is produced from surface reservoirs. We tested the effects of macrophyte allelochemicals on Microcystis aeruginosa and on the fundamental role of bacteria in nutrient recycling. The effects of Ranunculus aquatilis aqueous extract, the most bioactive of four Moroccan macrophyte extracts, were tested in batch systems on M. aeruginosa growth, toxin production and oxidative stress response and on the ectoenzymatic activity associated with the bacterial community. M. aeruginosa density was reduced by 82.18%, and a significant increase in oxidative stress markers was evidenced in cyanobacterial cells. Microcystin concentration significantly decreased, and they were detected only intracellularly, an important aspect in managing toxic blooms. R. aquatilis extract had no negative effects on associated bacteria. These results confirm a promising use of macrophyte extracts, but they cannot be generalized. The use of the extract on other toxic strains, such as Planktothrix rubescens , Raphidiopsis raciborskii and Chrysosporum ovalisporum , caused a reduction in growth rate but not in cyanotoxin content, increasing toxicity. The need to assess species-specific cyanobacteria responses to verify the efficacy and safety of the extracts for human health and the environment is highlighted.
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- 2021
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12. In vitro detoxication of microcystins in human samples: variability among variants with different hydrophilicity and structure.
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Santori N, Buratti FM, Scardala S, Dorne JCM, and Testai E
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- Dose-Response Relationship, Drug, Female, Glutathione metabolism, Glutathione Transferase genetics, Humans, Hydrophobic and Hydrophilic Interactions, Inactivation, Metabolic, Isoenzymes, Male, Microcystins chemistry, Microcystins toxicity, Molecular Structure, Polymorphism, Genetic, Recombinant Proteins metabolism, Risk Assessment, Substrate Specificity, Toxicokinetics, Glutathione Transferase metabolism, Liver enzymology, Microcystins metabolism
- Abstract
Cyanotoxins, among which >200 variants of Microcystins (MC), constitute an emerging issue in food safety. Microcystins (MC) toxicity is congener-specific; however, the in vitro inhibition of PP1/PP2A (the key molecular event of MC toxicity) by single MC variants is comparable and MC toxicokinetics seems to be the critical point. Here, the variability in GSH conjugation catalysed by human recombinant enzymes and human hepatic cytosol has been compared between hydrophilic (MC-LR and MC-RR) and hydrophobic (MC-LW, MC-YR and MC-LF) variants, according to measured logPow. In vitro detoxication reaction (spontaneous plus enzymatic) is favored by the variant hydrophilicity, with MC-LF very poorly detoxified. With MC-YR and -LW the spontaneous reaction always gave the major contribution, whereas with MC-LR and -RR the enzymatic reaction became by far predominant when GSH was depleted. Consequently, the well-known GST polymorphisms seems not to be the major driver for potential human variability in susceptibility towards the MC-toxicity, except for MC-RR and -LR when GSH is depleted. Looking at these results and literature data, MC-RR (the least cytotoxic and acutely toxic in rodents) is the more hydrophilic, has the lowest OATP-mediated hepatic uptake and the highest detoxication efficiency. The opposite is true for the most lipophilic MC-LF: once entered in the cells with the highest uptake, it is very poorly detoxified, and resulted as the most toxic in various cell types. MC-dependent TK should be considered in order to estimate the variability in toxicity and to support the use of quantitative in vitro-in vivo extrapolation models of single toxins and their mixtures co-occurring in the environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)
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- 2020
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13. Cyanotoxins: producing organisms, occurrence, toxicity, mechanism of action and human health toxicological risk evaluation.
