Science.gov

Sample records for algal toxin exposure

  1. Indicators: Algal Toxins (microcystin)

    EPA Pesticide Factsheets

    Algal toxins are toxic substances released by some types of algae (phytoplankton) when they are present in large quantities (blooms) and decay or degrade. High nutrient levels and warm temperatures often result in favorable conditions for algae blooms.

  2. A Novel Antibody-Based Biomarker for Chronic Algal Toxin Exposure and Sub-Acute Neurotoxicity

    PubMed Central

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins. PMID:22567140

  3. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity

    USGS Publications Warehouse

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  4. Concurrent Exposure of Bottlenose Dolphins (Tursiops truncatus) to Multiple Algal Toxins in Sarasota Bay, Florida, USA

    PubMed Central

    Twiner, Michael J.; Fire, Spencer; Schwacke, Lori; Davidson, Leigh; Wang, Zhihong; Morton, Steve; Roth, Stephen; Balmer, Brian; Rowles, Teresa K.; Wells, Randall S.

    2011-01-01

    Sentinel species such as bottlenose dolphins (Tursiops truncatus) can be impacted by large-scale mortality events due to exposure to marine algal toxins. In the Sarasota Bay region (Gulf of Mexico, Florida, USA), the bottlenose dolphin population is frequently exposed to harmful algal blooms (HABs) of Karenia brevis and the neurotoxic brevetoxins (PbTx; BTX) produced by this dinoflagellate. Live dolphins sampled during capture-release health assessments performed in this region tested positive for two HAB toxins; brevetoxin and domoic acid (DA). Over a ten-year study period (2000–2009) we have determined that bottlenose dolphins are exposed to brevetoxin and/or DA on a nearly annual basis (i.e., DA: 2004, 2005, 2006, 2008, 2009; brevetoxin: 2000, 2004, 2005, 2008, 2009) with 36% of all animals testing positive for brevetoxin (n = 118) and 53% positive for DA (n = 83) with several individuals (14%) testing positive for both neurotoxins in at least one tissue/fluid. To date there have been no previously published reports of DA in southwestern Florida marine mammals, however the May 2008 health assessment coincided with a Pseudo-nitzschia pseudodelicatissima bloom that was the likely source of DA observed in seawater and live dolphin samples. Concurrently, both DA and brevetoxin were observed in common prey fish. Although no Pseudo-nitzschia bloom was identified the following year, DA was identified in seawater, fish, sediment, snails, and dolphins. DA concentrations in feces were positively correlated with hematologic parameters including an increase in total white blood cell (p = 0.001) and eosinophil (p<0.001) counts. Our findings demonstrate that dolphins within Sarasota Bay are commonly exposed to two algal toxins, and provide the impetus to further explore the potential long-term impacts on bottlenose dolphin health. PMID:21423740

  5. Algal toxins alter copepod feeding behavior.

    PubMed

    Hong, Jiarong; Talapatra, Siddharth; Katz, Joseph; Tester, Patricia A; Waggett, Rebecca J; Place, Allen R

    2012-01-01

    Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major) to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms) and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods.

  6. Algal Toxins Alter Copepod Feeding Behavior

    PubMed Central

    Hong, Jiarong; Talapatra, Siddharth; Katz, Joseph; Tester, Patricia A.; Waggett, Rebecca J.; Place, Allen R.

    2012-01-01

    Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major) to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod’s feeding appendages–a “sampling beating” that has short durations (<100 ms) and involves little fluid entrainment and a longer duration “grazing beating” that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod’s grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod’s feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods. PMID:22629336

  7. Marine algal toxins: origins, health effects, and their increased occurrence.

    PubMed Central

    Van Dolah, F M

    2000-01-01

    Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in global warming. The extent to which human activities have contributed to their increase therefore comes into question. This review summarizes the origins and health effects of marine algal toxins, as well as changes in their current global distribution, and examines possible causes for the recent increase in their occurrence. Images Figure 2 Figure 3 PMID:10698729

  8. EFFECTS OF MARINE ALGAL TOXINS ON THERMOREGULATION IN MICE.

    EPA Science Inventory

    Hypothermia is often seen in mice and rats exposed acutely to marine algal toxins, but the mechanism of action of these toxins on thermoregulation is not well understood. Our laboratory has assessed the thermoregulatory mechanisms of two marine algal toxins, maitotoxin and brevet...

  9. EFFECTS OF MARINE ALGAL TOXINS ON THERMOREGULATION IN MICE.

    EPA Science Inventory

    Hypothermia is often seen in mice and rats exposed acutely to marine algal toxins, but the mechanism of action of these toxins on thermoregulation is not well understood. Our laboratory has assessed the thermoregulatory mechanisms of two marine algal toxins, maitotoxin and brevet...

  10. Freshwater harmful algal blooms: toxins and children's health.

    PubMed

    Weirich, Chelsea A; Miller, Todd R

    2014-01-01

    Massive accumulations of cyanobacteria (a.k.a. "blue-green algae"), known as freshwater harmful algal blooms (FHABs), are a common global occurrence in water bodies used for recreational purposes and drinking water purification. Bloom prevalence is increased due to anthropogenic changes in land use, agricultural activity, and climate change. These photosynthetic bacteria produce a range of toxic secondary metabolites that affect animals and humans at both chronic and acute dosages. Children are especially at risk because of their lower body weight, behavior, and toxic effects on development. Here we review common FHAB toxins, related clinical symptoms, acceptable concentrations in drinking water, case studies of children's and young adults' exposures to FHAB toxins through drinking water and food, methods of environmental and clinical detection in potential cases of intoxication, and best practices for FHAB prevention. © 2013 Published by Mosby, Inc.

  11. Evidence of freshwater algal toxins in marine shellfish: Implications for human and aquatic health.

    PubMed

    Gibble, Corinne M; Peacock, Melissa B; Kudela, Raphael M

    2016-11-01

    The occurrence of freshwater harmful algal bloom toxins impacting the coastal ocean is an emerging threat, and the potential for invertebrate prey items to concentrate toxin and cause harm to human and wildlife consumers is not yet fully recognized. We examined toxin uptake and release in marine mussels for both particulate and dissolved phases of the hepatotoxin microcystin, produced by the freshwater cyanobacterial genus Microcystis. We also extended our experimental investigation of particulate toxin to include oysters (Crassostrea sp.) grown commercially for aquaculture. California mussels (Mytilus californianus) and oysters were exposed to Microcystis and microcystin toxin for 24h at varying concentrations, and then were placed in constantly flowing seawater and sampled through time simulating riverine flushing events to the coastal ocean. Mussels exposed to particulate microcystin purged the toxin slowly, with toxin detectable for at least 8 weeks post-exposure and maximum toxin of 39.11ng/g after exposure to 26.65μg/L microcystins. Dissolved toxin was also taken up by California mussels, with maximum concentrations of 20.74ng/g after exposure to 7.74μg/L microcystin, but was purged more rapidly. Oysters also took up particulate toxin but purged it more quickly than mussels. Additionally, naturally occurring marine mussels collected from San Francisco Bay tested positive for high levels of microcystin toxin. These results suggest that ephemeral discharge of Microcystis or microcystin to estuaries and the coastal ocean accumulate in higher trophic levels for weeks to months following exposure.

  12. Biotransport of Algal Toxins to Riparian Food Webs.

    PubMed

    Moy, Nicholas J; Dodson, Jenna; Tassone, Spencer J; Bukaveckas, Paul A; Bulluck, Lesley P

    2016-09-20

    The occurrence of harmful algal blooms has resulted in growing worldwide concern about threats to aquatic life and human health. Microcystin (MC), a cyanotoxin, is the most widely reported algal toxin in freshwaters. Prior studies have documented its presence in aquatic food webs including commercially important fish and shellfish. In this paper we present the first evidence that algal toxins propagate into riparian food webs. We show that MC is present in emerging aquatic insects (Hexagenia mayflies) from the James River Estuary and their consumers (Tetragnathidae spiders and Prothonotary Warblers, Protonotaria citrea). MC levels in Prothonotary Warblers varied by age class, with nestlings having the highest levels. At the site where nestlings received a higher proportion of aquatic prey (i.e., mayflies) in their diet, we observed higher MC concentrations in liver tissue and fecal matter. Warbler body condition and growth rate were not related to liver MC levels, suggesting that aquatic prey may provide dietary benefits that offset potential deleterious effects of the toxin. This study provides evidence that threats posed by algal toxins extend beyond the aquatic environments in which blooms occur.

  13. A convenient and cost-effective method for monitoring marine algal toxins with passive samplers.

    PubMed

    Rundberget, Thomas; Gustad, Eli; Samdal, Ingunn A; Sandvik, Morten; Miles, Christopher O

    2009-04-01

    Passive sampling disks were developed based on the method of MacKenzie, L, Beuzenberg, V., Holland, P., McNabb, P., Selwood, A. [2004. Solid phase adsorption toxin tracking (SPATT): a new monitoring tool that simulates the biotoxin contamination of filter feeding bivalves. Toxicon 44, 901-918] and protocols were formulated for recovering toxins from the adsorbent resin via elution from small columns. The disks were used in field studies to monitor in situ toxin dynamics during mixed algal blooms at Flødevigen in Norway. Examples are given from time-integrated sampling using the disks followed by extraction and high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis for azaspiracids, okadaic acid analogues, pectenotoxins, yessotoxins and spirolides. Profiles of accumulated toxins in the disks and toxin profiles in blue mussels (Mytilus edulis) were compared with the relative abundance of toxin-producing algal species. Results obtained showed that passive sampling disks correlate with the toxin profiles in shellfish. The passive sampling disks were cheap to produce and convenient to use and, when combined with HPLC-MS or enzyme-linked immunosorbent assay (ELISA) analysis, provide detailed time-averaged information on the profile of lipophilic toxin analogues in the water. Passive sampling is therefore a useful tool for monitoring the exposure of shellfish to the toxigenic algae of concern in northern Europe.

  14. Reporter gene assays for algal-derived toxins.

    PubMed

    Fairey, E R; Ramsdell, J S

    1999-01-01

    We have modified the cell-based directed cytotoxicity assay for sodium channel and calcium channel active phycotoxins using a c-fos-luciferase reporter gene construct. In this report we describe the conceptual basis to the development of reporter gene assays for algal-derived toxins and summarize both published and unpublished data using this method. N2A mouse neuroblastoma cells, which express voltage-dependent sodium channels, were stably transfected with the reporter gene c-fos-luc, which contains the firefly luciferase gene under the transcriptional regulation of the human c-fos response element. The characteristics of the N2A reporter gene assay were determined by dose response with brevetoxin and ciguatoxin. Brevetoxin-1 and ciguatoxin-1 induced c-fos-luc with an EC50 of 4.6 and 3.0 ng ml(-1), respectively. Saxitoxin caused a concentration-dependent inhibition of brevetoxin-1 induction of c-fos-luc with an EC50 of 3.5 ng ml(-1). GH4C1 rat pituitary cells, which lack voltage-dependent sodium channels but express voltage-dependent calcium channels, were also stably transfected with the c-fos-luc. GH4C1 cells expressing c-fos-luciferase were responsive to maitotoxin (1 ng ml(-1)) and a putative toxin produced by Pfiesteria piscicida. Although reporter gene assays are not designed to replace existing detection methods used to measure toxin activity in seafood, they do provide a valuable means to screen algal cultures for toxin activity, to conduct assay-guided fractionation and to characterize pharmacologic properties of algal toxins.

  15. EPA Issues Health Advisories to Protect Americans from Algal Toxins in Drinking Water

    EPA Pesticide Factsheets

    WASHINGTON - The U.S. Environmental Protection Agency (EPA) today issued health advisory values that states and utilities can use to protect Americans from elevated levels of algal toxins in drinking water. Algal blooms in rivers, lakes, and bays so

  16. Possible importance of algal toxins in the Salton Sea, California

    USGS Publications Warehouse

    Reifel, K.M.; McCoy, M.P.; Rocke, T.E.; Tiffany, M.A.; Hurlbert, S.H.; Faulkner, D.J.

    2002-01-01

    In response to wildlife mortality including unexplained eared grebe (Podiceps nigricollis) die-off events in 1992 and 1994 and other mortality events including large fish kills, a survey was conducted for the presence of algal toxins in the Salton Sea. Goals of this survey were to determine if and when algal toxins are present in the Salton Sea and to describe the phytoplankton composition during those times. A total of 29 samples was collected for toxicity analysis from both nearshore and midlake sites visited biweekly from January to December 1999. Dinoflagellates and diatoms dominated most samples, but some were dominated by a prymnesiophyte (Pleurochrysis pseudoroscoffensis) or a raphidophyte (Chattonella marina). Several types of blooms were observed and sampled. The dinoflagellate Gyrodinium uncatenum formed an extensive, dense (up to 310 000 cells ml-1) and long-lasting bloom during the winter in 1999. A coccolithophorid, Pleurochrysis pseudoroscoffensis, occurred at high densities in surface films and nearshore areas during the spring and summer of 1999. These surface films also contained high densities of one or two other species (an unidentified scrippsielloid, Heterocapsa niei, Chattonella marina). Localized blooms were also observed in the Salton Sea. An unknown small dinoflagellate reached high densities (110 000 cells ml-1) inside Varner Harbor, and an unidentified species of Gymnodinium formed a dense (270 000 cells ml-1) band along part of the southern shoreline during the summer. Three species known to produce toxins in other systems were found. Protoceratium reticulatum (=Gonyaulax grindleyi) and Chattonella marina were found in several samples taken during summer months, and Prorocentrum minimum was found in low densities in several samples. Extracts of most samples, including those containing known toxic species, showed a low level (<10% mortality across all concentrations) of activity in the brine shrimp lethality assay and were not considered

  17. Ozonation of NOM and algal toxins in four treated waters.

    PubMed

    Rositano, J; Newcombe, G; Nicholson, B; Sztajnbok, P

    2001-01-01

    The occurrence of cyanobacteria (blue-green algae) blooms and the possibility of production of cyanotoxins (algal toxins) have become major concerns for drinking water providers worldwide. Ozone has been shown to be effective for the destruction of some classes of toxins under specific conditions, although most researchers agree that the dose and contact time required will depend on water quality. The clarification of the relative effects of water quality parameters such as dissolved organic carbon concentration and character, and alkalinity, has not been previously attempted. In this study the cyanotoxins microcystin LR and LA and anatoxin-a were ozonated at a range of ozone doses in four treated waters with very different water quality. For both the toxins, 100% destruction was related to a residual ozone concentration present after 5 min. This was, in turn, related to the water quality and indicated that a direct reaction with molecular ozone could be responsible for the destruction. The results confirmed that both the toxins would be destroyed under conditions usually utilised for ozonation prior to granular activated carbon (GAC) filtration. This will apply under a range of water quality conditions but not necessarily a range of temperatures. The saxitoxin class of compounds was very resistant to oxidation by ozone and would require further treatment such as GAC filtration.

  18. Monitoring and removal of cyanobacterial toxins from drinking water by algal-activated carbon.

    PubMed

    Ibrahim, Wael M; Salim, Emad H; Azab, Yahia A; Ismail, Abdel-Hamid M

    2016-10-01

    Microcystins (MCs) are the most potent toxins that can be produced by cyanobacteria in drinking water supplies. This study investigated the abundance of toxin-producing algae in 11 drinking water treatment plants (DWTPs). A total of 26 different algal taxa were identified in treated water, from which 12% were blue green, 29% were green, and 59% were diatoms. MC levels maintained strong positive correlations with number of cyanophycean cells in raw and treated water of different DWTPs. Furthermore, the efficiency of various algal-based adsorbent columns used for the removal of these toxins was evaluated. The MCs was adsorbed in the following order: mixed algal-activated carbon (AAC) ≥ individual AAC > mixed algal powder > individual algal powder. The results showed that the AAC had the highest efficient columns capable of removing 100% dissolved MCs from drinking water samples, thereby offering an economically feasible technology for efficient removal and recovery of MCs in DWTPs.

  19. Prevalence of algal toxins in Alaskan marine mammals foraging in a changing arctic and subarctic environment.

    PubMed

    Lefebvre, Kathi A; Quakenbush, Lori; Frame, Elizabeth; Huntington, Kathy Burek; Sheffield, Gay; Stimmelmayr, Raphaela; Bryan, Anna; Kendrick, Preston; Ziel, Heather; Goldstein, Tracey; Snyder, Jonathan A; Gelatt, Tom; Gulland, Frances; Dickerson, Bobette; Gill, Verena

    2016-05-01

    Current climate trends resulting in rapid declines in sea ice and increasing water temperatures are likely to expand the northern geographic range and duration of favorable conditions for harmful algal blooms (HABs), making algal toxins a growing concern in Alaskan marine food webs. Two of the most common HAB toxins along the west coast of North America are the neurotoxins domoic acid (DA) and saxitoxin (STX). Over the last 20 years, DA toxicosis has caused significant illness and mortality in marine mammals along the west coast of the USA, but has not been reported to impact marine mammals foraging in Alaskan waters. Saxitoxin, the most potent of the paralytic shellfish poisoning toxins, has been well-documented in shellfish in the Aleutians and Gulf of Alaska for decades and associated with human illnesses and deaths due to consumption of toxic clams. There is little information regarding exposure of Alaskan marine mammals. Here, the spatial patterns and prevalence of DA and STX exposure in Alaskan marine mammals are documented in order to assess health risks to northern populations including those species that are important to the nutritional, cultural, and economic well-being of Alaskan coastal communities. In this study, 905 marine mammals from 13 species were sampled including; humpback whales, bowhead whales, beluga whales, harbor porpoises, northern fur seals, Steller sea lions, harbor seals, ringed seals, bearded seals, spotted seals, ribbon seals, Pacific walruses, and northern sea otters. Domoic acid was detected in all 13 species examined and had the greatest prevalence in bowhead whales (68%) and harbor seals (67%). Saxitoxin was detected in 10 of the 13 species, with the highest prevalence in humpback whales (50%) and bowhead whales (32%). Pacific walruses contained the highest concentrations of both STX and DA, with DA concentrations similar to those detected in California sea lions exhibiting clinical signs of DA toxicosis (seizures) off the coast

  20. Recreational exposure to microcystins during algal blooms in two California lakes.

    PubMed

    Backer, Lorraine C; McNeel, Sandra V; Barber, Terry; Kirkpatrick, Barbara; Williams, Christopher; Irvin, Mitch; Zhou, Yue; Johnson, Trisha B; Nierenberg, Kate; Aubel, Mark; LePrell, Rebecca; Chapman, Andrew; Foss, Amanda; Corum, Susan; Hill, Vincent R; Kieszak, Stephanie M; Cheng, Yung-Sung

    2010-05-01

    We conducted a study of recreational exposure to microcystins among 81 children and adults planning recreational activities on either of three California reservoirs, two with significant, ongoing blooms of toxin-producing cyanobacteria, including Microcystis aeruginosa (Bloom Lakes), and one without a toxin-producing algal bloom (Control Lake). We analyzed water samples for algal taxonomy, microcystin concentrations, and potential respiratory viruses (adenoviruses and enteroviruses). We measured microcystins in personal air samples, nasal swabs, and blood samples. We interviewed study participants for demographic and health symptoms information. We found highly variable microcystin concentrations in Bloom Lakes (<10 microg/L to >500 microg/L); microcystin was not detected in the Control Lake. We did not detect adenoviruses or enteroviruses in any of the lakes. Low microcystin concentrations were found in personal air samples (<0.1 ng/m(3) [limit of detection]-2.89 ng/m(3)) and nasal swabs (<0.1 ng [limit of detection]-5 ng). Microcystin concentrations in the water-soluble fraction of all plasma samples were below the limit of detection (1.0 microg/L). Our findings indicate that recreational activities in water bodies that experience toxin-producing cyanobacterial blooms can generate aerosolized cyanotoxins, making inhalation a potential route of exposure. Future studies should include collecting nasal swabs to assess upper respiratory tract deposition of toxin-containing aerosols droplets.

  1. Algal toxins and producers in the marine waters of Qatar, Arabian Gulf.

    PubMed

    Al Muftah, Abdulrahman; Selwood, Andrew I; Foss, Amanda J; Al-Jabri, Hareb Mohammed S J; Potts, Malcolm; Yilmaz, Mete

    2016-11-01

    Harmful Algal Bloom species are ubiquitous and their blooms occur in the Arabian Gulf. In this study, two cruises were performed in 2012 and 2013 to collect phytoplankton samples from 4 sites in the Arabian Gulf. Toxin analyses of phytoplankton samples for 32 algal toxins from 5 different toxin groups were conducted on the samples using both enzyme linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results demonstrated, for the first time, the presence of paralytic shellfish toxins (PSTs), diarrhetic shellfish toxin (DST), amnesic shellfish toxin (AST), cyclic imines (CIs) and polyether-lactone toxins in freeze-dried phytoplankton samples. Four Vulcanodinium rugosum cultures were established from field samples and these proved to contain between 603 and 981 ng pinnatoxin (PnTx) H per mg dry weight in addition to being positive for portimine. These strains from Qatar clustered with strains from Japan and Florida based on large subunit rRNA and rRNA internal transcribed spacer gene sequences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. The laboratory mouse in routine food safety testing for marine algal biotoxins and harmful algal bloom toxin research: past, present and future.