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Buratti FM, Manganelli M, Vichi S, Stefanelli M, Scardala S, Testai E, and Funari E
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- Alkaloids, Animals, Crops, Agricultural, Cyanobacteria Toxins, Drinking Water, Food Contamination, Humans, Marine Toxins metabolism, Marine Toxins toxicity, Microcystins metabolism, Microcystins toxicity, Neurotoxins toxicity, Peptides, Cyclic toxicity, Seafood, Toxicity Tests methods, Uracil analogs & derivatives, Uracil toxicity, Bacterial Toxins metabolism, Bacterial Toxins toxicity, Cyanobacteria metabolism, Risk Assessment methods
- Abstract
Cyanobacteria were present on the earth 3.5 billion years ago; since then they have colonized almost all terrestrial and aquatic ecosystems. They produce a high number of bioactive molecules, among which some are cyanotoxins. Cyanobacterial growth at high densities, forming blooms, is increasing in extension and frequency, following anthropogenic activities and climate changes, giving rise to some concern for human health and animal life exposed to cyanotoxins. Numerous cases of lethal poisonings have been associated with cyanotoxins ingestion in wild animal and livestock. In humans few episodes of lethal or severe human poisonings have been recorded after acute or short-term exposure, but the repeated/chronic exposure to low cyanotoxin levels remains a critical issue. The properties of the most frequently detected cyanotoxins (namely, microcystins, nodularins, cylindrospermopsin and neurotoxins) are here critically reviewed, describing for each toxin the available information on producing organisms, biosynthesis/genetic and occurrence, with a focus on the toxicological profile (including kinetics, acute systemic toxicity, mechanism and mode of action, local effects, repeated toxicity, genotoxicity, carcinogenicity, reproductive toxicity; human health effects and epidemiological studies; animal poisoning) with the derivation of health-based values and considerations on the risks for human health.
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- 2017
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14. Cyanobacteria biennal dynamic in a volcanic mesotrophic lake in central Italy: Strategies to prevent dangerous human exposures to cyanotoxins.
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Manganelli M, Stefanelli M, Vichi S, Andreani P, Nascetti G, Scialanca F, Scardala S, Testai E, and Funari E
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- Chemical Phenomena, Drinking Water chemistry, Drinking Water microbiology, Environmental Monitoring, Humans, Italy, Microcystins analysis, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 16S isolation & purification, Seasons, Cyanobacteria isolation & purification, Cyanobacteria metabolism, Lakes microbiology, Microcystins toxicity
- Abstract
Vico Lake, a volcanic meso-eutrophic lake in Central Italy, whose water is used for drinking and recreational activities, experienced the presence of the microcystins (MC) producing cyanobacterium Planktothrix rubescens. In order to assess the human health risks and to provide the local health authorities with a scientific basis for planning tailored monitoring activities, we studied P. rubescens ecology and toxicity for two years. P. rubescens generally dominated the phytoplankton community, alternating with Limnothrix redekei, potentially toxic. P. rubescens was distributed throughout the water column during winter; in summer it produced intense blooms where drinking water is collected (-20 m); here MC were detected all year round (0.5-5 μg/L), with implications for drinking water quality. In surface waters, MC posed no risk for recreational activities in summer, while in winter surface blooms and foams (containing up to 56 μg MC/L) can represent a risk for people and children practicing water sports and for animals consuming raw water. Total phosphorus, phosphate and inorganic nitrogen were not relevant to predict densities nor toxicity; however, a strong correlation between P. rubescens density and aminopeptidase ectoenzymatic activity, an enzyme involved in protein degradation, suggested a role of organic nitrogen for this species. The fraction of potentially toxic population, determined both as mcyB(+)/16SrDNA (10-100%) and as the MC/mcyB(+) cells (0.03-0.79 pg MC/cell), was much more variable than usually observed for P. rubescens. Differently from other Italian and European lakes, the correlation between cell density or the mcyB(+) cells and MC explained only ∼50 and 30% of MC variability, respectively: for Vico Lake, monitoring only cell or the mcyB(+) cell density is not sufficient to predict MC concentrations, and consequently to protect population health. Finally, during a winter bloom one site has been sampled weekly, showing that monthly sampling during such a phase could greatly underestimate the 'hazard'. Our results highlight the need to adopt a stepwise monitoring activity, considering the lake and the cyanobacteria specific features. This activity should be complemented with communication to the public and involvement of stakeholders., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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15. Risk to human health associated with the environmental occurrence of cyanobacterial neurotoxic alkaloids anatoxins and saxitoxins.