    PubMed

    Stewart, Ian; McLeod, Catherine

    2014-01-01

    Mouse bioassays have been a mainstay for detecting harmful concentrations of marine algal toxins in shellfish for over 70 years. Routine monitoring involves intraperitoneal injection of shellfish extracts into mice; shellfish contaminated with algal toxins are thus identified by mortality in exposed mice. With the advent of alternative test methods to detect and quantify specific algal toxins has come increasing criticism of enduring use of mouse bioassays for shellfish safety testing. However, the complete replacement of shellfish safety mouse bioassays by chemical, antibody-based, and functional assays has been and will continue to be a gradual process for various reasons, including skills availability and instrument costs for chromatography-based toxin monitoring. Mouse bioassays for shellfish safety testing do not comply with modern standards for laboratory animal welfare, specifically the requirement in published official methods for death as a test outcome. Mouse bioassays for algal biotoxins in shellfish, as well as fundamental algal toxin research endeavors using in vivo models, are amenable to revision and refinement from a humane endpoints perspective. Regulated hypothermia may be a useful and easily acquired nonlethal toxicological endpoint; objective determination of neuromuscular blockade may allow algal neurotoxin testing and research to enter the domain of humane endpoints evaluation. Relinquishing reliance on subjective test endpoints, including death, will likely also deliver collateral improvements in assay variability and sensitivity.

  3. Polymyositis after ciguatera toxin exposure.

    PubMed

    Stommel, E W; Parsonnet, J; Jenkyn, L R

    1991-08-01

    Biopsy-proved polymyositis subsequently developed in two patients who were severely poisoned by ciguatera fish toxin. Ciguatera toxin may have several mechanisms of action and may represent more than one toxin. The patients' clinical courses and the unlikelihood of coincidence of contracting both diseases suggested to us a causal relationship. Although we cannot prove this relationship, we suggest a mechanism by which the toxin predisposed the muscle to inflammation.

  4. Cyanobacterial (blue-green algal) toxins in water supplies: Cylindrospermopsins.

    PubMed

    Falconer, Ian R; Humpage, Andrew R

    2006-08-01

    The toxic alkaloid cylindrospermopsin is produced by a range of cyanobacterial species worldwide. It was first identified in the species Cylindrospermopsis raciborskii from tropical waters, and has since been isolated from four other genera in locations ranging from Israel to Japan. High concentrations of the organisms and toxin have been identified in reservoirs, natural lakes, and rivers in summer in the USA and in Australia. The toxin is a particular problem in drinking water sources as concentrations in the free water are appreciable, so that removal of the filaments during water treatment does not remove the toxin. The toxicity resulting from oral ingestion is seen in the liver, kidneys, stomach, intestine, and white blood cells, with some vascular damage in mice. Gastrointestinal as well as liver injury has been observed in human poisoning. Studies of toxicity in vitro have shown inhibition of protein synthesis. Genotoxicity has also been demonstrated, and there is preliminary evidence for carcinogenicity. A Guideline Value for safe water supply of 1 microg/L has been proposed. Research into toxin measurement techniques and water treatment methods has indicated that effective control measures may be practicable for this toxin in drinking water. Considerably more research is needed to fully define the health risks from this toxin.

  5. Determination of the cyanobacterial toxin cylindrospermopsin in algal food supplements

    PubMed Central

    Liu, H.; Scott, P.M.

    2011-01-01

    For the analysis of blue–green algal food supplements for cylindrospermopsin (CYN), a C18 solid-phase extraction column and a polygraphitized carbon solid-phase extraction column in series was an effective procedure for the clean-up of extracts. Determination of CYN was by liquid chromatography with ultraviolet light detection. At extract spiking levels of CYN equivalent to 25–500 μg g−1, blue–green algal supplement recoveries were in the range 70–90%. CYN was not detected in ten samples of food supplements and one chocolate product, all containing blue–green algae. The limit of detection for the method was 16 μg g−1, and the limit of quantification was 52 μg g−1. PMID:21623503

  6. Determination of the cyanobacterial toxin cylindrospermopsin in algal food supplements.

    PubMed

    Liu, H; Scott, P M

    2011-06-01

    For the analysis of blue-green algal food supplements for cylindrospermopsin (CYN), a C18 solid-phase extraction column and a polygraphitized carbon solid-phase extraction column in series was an effective procedure for the clean-up of extracts. Determination of CYN was by liquid chromatography with ultraviolet light detection. At extract spiking levels of CYN equivalent to 25-500 µg g(-1), blue-green algal supplement recoveries were in the range 70-90%. CYN was not detected in ten samples of food supplements and one chocolate product, all containing blue-green algae. The limit of detection for the method was 16 µg g(-1), and the limit of quantification was 52 µg g(-1).

  7. Algal Toxin Removal Capabilities of Common Drinking Water ...

    EPA Pesticide Factsheets

    This presentation delivers information on the control of cyanobacteria and toxins through potassium permanganate oxidation, powdered activated carbon application, coagulation/flocculation/sedimentation, filtration and chlorination. This presentation will help to disseminate Agency research results to the international drinking water community

  8. Algal Toxin Removal Capabilities of Common Drinking Water ...

    EPA Pesticide Factsheets

    This presentation discusses the removal of cyanobacteria and cyanobacteria toxins through permanganate addition, powdered activated carbon addition, sedimentation, filtration and chlorination. The presentation is intended to help transfer the results of ORD research to state primacy agency personnel, practicing drinking water treatment personnel and consulting engineers.

  9. Toxin content and cytotoxicity of algal dietary supplements

    SciTech Connect

    Heussner, A.H.; Mazija, L.; Fastner, J.; Dietrich, D.R.

    2012-12-01

    Blue-green algae (Spirulina sp., Aphanizomenon flos-aquae) and Chlorella sp. are commercially distributed as organic algae dietary supplements. Cyanobacterial dietary products in particular have raised serious concerns, as they appeared to be contaminated with toxins e.g. microcystins (MCs) and consumers repeatedly reported adverse health effects following consumption of these products. The aim of this study was to determine the toxin contamination and the in vitro cytotoxicity of algae dietary supplement products marketed in Germany. In thirteen products consisting of Aph. flos-aquae, Spirulina and Chlorella or mixtures thereof, MCs, nodularins, saxitoxins, anatoxin-a and cylindrospermopsin were analyzed. Five products tested in an earlier market study were re-analyzed for comparison. Product samples were extracted and analyzed for cytotoxicity in A549 cells as well as for toxin levels by (1) phosphatase inhibition assay (PPIA), (2) Adda-ELISA and (3) LC–MS/MS. In addition, all samples were analyzed by PCR for the presence of the mcyE gene, a part of the microcystin and nodularin synthetase gene cluster. Only Aph. flos-aquae products were tested positive for MCs as well as the presence of mcyE. The contamination levels of the MC-positive samples were ≤ 1 μg MC-LR equivalents g{sup −1} dw. None of the other toxins were found in any of the products. However, extracts from all products were cytotoxic. In light of the findings, the distribution and commercial sale of Aph. flos-aquae products, whether pure or mixed formulations, for human consumption appear highly questionable. -- Highlights: ► Marketed algae dietary supplements were analyzed for toxins. ► Methods: Phosphatase inhibition assay (PPIA), Adda-ELISA, LC-MS/MS. ► Aph. flos-aquae products all tested positive for microcystins. ► Products tested negative for nodularins, saxitoxins, anatoxin-a, cylindrospermopsin. ► Extracts from all products were cytotoxic.

  10. Toxin content and cytotoxicity of algal dietary supplements.

    PubMed

    Heussner, A H; Mazija, L; Fastner, J; Dietrich, D R

    2012-12-01

    Blue-green algae (Spirulina sp., Aphanizomenon flos-aquae) and Chlorella sp. are commercially distributed as organic algae dietary supplements. Cyanobacterial dietary products in particular have raised serious concerns, as they appeared to be contaminated with toxins e.g. microcystins (MCs) and consumers repeatedly reported adverse health effects following consumption of these products. The aim of this study was to determine the toxin contamination and the in vitro cytotoxicity of algae dietary supplement products marketed in Germany. In thirteen products consisting of Aph. flos-aquae, Spirulina and Chlorella or mixtures thereof, MCs, nodularins, saxitoxins, anatoxin-a and cylindrospermopsin were analyzed. Five products tested in an earlier market study were re-analyzed for comparison. Product samples were extracted and analyzed for cytotoxicity in A549 cells as well as for toxin levels by (1) phosphatase inhibition assay (PPIA), (2) Adda-ELISA and (3) LC-MS/MS. In addition, all samples were analyzed by PCR for the presence of the mcyE gene, a part of the microcystin and nodularin synthetase gene cluster. Only Aph. flos-aquae products were tested positive for MCs as well as the presence of mcyE. The contamination levels of the MC-positive samples were ≤ 1 μg MC-LR equivalents g(-1) dw. None of the other toxins were found in any of the products. However, extracts from all products were cytotoxic. In light of the findings, the distribution and commercial sale of Aph. flos-aquae products, whether pure or mixed formulations, for human consumption appear highly questionable. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Recreational Exposure to Low Concentrations of Microcystins During an Algal Bloom in a Small Lake

    PubMed Central

    Backer, Lorraine C.; Carmichael, Wayne; Kirkpatrick, Barbara; Williams, Christopher; Irvin, Mitch; Zhou, Yue; Johnson, Trisha B.; Nierenberg, Kate; Hill, Vincent R.; Kieszak, Stephanie M.; Cheng, Yung-Sung

    2008-01-01

    We measured microcystins in blood from people at risk for swallowing water or inhaling spray while swimming, water skiing, jet skiing, or boating during an algal bloom. We monitored water samples from a small lake as a Microcystis aeruginosa bloom developed. We recruited 97 people planning recreational activities in that lake and seven others who volunteered to recreate in a nearby bloom-free lake. We conducted our field study within a week of finding a 10-μg/L microcystin concentration. We analyzed water, air, and human blood samples for water quality, potential human pathogens, algal taxonomy, and microcystin concentrations. We interviewed study participants for demographic and current health symptom information. Water samples were assayed for potential respiratory viruses (adenoviruses and enteroviruses), but none were detected. We did find low concentrations of Escherichia coli, indicating fecal contamination. We found low levels of microcystins (2 μg/L to 5 μg/L) in the water and (<0.1 ng/m3) in the aerosol samples. Blood levels of microcystins for all participants were below the limit of detection (0.147μg/L). Given this low exposure level, study participants reported no symptom increases following recreational exposure to microcystins. This is the first study to report that water-based recreational activities can expose people to very low concentrations of aerosol-borne microcystins; we recently conducted another field study to assess exposures to higher concentrations of these algal toxins. PMID:18728733

  12. Occurrence of marine algal toxins in oyster and phytoplankton samples in Daya Bay, South China Sea.

    PubMed

    Jiang, Tao; Liu, Lei; Li, Yang; Zhang, Jing; Tan, Zhijun; Wu, Haiyan; Jiang, Tianjiu; Lu, Songhui

    2017-09-01

    The occurrence and seasonal variations of marine algal toxins in phytoplankton and oyster samples in Daya Bay (DYB), South China Sea were investigated. Two Dinophysis species, namely, D. caudata and D. acuminata complex, were identified as Okadaic acid (OA)/pectenotoxin (PTX) related species. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis demonstrated that 2.04-14.47 pg PTX2 per cell was the predominant toxin in single-cell isolates of D. caudata. D. acuminata was not subjected to toxin analysis. The occurrence of OAs in phytoplankton concentrates of net-haul sample coincided with the presence of D. accuminata complex, suggesting that this species is most likely an OA producer in this sea area. OA, dinophysistoxins-1 (DTX1), PTX2, PTX2sa, gymnodimine (GYM), homoyessotoxin (homoYTX), and domoic acid (DA) demonstrated positive results in net haul samples. To our best knowledge, this paper is the first to report the detection of GYM, DA, and homoYTX in phytoplankton samples in Chinese coastal waters. Among the algal toxins, GYM demonstrated the highest frequency of positive detections in phytoplankton concentrates (13/17). Five compounds of algal toxins, including OA, DTX1, PTX2, PTX2sa, and GYM, were detected in oyster samples. DA and homoYTX were not detected in oysters despite of positive detections for both in the phytoplankton concentrates. However, neither the presence nor absence of DA in oysters can be determined because extraction conditions with 100% methanol used to isolate toxins from oysters (recommended by the EU-Harmonised Standard Operating Procedure, 2015) would likely be unsuitable for this water-soluble toxin. In addition, transformation of DA during the digestion process of oysters may also be involved in the negative detections of this toxin. GYM exhibited the highest frequency of positive results in oysters (14/17). OAs were only detected in the hydrolyzed oyster samples. The detection rates of PTX and PTX2sa in

  13. Cephalopods as Vectors of Harmful Algal Bloom Toxins in Marine Food Webs

    PubMed Central

    Lopes, Vanessa M.; Lopes, Ana Rita; Costa, Pedro; Rosa, Rui

    2013-01-01

    Here we summarize the current knowledge on the transfer and accumulation of harmful algal bloom (HAB)-related toxins in cephalopods (octopods, cuttlefishes and squids). These mollusks have been reported to accumulate several HAB-toxins, namely domoic acid (DA, and its isomers), saxitoxin (and its derivatives) and palytoxin (and palytoxin-like compounds) and, therefore, act as HAB-toxin vectors in marine food webs. Coastal octopods and cuttlefishes store considerably high levels of DA (amnesic shellfish toxin) in several tissues, but mainly in the digestive gland (DG)—the primary site of digestive absorption and intracellular digestion. Studies on the sub-cellular partitioning of DA in the soluble and insoluble fractions showed that nearly all DA (92.6%) is found in the cytosol. This favors the trophic transfer of the toxins since cytosolic substances can be absorbed by predators with greater efficiency. The available information on the accumulation and tissue distribution of DA in squids (e.g., in stranded Humboldt squids, Dosidicus gigas) is scarcer than in other cephalopod groups. Regarding paralytic shellfish toxins (PSTs), these organisms accumulate them at the greatest extent in DG >> kidneys > stomach > branchial hearts > posterior salivary glands > gills. Palytoxins are among the most toxic molecules identified and stranded octopods revealed high contamination levels, with ovatoxin (a palytoxin analogue) reaching 971 μg kg−1 and palytoxin reaching 115 μg kg−1 (the regulatory limit for PlTXs is 30 μg kg−1 in shellfish). Although the impacts of HAB-toxins in cephalopod physiology are not as well understood as in fish species, similar effects are expected since they possess a complex nervous system and highly developed brain comparable to that of the vertebrates. Compared to bivalves, cephalopods represent a lower risk of shellfish poisoning in humans, since they are usually consumed eviscerated, with exception of traditional dishes from the

  14. Cephalopods as vectors of harmful algal bloom toxins in marine food webs.

    PubMed

    Lopes, Vanessa M; Lopes, Ana Rita; Costa, Pedro; Rosa, Rui

    2013-09-06

    Here we summarize the current knowledge on the transfer and accumulation of harmful algal bloom (HAB)-related toxins in cephalopods (octopods, cuttlefishes and squids). These mollusks have been reported to accumulate several HAB-toxins, namely domoic acid (DA, and its isomers), saxitoxin (and its derivatives) and palytoxin (and palytoxin-like compounds) and, therefore, act as HAB-toxin vectors in marine food webs. Coastal octopods and cuttlefishes store considerably high levels of DA (amnesic shellfish toxin) in several tissues, but mainly in the digestive gland (DG)--the primary site of digestive absorption and intracellular digestion. Studies on the sub-cellular partitioning of DA in the soluble and insoluble fractions showed that nearly all DA (92.6%) is found in the cytosol. This favors the trophic transfer of the toxins since cytosolic substances can be absorbed by predators with greater efficiency. The available information on the accumulation and tissue distribution of DA in squids (e.g., in stranded Humboldt squids, Dosidicus gigas) is scarcer than in other cephalopod groups. Regarding paralytic shellfish toxins (PSTs), these organisms accumulate them at the greatest extent in DG > kidneys > stomach > branchial hearts > posterior salivary glands > gills. Palytoxins are among the most toxic molecules identified and stranded octopods revealed high contamination levels, with ovatoxin (a palytoxin analogue) reaching 971 μg kg⁻¹ and palytoxin reaching 115 μg kg⁻¹ (the regulatory limit for PlTXs is 30 μg kg⁻¹ in shellfish). Although the impacts of HAB-toxins in cephalopod physiology are not as well understood as in fish species, similar effects are expected since they possess a complex nervous system and highly developed brain comparable to that of the vertebrates. Compared to bivalves, cephalopods represent a lower risk of shellfish poisoning in humans, since they are usually consumed eviscerated, with exception of traditional dishes from the

  15. Harmful Algal Bloom Toxins: c-Fos Protein Expression in the Brain of Killifish, Fundulus heteroclitus

    DTIC Science & Technology

    2006-04-21

    expression significantly increased in the anterior optic ectum of DA-exposed fish compared to controls (p= 0.055, J.D. Salierno et al. / Aquatic Toxicology ... Aquatic Toxicology 78 (2006) 350–357 Harmful algal bloom toxins alter c-Fos protein expression in the brain of killifish, Fundulus heteroclitus J.D...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 J.D. Salierno et al. / Aquatic Toxicology 78 (2006) 350–357 351 induction can be used as

  16. Harmful algal bloom toxins alter c-Fos protein expression in the brain of killifish, Fundulus heteroclitus

    PubMed Central

    Salierno, J.D.; Snyder, N.S.; Murphy, A.Z.; Poli, M.; Hall, S.; Baden, D.; Kane, A.S.

    2009-01-01

    The immediate early gene c-fos, and its protein product c-Fos, are known to be induced in neurons of mammals and fish as a result of neuronal stimulation. The purpose of this study was to quantitatively examine CNS alterations in killifish, Fundulus heteroclitus, in relation to harmful algal bloom (HAB) toxin exposure. c-Fos expression was visualized using immunocytochemistry in the brains of killifish exposed to the excitatory neurotoxins domoic acid (DA) and brevetoxin (PbTx-2), and a paralytic neurotoxin, saxitoxin (STX), released from HABs. In addition, a simulated transport stress experiment was conducted to investigate effects of physical stress on c-Fos induction. Groups of fish were exposed to the different stress agents, brain sections were processed for c-Fos staining, and expression was quantified by brain region. Fish exposed to DA, STX, and transport stress displayed significant alterations in neuronal c-Fos expression when compared to control fish (p ≤ 0.05). DA, PbTx-2, and transport stress increased c-Fos expression in the optic tecta regions of the brain, whereas STX significantly decreased expression. This is the first study to quantify c-Fos protein expression in fish exposed to HAB toxins. General alterations in brain activity, as well as knowledge of specific regions within the brain activated in association with HABs or other stressors, provides valuable insights into the neural control of fish behavior as well as sublethal effects of specific stressors in the CNS. PMID:16750577

  17. Algal toxin impairs sea lion memory and hippocampal connectivity, with implications for strandings.

    PubMed

    Cook, Peter F; Reichmuth, Colleen; Rouse, Andrew A; Libby, Laura A; Dennison, Sophie E; Carmichael, Owen T; Kruse-Elliott, Kris T; Bloom, Josh; Singh, Baljeet; Fravel, Vanessa A; Barbosa, Lorraine; Stuppino, Jim J; Van Bonn, William G; Gulland, Frances M D; Ranganath, Charan

    2015-12-18

    Domoic acid (DA) is a naturally occurring neurotoxin known to harm marine animals. DA-producing algal blooms are increasing in size and frequency. Although chronic exposure is known to produce brain lesions, the influence of DA toxicosis on behavior in wild animals is unknown. We showed, in a large sample of wild sea lions, that spatial memory deficits are predicted by the extent of right dorsal hippocampal lesions related to natural exposure to DA and that exposure also disrupts hippocampal-thalamic brain networks. Because sea lions are dynamic foragers that rely on flexible navigation, impaired spatial memory may affect survival in the wild.

  18. Algal toxin profiles in Nigerian coastal waters (Gulf of Guinea) using passive sampling and liquid chromatography coupled to mass spectrometry.