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Testai E, Scardala S, Vichi S, Buratti FM, and Funari E
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- Animals, Bacterial Toxins poisoning, Bacterial Toxins toxicity, Cyanobacteria chemistry, Cyanobacteria metabolism, Cyanobacteria Toxins, Humans, Marine Toxins poisoning, Marine Toxins toxicity, Microcystins poisoning, Microcystins toxicity, Neurotoxins poisoning, Neurotoxins toxicity, Risk Assessment, Saxitoxin poisoning, Saxitoxin toxicity, Bacterial Toxins analysis, Marine Toxins analysis, Microcystins analysis, Neurotoxins analysis, Saxitoxin analysis
- Abstract
Cyanobacteria are ubiquitous photosynthetic micro-organisms forming blooms and scums in surface water; among them some species can produce cyanotoxins giving rise to some concern for human health and animal life. To date, more than 65 cyanobacterial neurotoxins have been described, of which the most studied are the groups of anatoxins and saxitoxins (STXs), comprising many different variants. In freshwaters, the hepatotoxic microcystins represent the most frequently detected cyanotoxin: on this basis, it could appear that neurotoxins are less relevant, but the low frequency of detection may partially reflect an a priori choice of target analytes, the low method sensitivity and the lack of certified standards. Cyanobacterial neurotoxins target cholinergic synapses or voltage-gated ion channels, blocking skeletal and respiratory muscles, thus leading to death by respiratory failure. This review reports and analyzes the available literature data on environmental occurrence of cyanobacterial neurotoxic alkaloids, namely anatoxins and STXs, their biosynthesis, toxicology and epidemiology, derivation of guidance values and action limits. These data are used as the basis to assess the risk posed to human health, identify critical exposure scenarios and highlight the major data gaps and research needs.
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- 2016
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16. Survival, growth and toxicity of Microcystis aeruginosa PCC 7806 in experimental conditions mimicking some features of the human gastro-intestinal environment.
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Stefanelli M, Vichi S, Stipa G, Funari E, Testai E, Scardala S, and Manganelli M
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- Culture Media chemistry, Darkness, Humans, Hydrogen-Ion Concentration, Leucine metabolism, Microcystis metabolism, Microcystis physiology, Microcystis radiation effects, Survival Analysis, Temperature, Gastrointestinal Tract microbiology, Microcystis growth & development, Toxins, Biological metabolism
- Abstract
Cyanotoxins (CTX) are widely produced by several cyanobacteria (CB), increasingly spreading in most water bodies and terrestrial habitats, and represent a risk for human health. CB are prokaryotes, and although mostly autotrophic, several examples of heterotrophy in symbiotic relationship with different organisms have been described. In addition to the known routes of exposure, it has been hypothesized that CB might 'colonize' human intestine with relevant implications for human health. Colonization is a complex process and requires specific features of the possible invaders. Still, a short-term persistence as living and toxin-producing organisms within the intestinal lumen of the host could represent an 'internal' source of exposure to CTX. In this work we ran microcosm experiments (4-18days), looking at Microcystis aeruginosa PCC7806 resistance and cyanotoxin-producing capabilities in darkness, 37°C, pH 2, and subsequent recovery in a rich medium, in darkness, 37°C, in the presence of enteric bacteria, mimicking few important features of the gastrointestinal environment. We measured cyanobacterial populations and growth, microcystin (MC) production and the presence of mcyB gene. M. aeruginosa could grow in the dark at 37°C up to 17days, and survive at pH 2 at a rate between 30% and 70%, depending on the age and toxicity of the starting culture. Cell lysis resulted in a substantial amounts of MC released, not degraded at gastric pH. Following the acidic passage, still in the dark at 37°C, M. aeruginosa restarted to grow within 24h for the next 3-4days, independently on the presence of intestinal bacteria, maintaining the MC cell quota and mcyB gene. Our results show new features of CB: a significant resistance of M. aeruginosa in conditions far from its optimal one, that is an environment mimicking some of the important characteristics of human gastrointestinal tract, suggesting the possibility of an internal source of exposure to CTX, with implications for the risk assessment., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2014
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17. The conjugation of microcystin-RR by human recombinant GSTs and hepatic cytosol.