    PubMed

    Zendong, Zita; Kadiri, Medina; Herrenknecht, Christine; Nézan, Elisabeth; Mazzeo, Antonia; Hess, Philipp

    2016-05-01

    Algal toxins may accumulate in fish and shellfish and thus cause poisoning in consumers of seafood. Such toxins and the algae producing them are regularly surveyed in many countries, including Europe, North America, Japan and others. However, very little is known regards the occurrence of such algae and their toxins in most African countries. This paper reports on a survey of phytoplankton and algal toxins in Nigerian coastal waters. Seawater samples were obtained from four sites for phytoplankton identification, on three occasions between the middle of October 2014 and the end of February 2015 (Bar Beach and Lekki in Lagos State, Port Harcourt in Rivers State and Uyo in Akwa Ibom State). The phytoplankton community was generally dominated by diatoms and cyanobacteria; however several species of dinoflagellates were also identified: Dinophysis caudata, Lingulodinium polyedrum and two benthic species of Prorocentrum. Passive samplers (containing Diaion(®) HP-20 resin) were deployed for several 1-week periods on the same four sites to obtain profiles of algal toxins present in the seawater. Quantifiable amounts of okadaic acid (OA) and pectenotoxin 2 (PTX2), as well as traces of dinophysistoxin 1 (DTX1) were detected at several sites. Highest concentrations (60 ng OA g(-1) HP-20 resin) were found at Lekki and Bar Beach stations, which also had the highest salinities. Non-targeted analysis using full-scan high resolution mass spectrometry showed that algal metabolites differed from site to site and for different sampling occasions. Screening against a marine natural products database indicated the potential presence of cyanobacterial compounds in the water column, which was also consistent with phytoplankton analysis. During this study, the occurrence of the marine dinoflagellate toxins OA and PTX2 has been demonstrated in coastal waters of Nigeria, despite unfavourable environmental conditions, with regards to the low salinities measured. Hence shellfish samples

  19. Addressing harmful algal blooms (HABs) impacts with ferrate(VI): Simultaneous removal of algal cells and toxins for drinking water treatment.

    PubMed

    Deng, Yang; Wu, Meiyin; Zhang, Huiqin; Zheng, Lei; Acosta, Yaritza; Hsu, Tsung-Ta D

    2017-11-01

    Although ferrate(VI) has long been recognized as a multi-purpose treatment agent, previous investigations regarding ferrate(VI) for addressing harmful algal blooms (HABs) impacts in drinking water treatment only focused on a single HAB pollutant (e.g. algal cells or algal toxins). Moreover, the performance of ferrate(VI)-driven coagulation was poorly investigated in comparison with ferrate(VI) oxidation, though it has been widely acknowledged as a major ferrate(VI) treatment mechanism. We herein reported ferrate(VI) as an emerging agent for simultaneous and effective removal of algal cells and toxins in a simulated HAB-impacted water. Ferrate(VI)-driven oxidation enabled algal cell inactivation and toxin decomposition. Subsequently, Fe(III) from ferrate(VI) reduction initiated an in-situ coagulation for cell aggregation. Cell viability (initial 4.26 × 10(4) cells/mL at pH 5.5 and 5.16 × 10(4) cells/mL at pH 7.5) decreased to 0.0% at ≥ 7 mg/L Fe(VI) at pH 5.5 and 7.5, respectively. Cell density and turbidity were dramatically decreased at pH 5.5 once ferrate(VI) doses were beyond their respective threshold levels, which are defined as minimum effective iron doses (MEIDs). However, the particulate removal at pH 7.5 was poor, likely because the coagulation was principally driven by charge neutralization and a higher pH could not sufficiently lower the particle surface charge. Meanwhile, algal toxins (i.e., microcystins) of 3.98 μg/L could be substantially decomposed at either pH. And the greater degradation achieved at pH 5.5 was due to the higher reactivity of ferrate(VI) at the lower pH. This study represents the first step toward the ferrate(VI) application as a promising approach for addressing multiple HABs impacts for water treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Rachael Carson Lecture - Algal Toxins in the Deep Blue Sea: an Environmental Concern?

    NASA Astrophysics Data System (ADS)

    Silver, M. W.; Bargu, S.

    2008-05-01

    Many land plants are known to possess toxins, presumably for grazer deterrence, whereas toxins in marine phytoplankton are a much rarer phenomenon, particularly in open ocean (blue water) environments. Several dozen phytoplankton species, frequently dinoflagellates but also some diatoms, form "harmful algal blooms" nearshore: here their toxins can contaminate filter-feeding shellfish resulting in poisoning "syndromes" when humans consume the tainted shellfish. The present rise in such coastal events is a likely consequence of human activities. In blue water, open ocean environments, the filamentous cyanobacterium Trichodesmium (a blue green alga) is one of the few bloom-forming toxin producers and hosts a consortium of microorganisms that may be partially immune to its toxins. Pseudo-nitzschia, a ubiquitous genus of diatoms recently has been shown to include coastal species that produce domoic acid (DA), a neurotoxin that passes through the food web, sometimes with resulting deaths of marine birds and mammals. Oceanic species of Pseudo-nitzschia also exist but are less well known, and DA has not yet been found in them. Here we review some general features of toxic marine phytoplankton, recent studies on DA in coastal ecosystems and describe some of our findings on blue water Pseudo-nitzschia. We will summarize laboratory experiments that show complex patterns of DA retention and release into the water when Fe is added to coastal Pseudo-nitzschia cultures. In oceanic species, equivalent experiments on cell physiology are limited and the natural species and abundance patterns poorly known. Here we present our recent discovery that DA occurs in oceanic Pseudo-nitzschia and review evidence from the literature that this genus may be preferentially enhanced when iron is added to HNLC (high nutrient, low chlorophyll) waters: areas where nitrogen and phosphorus are not yet depleted, but iron concentrations and phytoplankton biomass are low. The rapid growth of these DA

  1. Bioaccumulation of algal toxins and changes in physiological parameters in Mediterranean mussels from the North Adriatic Sea (Italy).

    PubMed

    Buratti, Sara; Franzellitti, Silvia; Poletti, Roberto; Ceredi, Alfiero; Montanari, Giuseppe; Capuzzo, Antonio; Fabbri, Elena

    2013-08-01

    The Northwestern Adriatic Sea is a commercially important area in aquaculture, accounting for about 90% of the Italian mussel production, and it was subjected to recurring cases of mussel farm closures due to toxic algae poisoning. A spatial and temporal survey of four sites along the North Adriatic Sea coasts of Emilia Romagna (Italy) was undertaken to study the possible impairments of physiological parameters in Mytilus galloprovincialis naturally exposed to algal toxins. The sites were selected as part of the monitoring network for the assessment of algal toxins bioaccumulation by the competent Authority. Samples positive to paralytic shellfish toxins and to lipophilic toxins were detected through the mouse bioassay. Lipophilic toxins were assessed by HPLC. Decreasing yessotoxins (YTX) levels were observed in mussels from June to December, while homo-YTX contents increased concomitantly. Lysosome membrane stability (LMS), glutathione S-transferase and catalase activities, and multixenobiotic resistance (MXR)-related gene expressions were assessed as parameters related to the mussel health status and widely utilized in environmental biomonitoring. Levels of cAMP were also measured, as possibly involved in the algal toxin mechanisms of action. Low LMS values were observed in hemocytes from mussels positive to the mouse bioassay. MXR-related gene expressions were greatly inhibited in mussels positive to the mouse bioassay. Clear correlations were established between increasing homo-YTX contents (and decreasing YTX) and increasing cAMP levels in the tissues. Similarly, significant correlations were established between the increase of homo-YTX and cAMP levels, and the expressions of three MXR-related genes at submaximal toxin concentrations. In conclusion, YTXs may affect mussel physiological parameters, including hemocyte functionality, gene expression and cell signaling. Copyright © 2011 Wiley Periodicals, Inc.

  2. A shift in the dominant toxin-producing algal species in central California alters phycotoxins in food webs

    USGS Publications Warehouse

    Jester, R.; Lefebvre, K.; Langlois, G.; Vigilant, V.; Baugh, K.; Silver, M.W.

    2009-01-01

    In California, the toxic algal species of primary concern are the dinoflagellate Alexandrium catenella and members of the pennate diatom genus Pseudo-nitzschia, both producers of potent neurotoxins that are capable of sickening and killing marine life and humans. During the summer of 2004 in Monterey Bay, we observed a change in the taxonomic structure of the phytoplankton community-the typically diatom-dominated community shifted to a red tide, dinoflagellate-dominated community. Here we use a 6-year time series (2000-2006) to show how the abundance of the dominant harmful algal bloom (HAB) species in the Bay up to that point, Pseudo-nitzschia, significantly declined during the dinoflagellate-dominated interval, while two genera of toxic dinoflagellates, Alexandrium and Dinophysis, became the predominant toxin producers. This change represents a shift from a genus of toxin producers that typically dominates the community during a toxic bloom, to HAB taxa that are generally only minor components of the community in a toxic event. This change in the local HAB species was also reflected in the toxins present in higher trophic levels. Despite the small contribution of A. catenella to the overall phytoplankton community, the increase in the presence of this species in Monterey Bay was associated with an increase in the presence of paralytic shellfish poisoning (PSP) toxins in sentinel shellfish and clupeoid fish. This report provides the first evidence that PSP toxins are present in California's pelagic food web, as PSP toxins were detected in both northern anchovies (Engraulis mordax) and Pacific sardines (Sardinops sagax). Another interesting observation from our data is the co-occurrence of DA and PSP toxins in both planktivorous fish and sentinel shellfish. We also provide evidence, based on the statewide biotoxin monitoring program, that this increase in the frequency and abundance of PSP events related to A. catenella occurred not just in Monterey Bay, but also

  3. Exposure to anthrax toxin alters human leucocyte expression of anthrax toxin receptor 1.

    PubMed

    Ingram, R J; Harris, A; Ascough, S; Metan, G; Doganay, M; Ballie, L; Williamson, E D; Dyson, H; Robinson, J H; Sriskandan, S; Altmann, D M

    2013-07-01

    Anthrax is a toxin-mediated disease, the lethal effects of which are initiated by the binding of protective antigen (PA) with one of three reported cell surface toxin receptors (ANTXR). Receptor binding has been shown to influence host susceptibility to the toxins. Despite this crucial role for ANTXR in the outcome of disease, and the reported immunomodulatory consequence of the anthrax toxins during infection, little is known about ANTXR expression on human leucocytes. We characterized the expression levels of ANTXR1 (TEM8) on human leucocytes using flow cytometry. In order to assess the effect of prior toxin exposure on ANTXR1 expression levels, leucocytes from individuals with no known exposure, those exposed to toxin through vaccination and convalescent individuals were analysed. Donors could be defined as either 'low' or 'high' expressers based on the percentage of ANTXR1-positive monocytes detected. Previous exposure to toxins appears to modulate ANTXR1 expression, exposure through active infection being associated with lower receptor expression. A significant correlation between low receptor expression and high anthrax toxin-specific interferon (IFN)-γ responses was observed in previously infected individuals. We propose that there is an attenuation of ANTXR1 expression post-infection which may be a protective mechanism that has evolved to prevent reinfection.

  4. Harmful algal toxins of the Florida red tide (Karenia brevis): natural chemical stressors in South Florida coastal ecosystems.

    PubMed

    Pierce, R H; Henry, M S

    2008-10-01

    The Florida red tide is a descriptive name for high concentrations of the harmful marine alga, Karenia brevis. Although most prevalent along the south-west Florida coast, periodic blooms have occurred throughout the entire US and Mexico Gulf coasts and the Atlantic coast to North Carolina. This dinoflagellate produces a suite of polyether neurotoxins, called brevetoxins, that cause severe impacts to natural resources, as well as public health. These naturally produced biotoxins may represent one of the most common chemical stressors impacting South Florida coastal and marine ecosystems. Impacts include massive fish kills, marine mammal, sea turtle and sea bird mortalities, benthic community die-off and public health effects from shellfish contamination and inhalation of air-borne toxins. The primary mode of action is binding to voltage-gated sodium channels causing depolarization of nerve cells, thus interfering with nerve transmission. Other effects include immune depression, bronchial constriction and haemolysis. Parent algal toxins are synthesized within the unicellular organism, others are produced as metabolic products. Recent studies into the composition of brevetoxins in cells, water, air and organisms have shown PbTx-2 to be the primary intracellular brevetoxin that is converted over time to PbTx-3 when the cells are ruptured, releasing extracellular brevetoxins into the environment. Brevetoxins become aerosolized by bubble-mediated transport of extracellular toxins, the composition of which varies depending on the composition in the source water. Bivalved molluscs rapidly accumulate brevetoxins as they filter feed on K. brevis cells. However, the parent algal toxins are rapidly metabolized to other compounds, some of which are responsible for neurotoxic shellfish poisoning (NSP). These results provide new insight into the distribution, persistence and impacts of red tide toxins to south-west Florida ecosystems.

  5. Harmful algal toxins of the Florida red tide (Karenia brevis): natural chemical stressors in South Florida coastal ecosystems

    PubMed Central

    Henry, M. S.

    2009-01-01

    The Florida red tide is a descriptive name for high concentrations of the harmful marine alga, Karenia brevis. Although most prevalent along the south-west Florida coast, periodic blooms have occurred throughout the entire US and Mexico Gulf coasts and the Atlantic coast to North Carolina. This dinoflagellate produces a suite of polyether neurotoxins, called brevetoxins, that cause severe impacts to natural resources, as well as public health. These naturally produced biotoxins may represent one of the most common chemical stressors impacting South Florida coastal and marine ecosystems. Impacts include massive fish kills, marine mammal, sea turtle and sea bird mortalities, benthic community die-off and public health effects from shellfish contamination and inhalation of air-borne toxins. The primary mode of action is binding to voltage-gated sodium channels causing depolarization of nerve cells, thus interfering with nerve transmission. Other effects include immune depression, bronchial constriction and haemolysis. Parent algal toxins are synthesized within the unicellular organism, others are produced as metabolic products. Recent studies into the composition of brevetoxins in cells, water, air and organisms have shown PbTx-2 to be the primary intracellular brevetoxin that is converted over time to PbTx-3 when the cells are ruptured, releasing extracellular brevetoxins into the environment. Brevetoxins become aerosolized by bubble-mediated transport of extracellular toxins, the composition of which varies depending on the composition in the source water. Bivalved molluscs rapidly accumulate brevetoxins as they filter feed on K. brevis cells. However, the parent algal toxins are rapidly metabolized to other compounds, some of which are responsible for neurotoxic shellfish poisoning (NSP). These results provide new insight into the distribution, persistence and impacts of red tide toxins to south-west Florida ecosystems. PMID:18758951

  6. Embryotoxic effects of prenatal T-2 toxin exposure in mice.

    PubMed Central

    Blakley, B R; Hancock, D S; Rousseaux, C G

    1987-01-01

    Pregnant CD-1 mice were administered T-2 toxin by gastric intubation on day 11 of gestation at dosages of 0, 0.75 and 1.5 mg/kg. The T-lymphocyte dependent antibody response against sheep red blood cells which was evaluated in the offspring at six weeks of age was not affected by T-2 toxin exposure. Individual birth and weaning weights were not influenced by T-2 toxin, but the litter size was reduced in the high dose group, without affecting the number of implantation sites per dam. The number of female offspring produced by dams exposed to 1.5 mg/kg T-2 toxin was less compared to other treatment groups, suggesting that the female fetus was more susceptible to embryolethal effects of prenatal T-2 toxin exposure. These results suggest that prenatal T-2 toxin exposure is unlikely to be a significant health problem with respect to primary humoral immunity. At the dosages given, T-2 toxin produced substantial embryotoxicity without alteration in antibody production. The embryolethal effects are a primary limiting factor which may preclude the expression of any immunoteratological manifestations associated with humoral immunity under natural field conditions. PMID:3651897

  7. Nutrients and toxin producing phytoplankton control algal blooms - a spatio-temporal study in a noisy environment.

    PubMed

    Sarkar, Ram Rup; Malchow, Horst

    2005-12-01

    A phytoplankton-zooplankton prey-predator model has been investigated for temporal, spatial and spatio-temporal dissipative pattern formation in a deterministic and noisy environment, respectively. The overall carrying capacity for the phytoplankton population depends on the nutrient level. The role of nutrient concentrations and toxin producing phytoplankton for controlling the algal blooms has been discussed. The local analysis yields a number of stationary and/or oscillatory regimes and their combinations. Correspondingly interesting is the spatio-temporal behaviour, modelled by stochastic reaction-diffusion equations. The present study also reveals the fact that the rate of toxin production by toxin producing phytoplankton (TPP) plays an important role for controlling oscillations in the plankton system. We also observe that different mortality functions of zooplankton due to TPP have significant influence in controlling oscillations, coexistence, survival or extinction of the zoo-plankton population. External noise can enhance the survival and spread of zooplankton that would go extinct in the deterministic system due to a high rate of toxin production.

  8. Overview of Aerosolized Florida Red Tide Toxins: Exposures and Effects

    PubMed Central

    Fleming, Lora E.; Backer, Lorraine C.; Baden, Daniel G.

    2005-01-01

    Florida red tide is caused by Karenia brevis, a dinoflagellate that periodically blooms, releasing its potent neurotoxin, brevetoxin, into the surrounding waters and air along the coast of the Gulf of Mexico. Exposure to Florida red tide toxins has been associated with adverse human health effects and massive fish and marine mammal deaths. The articles in this mini-monograph describe the ongoing interdisciplinary and interagency research program that characterizes the exposures and health effects of aerosolized Florida red tide toxins (brevetoxins). The interdisciplinary research program uses animal models and laboratory studies to develop hypotheses and apply these findings to in situ human exposures. Our ultimate goal is to develop appropriate prevention measures and medical interventions to mitigate or prevent adverse health effects from exposure to complex mixtures of aerosolized red tide toxins. PMID:15866773

  9. Harmful Algal Bloom Webinar

    EPA Pesticide Factsheets

    The problem is complex. Excessive nitrogen and phosphorous levels can cause harmful algal blooms. Different algal/cyanobacteria strains bloom under different conditions. Different strains produce different toxins at varying amounts.

  10. Freshwater harmful algal bloom exposure – an emerging health risk for recreational water users

    EPA Science Inventory

    Freshwater harmful algal bloom exposure – an emerging health risk for recreational water users Elizabeth D. Hilborn1, Virginia A. Roberts2, Lorraine C. Backer3, Jonathan S. Yoder2, Timothy J. Wade1, Michele C. Hlavsa2 1Environmental Public Health Division, Office of Researc...

  11. Freshwater harmful algal bloom exposure – an emerging health risk for recreational water users

    EPA Science Inventory

    Freshwater harmful algal bloom exposure – an emerging health risk for recreational water users Elizabeth D. Hilborn1, Virginia A. Roberts2, Lorraine C. Backer3, Jonathan S. Yoder2, Timothy J. Wade1, Michele C. Hlavsa2 1Environmental Public Health Division, Office of Researc...

  12. Health risk assessment of cyanobacterial (blue-green algal) toxins in drinking water.

    PubMed

    Falconer, Ian R; Humpage, Andrew R

    2005-04-01

    Cyanobacterial toxins have caused human poisoning in the Americas, Europe and Australia. There is accumulating evidence that they are present in treated drinking water supplies when cyanobacterial blooms occur in source waters. With increased population pressure and depleted groundwater reserves, surface water is becoming more used as a raw water source, both from rivers and lakes/reservoirs. Additional nutrients in water which arise from sewage discharge, agricultural run-off or storm water result in overabundance of cyanobacteria, described as a 'water bloom'. The majority of cyanobacterial water-blooms are of toxic species, producing a diversity of toxins. The most important toxins presenting a risk to the human population are the neurotoxic alkaloids (anatoxins and paralytic shellfish poisons), the cyclic peptide hepatotoxins (microcystins) and the cytotoxic alkaloids (cylindrospermopsins). At the present time the only cyanobacteral toxin family that have been internationally assessed for health risk by the WHO are the microcystins, which cause acute liver injury and are active tumour promoters. Based on sub-chronic studies in rodents and pigs, a provisional Guideline Level for drinking water of 1 microg/L of microcystin-LR has been determined. This has been adopted in legislation in countries in Europe, South America and Australasia. This may be revised in the light of future teratogenicity, reproductive toxicity and carcinogenicity studies. The other cyanobacterial toxin which has been proposed for detailed health risk assessment is cylindrospermopsin, a cytotoxic compound which has marked genotoxicity, probable mutagenicity, and is a potential carcinogen. This toxin has caused human poisoning from drinking water, and occurs in water supplies in the USA, Europe, Asia, Australia and South America. An initial health risk assessment is presented with a proposed drinking water Guideline Level of 1 microg/L. There is a need for both increased monitoring data for

  13. Health Risk Assessment of Cyanobacterial (Blue-green Algal) Toxins in Drinking Water

    PubMed Central

    Falconer, Ian R.; Humpage, Andrew R.

    2005-01-01

    Cyanobacterial toxins have caused human poisoning in the Americas, Europe and Australia. There is accumulating evidence that they are present in treated drinking water supplies when cyanobacterial blooms occur in source waters. With increased population pressure and depleted groundwater reserves, surface water is becoming more used as a raw water source, both from rivers and lakes/reservoirs. Additional nutrients in water which arise from sewage discharge, agricultural run-off or storm water result in overabundance of cyanobacteria, described as a ‘water bloom’. The majority of cyanobacterial water-blooms are of toxic species, producing a diversity of toxins. The most important toxins presenting a risk to the human population are the neurotoxic alkaloids (anatoxins and paralytic shellfish poisons), the cyclic peptide hepatotoxins (microcystins) and the cytotoxic alkaloids (cylindrospermopsins). At the present time the only cyanobacteral toxin family that have been internationally assessed for health risk by the WHO are the microcystins, which cause acute liver injury and are active tumour promoters. Based on sub-chronic studies in rodents and pigs, a provisional Guideline Level for drinking water of 1μg/L of microcystin-LR has been determined. This has been adopted in legislation in countries in Europe, South America and Australasia. This may be revised in the light of future teratogenicity, reproductive toxicity and carcinogenicity studies. The other cyanobacterial toxin which has been proposed for detailed health risk assessment is cylindrospermopsin, a cytotoxic compound which has marked genotoxicity, probable mutagenicity, and is a potential carcinogen. This toxin has caused human poisoning from drinking water, and occurs in water supplies in the USA, Europe, Asia, Australia and South America. An initial health risk assessment is presented with a proposed drinking water Guideline Level of 1μg/L. There is a need for both increased monitoring data for

  14. Dietary exposure and neurotoxicity of the environmental free and bound toxin β-N-methylamino-l-alanine.

    PubMed

    Regueiro, Jorge; Negreira, Noelia; Carreira-Casais, Anxo; Pérez-Lamela, Conchi; Simal-Gándara, Jesús

    2017-10-01

    The growing evidence supporting a link between exposure to the naturally occurring toxin β-N-methylamino-l-alanine (BMAA) and progressive neurodegenerative diseases, has recently arisen the interest of the scientific community. Latest investigations suggest that dietary exposure to this algal toxin may have been largely underestimated. This paper reviews the state of the art regarding BMAA, with special attention paid to its neurotoxicity, its concentration levels in food, and human exposure. As for other environmental toxins, dietary intake is most likely the main route of exposure to BMAA for the general population. However, data concerning BMAA levels in foodstuffs are still scarce. It is concluded that further investigations on dietary intake and potential human health effects are clearly necessary to assess the risks to public health associated with BMAA exposure. Some critical remarks and recommendations on future research in this area are provided, which may help to identify approaches to reduce dietary BMAA exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Algal toxins and reverse osmosis desalination operations: laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid.

    PubMed

    Seubert, Erica L; Trussell, Shane; Eagleton, John; Schnetzer, Astrid; Cetinić, Ivona; Lauri, Phil; Jones, Burton H; Caron, David A

    2012-12-01

    The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

  16. Detection and effects of harmful algal toxins in Scottish harbour seals and potential links to population decline.

    PubMed

    Jensen, Silje-Kristin; Lacaze, Jean-Pierre; Hermann, Guillaume; Kershaw, Joanna; Brownlow, Andrew; Turner, Andrew; Hall, Ailsa

    2015-04-01

    Over the past 15 years or so, several Scottish harbour seal (Phoca vitulina) populations have declined in abundance and several factors have been considered as possible causes, including toxins from harmful algae. Here we explore whether a link could be established between two groups of toxins, domoic acid (DA) and saxitoxins (STXs), and the decline in the harbour seal populations in Scotland. We document the first evidence that harbour seals are exposed to both DA and STXs from consuming contaminated fish. Both groups of toxins were found in urine and faeces sampled from live captured (n = 162) and stranded animals (n = 23) and in faecal samples collected from seal haul-out sites (n = 214) between 2008 and 2013. The proportion of positive samples and the toxins levels measured in the excreta were significantly higher in areas where harbour seal abundance is in decline. There is also evidence that DA has immunomodulatory effects in harbour seals, including lymphocytopenia and monocytosis. Scottish harbour seals are exposed to DA and STXs through contaminated prey at potentially lethal levels and with this evidence we suggest that exposure to these toxins are likely to be important factors driving the harbour seal decline in some regions of Scotland.

  17. Algal toxins and human health: A brief overview and notes on needed research directions

    EPA Science Inventory

    Marine and freshwater algae, both algae and cyanobacteria, are known to produce a wide variety of toxins that have caused severe adverse health effects in humans and other vertebrate species. There is general agreement that there is currently an increase in the incidence of hazar...

  18. Algal toxins and human health: A brief overview and notes on needed research directions

    EPA Science Inventory

    Marine and freshwater algae, both algae and cyanobacteria, are known to produce a wide variety of toxins that have caused severe adverse health effects in humans and other vertebrate species. There is general agreement that there is currently an increase in the incidence of hazar...

  19. Controlling silver nanoparticle exposure in algal toxicity testing--a matter of timing.

    PubMed

    Sørensen, Sara Nørgaard; Baun, Anders

    2015-03-01

    The aquatic ecotoxicity testing of nanoparticles is complicated by unstable exposure conditions resulting from various transformation processes of nanoparticles in aqueous suspensions. In this study, we investigated the influence of exposure timing on the algal test response to silver nanoparticles (AgNPs), by reducing the incubation time and by aging the AgNPs in algal medium prior to testing. The freshwater green algae Pseudokirchneriella subcapitata were exposed to AgNO3, NM-300 K (a representative AgNP) and citrate stabilized AgNPs from two different manufacturers (AgNP1 and AgNP2) in a standard algal growth inhibition test (ISO 8692:2004) for 48 h and a short-term (2 h) (14)C-assimilation test. For AgNO3, similar responses were obtained in the two tests, whereas freshly prepared suspensions of citrate stabilized AgNPs were less toxic in the 2-h tests compared to the 48-h tests. The 2-h test was found applicable for dissolved silver, but yielded non-monotonous concentration-response relationships and poor reproducibility for freshly prepared AgNP suspensions. However, when aging AgNPs in algal medium 24 h prior to testing, clear concentration-response patterns emerged and reproducibility increased. Prolonged aging to 48 h increased toxicity in the 2-h tests whereas aging beyond 48 h reduced toxicity. Our results demonstrate that the outcome of algal toxicity testing of AgNPs is highly influenced not only by the test duration, but also by the time passed from the moment AgNPs are added to the test medium. This time-dependency should be considered when nanomaterial dispersion protocols for ecotoxicity testing are developed.

  20. Controlling silver nanoparticle exposure in algal toxicity testing – A matter of timing

    PubMed Central

    Baun, Anders

    2015-01-01

    The aquatic ecotoxicity testing of nanoparticles is complicated by unstable exposure conditions resulting from various transformation processes of nanoparticles in aqueous suspensions. In this study, we investigated the influence of exposure timing on the algal test response to silver nanoparticles (AgNPs), by reducing the incubation time and by aging the AgNPs in algal medium prior to testing. The freshwater green algae Pseudokirchneriella subcapitata were exposed to AgNO3, NM-300 K (a representative AgNP) and citrate stabilized AgNPs from two different manufacturers (AgNP1 and AgNP2) in a standard algal growth inhibition test (ISO 8692:2004) for 48 h and a short-term (2 h) 14C-assimilation test. For AgNO3, similar responses were obtained in the two tests, whereas freshly prepared suspensions of citrate stabilized AgNPs were less toxic in the 2-h tests compared to the 48-h tests. The 2-h test was found applicable for dissolved silver, but yielded non-monotonous concentration–response relationships and poor reproducibility for freshly prepared AgNP suspensions. However, when aging AgNPs in algal medium 24 h prior to testing, clear concentration–response patterns emerged and reproducibility increased. Prolonged aging to 48 h increased toxicity in the 2-h tests whereas aging beyond 48 h reduced toxicity. Our results demonstrate that the outcome of algal toxicity testing of AgNPs is highly influenced not only by the test duration, but also by the time passed from the moment AgNPs are added to the test medium. This time-dependency should be considered when nanomaterial dispersion protocols for ecotoxicity testing are developed. PMID:24842597

  1. Further improvements in the application of high-performance liquid chromatography, capillary electrophoresis and capillary electrochromatography to the analysis of algal toxins in the aquatic environment.

    PubMed

    Gago-Martínez, Ana; Piñeiro, N; Aguete, E C; Vaquero, E; Nogueiras, M; Leão, J M; Rodríguez-Vázquez, J A; Dabek-Zlotorzynska, E

    2003-04-11

    The presence of algal toxins in the aquatic environment represents an important socioeconomic concern in many places worldwide, due to the toxicity that these compounds can induce in seafood or freshwater organisms at very low levels. Several analytical alternatives have been proposed over the last years for the control of these contaminants, which acute or chronic toxicity requires low detection levels and demands for the search of sensitive methods for their detection and determination. HPLC has been widely used for this purpose, although several alternatives such as CE or capillary electrochromatography (CEC) are being lately developed with this aim. In this work we report on the application of improved HPLC, as well as CE and CEC, for the analysis of diarrhetic shellfish poisoning toxins, amnesic shellfish poisoning (ASP) toxins and microcystins (MCs) present in different matrices such as water, shellfish or algae. Improvements in sample preparation for increasing sensitivity and selectivity are also shown. While UV and fluorimetric detection are the detection methods generally used, mass spectrometric detection was also applied for ASP toxins and MCs, especially for confirmatory purposes. From the results obtained it can be concluded that both HPLC and CE offer a good potential for a sensitive and selective determination of these algal toxins in such complex matrices. The results obtained for CEC allow also to conclude that this technique can result in a promising technique for such application.

  2. EFFECT OF MARINE TOXINS ON THERMOREGULATION IN MICE.

    EPA Science Inventory

    Marine algal toxins are extremely toxic and can represent a major health problem to humans and animals. Temperature regulation is one of many processes to be affected by exposure to these toxins. Mice and rats become markedly hypothermic when subjected to acute exposure to the ma...

  3. EFFECT OF MARINE TOXINS ON THERMOREGULATION IN MICE.

    EPA Science Inventory

    Marine algal toxins are extremely toxic and can represent a major health problem to humans and animals. Temperature regulation is one of many processes to be affected by exposure to these toxins. Mice and rats become markedly hypothermic when subjected to acute exposure to the ma...

  4. Transplantation of microbenthic algal assemblages to assess structural and functional recovery after diuron exposure.

    PubMed

    Dorigo, Ursula; Bérard, Annette; Bouchez, Agnès; Rimet, Frédéric; Montuelle, Bernard

    2010-11-01

    The potential of microbenthic algal assemblages to recover after diuron exposure was investigated. Microbenthic algal assemblages (periphyton) were grown on glass slides in correspondence to a diuron-polluted and adiuron-free sampling site of a river. After 5 weeks of colonization, the impacted periphyton was transferred by translocating the colonized glass slides to the unpolluted site. To monitor the changes in functional and structural parameters and to assess recovery, both the transferred and the local reference periphyton were sampled at the day of transfer (t0) and 1, 3, and 5 weeks after the transfer (t1, t3,t5). Structural transitions of eukaryotic communities were characterized by denaturing gradient gel electrophoresis (DGGE) and functional ones were characterized by short-term incubation toxicity tests with diuron. As shown by Bray–Curtis similarity values based on DGGE band patterns, almost total structural recovery of the transferred periphyton took place 5 weeks after transfer. For the transferred periphyton, previous diuron exposure at the contaminated site induced the development of diuron tolerance,which decreased after 1 week and became very similar to the tolerance of the nonimpacted community after 5 weeks. It is concluded that 5-week-old eukaryotic periphyton communities are capable of restoring their structural and functional attributes after 5 weeks within a noncontaminated environment.

  5. Environmental risk factors for temporal lobe epilepsy--is prenatal exposure to the marine algal neurotoxin domoic acid a potentially preventable cause?

    PubMed

    Stewart, Ian

    2010-03-01

    Temporal lobe epilepsy with hippocampal sclerosis (TLE-HS) is one of the more common forms of chronic epilepsy. Its aetiology is unknown, though an early developmental insult is thought by some to be an important trigger. There is not a strong genetic predisposition; gene-environment interactions are more significant considerations. Environmental risk factors for TLE-HS are under-researched. Domoic acid (DA) is an environmental neurotoxin of algal origin that can contaminate marine food webs. DA can cross the placenta, is significantly more toxic to the developing brain compared to the adult brain, and has affected humans and marine wildlife through mass poisonings. DA coincidentally has a decades-long history of use as a chemical model of temporal lobe epilepsy, along with its close structural analogue kainic acid (also of algal origin). The principal hypothesis presented here is that dietary exposure to doses of DA that are sub-clinical in pregnant women may be sufficient to damage the foetal hippocampus and initiate epileptogenesis. The hypothesis could be tested both experimentally by in vivo proof-of-concept animal studies that expand on current knowledge of prenatal susceptibility to DA neurotoxicity, and by epidemiological investigations directed towards dietary exposure to marine food products. If only a small proportion of the attributable risk for TLE-HS is found to be due to gestational exposure to DA, the public health implications would still be of great significance, as this would represent a potentially preventable exposure. Other potent neurotoxins are produced by marine microalgae and freshwater cyanobacteria. These structurally and mechanistically diverse toxins can also contaminate water supplies, seafood and shellfish. Several operate by modulating ion channels, so may also be of interest to epilepsy researchers. DA is also the subject of preliminary scrutiny in strandings involving odontocete cetaceans. The implications of such work are

  6. Profiles of paralytic shellfish toxins in bivalves of low and elevated toxicities following exposure to Gymnodinium catenatum blooms in Portuguese estuarine and coastal waters.

    PubMed

    Botelho, Maria João; Vale, Carlos; Ferreira, João Gomes

    2015-11-01

    Profiles of paralytic shellfish toxins (PSTs) were examined in 405 composite samples of Mytilus spp., Cerastoderma edule, Donax trunculus and Spisula solida collected between 2007 and 2012 from natural production areas in two estuaries (Aveiro and Mondego), two coastal lagoons (Óbidos and Formosa), and three open coastal areas (Aguda, Comporta and Culatra). Toxin concentrations were obtained from the biotoxin monitoring programme database. Episodes of PST toxicity in Portugal have been associated with Gymnodinium catenatum blooms. Toxin profiles for each species showed no trend over the surveyed years. In general, profiles differ only slightly among areas, except for Óbidos. However, toxin profiles in bivalves varied between low and elevated toxicities, corresponding to below and above the PST regulatory limit, respectively. The ratio R1=(C1+2):B1, which were the main toxins produced by G. catenatum cells, decreased considerably between elevated and low toxicity cockles, indicating the elimination of C1+2 or conversion of compounds into B1. R2=[(dcSTX)+(dcGTX2+3)]:[(C1+2)+(B1)], which represents the ratio of minor to major toxins in G. catenatum cells, increased substantially in wedge clams (D. trunculus) of low toxicity and less markedly in cockles (C. edule) and mussels (Mytilus spp.). These differences are interpreted as the predominance of a biotransformation phase after exposure to the algal bloom. The toxin profile of surf clams (S. solida) was dominated by decarbamoyl compounds, reflecting intense biotransformation during exposure to blooms. The higher ratio R2 in low toxicity samples suggests that elimination of the produced decarbamoyl toxins was slower than biotransformation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Calcifying algae maintain settlement cues to larval abalone following algal exposure to extreme ocean acidification.

    PubMed

    O'Leary, Jennifer K; Barry, James P; Gabrielson, Paul W; Rogers-Bennett, Laura; Potts, Donald C; Palumbi, Stephen R; Micheli, Fiorenza

    2017-07-18

    Ocean acidification (OA) increasingly threatens marine systems, and is especially harmful to calcifying organisms. One important question is whether OA will alter species interactions. Crustose coralline algae (CCA) provide space and chemical cues for larval settlement. CCA have shown strongly negative responses to OA in previous studies, including disruption of settlement cues to corals. In California, CCA provide cues for seven species of harvested, threatened, and endangered abalone. We exposed four common CCA genera and a crustose calcifying red algae, Peyssonnelia (collectively CCRA) from California to three pCO2 levels ranging from 419-2,013 µatm for four months. We then evaluated abalone (Haliotis rufescens) settlement under ambient conditions among the CCRA and non-algal controls that had been previously exposed to the pCO2 treatments. Abalone settlement and metamorphosis increased from 11% in the absence of CCRA to 45-69% when CCRA were present, with minor variation among CCRA genera. Though all CCRA genera reduced growth during exposure to increased pCO2, abalone settlement was unaffected by prior CCRA exposure to increased pCO2. Thus, we find no impacts of OA exposure history on CCRA provision of settlement cues. Additionally, there appears to be functional redundancy in genera of CCRA providing cues to abalone, which may further buffer OA effects.

  8. Personal exposure to aerosolized red tide toxins (brevetoxins).

    PubMed

    Cheng, Yung Sung; Zhou, Yue; Naar, Jerome; Irvin, C Mitch; Su, Wei-Chung; Fleming, Lora E; Kirkpatrick, Barbara; Pierce, Richard H; Backer, Lorraine C; Baden, Daniel G

    2010-06-01

    Florida red tides occur annually in the Gulf of Mexico from blooms of the marine dinoflagellate, Karenia brevis, which produces highly potent natural polyether toxins, brevetoxins. Several epidemiologic studies have demonstrated that human exposure to red tide aerosol could result in increased respiratory symptoms. Environmental monitoring of aerosolized brevetoxins was performed using a high-volume sampler taken hourly at fixed locations on Siesta Beach, Florida. Personal exposure was monitored using personal air samplers and taking nasal swab samples from the subjects who were instructed to spend 1 hr on Sarasota Beach during two sampling periods of an active Florida red tide event in March 2005, and in May 2008 when there was no red tide. Results showed that the aerosolized brevetoxins from the personal sampler were in modest agreement with the environmental concentration taken from a high-volume sampler. Analysis of nasal swab samples for brevetoxins demonstrated 68% positive samples in the March 2005 sampling period when air concentrations of brevetoxins were between 50 to 120 ng/m(3) measured with the high-volume sampler. No swab samples showed detectable levels of brevetoxins in the May 2008 study, when all personal samples were below the limit of detection. However, there were no statistical correlations between the amounts of brevetoxins detected in the swab samples with either the environmental or personal concentration. Results showed that the personal sample might provide an estimate of individual exposure level. Nasal swab samples showed that brevetoxins indeed were inhaled and deposited in the nasal passage during the March 2005 red tide event.

  9. Cytotoxicity of aluminium oxide nanoparticles towards fresh water algal isolate at low exposure concentrations.

    PubMed

    Pakrashi, Sunandan; Dalai, Swayamprava; T C, Prathna; Trivedi, Shruti; Myneni, Radhika; Raichur, Ashok M; Chandrasekaran, N; Mukherjee, Amitava

    2013-05-15

    The growing commercial applications had brought aluminium oxide nanoparticles under toxicologists' purview. In the present study, the cytotoxicity of two different sized aluminium oxide nanoparticles (ANP(1), mean hydrodynamic diameter 82.6±22nm and ANP(2), mean hydrodynamic diameter 246.9±39nm) towards freshwater algal isolate Chlorella ellipsoids at low exposure levels (≤1μg/mL) using sterile lake water as the test medium was assessed. The dissolution of alumina nanoparticles and consequent contribution towards toxicity remained largely unexplored owing to its presumed insoluble nature. Herein, the leached Al(3+) ion mediated toxicity has been studied along with direct particulate toxicity to bring out the dynamics of toxicity through colloidal stability, biochemical, spectroscopic and microscopic analyses. The mean hydrodynamic diameter increased with time both for ANP(1) [82.6±22nm (0h) to 246.3±59nm (24h), to 1204±140nm (72h)] and ANP(2) [246.9±39nm (0h) to 368.28±48nm (24h), to 1225.96±186nm (72h)] signifying decreased relative abundance of submicron sized particles (<1000nm). The detailed cytotoxicity assays showed a significant reduction in the viability dependent on dose and exposure. A significant increase in ROS and LDH levels were noted for both ANPs at 1μg/mL concentration. The zeta potential and FT-IR analyses suggested surface chemical interaction between nanoparticles and algal cells. The substantial morphological changes and cell wall damage were confirmed through microscopic analyses (SEM, TEM, and CLSM). At 72h, significant Al(3+) ion release in the test medium [0.092μg/mL for ANP(1), and 0.19μg/mL for ANP(2)] was noted, and the resulting suspension containing leached ions caused significant cytotoxicity, revealing a substantial ionic contribution. This study indicates that both the nano-size and ionic dissolution play a significant role in the cytotoxicity of ANPs towards freshwater algae, and the exposure period largely determines

  10. CURRENT ISSUES IN HTE DETECTION OF HUMAN EXPOSURE TO THE CYANOBACTERIA TOXINS, MICROCYSTINS

    EPA Science Inventory

    Introduction: Toxic cyanobacteria are contaminants of surface waters worldwide. Microcystins are some of the most commonly detected toxins. Biological evidence of human exposure has been difficult to obtain due to technical, temporal, and biological limitations. However, evide...

  11. Toxicity and recovery in the pregnant mouse after gestational exposure to the cyanobacterial toxin, cylindrospermopsin.

    EPA Science Inventory

    Cylindrospermopsin (CYN) is a tricyclic alkaloid toxin produced by fresh water cyanobacterial species worldwide. CYN has been responsible for both livestock and human poisoning after oral exposure. This study investigated the toxicity of CYN to pregnant mice exposed during differ...

  12. Toxicity and recovery in the pregnant mouse after gestational exposure to the cyanobacterial toxin, cylindrospermopsin.

    EPA Science Inventory

    Cylindrospermopsin (CYN) is a tricyclic alkaloid toxin produced by fresh water cyanobacterial species worldwide. CYN has been responsible for both livestock and human poisoning after oral exposure. This study investigated the toxicity of CYN to pregnant mice exposed during differ...

  13. Cyanobacteria Toxin and Cell Propagation through Seven Lake Erie Treatment Plants during the 2013 Algal Bloom Season - abstract

    EPA Science Inventory

    Over the past five years, Lake Erie has been experiencing harmful algal blooms (HABs) of progressively increasing severity. Cognizant of the potential health and economic impacts, the United States Environmental Protection Agency’s (USEPA’s) Water Supply and Water Resources Divis...