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Buratti FM, Scardala S, Funari E, and Testai E
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- Cytosol enzymology, Cytosol metabolism, Female, Humans, Liver enzymology, Male, Recombinant Proteins metabolism, Glutathione Transferase metabolism, Liver metabolism, Marine Toxins metabolism, Microcystins metabolism
- Abstract
Many cyanobacterial species can produce cyanotoxins, among which mycrocistins (MC) are a group of ≈100 congeners of hepatotoxic cyclic heptapeptides. MC-RR differs from MC-LR, the most studied congener only for one residue (arginine vs leucine), resulting in a ten-fold difference in the acute toxicity in mice. Although humans may be exposed to MC through several routes and kinetics appeared to be the major factor affecting congener-specific toxicity, little is known on MC metabolism. The accepted pathway for MC detoxication is GSH conjugation: here the MC-RR conjugation with GSH catalyzed by 5 recombinant human GSTs and human liver cytosol (HLC) has been characterized and appeared to be more efficient than MC-LR conjugation. The catalytic efficiency score is T1-1>A1-1≈P1-1>M1-1>A3-3 (0.161-0.056pmol GSMC-RR (μgproteinminμM)(-1)). In HLC the spontaneous reaction is favored vs the enzymatic one (ratio 3:1) at physiological GSH content. However, at low MC-RR concentrations, representative of repeated oral exposure, and low GSH content (down to 0.05mM), possibly associated to exposure to drugs or in patients affected by several pathologies, the relevance of the enzymatic reaction progressively increases, providing the predominant contribution to MC-RR detoxication., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2013
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18. Carbon and nitrogen removal and enhanced methane production in a microbial electrolysis cell.
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Villano M, Scardala S, Aulenta F, and Majone M
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- Acetates metabolism, Bioelectric Energy Sources, Carbon metabolism, Electrolysis, Nitrogen metabolism, Biofuels, Methane metabolism, Waste Management
- Abstract
The anode of a two-chamber methane-producing microbial electrolysis cell (MEC) was poised at +0.200V vs. the standard hydrogen electrode (SHE) and continuously fed (1.08gCOD/Ld) with acetate in anaerobic mineral medium. A gas mixture (carbon dioxide 30vol.% in N(2)) was continuously added to the cathode for both pH control and carbonate supply. At the anode, 94% of the influent acetate was removed, mostly through anaerobic oxidation (91% coulombic efficiency); the resulting electric current was mainly recovered as methane (79% cathode capture efficiency). Low biomass growth was observed at the anode and ammonium was transferred through the cationic membrane and concentrated at the cathode. These findings suggest that the MEC can be used for the treatment of low-strength wastewater, with good energy efficiency and low sludge production., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
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- 2013
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19. Contamination by Microcystis and microcystins of blue-green algae food supplements (BGAS) on the Italian market and possible risk for the exposed population.
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Vichi S, Lavorini P, Funari E, Scardala S, and Testai E
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- Aphanizomenon chemistry, Chromatography, Liquid, Consumer Product Safety, Dietary Supplements analysis, Enzyme-Linked Immunosorbent Assay, Humans, Italy, Liver drug effects, Liver pathology, Microcystins analysis, Risk Factors, Spirulina chemistry, Tandem Mass Spectrometry, Cyanobacteria chemistry, Dietary Supplements microbiology, Food Contamination analysis, Food Microbiology, Microcystins toxicity, Microcystis chemistry
- Abstract
Blue green algae supplements (BGAS) are generally proposed as health-promoting natural products for their purported beneficial effects. Spirulina spp. and Aphanizomenon flos aquae are mainly used in BGAS production. They are usually collected from the natural environment, where other potentially toxic cyanobacteria can be present, making possible BGAS contamination by cyanotoxins, with potential risk for human health. In this work we apply a combined approach, by using chemical and molecular techniques, on BGAS of 17 brands available in Italy. Samples containing Spirulina-only were free of contamination. The Aphanizomenon flos aquae-based samples were contaminated by highly variable levels of microcystins (MC-LR and MC-LA congeners), up to 5.2 μg MC-LR equivalents per gram product. The highest variability (up to 50 fold) was among batches of the same brand, although intra-batch differences were also evidenced. PCR analyses were positive only for the presence of Microcystis sp., identified as the toxin-producing species responsible for contamination. At the maximum contamination levels found, a risk for consumers can be expected following chronic or sub-chronic exposure to a reasonable daily BGAS consumption of 4 g. The need for a strict monitoring by producers and Health Authority to assure an adequate protection for consumers is underscored., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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20. Emerging health issues of cyanobacterial blooms.
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Manganelli M, Scardala S, Stefanelli M, Palazzo F, Funari E, Vichi S, Buratti FM, and Testai E
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- Animal Diseases, Animals, Food Contamination, Health Status Indicators, Humans, Marine Toxins, Seafood adverse effects, Water Microbiology, Water Supply analysis, Cyanobacteria, Eutrophication, Public Health
- Abstract
This paper describes emerging issue related to cyanobacterial dynamics and toxicity and human health risks. Data show an increasing cyanobacteria expansion and dominance in many environments. However there are still few information on the toxic species fitness, or on the effects of specific drivers on toxin production. Open research fields are related to new exposure scenario (cyanotoxins in water used for haemodialysis and in food supplements); to new patterns of co-exposure between cyanotoxins and algal toxins and/or anthropogenic chemicals; to dynamics affecting toxicity and production of different cyanotoxin variants under environmental stress; to the accumulation of cyanotoxins in the food web. In addition, many data gaps exist in the characterization of the toxicological profiles, especially about long term effects.
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- 2012
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21. Human glutathione transferases catalyzing the conjugation of the hepatoxin microcystin-LR.
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Buratti FM, Scardala S, Funari E, and Testai E
- Subjects
- Bacterial Toxins isolation & purification, Bacterial Toxins metabolism, Escherichia coli genetics, Gene Expression, Glutathione metabolism, Glutathione Transferase genetics, Humans, Inactivation, Metabolic, Marine Toxins, Microcystins isolation & purification, Microcystins metabolism, Recombinant Proteins genetics, Recombinant Proteins metabolism, Bacterial Toxins pharmacokinetics, Glutathione Transferase metabolism, Microcystins pharmacokinetics, Microcystis metabolism
- Abstract
Many cyanobacterial species are able to produce cyanotoxins as secondary metabolites. Among them, microcystins (MC) are a group of around 80 congeners of toxic cyclic heptapeptides. MC-LR is the most studied MC congener, in view of its high acute hepatotoxicity and tumor promoting activity. Humans may be exposed to cyanotoxins through several routes, the oral one being the most important. The accepted pathway for MC-LR detoxication and excretion in the urine is GSH conjugation. The GSH adduct (GS-MCLR) formation has been shown to occur spontaneously and enzymatically, catalyzed by glutathione transferases (GSTs). The enzymatic reaction has been reported but not characterized both in vitro and in vivo in animal and plant species. No data are available on humans. In the present work, the MC-LR conjugation with GSH catalyzed by five recombinant human GSTs (A1-1, A3-3, M1-1, P1-1, and T1-1) has been characterized for the first time. All GSTs are able to catalyze the reaction; kinetic parameters K(m), k(cat), and their relative specific activities to form GS-MCLR were derived (T1-1 > A1-1 > M1-1 > A3-3 ≫ P1-1). In the range of MC tested concentrations used (0.25-50 μM) GSTT1-1 and A1-1 showed a typical saturation curve with similar affinity for MC-LR (≈80 μM; k(cat) values 0.18 and 0.10 min(-1), respectively), A3-3 and M1-1 were linear, whereas GSTP1-1 showed a temperature-dependent sigmoidal allosteric curve with a k(cat) = 0.11 min(-1). The enzymes mainly expressed in the liver and gastrointestinal tract, GSTA1-1, T1-1, and M1-1, seemed to be mainly involved in the MC-LR detoxification after oral exposure, whereas P1-1 kinetics and location in the skin suggest a role related to dermal exposure. Considering the high frequency of some GST polymorphism, especially M1 and T1 gene deletion, with complete loss in activity, this information could be the first step to identify groups of individual at higher risk associated with MC exposure.