  14. Cyanobacteria Toxin and Cell Propagation through Seven Lake Erie Treatment Plants during the 2013 Algal Bloom Season - abstract

    EPA Science Inventory

    Over the past five years, Lake Erie has been experiencing harmful algal blooms (HABs) of progressively increasing severity. Cognizant of the potential health and economic impacts, the United States Environmental Protection Agency’s (USEPA’s) Water Supply and Water Resources Divis...

  15. Investigation on Toxins and Venoms by Novel MS Techniques. Mass Spectral Investigations on Blue-Green Algal Toxic Peptides and Other Toxins

    DTIC Science & Technology

    1990-08-15

    HPLC column and detection by Thermospray-MS techniques. INTRODUCTION Most of the naturally occurring peptides and proteins are made up of 1-amino...in various hydrolysates of the blue-green algal peptides . The observed sensitivity for most amino acids was in the picomole range. The unknown...with Marfey’s Reagent: Amino acid standards or hydrolysates of peptides (200 pmole - 50 nmole) in aqueous solution (50-100 gl) was treated with 1

  16. CYANOBACTERIAL TOXINS AND 2005 ISOCHAB EXPOSURE ASSESSMENT WORKGROUP

    EPA Science Inventory

    The US EPA, Office of Research and Development, in collaboration with other US federal agencies, is leading the organization of an International Symposium on Cyanobacterial Harmful Algal Blooms on 6-10 September, 2005. The goal of this symposium is to develop a comprehensive nat...

  17. CYANOBACTERIAL TOXINS AND 2005 ISOCHAB EXPOSURE ASSESSMENT WORKGROUP

    EPA Science Inventory

    The US EPA, Office of Research and Development, in collaboration with other US federal agencies, is leading the organization of an International Symposium on Cyanobacterial Harmful Algal Blooms on 6-10 September, 2005. The goal of this symposium is to develop a comprehensive nat...

  18. Reduced Foodborne Toxin Exposure Is a Benefit of Improving Dietary Diversity

    PubMed Central

    Wu, Felicia; Mitchell, Nicole J.; Male, Denis; Kensler, Thomas W.

    2014-01-01

    Naturally occurring foodborne toxins are common in subsistence diets of low-income human populations worldwide. Often, these populations rely on one or two staple foods for the bulk of their calories, making them more susceptible to chronic intake of certain toxins. Exposure to common foodborne toxins is associated with diverse conditions such as cancer, immunotoxicity, growth impairment, and neurological deficits. Interventions focused solely on reducing toxin levels have proven difficult to sustain. Using case studies of two foodborne toxins, aflatoxin and cassava cyanide, this article addresses the heightened risk of particular diseases from eating monotonous diets based in maize, groundnuts, and cassava: common in sub-Saharan Africa and parts of Asia. We also discuss the potential role of increased dietary diversity in counteracting these diseases. Increased dietary diversity can reduce consumption of toxins and increase intake of nutrients that could counteract the toxicity of such chemicals. In Qidong, China, a population that previously consumed a monotonous maize-based diet and increased dietary diversity since the 1980s has experienced a dramatic reduction in liver cancer mortalities. That liver cancer decreased as dietary diversity increased is the catalyst for the hypothesis that dietary diversity could have a direct impact on reducing health effects of foodborne toxins. Future research, agricultural development, and food policy reforms should take into consideration the multifaceted benefits associated with improved dietary diversity. Collaborations between toxicologists, nutritionists, and policymakers are important to development of sustainable interventions to reduce foodborne toxin exposure and promote health through increased dietary diversity. PMID:25015663

  19. Smoking behaviour and toxin exposure during six weeks use of a potential reduced exposure product: Omni.

    PubMed

    Hughes, J R; Hecht, S S; Carmella, S G; Murphy, S E; Callas, P

    2004-06-01

    To determine smoking behaviour, acceptability, and toxin exposure when smokers switch to the potential reduced exposure product-Omni cigarette. 12 week randomised, crossover study of Omni versus own cigarettes. 19 light/ultralight and 15 regular smokers. Cigarettes/day, smoking topography, craving, withdrawal symptoms, urinary cotinine plus its glucuronide (total cotinine), nicotine plus its glucuronide (total nicotine), and carcinogen metabolites (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol plus its glucuronides and 1-hydroxypyrene). When switched to Omni, smokers smoked the same number of cigarettes/day, smoked Omni cigarettes less intensely (total puff volume = -11%) and had slightly lower total cotinine (-18%) levels than their own cigarettes, but had a slightly greater carbon monoxide boost/cig (+21%). Craving and withdrawal ratings were similar with Omni and own cigarettes. Carcinogen metabolite levels were somewhat but not significantly lower with Omni. About half of smokers rated Omni as better for their health and about two thirds stated it was weaker and worse tasting than their own cigarettes. Although Omni may be an adequate behavioural and pharmacological substitute for traditional cigarettes, it may not decrease carcinogen exposure and may increase carbon monoxide. Replications with larger sample sizes and longer follow up are needed. These results indicate the need for regulation of reduced exposure and reduced risk claims.

  20. Monitoring firefighter exposure to air toxins at prescribed burns of forest and range biomass.

    Treesearch

    Timothy E. Reinhardt

    1991-01-01

    A variety of potent air toxins are in the smoke produced by burning forest and range biomass. Preliminary data on flrefighter exposures to carbon monoxide and formaldehyde at four prescribed burns of Western United States natural fuels are presented. Formaldehyde may be correlated to carbon monoxide emissions. The firefighters' exposures to these compounds...

  1. Algal growth stimulation and toxicity in response to exposure to the new insensitive military high-nitrogen energetic triaminoguanidinium-1-methyl-5-nitriminotetrazolate.

    PubMed

    Stanley, Jacob K; Biedenbach, James M; Russell, Amber L; Bednar, Anthony J

    2014-03-01

    Triaminoguanidinium-1-methyl-5-nitriminotetrazolate (TAG-MNT) is a nitrogen-rich energetic compound being developed as a potential component of insensitive munition formulations. The purpose of the present study was to assess the toxicity of TAG-MNT to the green alga Pseudokirchneriella subcapitata as well as to determine whether the high N content of TAG-MNT could result in increased algal growth in aquatic systems and potentially contribute to eutrophication using a 96-h algal growth bioassay in N-limited test media. Results were compared with algal exposures to current-use energetics 2,4,6-trinitrotoluene (TNT) and royal demolition explosive (RDX). The TNT exposure resulted in a lowest-observed-adverse-effect concentration (LOAEC) for algal growth of 1.72 mg/L and a 50% inhibition concentration (IC50) and 95% confidence limits of 0.972 mg/L (0.955, 0.973). The RDX algal growth LOAEC was 0.10 mg/L, and the RDX IC50 was 0.635 (0.416, 0.875). Neither TNT nor RDX exposure resulted in stimulation of algal growth. In repeated testing, TAG-MNT exposure resulted in LOAECs of 0.55 and 5.20 mg/L. Stimulation of algal growth was observed at 0.06 mg/L at a mean increase of 163.2% (± 71.7) relative to the control in TAG-MNT test A and at the 0.005 mg/L treatment at a mean increase of 174.3% (± 59.9) in TAG-MNT test B. The authors' results indicate the potential for high-N energetics to significantly stimulate algal growth at low concentrations in N-limited systems. © 2013 SETAC. This article is a US Government work and is in the public domain in the USA.

  2. Toxicologic evaluations of DHA-rich algal oil in rats: developmental toxicity study and 3-month dietary toxicity study with an in utero exposure phase.

    PubMed

    Schmitt, D; Tran, N; Peach, J; Edwards, T; Greeley, M

    2012-11-01

    DHA-rich algal oil ONC-T18, tested for subchronic, reproductive, and developmental toxicity in the rat, did not produce any significant toxicologic manifestations. Based on the absence of maternal or developmental toxicity at any dosage level, a dosage level of 2000 mg/kg/day was considered to be the no observed adverse-effect level (NOAEL) for maternal toxicity and embryo/fetal development when DHA-rich algal oil was administered orally by gavage to pregnant Crl:CD(SD) rats during gestation days 6-19. In a dietary combined one-generation/90-day reproductive toxicity study in rats, the NOAEL for F0 male and female and F1 male systemic toxicity was considered to be 50,000 ppm (highest concentration administered) and 25,000 ppm for F1 female systemic toxicity (higher mean body weight, body weight gain, and food consumption). F0 reproductive performance values, estrous cycle length, gestation length, or the process of parturition, and the numbers of former implantation sites and unaccounted-for sites were unaffected by algal oil exposure. Postnatal survival and developmental parameters in the F1 generation were unaffected by algal oil exposure at all dietary concentrations. There were no neurotoxic effects noted at any algal oil exposure level. The results support the safety of DHA-rich algal oil for its proposed use in food. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Reduced foodborne toxin exposure is a benefit of improving dietary diversity.

    PubMed

    Wu, Felicia; Mitchell, Nicole J; Male, Denis; Kensler, Thomas W

    2014-10-01

    Naturally occurring foodborne toxins are common in subsistence diets of low-income human populations worldwide. Often, these populations rely on one or two staple foods for the bulk of their calories, making them more susceptible to chronic intake of certain toxins. Exposure to common foodborne toxins is associated with diverse conditions such as cancer, immunotoxicity, growth impairment, and neurological deficits. Interventions focused solely on reducing toxin levels have proven difficult to sustain. Using case studies of two foodborne toxins, aflatoxin and cassava cyanide, this article addresses the heightened risk of particular diseases from eating monotonous diets based in maize, groundnuts, and cassava: common in sub-Saharan Africa and parts of Asia. We also discuss the potential role of increased dietary diversity in counteracting these diseases. Increased dietary diversity can reduce consumption of toxins and increase intake of nutrients that could counteract the toxicity of such chemicals. In Qidong, China, a population that previously consumed a monotonous maize-based diet and increased dietary diversity since the 1980s has experienced a dramatic reduction in liver cancer mortalities. That liver cancer decreased as dietary diversity increased is the catalyst for the hypothesis that dietary diversity could have a direct impact on reducing health effects of foodborne toxins. Future research, agricultural development, and food policy reforms should take into consideration the multifaceted benefits associated with improved dietary diversity. Collaborations between toxicologists, nutritionists, and policymakers are important to development of sustainable interventions to reduce foodborne toxin exposure and promote health through increased dietary diversity. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Undifferentiated murine embryonic stem cells used to model the effects of the blue-green algal toxin cylindrospermopsin on preimplantation embryonic cell proliferation.

    PubMed

    Reid, Katherine J; Lang, Kenneth; Froscio, Suzanne; Humpage, Andrew J; Young, Fiona M

    2015-11-01

    Undifferentiated mouse embryonic stem cell (mES) proliferation in vitro resembles aspects of in vivo pre-implantation embryonic development. mES were used to assess the embryo-toxicity of cylindrospermopsin (CYN), a water contaminant with an Australian Drinking Water Guideline (ADWG) of 1 μg/L. mES exposed to 0-1 μg/mL CYN for 24-168 h were subjected to an optimised crystal violet viability assay. mES exposed to retinoic acid ± 1 μg/L CYN differentiated into neural-like cells confirmed by morphological examination and RT-PCR for Oct4, Brachyury and Nestin. The CYN No Observed Effect Concentration (OEC) was 0.5 μg/mL, the Lowest OEC was 1 μg/mL (p < 0.001, n = 3), and the IC50 was 0.86 μg/mL after 24 h. The ADWG 1 μg/L CYN did not affect differentiation or proliferation after 72 h, but decreased proliferation after 168 h (p < 0.05). We conclude that higher algal bloom-associated CYN concentrations have the potential to impair in vivo pre-implantation development, and the mES crystal violet assay has broad application to screening environmental toxins.

  5. Mortality and toxin bioaccumulation in Bufo marinus following exposure to Cylindrospermopsis raciborskii cell extracts and live cultures.

    PubMed

    White, S H; Duivenvoorden, L J; Fabbro, L D; Eaglesham, G K

    2007-05-01

    Cylindrospermopsis raciborskii is a cyanobacterium responsible for the production of the toxin, cylindrospermopsin (CYN). Tadpoles of the cane toad Bufo marinus were exposed to freeze-thawed whole cell extracts or live cultures of C. raciborskii containing maximum CYN concentrations of 400 microg L-1 or 232 microg L-1, respectively. Exposure to live culture treatment solutions resulted in up to 66% mortality of B. marinus, whereas tadpoles exposed to whole cell extracts containing similar toxin concentrations survived. Decreases in relative growth rates and time spent for swimming were recorded from tadpoles during both types of exposure regimes. Bioconcentration of CYN was not evident following exposure to whole cell extracts containing extracellular toxin. In contrast exposure to live cultures, which contained cell-bound toxin, resulted in maximum average tissue concentrations of 895 microg free-CYN kg-1 fresh weight. This is the first investigation of C. raciborskii exposure effects and toxin bioaccumulation in the developmental stages of an amphibian.

  6. Harmful Algal Blooms

    USGS Publications Warehouse

    Graham, Jennifer L.

    2007-01-01

    What are Harmful Algal Blooms (HABs)? Freshwater and marine harmful algal blooms (HABs) can occur anytime water use is impaired due to excessive accumulations of algae. HAB occurrence is affected by a complex set of physical, chemical, biological, hydrological, and meteorological conditions making it difficult to isolate specific causative environmental factors. Potential impairments include reduction in water quality, accumulation of malodorous scums in beach areas, algal production of toxins potent enough to poison both aquatic and terrestrial organisms, and algal production of taste-and-odor compounds that cause unpalatable drinking water and fish. HABs are a global problem, and toxic freshwater and (or) marine algae have been implicated in human and animal illness and death in over 45 countries worldwide and in at least 27 U.S. States (Yoo and others, 1995; Chorus and Bartram, 1999; Huisman and others, 2005).

  7. Applying Genomic and Genetic Tools to Understand and Mitigate Damage from Exposure to Toxins

    DTIC Science & Technology

    2011-10-01

    Understand and Mitigate Damage from Exposure to Toxins PRINCIPAL INVESTIGATOR: Richard Myers, Ph.D...2010 – 22 September 2011 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Applying Genomic and Genetic Tools to Understand and Mitigate Damage from...dose-response to PB in larval and adult zebrafish at the biochemical and transcriptomic levels, validated a methods of treatment for inducing stress

  8. Harmful Algal Blooms and Public Health

    PubMed Central

    Grattan, Lynn M.; Holobaugh, Sailor; Morris, J. Glenn

    2015-01-01

    The five most commonly recognized Harmful Algal Bloom related illnesses include Ciguatera poisoning, Paralytic Shellfish poisoning, Neurotoxin Shellfish poisoning, Diarrheic Shellfish Poisoning and Amnesic Shellfish poisoning. Although they are each the product of different toxins, toxin assemblages or HAB precursors these clinical syndromes have much in common. Exposure occurs through the consumption of fish or shellfish; routine clinical tests are not available for diagnosis; there is no known antidote for exposure; and the risk of these illnesses can negatively impact local fishing and tourism industries. Thus, illness prevention is of paramount importance to minimize human and public health risks. To accomplish this, close communication and collaboration is needed among HAB scientists, public health researchers and local, state and tribal health departments at academic, community outreach, and policy levels. PMID:27616971

  9. Harmful Algal Blooms and Public Health.

    PubMed

    Grattan, Lynn M; Holobaugh, Sailor; Morris, J Glenn

    2016-07-01

    The five most commonly recognized Harmful Algal Bloom related illnesses include Ciguatera poisoning, Paralytic Shellfish poisoning, Neurotoxin Shellfish poisoning, Diarrheic Shellfish Poisoning and Amnesic Shellfish poisoning. Although they are each the product of different toxins, toxin assemblages or HAB precursors these clinical syndromes have much in common. Exposure occurs through the consumption of fish or shellfish; routine clinical tests are not available for diagnosis; there is no known antidote for exposure; and the risk of these illnesses can negatively impact local fishing and tourism industries. Thus, illness prevention is of paramount importance to minimize human and public health risks. To accomplish this, close communication and collaboration is needed among HAB scientists, public health researchers and local, state and tribal health departments at academic, community outreach, and policy levels.

  10. Determining important parameters related to cyanobacterial alkaloid toxin exposure

    SciTech Connect

    Love, A H

    2005-09-16

    Science-based decision making required robust and high-fidelity mechanistic data about the system dynamics and impacts of system changes. Alkaloid cyanotoxins have the characteristics to warrant consideration for their potential threat. Since insufficient information is available to construct a systems model for the alkaloid cyanotoxins, saxitoxins, anatoxins, and anatoxin-a(S), an accurate assessments of these toxins as a potential threat for use for intentional contamination is not possible. Alkaloid cyanotoxin research that contributed to such a model has numerous areas of overlap for natural and intentional health effects issues that generates dual improvements to the state of the science. The use of sensitivity analyses of systems models can identify parameters that, when determined, result in the greatest impact to the overall system and may help to direct the most efficient use of research funding. This type of modeling-assisted experimentation may allow rapid progress for overall system understanding compared to observational or disciplinary research agendas. Assessment and management of risk from intentional contamination can be performed with greater confidence when mechanisms are known and the relationships between different components are validated. This level of understanding allows high-fidelity assessments that do not hamper legitimate possession of these toxins for research purposes, while preventing intentional contamination that would affect public health. It also allows for appropriate response to an intentional contamination event, even if the specific contamination had not been previous considered. Development of science-based decision making tools will only improve our ability to address the new requirements addressing potential threats to our nation.

  11. Membrane-aerated biofilm proton and oxygen flux during chemical toxin exposure.

    PubMed

    McLamore, E S; Zhang, W; Porterfield, D M; Banks, M K

    2010-09-15

    Bioreactors containing sessile bacteria (biofilms) grown on hollow fiber membranes have been used for treatment of many wastestreams. Real time operational control of bioreactor performance requires detailed knowledge of the relationship between bulk liquid water quality and physiological transport at the biofilm-liquid interface. Although large data sets exist describing membrane-aerated bioreactor effluent quality, very little real time data is available characterizing boundary layer transport under physiological conditions. A noninvasive, microsensor technique was used to quantify real time (≈1.5 s) changes in oxygen and proton flux for mature Nitrosomonas europaea and Pseudomonas aeruginosa biofilms in membrane-aerated bioreactors following exposure to environmental toxins. Stress response was characterized during exposure to toxins with known mode of action (chlorocarbonyl cyanide phenyl-hydrazone and potassium cyanide), and four environmental toxins (rotenone, 2,4-dinitrophenol, cadmium chloride, and pentachlorophenol). Exposure to sublethal concentrations of all environmental toxins caused significant increases in O(2) and/or H(+) flux (depending on the mode of action). These real time microscale signatures (i.e., fingerprints) of O(2) and H(+) flux can be coupled with bulk liquid analysis to improve our understanding of physiology in counter-diffusion biofilms found within membrane aerated bioreactors; leading to enhanced monitoring/modeling strategies for bioreactor control.

  12. The potential utility of animal poisoning data to identify human exposure to environmental toxins.

    PubMed

    Hungerford, L L; Trammel, H L; Clark, J M

    1995-04-01

    The database of the National Animal Poison Control Center (NAPCC) was evaluated as a source for animal poison data indicating human health hazards in indoor and outdoor environments. From 14,150 calls in the 1985 database, 259 cases were identified with histories suggesting human exposure. A subgroup of 25 cases with known human exposure was found. Dogs were the most common sentinel animal, but bird cases represented the highest proportional selection from the total 1985 call list. Indoor exposures represented 43.2% of cases; the most common toxicants were insecticides, lead and toxic fumes. Exposures associated with lawns were mainly due to insecticides and herbicides and constituted 25.5% of cases. Other outdoor exposures composed the remaining 31.7% of cases, with insecticides, herbicides and unidentified toxins the leading categories. Many of the specific agents identified, such as organophosphate insecticides, lead, gas and fume toxins, and phenoxy herbicides are also risk factors in human diseases. This study indicates that databases such as NAPCC could serve as sources of sentinel animal intoxications for followup studies to evaluate known and potential human health hazards.

  13. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure

    PubMed Central

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2010-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide. Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols. PMID:21499552

  14. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols.