- Published
- 2011
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22. Health risk evaluation associated to Planktothrix rubescens: An integrated approach to design tailored monitoring programs for human exposure to cyanotoxins.
- Author
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Manganelli M, Scardala S, Stefanelli M, Vichi S, Mattei D, Bogialli S, Ceccarelli P, Corradetti E, Petrucci I, Gemma S, Testai E, and Funari E
- Subjects
- Cyanobacteria drug effects, Cyanobacteria enzymology, Fresh Water microbiology, Humans, Microcystins analysis, Risk Assessment, Seasons, Cyanobacteria metabolism, Environmental Exposure analysis, Environmental Monitoring methods, Marine Toxins toxicity, Public Health
- Abstract
Increasing concern for human health related to cyanotoxin exposure imposes the identification of pattern and level of exposure; however, current monitoring programs, based on cyanobacteria cell counts, could be inadequate. An integrated approach has been applied to a small lake in Italy, affected by Planktothrix rubescens blooms, to provide a scientific basis for appropriate monitoring program design. The cyanobacterium dynamic, the lake physicochemical and trophic status, expressed as nutrients concentration and recycling rates due to bacterial activity, the identification/quantification of toxic genotype and cyanotoxin concentration have been studied. Our results indicate that low levels of nutrients are not a marker for low risk of P. rubescens proliferation and confirm that cyanobacterial density solely is not a reliable parameter to assess human exposure. The ratio between toxic/non-toxic cells, and toxin concentrations, which can be better explained by toxic population dynamic, are much more diagnostic, although varying with time and environmental conditions. The toxic fraction within P. rubescens population is generally high (30-100%) and increases with water depth. The ratio toxic/non-toxic cells is lowest during the bloom, suggesting a competitive advantage for non-toxic cells. Therefore, when P. rubescens is the dominant species, it is important to analyze samples below the thermocline, and quantitatively estimate toxic genotype abundance. In addition, the identification of cyanotoxin content and congeners profile, with different toxic potential, are crucial for risk assessment., (Copyright 2009 Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
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23. Pesticides and their metabolites in selected Italian groundwater and surface water used for drinking.
- Author
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Fava L, Orrù MA, Scardala S, Alonzo E, Fardella M, Strumia C, Martinelli A, Finocchiaro S, Previtera M, Franchi A, Calà P, Dovis M, Bartoli D, Sartori G, Broglia L, and Funari E
- Subjects
- Agriculture, Chromatography, High Pressure Liquid, Italy, Mass Spectrometry, Oryza, Seasons, Spectrophotometry, Ultraviolet, Zea mays, Pesticides analysis, Water Pollutants, Chemical analysis, Water Supply analysis
- Abstract
The control of groundwater and surface water quality in relation to the presence of pesticides and their metabolites is a rather complicated task. National and local authorities with the responsibility to guarantee an adequate quality of water cannot rely on international guidelines for monitoring activities. In a national project, forty-three pesticides and pesticide metabolites were selected on the basis of sale, monitoring and physical-chemical data, and investigated from some of the main Italian agricultural areas, susceptible to pesticide contamination. Twelve compounds were found in the tested water samples at levels exceeding the 0.1 µg/L European Union (EU) limit for drinking water (European Directive 98/83/EC). Maximum levels up to 0.62 were determined. Several water samples were characterized by the simultaneous occurrence of pesticides and their metabolites (up to ten). In some samples, the total concentration of pesticides and their metabolites was higher than the EU limit of 0.5 µg/L. Total triazine concentrations up to 1.02 µg/L were found. In all the cases the highest concentrations were well below the respective guideline values defined by the World Health Organization (WHO) for drinking water quality.