  15. Mitochondrial DNA Damage as a Peripheral Biomarker for Mitochondrial Toxin Exposure in Rats

    PubMed Central

    Sanders, Laurie H.; Howlett, Evan H.; McCoy, Jennifer

    2014-01-01

    Demonstrating or verifying a current or past exposure to an environmental mitochondrial toxin or toxicant is extraordinarily difficult. Thus, there is a pressing need to develop a biomarker for exposure to environmental mitochondrial inhibitors. Rotenone, an environmental toxicant, is a potent inhibitor of the mitochondrial electron transfer chain. Rotenone specifically inhibits complex I throughout the body and brain, thereby producing systemic mitochondrial impairment. As such, rotenone is a prototypical clinically relevant, environmental mitochondrial toxicant that may be used as an ideal initial platform to develop accessible biomarkers of exposure. The over-arching goal of this work is to explore and validate peripheral (blood and skeletal muscle) DNA damage as a biomarker of mitochondrial toxicant exposure using the rat rotenone model. In this effort, we utilized an extremely sensitive quantitative polymerase chain reaction (QPCR)-based assay that simultaneously allows the assessment of multiple forms of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) damage. We found mtDNA damage in blood is detected after subclinical rotenone exposure and the damage persists even after complex I activity has returned to normal. With a more sustained rotenone exposure, mtDNA damage is also detected in skeletal muscle, suggesting that mtDNA damage in this tissue simply lags behind blood. Using the QPCR-based assay, we have no evidence for nDNA damage in peripheral tissues after rotenone exposure either acutely or chronically. Overall, these data support the idea that mtDNA damage in peripheral tissues in the rotenone model may provide a biomarker of past or ongoing mitochondrial toxin exposure. PMID:25237061

  16. High Frequency Monitoring for Harmful Algal Blooms

    EPA Science Inventory

    Harmful algal blooms (HABs) are increasingly becoming a significant ecologic, economic, and social driver in the use of water resources. Cyanobacteria and their toxins play an important role in management decisions for drinking water utilities and public health officials. Online ...

  17. High Frequency Monitoring for Harmful Algal Blooms

    EPA Science Inventory

    Harmful algal blooms (HABs) are increasingly becoming a significant ecologic, economic, and social driver in the use of water resources. Cyanobacteria and their toxins play an important role in management decisions for drinking water utilities and public health officials. Online ...

  18. Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities

    USGS Publications Warehouse

    Rosen, Barry H.; Ann St. Amand,

    2015-09-14

    Cyanobacteria can produce toxins and form harmful algal blooms. The Native American and Alaska Native communities that are dependent on subsistence fishing have an increased risk of exposure to these cyanotoxins. It is important to recognize the presence of an algal bloom in a waterbody and to distinguish a potentially toxic harmful algal bloom from a non-toxic bloom. This guide provides field images that show cyanobacteria blooms, some of which can be toxin producers, as well as other non-toxic algae blooms and floating plants that might be confused with algae. After recognition of a potential toxin-producing cyanobacterial bloom in the field, the type(s) of cyanobacteria present needs to be identified. Species identification, which requires microscopic examination, may help distinguish a toxin-producer from a non-toxin producer. This guide also provides microscopic images of the common cyanobacteria that are known to produce toxins, as well as images of algae that form blooms but do not produce toxins.

  19. Clinical and Pathological Findings Associated with Aerosol Exposure of Macaques to Ricin Toxin.

    PubMed

    Pincus, Seth H; Bhaskaran, Manoj; Brey, Robert N; Didier, Peter J; Doyle-Meyers, Lara A; Roy, Chad J

    2015-06-09

    Ricin is a potential bioweapon that could be used against civilian and military personnel. Aerosol exposure is the most likely route of contact to ricin toxin that will result in the most severe toxicity. Early recognition of ricin exposure is essential if specific antidotes are to be applied. Initial diagnosis will most likely be syndromic, i.e., fitting clinical and laboratory signs into a pattern which then will guide the choice of more specific diagnostic assays and therapeutic interventions. We have studied the pathology of ricin toxin in rhesus macaques exposed to lethal and sublethal ricin aerosols. Animals exposed to lethal ricin aerosols were followed clinically using telemetry, by clinical laboratory analyses and by post-mortem examination. Animals exposed to lethal aerosolized ricin developed fever associated with thermal instability, tachycardia, and dyspnea. In the peripheral blood a marked neutrophilia (without immature bands) developed at 24 h. This was accompanied by an increase in monocytes, but depletion of lymphocytes. Red cell indices indicated hemoconcentration, as did serum chemistries, with modest increases in sodium and blood urea nitrogen (BUN). Serum albumin was strikingly decreased. These observations are consistent with the pathological observations of fluid shifts to the lungs, in the form of hemorrhages, inflammatory exudates, and tissue edema. In macaques exposed to sublethal aerosols of ricin, late pathologic consequences included chronic pulmonary fibrosis, likely mediated by M2 macrophages. Early administration of supportive therapy, specific antidotes after exposure or vaccines prior to exposure have the potential to favorably alter this outcome.

  20. Natural Occurrence of Alternaria Toxins in Wheat-Based Products and Their Dietary Exposure in China

    PubMed Central

    Zhao, Kai; Shao, Bing; Yang, Dajin; Li, Fengqin; Zhu, Jianghui

    2015-01-01

    A total of 181 wheat flour and 142 wheat-based foods including dried noodle, steamed bread and bread collected in China were analyzed for alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and tenuazonic acid (TeA) by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. TeA was the predominant toxin found in 99.4% wheat flour samples at levels ranging from 1.76 μg/kg to 520 μg/kg. TEN was another Alternaria toxin frequently detected in wheat flour samples (97.2%) at levels between 2.72 μg/kg and 129 μg/kg. AOH and AME were detected in 11 (6.1%) samples at levels ranging from 16.0 μg/kg to 98.7 μg/kg (AOH) and in 165 (91.2%) samples with a range between 0.320 μg/kg and 61.8 μg/kg (AME). AOH was quantified at higher levels than AME with the ratio of AOH/AME ranging from 1.0 to 3.7. Significant linear regressions of correlation in toxin concentrations were observed between AOH and AME, AME and TeA, TEN and TeA, AOH+AME and TeA. At an average and 95th percentile, dietary exposure to AOH and AME in the Chinese general population and different age subgroups exceeded the relevant threshold value of toxicological concern (TTC), with the highest exposure found in children which deserves human health concern. TEN and TeA seem unlikely to be health concerns for the Chinese via wheat-based products but attention should be paid to synergistic or additive effects of TeA with AOH, AME, TEN and a further assessment will be performed once more data on toxicity-guided fractionation of the four toxins are available. It is necessary to conduct a systemic surveillance of Alternaria toxins in raw and processed foods in order to provide the scientific basis for making regulations on these toxins in China. PMID:26121047

  1. Monitoring firefighter exposure to air toxins at prescribed burns of forest and range biomass. Forest Service research paper

    SciTech Connect

    Reinhardt, T.E.

    1991-10-01

    A variety of potent air toxins are in the smoke produced by burning forest and range biomass. Preliminary data on firefighter exposures to carbon monoxide and formaldehyde at four prescribed burns of Western United States natural fuels are presented. Formaldehyde may be correlated to carbon monoxide emissions. The firefighters' exposures to these compounds relative to workplace standards are discussed.

  2. Exposure to 50 Hz electromagnetic field changes the efficiency of the scorpion alpha toxin.

    PubMed

    Jankowska, Milena; Pawlowska-Mainville, Agnieszka; Stankiewicz, Maria; Rogalska, Justyna; Wyszkowska, Joanna

    2015-01-01

    Extremely low-frequency (50 Hz) electromagnetic field (ELF-EMF) is produced by electric power transmission lines and electronic devices of everyday use. Some phenomena are proposed as "first effects" of ELF-EMF: the discrete changes in the membrane potential and the increase of the calcium channel activity as well as the intracellular concentration of Ca(2+). Interaction of the scorpion alpha toxin with the sodium channel depends on the orientation of the charges and may be perturbed by changes in the membrane polarization. The toxin induces overexcitability in the nervous system and an increase in the neurotransmitters released with different consequences, mainly the paralysis of muscles. We assumed that the exposure to ELF-EMF 0.7 mT will change the effects of the insect selective scorpion alpha toxin (recombinant LqhαIT from Leiurus quinquestriatus hebraeus) at the level of the cercal nerve function, the synaptic transmission and on the level of entire insect organism. Taking into account the compensatory mechanisms in organisms, we tested in addition ten times higher ELF-EMF on whole insects. Experiments were performed in vivo on cockroaches (Periplaneta americana) and in vitro - on isolated cockroach abdominal nerve cord with cerci. In biotests, the effects of LqhαIT (10(-8) M) were estimated on the basis of the insect ability to turn back from dorsal to ventral side. Three groups were compared: the control one and the two exposed to ELF-EMF - 0.7 and 7 mT. Bioelectrical activity of the cercal nerve and of the connective nerve that leaves the terminal abdominal ganglion was recorded using extracellular electrodes. LqhαIT (5 × 10(-8) M) induced modifications of neuronal activity that were observed in the control cockroach preparations and in the ones exposed to ELF-EMF (0.7 mT). The exposure to ELF-EMF was carried out using coils with a size appropriate to the examined objects. The exposure to ELF-EMF (0.7 mT) modified the effects of LqhαIT (5

  3. [Dietary exposure assessment of some important Fusarium toxins in cereal-based products in China].

    PubMed

    Wang, Wei; Shao, Bing; Zhu, Jianghui; Yu, Hongxia; Li, Fengqin

    2010-11-01

    To elucidate the dietary exposure of Chinese populations to deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN). Ten Fusarium toxins including DON, NIV, ZEN in domestic wheat flour and corn-based products harvested and collected in 2009 were analyzed by UPLC-MS/MS. Dietary intake assessments of human exposure to DON, NIV and ZEN were carried out in combination of national food consumption data with toxin concentration data by deterministic estimate method. (1) There are 2.5% adults and 10% children with the dietary exposure to DON exceeding the tolerable daily intake (TDI) on the basis of the average food consumption. At the 75th percentile food consumption level, the dietary exposure of populations to DON was higher than its TDI, 1.72 and 2.02 times (adults) as well as 1.19 and 1.09 times higher than TDI (children), respectively, based on the higher DON exposure (adults : P90 for wheat flour and P97. 5 for corn-based products, children: P50 for wheat flour and P75 for corn-based products). At the average toxin concentration, children with the high consumption level (90th, 97. 5th and 99th percentile) of either wheat flour or corn-based products, the dietary exposure to DON exceed the TDI, 1.81 to 3.17 times (wheat flour) and 1.47 - 3.97 times (corn-based products) higher than TDI, respectively. The dietary exposure of adults to ZEN exceed the TDI, based on the average food consumption data and higher ZEN level (P99), the 75th consumption data combined with P97. 5th toxin concentration, as well as 90th percentile of both food consumption data and ZEN concentration, respectively. There are 1%, 2.5%, 25%, 25% and 50% populations of children exposed ZEN higher than TDI, respectively at the 50th, 75th, 90th, 97. 5th and 99th percentile of food consumption data. (2) The level of concern (LOC) of DON in wheat flour calculated with high consumption data (90th, 97. 5th and 99th percentile) for all populations as well as DON and ZEN in corn-based products calculated

  4. Workplace chemical and toxin exposures reported to a Poisons Information Centre: a diverse range causing variable morbidity.

    PubMed

    Ling, Sophia L-Y; McD Taylor, David; Robinson, Jeffery

    2016-10-18

    The aim of this study is to determine the period prevalence, nature and causes of workplace chemical and toxin exposures reported to the Victorian Poisons Information Centre (VPIC). All cases classified as 'workplace: acute' when entered into the VPIC database (June 2005-December 2013) were analysed. Data were collected on patient sex, the nature of the chemical or toxin, route of exposure and season. Overall, 4928 cases were extracted. Exposures to men (71.5% of calls) differed from women (P<0.001), with most exposures relating to industry/trade substances (23.7%) and cleaners/bleaches/detergents (36.9%), respectively. Ocular (33.2%), inhalational (27.7%) and dermal (22.1%) exposures were most common. Exposures were most common in Spring and most seasonal variation was found for veterinary/animal, agricultural/plant and household categories (P<0.05). In all, 3445 (69.9%) cases had symptoms related to their exposure at the time of the call. However, the proportion of symptomatic cases within the major substance categories differed significantly (P<0.001). Chemicals associated with the most symptoms were cleaners/bleaches/detergents, industrial/trade substances and acids. Mild-moderately important workplace exposures are common. Significant variations exist between the sexes and seasons. Poisons Information Centres may play a role in ongoing surveillance of chemical and toxin exposures and a minimum exposure dataset is recommended.

  5. Dietary exposure to an environmental toxin triggers neurofibrillary tangles and amyloid deposits in the brain

    PubMed Central

    Cox, Paul Alan; Davis, David A.; Mash, Deborah C.; Metcalf, James S.; Banack, Sandra Anne

    2016-01-01

    Neurofibrillary tangles (NFT) and β-amyloid plaques are the neurological hallmarks of both Alzheimer's disease and an unusual paralytic illness suffered by Chamorro villagers on the Pacific island of Guam. Many Chamorros with the disease suffer dementia, and in some villages one-quarter of the adults perished from the disease. Like Alzheimer's, the causal factors of Guamanian amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC) are poorly understood. In replicated experiments, we found that chronic dietary exposure to a cyanobacterial toxin present in the traditional Chamorro diet, β-N-methylamino-l-alanine (BMAA), triggers the formation of both NFT and β-amyloid deposits similar in structure and density to those found in brain tissues of Chamorros who died with ALS/PDC. Vervets (Chlorocebus sabaeus) fed for 140 days with BMAA-dosed fruit developed NFT and sparse β-amyloid deposits in the brain. Co-administration of the dietary amino acid l-serine with l-BMAA significantly reduced the density of NFT. These findings indicate that while chronic exposure to the environmental toxin BMAA can trigger neurodegeneration in vulnerable individuals, increasing the amount of l-serine in the diet can reduce the risk. PMID:26791617

  6. Distribution of green algal mats throughout shallow soft bottoms of the Swedish Skagerrak archipelago in relation to nutrient sources and wave exposure

    NASA Astrophysics Data System (ADS)

    Pihl, Leif; Svenson, Anders; Moksnes, Per-Olav; Wennhage, Håkan

    1999-06-01

    Distribution and biomass of green algal mats were studied in marine shallow (0-1 m) soft-bottom areas on the Swedish west coast from 1994 to 1996, by combining aerial photography surveys with ground truth sampling. Filamentous green algae, dominated by species of the genera Cladophora and Enteromorpha, were generally present throughout the study area during July and August, and largely absent in late April and early May. These algae occurred at 60 to 90% of the locations investigated during the summer, and were estimated to cover between 30 and 50% of the total area of shallow soft bottoms of the Swedish Skagerrak archipelago. The distributional patterns were similar during the three years of the investigation and appeared unrelated to annual local nutrient inputs from point sources and river discharge. We postulate that the apparent lack of such a relationship is due to an altered state of nutrient dynamics throughout the archipelago. Mechanisms are likely to involve long-term, diffuse elevations in nutrient levels in coastal waters of the Skagerrak and the Kattegat over several decades leading to current eutrophic conditions, exceeding nutrient requirements for abundant filamentous algal growth. Patterns of algal abundance in our study were largely related to physical factors such as exposure to wind, waves and water exchange under conditions where nutrient loads among embayments seemed to be unlimited. Further, our results show that sediments covered by algal mats had higher carbon and nitrogen contents than unvegetated sediments. We hypothesise that sustained high nutrient loads, manifested in extensive biomass of filamentous algae during summer months, are re-mineralised via decay and sedimentation in the benthic realm. Hence, accumulated carbon and nutrients in the sediment could, in turn, constitute the basic pool for future algal mat production overlying soft bottoms in areas where tidal exchange is limited.

  7. Change in algal symbiont communities after bleaching, not prior heat exposure, increases heat tolerance of reef corals.

    PubMed

    Silverstein, Rachel N; Cunning, Ross; Baker, Andrew C

    2015-01-01

    Mutualistic organisms can be particularly susceptible to climate change stress, as their survivorship is often limited by the most vulnerable partner. However, symbiotic plasticity can also help organisms in changing environments by expanding their realized niche space. Coral-algal (Symbiodinium spp.) symbiosis exemplifies this dichotomy: the partnership is highly susceptible to 'bleaching' (stress-induced symbiosis breakdown), but stress-tolerant symbionts can also sometimes mitigate bleaching. Here, we investigate the role of diverse and mutable symbiotic partnerships in increasing corals' ability to thrive in high temperature conditions. We conducted repeat bleaching and recovery experiments on the coral Montastraea cavernosa, and used quantitative PCR and chlorophyll fluorometry to assess the structure and function of Symbiodinium communities within coral hosts. During an initial heat exposure (32 °C for 10 days), corals hosting only stress-sensitive symbionts (Symbiodinium C3) bleached, but recovered (at either 24 °C or 29 °C) with predominantly (>90%) stress-tolerant symbionts (Symbiodinium D1a), which were not detected before bleaching (either due to absence or extreme low abundance). When a second heat stress (also 32 °C for 10 days) was applied 3 months later, corals that previously bleached and were now dominated by D1a Symbiodinium experienced less photodamage and symbiont loss compared to control corals that had not been previously bleached, and were therefore still dominated by Symbiodinium C3. Additional corals that were initially bleached without heat by a herbicide (DCMU, at 24 °C) also recovered predominantly with D1a symbionts, and similarly lost fewer symbionts during subsequent thermal stress. Increased thermotolerance was also not observed in C3-dominated corals that were acclimated for 3 months to warmer temperatures (29 °C) before heat stress. These findings indicate that increased thermotolerance post-bleaching resulted from

  8. Gummy smile and botulinum toxin: a new approach based on the gingival exposure area.

    PubMed

    Mazzuco, Rosemarie; Hexsel, Dóris

    2010-12-01

    Gummy smile (GS) is an aesthetic disorder for some patients, which can be corrected by injection of botulinum toxin. We sought to classify GS according to the area of gingival exposure and the respective muscles involved in order to perfect the botulinum toxin injection technique for each patient. Sixteen patients with GS were evaluated before receiving botulinum toxin injections. Based on the area of excessive gum displayed and identification of the muscles involved, 4 different types of GS were identified: anterior, posterior, mixed, and asymmetric. AbobotulinumtoxinA (Dysport, Ipsen Biopharm Limited, Wrexham, UK) was injected using a different injection technique for each type of GS, based on the main muscles involved. With the aid of two computer programs, the area of gum exposed was measured before and after the application of abobotulinumtoxinA, to evaluate the level of improvement. There was a decrease in the degree of gum display in all patients. The general average improvement achieved was 75.09%. Two patients showed slight adverse effects that were easily corrected with additional doses of abobotulinumtoxinA. For this study, there was no sample size calculation and no statistical analysis of the cases. The authors conclude that it is important to identify the type of GS and therefore the main muscles involved, so that the correct injection technique can be used. AbobotulinumtoxinA was shown to be effective and safe for use in all types of GS in the present sample. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  9. Transcriptomic profile of host response in mouse brain after exposure to plant toxin abrin.

    PubMed

    Bhaskar, A S Bala; Gupta, Nimesh; Rao, P V Lakshmana

    2012-09-04

    Abrin toxin is a plant glycoprotein, which is similar in structure and properties to ricin and is obtained from the seeds of Abrus precatorius (jequirity bean). Abrin is highly toxic, with an estimated human fatal dose of 0.1-1 μg/kg, and has caused death after accidental and intentional poisoning. Abrin is a potent biological toxin warfare agent. There are no chemical antidotes available against the toxin. Neurological symptoms like delirium, hallucinations, reduced consciousness and generalized seizures were reported in human poisoning cases. Death of a patient with symptoms of acute demyelinating encephalopathy with gastrointestinal bleeding due to ingestion of abrin seeds was reported in India. The aim of this study was to examine both dose and time-dependent transcriptional responses induced by abrin in the adult mouse brain. Mice (n=6) were exposed to 1 and 2 LD50 (2.83 and 5.66 μg/kg respectively) dose of abrin by intraperitoneal route and observed over 3 days. A subset of animals (n=3) were sacrificed at 1 and 2 day intervals for microarray and histopathology analysis. None of the 2 LD50 exposed animals survived till 3 days. The histopathological analysis showed the severe damage in brain and the infiltration of inflammatory cells in a dose and time dependent manner. The abrin exposure resulted in the induction of rapid immune and inflammatory response in brain. Clinical biochemistry parameters like lactate dehydrogenase, aspartate aminotransferase, urea and creatinine showed significant increase at 2-day 2 LD50 exposure. The whole genome microarray data revealed the significant regulation of various pathways like MAPK pathway, cytokine-cytokine receptor interaction, calcium signaling pathway, Jak-STAT signaling pathway and natural killer cell mediated toxicity. The comparison of differential gene expression at both the doses showed dose dependent effects of abrin toxicity. The real-time qRT-PCR analysis of selected genes supported the microarray data

  10. Experience matters: prior exposure to plant toxins enhances diversity of gut microbes in herbivores.

    PubMed

    Kohl, Kevin D; Dearing, M D

    2012-09-01

    For decades, ecologists have hypothesised that exposure to plant secondary compounds (PSCs) modifies herbivore-associated microbial community composition. This notion has not been critically evaluated in wild mammalian herbivores on evolutionary timescales. We investigated responses of the microbial communities of two woodrat species (Neotoma bryanti and N. lepida). For each species, we compared experienced populations that independently converged to feed on the same toxic plant (creosote bush, Larrea tridentata) to naïve populations with no exposure to creosote toxins. The addition of dietary PSCs significantly altered gut microbial community structure, and the response was dependent on previous experience. Microbial diversity and relative abundances of several dominant phyla increased in experienced woodrats in response to PSCs; however, opposite effects were observed in naïve woodrats. These differential responses were convergent in experienced populations of both species. We hypothesise that adaptation of the foregut microbiota to creosote PSCs in experienced woodrats drives this differential response. © 2012 Blackwell Publishing Ltd/CNRS.