- Published
- 2010
- Full Text
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24. Leaching potential of some phenylureas and their main metabolites through laboratory studies.
- Author
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Fava L, Orrú MA, Businelli D, Scardala S, and Funari E
- Subjects
- Herbicides analysis, Pesticides analysis, Phenylurea Compounds analysis, Soil Pollutants analysis, Water Movements, Water Pollutants, Chemical analysis, Water Pollution analysis, Herbicides chemistry, Pesticides chemistry, Phenylurea Compounds chemistry, Soil Pollutants chemistry, Water Pollutants, Chemical chemistry
- Abstract
Background, Aims and Scope: Laboratory studies were conducted with the aim of defining the leaching potential of some phenylureas and their metabolites. A first study was performed for calculating their leaching index (as GUS) on the base of intrinsic properties: persistence (as DT50) and mobility (as Koc) in soil. Another study consisted of aged column leaching experiments whose meaning was to semi-quantify the occurrence of the tested compounds in the leachates, so simulating in field conditions., Methods: The tested compounds were: diuron, linuron and monolinuron (parents); 3,4-dichloroaniline (DCA), 4-chloroaniline (CLA), 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU), 1-(3,4-dichlorophenyl)urea (DCPU), 1-(4-chlorophenyl)urea (CPU) and monuron, this latter considered both as a metabolite and parent compound. The Koc values of the examined substances were determined by the HPLC screening methods, according to the OECD TG 121. DT50 determinations and aged column leaching experiments were carried out according to SETAC procedures., Results and Discussion: The examined compounds showed a rather wide range of persistence in soil, with DT50 values less than 2 days for DCA and CLA, close to 8 days for DCPU and CPU and from 16 (diuron) up to 24.8 (DCPMU) days for the others. Their mobility was generally high, based on their Koc values, which ranged from 33 (CPU) to 406 (linuron). The GUS indices indicated that monuron has a clear potential to contaminate groundwater (> 2.8); DCPMU, monolinuron, CPU and diuron are intermediate contaminants (1.8-2.8). Linuron, DCPU, CLA and DCA exhibited a non-leaching behaviour (< 1.8). The aged leaching column experiments showed that parents were found in the leachates at very high percentages respect to the doses applied. The metabolites reached much less percentages, the highest values were observed for monuron from diuron (5.7), CPU (7.2) and DCPMU (8.2%)., Conclusion: Diuron, Monuron, CPU and DCPMU on the basis of their intrinsic properties, formation from their parents and occurrence in leachates from aged column leaching studies, seem to possess the characteristics of groundwater contaminants. The methodological approach of this study is relatively easy and rapid, hence it can represent a tool for a first screening of compounds such as pesticide metabolites (generally available only in small quantities and for which a field study is not conceivable) or other compounds for which not adequate environmental data are available.
- Published
- 2006
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25. Ostreopsis ovata algal blooms affecting human health in Genova, Italy, 2005 and 2006.
- Author
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Brescianini C, Grillo C, Melchiorre N, Bertolotto R, Ferrari A, Vivaldi B, Icardi G, Gramaccioni L, Funari E, and Scardala S
- Subjects
- Animals, Bronchoconstriction, Dinoflagellida physiology, Humans, Italy epidemiology, Oceans and Seas, Phytoplankton growth & development, Phytoplankton physiology, Cough epidemiology, Dinoflagellida growth & development, Eutrophication physiology, Fever epidemiology
- Published
- 2006
- Full Text
- View/download PDF
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