  11. Biochemical Mechanisms for Geographical Adaptations to Novel Toxin Exposures in Butterflyfish.

    PubMed

    Maldonado, Aileen; Lavado, Ramon; Knuston, Sean; Slattery, Marc; Ankisetty, Sridevi; Goldstone, Jared V; Watanabe, Kayo; Hoh, Eunha; Gadepalli, Rama S; Rimoldi, John M; Ostrander, Gary K; Schlenk, Daniel

    2016-01-01

    Some species of butterflyfish have had preyed upon corals for millions of years, yet the mechanism of butterflyfish specialized coral feeding strategy remains poorly understood. Certain butterflyfish have the ability to feed on allelochemically rich soft corals, e.g. Sinularia maxima. Cytochrome P450 (CYP) is the predominant enzyme system responsible for the detoxification of dietary allelochemicals. CYP2-like and CYP3A-like content have been associated with butterflyfish that preferentially consumes allelochemically rich soft corals. To investigate the role of butterflyfish CYP2 and CYP3A enzymes in dietary preference, we conducted oral feeding experiments using homogenates of S. maxima and a toxin isolated from the coral in four species of butterflyfish with different feeding strategies. After oral exposure to the S. maxima toxin 5-episinulaptolide (5ESL), which is not normally encountered in the Hawaiian butterflyfish diet, an endemic specialist, Chaetodon multicinctus experienced 100% mortality compared to a generalist, Chaetodon auriga, which had significantly more (3-6 fold higher) CYP3A-like basal content and catalytic activity. The specialist, Chaetodon unimaculatus, which preferentially feed on S. maxima in Guam, but not in Hawaii, had 100% survival, a significant induction of 8-12 fold CYP3A-like content, and an increased ability (2-fold) to metabolize 5ESL over other species. Computer modeling data of CYP3A4 with 5ESL were consistent with microsomal transformation of 5ESL to a C15-16 epoxide from livers of C. unimaculatus. Epoxide formation correlated with CYP3A-like content, catalytic activity, induction, and NADPH-dependent metabolism of 5ESL. These results suggest a potentially important role for the CYP3A family in butterflyfish-coral diet selection through allelochemical detoxification.

  12. Biochemical Mechanisms for Geographical Adaptations to Novel Toxin Exposures in Butterflyfish

    PubMed Central

    Knuston, Sean; Slattery, Marc; Ankisetty, Sridevi; Goldstone, Jared V.; Watanabe, Kayo; Hoh, Eunha; Gadepalli, Rama S.; Rimoldi, John M.; Ostrander, Gary K.

    2016-01-01

    Some species of butterflyfish have had preyed upon corals for millions of years, yet the mechanism of butterflyfish specialized coral feeding strategy remains poorly understood. Certain butterflyfish have the ability to feed on allelochemically rich soft corals, e.g. Sinularia maxima. Cytochrome P450 (CYP) is the predominant enzyme system responsible for the detoxification of dietary allelochemicals. CYP2-like and CYP3A-like content have been associated with butterflyfish that preferentially consumes allelochemically rich soft corals. To investigate the role of butterflyfish CYP2 and CYP3A enzymes in dietary preference, we conducted oral feeding experiments using homogenates of S. maxima and a toxin isolated from the coral in four species of butterflyfish with different feeding strategies. After oral exposure to the S. maxima toxin 5-episinulaptolide (5ESL), which is not normally encountered in the Hawaiian butterflyfish diet, an endemic specialist, Chaetodon multicinctus experienced 100% mortality compared to a generalist, Chaetodon auriga, which had significantly more (3–6 fold higher) CYP3A-like basal content and catalytic activity. The specialist, Chaetodon unimaculatus, which preferentially feed on S. maxima in Guam, but not in Hawaii, had 100% survival, a significant induction of 8–12 fold CYP3A-like content, and an increased ability (2-fold) to metabolize 5ESL over other species. Computer modeling data of CYP3A4 with 5ESL were consistent with microsomal transformation of 5ESL to a C15-16 epoxide from livers of C. unimaculatus. Epoxide formation correlated with CYP3A-like content, catalytic activity, induction, and NADPH-dependent metabolism of 5ESL. These results suggest a potentially important role for the CYP3A family in butterflyfish-coral diet selection through allelochemical detoxification. PMID:27136924

  13. Systemic Metabolic Responses of Broiler Chickens and Piglets to Acute T-2 Toxin Intravenous Exposure.

    PubMed

    Wan, Qianfen; He, Qinghua; Deng, Xianbai; Hao, Fuhua; Tang, Huiru; Wang, Yulan

    2016-01-27

    The aim of this study is to thoroughly investigate the toxicity mechanism of mycotoxin T-2 toxin and to further understand the endogenous metabolic alterations induced by T-2 toxin. To achieve this, a nuclear magnetic resonance (NMR)-based metabonomics approach was used to analyze the metabolic alterations induced by a single intravenous injection of T-2 toxin (0.5 mg/kg of body weight) in piglets and broiler chickens. A range of metabolites in the plasma, liver, kidney, and spleen of broiler chickens and plasma of piglets was changed following T-2 toxin injection. For example, a rapid increase of amino acids together with a significant reduction of glucose and lipid occurred in the plasma of broiler chickens and piglets following T-2 toxin treatment. A significant accumulation of amino acids and modulated nucleotides were detected in the liver, kidney, and spleen of T-2 toxin-treated broiler chickens. These data indicated that T-2 toxin caused endogenous metabolic changes in multiple organs and perturbed various metabolic pathways, including energy, amino acid, and nucleotide metabolism, as well as oxidative stress. We also observed elevated levels of tryptophan in the T-2 toxin-treated broiler chickens, which may explain the reported neurotoxic effects of T-2 toxin. These findings provide important information on the toxicity of T-2 toxin and demonstrate the power of the NMR-based metabonomics approach in exploring the toxicity mechanism of xenobiotics.

  14. Impact of harmful algal blooms on several Lake Erie drinking water treatment facilities; methodology considerations

    EPA Science Inventory

    The propagation of cyanbacterial cells and their toxins were investigated at seven drinking water treatment plants (DWTPs) on Lake Erie were investigated with regards to harmful algal bloom (HAB) toxin concentrations, water quality variations in treatment plant influents, and pr...

  15. Impact of harmful algal blooms on several Lake Erie drinking water treatment facilities; methodology considerations

    EPA Science Inventory

    The propagation of cyanbacterial cells and their toxins were investigated at seven drinking water treatment plants (DWTPs) on Lake Erie were investigated with regards to harmful algal bloom (HAB) toxin concentrations, water quality variations in treatment plant influents, and pr...

  16. Prepubertal exposure to T-2 toxin advances pubertal onset and development in female rats via promoting the onset of hypothalamic-pituitary-gonadal axis function.

    PubMed

    Yang, R; Wang, Y-M; Zhang, L; Zhao, Z-M; Zhao, J; Peng, S-Q

    2016-12-01

    T-2 toxin, a naturally produced Type A trichothecene mycotoxin, has been shown to damage the reproductive and developmental functions in livestocks. However, whether T-2 toxin can disturb the pubertal onset and development following prepubertal exposure remains unclear. To clarify this point, infantile female Sprague-Dawley rats were given a daily intragastric administration of vehicle or T-2 toxin at a dose of 375 μg/kg body weight for 5 consecutive days from postnatal day (PND) 15-19 (PND15-PND19). The days of vaginal opening, first diestrus, and first estrus in regular estrous cycle were advanced following T-2 toxin treatment, indicating prepubertal exposure to T-2 toxin induced the advancement of puberty onset. The relative weights of uterus and ovaries and the incidence of corpora lutea were all increased in T-2 toxin-treated rats; serum hormone levels of luteinizing hormone and estradiol and the messenger RNA expressions of gonadotropin-releasing hormone (GnRH) and GnRH receptor also displayed marked increases following exposure to T-2 toxin, all of which were well consistent with the manifestations of the advanced puberty onset. In conclusion, the present study reveals that prepubertal exposure to a high level of T-2 toxin promotes puberty onset in infantile female rats by advancing the initiation of hypothalamic-pituitary-gonadal axis function in female rats.

  17. Daphnia magna negatively affected by chronic exposure to purified Cry-toxins.

    PubMed

    Bøhn, Thomas; Rover, Carina Macagnan; Semenchuk, Philipp Robert

    2016-05-01

    Cry-toxin genes originating from Bacillus thuringiensis are inserted into genetically modified (GM) plants, often called Bt-plants, to provide insect resistance to pests. Significant amounts of Bt-plant residues, and thus Cry-toxins, will be shed to soil and aquatic environments. We exposed Daphnia magna to purified Cry1Ab and Cry2Aa toxins for the full life-span of the animals. We used single toxins in different doses and combinations of toxins and Roundup(®), another potential stressor on the rise in agricultural ecosystems. Animals exposed to 4.5 mg/L (ppm) of Cry1Ab, Cry2Aa and the combination of both showed markedly higher mortality, smaller body size and very low juvenile production compared to controls. Animals exposed to 0.75 mg/L also showed a tendency towards increased mortality but with increased early fecundity compared to the controls. Roundup(®) stimulated animals to strong early reproductive output at the cost of later rapid mortality. We conclude that i) purified Cry-toxins in high concentrations are toxic to D. magna, indicating alternative modes-of-action for these Cry-toxins; ii) Cry-toxins act in combination, indicating that 'stacked events' may have stronger effects on non-target organisms; iii) further studies need to be done on combinatorial effects of multiple Cry-toxins and herbicides that co-occur in the environment.

  18. Zooplankton interactions with toxic phytoplankton: Some implications for food web studies and algal defence strategies of feeding selectivity behaviour, toxin dilution and phytoplankton population diversity

    NASA Astrophysics Data System (ADS)

    Barreiro, A.; Guisande, C.; Maneiro, I.; Vergara, A. R.; Riveiro, I.; Iglesias, P.

    2007-11-01

    This study focuses on the interactions between toxic phytoplankton and zooplankton grazers. The experimental conditions used are an attempt to simulate situations that have, so far, received little attention. We presume the phytoplankton community to be a set of species where a population of a toxic species is intrinsically diverse by the presence of coexisting strains with different toxic properties. The other species in the community may not always be high-quality food for herbivorous zooplankton. Zooplankton populations may have developed adaptive responses to sympatric toxic phytoplankton species. Zooplankton grazers may perform a specific feeding behaviour and its consequences on fitness will depend on the species ingested, the effect of toxins, and the presence of mechanisms of toxin dilution and compensatory feeding. Our target species are a strain of the dinoflagellate Alexandrium minutum and a sympatric population of the copepod Acartia clausi. Mixed diets were used with two kinds of A. minutum cells: non-toxic and toxic. The flagellate Rhodomonas baltica and the non-toxic dinoflagellate Alexandrium tamarense were added as accompanying species. The effect of each alga was studied in separate diets. The toxic A. minutum cells were shown to have negative effects on egg production, hatching success and total reproductive output, while, in terms of its effect on fitness, the non-toxic A. minutum was the best quality food offered. R. baltica and A. tamarense were in intermediate positions. In the mixed diets, copepods showed a strong preference for toxic A. minutum cells and a weaker one for A. tamarense cells, while non-toxic A. minutum was slightly negatively selected and R. baltica strongly negatively selected. Although the level of toxins accumulated by copepods was very similar, in both the diet with only toxic A. minutum cells and in the mixed diet, the negative effects on fitness in the mixed diet could be offset by toxin dilution mechanisms. The

  19. Physiological and antioxidant responses of Medicago sativa-rhizobia symbiosis to cyanobacterial toxins (Microcystins) exposure.

    PubMed

    El Khalloufi, Fatima; Oufdou, Khalid; Lahrouni, Majida; Faghire, Mustapha; Peix, Alvaro; Ramírez-Bahena, Martha Helena; Vasconcelos, Vitor; Oudra, Brahim

    2013-12-15

    Toxic cyanobacteria in freshwaters can induce potent harmful effects on growth and development of plants irrigated with contaminated water. In this study, the effect of cyanobacteria extract containing Microcystins (MC) on Medicago sativa-rhizobia symbiosis was investigated in order to explore plants response through biomass production, photosynthetic pigment and antioxidant enzymes analysis: Peroxidase (POD), Polyphenoloxidase (PPO) and Catalase (CAT). Alfalfa plants were inoculated with two endosymbiotic rhizobial strains: RhOL1 (MC less sensitive strain) and RhOL3 (MC more sensitive strain), to evaluate the rhizobial contribution on the plant response cultured under cyanobacterial toxins stress. The two rhizobia strains were identified as Ensifer meliloti by sequence analysis of their rrs and atpD genes. The chronic exposure to MC extract showed shoot, root and nodules dry weight decrease, in both symbiosis cultures. The rate of decline in plants inoculated with RhOL3 was higher than that in symbiosis with RhOL1 mainly at 20 μg L(-1) of MC. Cyanotoxins also reduced photosynthetic pigment content and generated an oxidative stress observed at cellular level. POD, PPO and CAT activities were significantly increased in leaves, roots and nodules of alfalfa plants exposed to MC. These enzyme activities were higher in plants inoculated with RhOL3 especially when alfalfa plants were exposed to 20 μg L(-1) of MC. The present paper reports new scientific finding related to the behavior of rhizobia-M. sativa associations to MC (Microcystins) for later recommendation concerning the possible use of these symbiosis face to crops exposure to MC contaminated water irrigation.

  20. Fast algal eco-toxicity assessment: Influence of light intensity and exposure time on Chlorella vulgaris inhibition by atrazine and DCMU.

    PubMed

    Camuel, Alexandre; Guieysse, Benoit; Alcántara, Cynthia; Béchet, Quentin

    2017-06-01

    In order to develop a rapid assay suitable for algal eco-toxicity assessments under conditions representative of natural ecosystems, this study evaluated the short-term (<1h) response of algae exposed to atrazine and DCMU using oxygen productivity measurements. When Chlorella vulgaris was exposed to these herbicides under 'standard' low light intensity (as prescribed by OECD201 guideline), the 20min-EC50 values recorded via oxygen productivity (atrazine: 1.32±0.07μM; DCMU: 0.31±0.005μM) were similar the 96-h EC50 recorded via algal growth (atrazine: 0.56μM; DCMU: 0.41μM), and within the range of values reported in the literature. 20min-EC50 values increased by factors of 3.0 and 2.1 for atrazine and DCMU, respectively, when light intensity increased from 60 to 1400μmolm(-2)s(-1) of photosynthetically active radiation, or PAR. Further investigation showed that exposure time significantly also impacted the sensitivity of C. vulgaris under high light intensity (>840μmolm(-2)s(-1) as PAR) as the EC50 for atrazine and DCMU decreased by up to 6.2 and 2.1 folds, respectively, after 50min of exposure at a light irradiance of 1400μmolm(-2)s(-1) as PAR. This decrease was particularly marked at high light intensities and low algae concentrations and is explained by the herbicide disruption of the electron transfer chain triggering photo-inhibition at high light intensities. Eco-toxicity assessments aiming to understand the potential impact of toxic compounds on natural ecosystems should therefore be performed over sufficient exposure times (>20min for C. vulgaris) and under light intensities relevant to these ecosystems.

  1. P-glycoprotein expression in Perna viridis after exposure to Prorocentrum lima, a dinoflagellate producing DSP toxins.

    PubMed

    Huang, Lu; Wang, Jie; Chen, Wen-Chang; Li, Hong-Ye; Liu, Jie-Sheng; Tao Jiang; Yang, Wei-Dong

    2014-08-01

    Bivalves naturally exposed to toxic algae have mechanisms to prevent from harmful effects of diarrhetic shellfish poisoning (DSP) toxins. However, quite few studies have examined the mechanisms associated, and the information currently available is still insufficient. Multixenobiotic resistance (MXR) is ubiquitous in aquatic invertebrates and plays an important role in defense against xenobiotics. Here, to explore the roles of P-glycoprotein (P-gp) in the DSP toxins resistance in shellfish, complete cDNA of P-gp gene in the mussel Perna viridis was cloned and analyzed. The accumulation of okadaic acid (OA), a main component of DSP toxins, MXR activity and expression of P-gp in gills of P. viridis were detected after exposure to Prorocentrum lima, a dinoflagellate producing DSP toxins in the presence or absence of P-gp inhibitors PGP-4008, verapamil (VER) and cyclosporin A (CsA). The mussel P. viridis P-gp closely matches MDR/P-gp/ABCB protein from various organisms, having a typical sequence organization as full transporters from the ABCB family. After exposure to P. lima, OA accumulation, MXR activity and P-gp expression significantly increased in gills of P. viridis. The addition of P-gp-specific inhibitors PGP-4008 and VER decreased MXR activity induced by P. lima, but had no effect on the OA accumulation in gills of P. viridis. However, CsA, a broad-spectrum inhibitor of ABC transporter not only decreased MXR activity, but also increased OA accumulation in gills of P. viridis. Together with the ubiquitous presence of other ABC transporters such as MRP/ABCC in bivalves and potential compensatory mechanism in P-gp and MRP-mediated resistance, we speculated that besides P-gp, other ABC transporters, especially MRP might be involved in the resistance mechanisms to DSP toxins.

  2. The Impact of Harmful Algal Blooms on USACE Operations

    DTIC Science & Technology

    2009-01-01

    algae multiply rapidly and accumulate in large numbers, creating an event referred to as an algal bloom. Algal blooms have occurred throughout... algae for their color (Woods Hole Oceanographic Institute 2008; Vézie et al. 1998, 2002). Algal blooms can prove harmful through reductions in...when algae species produce toxins such as microcystin, saxitoxin, brevetoxin, ciguatoxin, or domoic acid (Van Dolah 2000). There is still much to be

  3. What is causing the harmful algal blooms in Lake Erie?

    USDA-ARS?s Scientific Manuscript database

    Harmful and nuisance algal blooms have been increasing in size and extent since about 2000. In recent years, the release of the algal toxin microcystin has become a growing concern and has resulted in the inability to use water from Lake Erie as a drinking water source to the 400,000 residents of T...

  4. Ecological risk assessment of herbicides in Japan: Integrating spatiotemporal variation in exposure and effects using a multimedia model and algal density dynamics models.

    PubMed

    Hayashi, Takehiko I; Imaizumi, Yoshitaka; Yokomizo, Hiroyuki; Tatarazako, Norihisa; Suzuki, Noriyuki

    2016-01-01

    Application of herbicides to paddy fields in Japan has strong seasonality, and their environmental concentrations exhibit clear spatiotemporal variation. The authors developed an approach that combines a multimedia environmental exposure model (Grid-Catchment Integrated Modeling System) and density dynamics models for algae. This approach enabled assessment of ecological risk when the exposure concentration shows spatiotemporal variation. First, risk maps of 5 herbicides (pretilachlor, butachlor, simetryn, mefenacet, and esprocarb) were created from the spatial predictions of environmental concentrations and 50% inhibitory concentrations of the herbicides. Simulations of algal density dynamics at high-risk sites were then conducted by incorporating the predicted temporal dynamics of the environmental concentration of each herbicide at the sites. The results suggested that the risk of pretilachlor was clearly the highest of the 5 herbicides, in terms of both the spatial distributions and the temporal durations. The present study highlights the importance of integrating exposure models and effect models to clarify spatial and temporal risk and to develop management plans for chemical exposure that shows high spatiotemporal variation.

  5. Environmental controls, oceanography and population dynamics of pathogens and harmful algal blooms: connecting sources to human exposure.

    PubMed

    Dyble, Julianne; Bienfang, Paul; Dusek, Eva; Hitchcock, Gary; Holland, Fred; Laws, Ed; Lerczak, James; McGillicuddy, Dennis J; Minnett, Peter; Moore, Stephanie K; O'Kelly, Charles; Solo-Gabriele, Helena; Wang, John D

    2008-11-07

    Coupled physical-biological models are capable of linking the complex interactions between environmental factors and physical hydrodynamics to simulate the growth, toxicity and transport of infectious pathogens and harmful algal blooms (HABs). Such simulations can be used to assess and predict the impact of pathogens and HABs on human health. Given the widespread and increasing reliance of coastal communities on aquatic systems for drinking water, seafood and recreation, such predictions are critical for making informed resource management decisions. Here we identify three challenges to making this connection between pathogens/HABs and human health: predicting concentrations and toxicity; identifying the spatial and temporal scales of population and ecosystem interactions; and applying the understanding of population dynamics of pathogens/HABs to management strategies. We elaborate on the need to meet each of these challenges, describe how modeling approaches can be used and discuss strategies for moving forward in addressing these challenges.

  6. Environmental controls, oceanography and population dynamics of pathogens and harmful algal blooms: connecting sources to human exposure

    PubMed Central

    Dyble, Julianne; Bienfang, Paul; Dusek, Eva; Hitchcock, Gary; Holland, Fred; Laws, Ed; Lerczak, James; McGillicuddy, Dennis J; Minnett, Peter; Moore, Stephanie K; O'Kelly, Charles; Solo-Gabriele, Helena; Wang, John D

    2008-01-01

    Coupled physical-biological models are capable of linking the complex interactions between environmental factors and physical hydrodynamics to simulate the growth, toxicity and transport of infectious pathogens and harmful algal blooms (HABs). Such simulations can be used to assess and predict the impact of pathogens and HABs on human health. Given the widespread and increasing reliance of coastal communities on aquatic systems for drinking water, seafood and recreation, such predictions are critical for making informed resource management decisions. Here we identify three challenges to making this connection between pathogens/HABs and human health: predicting concentrations and toxicity; identifying the spatial and temporal scales of population and ecosystem interactions; and applying the understanding of population dynamics of pathogens/HABs to management strategies. We elaborate on the need to meet each of these challenges, describe how modeling approaches can be used and discuss strategies for moving forward in addressing these challenges. PMID:19025676

  7. Exposure to HT-2 toxin causes oxidative stress induced apoptosis/autophagy in porcine oocytes

    PubMed Central

    Zhang, Yue; Han, Jun; Zhu, Cheng-Cheng; Tang, Feng; Cui, Xiang-Shun; Kim, Nam-Hyung; Sun, Shao-Chen

    2016-01-01

    T-2 toxin is a main type A trichothecene mycotoxin which is the most toxic trichothecence. T-2 toxin has posed various toxic effects on human and animals in vigorous cell proliferation tissues like lymphoid, hematopoietic and gastrointestinal tissues, while HT-2 toxin is the major metabolite which is deacetylated by T-2 toxin. In this study, we focused on the toxic effects of HT-2 on porcine oocyte maturation. We treated the porcine oocyte with HT-2 toxin in vitro, and we first found that HT-2 treatment inhibited porcine oocyte polar body extrusion and cumulus cell expansion. We observed the disrupted meiotic spindle morphology after treatment, which might be due to the reduced p-MAPK protein level. Actin distribution was also disturbed, indicating that HT-2 affects cytoskeleton of porcine oocytes. We next explored the causes for the failure of oocyte maturation after HT-2 treatment. We found that HT-2 treated oocytes showed the increased ROS level, which indicated that oxidative stress had occurred. We also detected autophagy as well as early apoptosis in the treatment oocytes. Due to the fact that oxidative stress could induced apoptosis, our results indicated that HT-2 toxin caused oxidative stress induced apoptosis and autophagy, which further affected porcine oocyte maturation. PMID:27658477

  8. CYANOBACTERIA AND THEIR TOXINS

    EPA Science Inventory

    Science Questions

    Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Cyanobacteria and their highly potent toxins are a significant hazard for human health and ...

  9. CYANOBACTERIA AND THEIR TOXINS.

    EPA Science Inventory

    Science Questions

    Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Cyanobacteria and their highly potent toxins are a significant hazard for human health and ...

  10. CYANOBACTERIA AND THEIR TOXINS.

    EPA Science Inventory

    Science Questions

    Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Cyanobacteria and their highly potent toxins are a significant hazard for human health and ...

  11. CYANOBACTERIA AND THEIR TOXINS

    EPA Science Inventory

    Science Questions

    Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Cyanobacteria and their highly potent toxins are a significant hazard for human health and ...

  12. Detection of cylindrospermopsin toxin markers in cyanobacterial algal blooms using analytical pyrolysis (Py-GC/MS) and thermally-assisted hydrolysis and methylation (TCh-GC/MS).

    PubMed

    Ríos, V; Prieto, Ana I; Cameán, Ana M; González-Vila, F J; de la Rosa, J M; Vasconcelos, Vitor; González-Pérez, J A

    2014-08-01

    The hepatotoxin cylindrospermopsin (CYN) is produced by freshwater cyanobacteria becoming an emerging threat for human health. Methods for the rapid determination of CYN in environmental samples are needed. Conventional analytical pyrolysis (Py-GC/MS) and thermally-assisted hydrolysis and methylation (TCh-GC/MS) were used to study a CYN standard, two Aphanizomenon ovalisporum cultures (CYN+) and one culture of Cylindrospermopsis raciborskii (CYN-). A micro-furnace pyrolyzer was used directly attached to a GC/MS system fitted with a 30 m × 250 μm × 0.25 μm film thickness column (14% cyanopropyl phenyl, 86% dimethyl polysiloxane pahase composition). Oven temperature was held at 50 °C for 1 min and increased to 100 °C at 30 °C min(-1), from 100 °C to 300 °C at 10 °C min(-1), and stabilized at 300 °C for 10 min using helium (1 mL min(-1)) as carrier gas. Pyrolysis at 500 °C yield over 70 compounds with 20 specific for CYN+ samples. Two peaks containing a diagnostic fragment (m/z 194) were found at 25.0 and 28.9 min only in CYN+ samples. Fewer peaks with limited diagnostic value were released after TCh-GC/MS, including breakdown products and TMAH adducts. A compound was detected that may correspond to the CYN molecule (MW 415 Da) thermoevaporation product after the loss of SO3 (MW 80 Da). This TCh-GC/MS peak (m/z 336) together with the fragments obtained by conventional Py-GC/MS (m/z 194) are diagnostic ions with potential use for the direct detection of CYN toxin in environmental samples at last with an estimated 5 ppm detection threshold. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. THE CYANOBACTERIAL TOXIN, CYLINDROSPERMOPSIN, INDUCES FETAL TOXICITY IN THE MOUSE AFTER EXPOSURE LATE IN GESTATION

    EPA Science Inventory

    Cylindrospermopsin (cyn) is a cyanobacterial toxin implicated in human and wildlife poisonings. We have completed studies investigating the potential of purified cyn to induce developmental toxicity in mammals. The teratology study involved intraperitoneal injections (8.0¿128ug/k...

  14. THE CYANOBACTERIAL TOXIN, CYLINDROSPERMOPSIN, INDUCES FETAL TOXICITY IN THE MOUSE AFTER EXPOSURE LATE IN GESTATION

    EPA Science Inventory

    Cylindrospermopsin (cyn) is a cyanobacterial toxin implicated in human and wildlife poisonings. We have completed studies investigating the potential of purified cyn to induce developmental toxicity in mammals. The teratology study involved intraperitoneal injections (8.0¿128ug/k...

  15. Guidance values for microcystins in water and cyanobacterial supplement products (blue-green algal supplements): a reasonable or misguided approach?

    SciTech Connect

    Dietrich, Daniel; Hoeger, Stefan . E-mail: stefan.hoeger@uni-konstanz.de

    2005-03-15

    This article reviews current scientific knowledge on the toxicity and carcinogenicity of microcystins and compares this to the guidance values proposed for microcystins in water by the World Health Organization, and for blue-green algal food supplements by the Oregon State Department of Health. The basis of the risk assessment underlying these guidance values is viewed as being critical due to overt deficiencies in the data used for its generation: (i) use of one microcystin congener only (microcystin-LR), while the other presently known nearly 80 congeners are largely disregarded, (ii) new knowledge regarding potential neuro and renal toxicity of microcystins in humans and (iii) the inadequacies of assessing realistic microcystin exposures in humans and especially in children via blue-green algal food supplements. In reiterating the state-of-the-art toxicology database on microcystins and in the light of new data on the high degree of toxin contamination of algal food supplements, this review clearly demonstrates the need for improved kinetic data of microcystins in humans and for discussion concerning uncertainty factors, which may result in a lowering of the present guidance values and an increased routine control of water bodies and food supplements for toxin contamination. Similar to the approach taken previously by authorities for dioxin or PCB risk assessment, the use of a toxin equivalent approach to the risk assessment of microcystins is proposed.

  16. The state of U.S. freshwater harmful algal blooms assessments, policy and legislation.

    PubMed

    Hudnell, H Kenneth

    2010-05-01

    The incidence of harmful algal blooms (HABs) is increasing in the United States and worldwide. HAB toxins cause a substantial but unquantified amount of human and animal morbidity and mortality from exposures in recreational, commercial, drinking-source and potable waters. HAB biomass and toxins threaten the sustainability of aquatic ecosystems. U.S. Congressional legislation mandated the establishment of a National Research Plan for Coastal Harmful Algal Blooms, but no similar plan exists for freshwater HABs (FHABs). Eutrophication and FHABs are conservatively estimated to cost the U.S. economy 2.2-4.6 billion dollars annually. A National Research Plan for Freshwater Harmful Algal Blooms is needed to develop U.S. policy and regulations or guidelines to confront FHAB risks. This report reviews the state of FHAB occurrence, risk and risk management assessments in the U.S. Research is identified that must be accomplished to characterize occurrence and risks, and develop cost effective strategies for preventing, suppressing and mitigating FHABs. U.S. Congressional legislation is needed to mandate a National Research Plan for FHABs, establish a timeline for developing policy and fund competitive research-grant programs. The research results will provide a sound scientific basis for making policy determinations and implementing risk management strategies. Successfully confronting FHAB risks will strengthen the U.S. economy, protect human and animal health and help ensure the sustainability of our Nation's freshwater bodies.

  17. Algal biofuels.

    PubMed

    Razeghifard, Reza

    2013-11-01

    The world is facing energy crisis and environmental issues due to the depletion of fossil fuels and increasing CO2 concentration in the atmosphere. Growing microalgae can contribute to practical solutions for these global problems because they can harvest solar energy and capture CO2 by converting it into biofuel using photosynthesis. Microalgae are robust organisms capable of rapid growth under a variety of conditions including in open ponds or closed photobioreactors. Their reduced biomass compounds can be used as the feedstock for mass production of a variety of biofuels. As another advantage, their ability to accumulate or secrete biofuels can be controlled by changing their growth conditions or metabolic engineering. This review is aimed to highlight different forms of biofuels produced by microalgae and the approaches taken to improve their biofuel productivity. The costs for industrial-scale production of algal biofuels in open ponds or closed photobioreactors are analyzed. Different strategies for photoproduction of hydrogen by the hydrogenase enzyme of green algae are discussed. Algae are also good sources of biodiesel since some species can make large quantities of lipids as their biomass. The lipid contents for some of the best oil-producing strains of algae in optimized growth conditions are reviewed. The potential of microalgae for producing petroleum related chemicals or ready-make fuels such as bioethanol, triterpenic hydrocarbons, isobutyraldehyde, isobutanol, and isoprene from their biomass are also presented.

  18. Selected scorpion toxin exposures induce cytokine release in human peripheral blood mononuclear cells.

    PubMed

    Corzo, Gerardo; Espino-Solis, Gerardo Pavel

    2017-03-01

    A cytokine screening on human peripheral blood mononuclear cells (PBMCs) stimulated with selected scorpion toxins (ScTx's) was performed in order to evaluate their effect on human immune cells. The ScTx's chosen for this report were three typical buthid scorpion venom peptides, one with lethal effects on mammals Centruroides suffussus suffusus toxin II (CssII), another, with lethal effects on insects and crustaceans Centruroides noxius toxin 5 (Cn5), and one more without lethal effects Tityus discrepans toxin (Discrepin). A Luminex multiplex analysis was performed in order to determine the amounts chemokines and cytokines IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12-p40, IL-13, interferon alpha (IFN-α), interferon gamma (IFN-γ), tumor necrosis factor alpha TNF-α, and interferon-inducible protein-10 (IP-10) secreted from human PBMCs exposed to these toxins. Although, the ScTx Cn5 is not lethal for mammals, it was able to induce the secretion of cytokines IL-1β, IL-6, and TNF-α, IL-10 and IP-10 in comparison to the lethal CssII, which was able to induce only IP-10 secretion. Discrepin also was able to induce only IP-10. Interestingly, only low amounts of interferons α and β were induced in the presence of the ScTx's assayed. In a synergic experiment, the combination of Discrepin and Cn5 displayed considerable reverse effects on induction of IL-1β, IL-6, IL-10 and TNF-α, but they had a slight synergic effect on IP-10 cytokine production in comparison with the single effect obtained with the Cn5 alone. Thus, the results obtained suggest that the profile of secreted cytokines promoted by ScTx Cn5 is highly related with a cytokine storm event, and also it suggests that the mammalian lethal neurotoxins are not solely responsible of the scorpion envenomation symptomatology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Physiological responses of Manila clams Venerupis (=Ruditapes) philippinarum with varying parasite Perkinsus olseni burden to toxic algal Alexandrium ostenfeldii exposure.

    PubMed

    Lassudrie, Malwenn; Soudant, Philippe; Richard, Gaëlle; Henry, Nicolas; Medhioub, Walid; da Silva, Patricia Mirella; Donval, Anne; Bunel, Mélanie; Le Goïc, Nelly; Lambert, Christophe; de Montaudouin, Xavier; Fabioux, Caroline; Hégaret, Hélène

    2014-09-01

    Manila clam stock from Arcachon Bay, France, is declining, as is commercial harvest. To understand the role of environmental biotic interactions in this decrease, effects of a toxic dinoflagellate, Alexandrium ostenfeldii, which blooms regularly in Arcachon bay, and the interaction with perkinsosis on clam physiology were investigated. Manila clams from Arcachon Bay, with variable natural levels of perkinsosis, were exposed for seven days to a mix of the nutritious microalga T-Iso and the toxic dinoflagellate A. ostenfeldii, a producer of spirolides, followed by seven days of depuration fed only T-Iso. Following sacrifice and quantification of protozoan parasite Perkinsus olseni burden, clams were divided into two groups according to intensity of the infection ("Light-Moderate" and "Moderate-Heavy"). Hemocyte and plasma responses, digestive enzyme activities, antioxidant enzyme activities in gills, and histopathological responses were analyzed. Reactive oxygen species (ROS) production in hemocytes and catalase (CAT) activity in gills increased with P. olseni intensity of infection in control clams fed T-Iso, but did not vary among A. ostenfeldii-exposed clams. Exposure to A. ostenfeldii caused tissue alterations associated with an inflammatory response and modifications in hemocyte morphology. In the gills, superoxide dismutase (SOD) activity decreased, and an increase in brown cell occurrence was seen, suggesting oxidative stress. Observations of hemocytes and brown cells in tissues during exposure and depuration suggest involvement of both cell types in detoxication processes. Results suggest that exposure to A. ostenfeldii disrupted the pro-/anti-oxidant response of clams to heavy P. olseni intensity. In addition, depressed mitochondrial membrane potential (MMP) in hemocytes of clams exposed to A. ostenfeldii suggests that mitochondrial functions are regulated to maintain homeostasis of digestive enzyme activity and condition index.

  20. Prolonged exposure to bacterial toxins downregulated expression of toll-like receptors in mesenchymal stromal cell-derived osteoprogenitors.

    PubMed

    Mo, Irene Fung Ying; Yip, Kevin Hak Kong; Chan, Wing Keung; Law, Helen Ka Wai; Lau, Yu Lung; Chan, Godfrey Chi Fung

    2008-09-18

    Human mesenchymal stromal cells (MSCs, also known as mesenchymal stem cells) are multipotent cells with potential therapeutic value. Owing to their osteogenic capability, MSCs may be clinically applied for facilitating osseointegration in dental implants or orthopedic repair of bony defect. However, whether wound infection or oral microflora may interfere with the growth and osteogenic differentiation of human MSCs remains unknown. This study investigated whether proliferation and osteogenic differentiation of MSCs would be affected by potent gram-positive and gram-negative derived bacterial toxins commonly found in human settings. We selected lipopolysaccharide (LPS) from Escherichia coli and lipoteichoic acid (LTA) from Streptococcus pyogenes as our toxins of choice. Our findings showed both LPS and LTA did not affect MSC proliferation, but prolonged LPS challenge upregulated the osteogenic differentiation of MSCs, as assessed by alkaline phosphatase activity and calcium deposition. Because toll-like receptors (TLRs), in particularly TLR4 and TLR2, are important for the cellular responsiveness to LPS and LTA respectively, we evaluated their expression profiles serially from MSCs to osteoblasts by quantitative PCR. We found that during osteogenic differentiation, MSC-derived osteoprogenitors gradually expressed TLR2 and TLR4 by Day 12. But under prolonged incubation with LPS, MSC-derived osteoprogenitors had reduced TLR2 and TLR4 gene expression. This peculiar response to LPS suggests a possible adaptive mechanism when MSCs are subjected to continuous exposure with bacteria. In conclusion, our findings support the potential of using human MSCs as a biological graft, even under a bacterial toxin-rich environment.

  1. Characterizing the Role of Animal Exposures in Cryptosporidiosis and Shiga Toxin-producing Escherichia coli Infections: South Dakota, 2012.

    PubMed

    Daly, R F; Hill, N T

    2016-09-01

    Cryptosporidium spp. and Shiga toxin-producing Escherichia coli strains (STEC) are important causes of human illness. Incidence rates of these illnesses are high in South Dakota compared to the USA as a whole. Direct animal contact has been identified as a possible route of exposure for these illnesses. Ruminant animals may carry STEC subclinically, while young ruminants are common sources of zoonotic strains of Cryptosporidium. South Dakota patients with either STEC or cryptosporidiosis during 2012 were interviewed regarding seven categories of animal exposure: (i) petting zoo/fair attendance, (ii) animal event/rodeo attendance, (iii) feed/pet store visits, (iv) farm visits, (v) employment or residence at a farm, (vi) residence with pets and (vii) visiting other households with pets. Of the 50 STEC cases, 78.0% reported animal exposure prior to illness onset, with 23.3% having lived or worked on a farm. Farm visitors in particular had high degrees of animal contact and infrequently practiced personal protective measures. Of the 115 cryptosporidiosis cases, 87.8% reported animal exposures, with 45.6% having lived or worked on a farm and 29.0% having visited a farm prior to illness. Cases with farm exposures reported a high degree of direct animal contact and inconsistent use of personal protective measures. Cryptosporidiosis patients were significantly more likely than STEC patients to have lived or worked on a farm prior to their illness and were older on average. Patients with these illnesses had high rates of animal contact prior to illness. Animal contact on farms emerged as an important exposure route. Educational messages about personal protective measures should be directed at these individuals. © 2016 Blackwell Verlag GmbH.

  2. Satellite monitoring of cyanobacterial harmful algal bloom ...

    EPA Pesticide Factsheets

    Cyanobacterial harmful algal blooms (cyanoHABs) cause extensive problems in lakes worldwide, including human and ecological health risks, anoxia and fish kills, and taste and odor problems. CyanoHABs are a particular concern because of their dense biomass and the risk of exposure to toxins in both recreational waters and drinking source waters. Successful cyanoHAB assessment by satellites may provide a first-line of defense indicator for human and ecological health protection. In this study, assessment methods were developed to determine the utility of satellite technology for detecting cyanoHAB occurrence frequency at locations of potential management interest. The European Space Agency's MEdium Resolution Imaging Spectrometer (MERIS) was evaluated to prepare for the equivalent Sentinel-3 Ocean and Land Colour Imager (OLCI) launched in 2016. Based on the 2012 National Lakes Assessment site evaluation guidelines and National Hydrography Dataset, there were 275,897 lakes and reservoirs greater than 1 hectare in the 48 U.S. states. Results from this evaluation show that 5.6 % of waterbodies were resolvable by satellites with 300 m single pixel resolution and 0.7 % of waterbodies were resolvable when a 3x3 pixel array was applied based on minimum Euclidian distance from shore. Satellite data was also spatially joined to US public water surface intake (PWSI) locations, where single pixel resolution resolved 57% of PWSI and a 3x3 pixel array resolved 33% of

  3. Toxin-producing cyanobacteria in freshwater: a review of the problems, impact on drinking water safety, and efforts for protecting public health.

    PubMed

    Cheung, Melissa Y; Liang, Song; Lee, Jiyoung

    2013-02-01

    Cyanobacteria have adapted to survive in a variety of environments and have been found globally. Toxin-producing cyanobacterial harmful algal blooms (CHABs) have been increasing in frequency worldwide and pose a threat to drinking and recreational water. In this study, the prevalence, impact of CHABs and mitigation efforts were reviewed, focusing on the Lake Erie region and Ohio's inland lakes that have been impacted heavily as an example so that the findings can be transferrable to other parts of the world that face the similar problems due to the CHABs in their freshwater environments. This paper provides a basic introduction to CHABs and their toxins as well as an overview of public health implications including exposure routes, health effects, and drinking water issues, algal bloom advisory practices in Ohio, toxin measurements results in Ohio public water supplies, and mitigation efforts.

  4. Formation and Control of Cyanobacterial Toxins

    EPA Science Inventory

    This presentation will cover the formation of harmful algal blooms and the control of their toxins. Data will be presented from current ORD projects on the treatment of cyanobacterial toxins through drinking water treatment facilities. The results will demonstrate that current c...

  5. Developmental Implications for Prenatal Exposure to Environmental Toxins: Consumption Habits of Pregnant Women and Prenatal Nicotine Exposure in a Mouse Model

    NASA Astrophysics Data System (ADS)

    Santiago, Sarah Emily

    This dissertation provides a discussion of the effects of maternal consumption of environmental toxins, and will hopefully contribute to the prevention and understanding of developmental disorders and physiological deficits. Developing systems are particularly susceptible to toxic insults, and small changes in utero can result in long-term deficits. Chapter one of this dissertation reviews the potential teratogenicity of nicotine, alcohol, caffeine, MeHg, PCBs, BPA, and tap water contaminants, so as to characterize the current body of literature detailing the effects and implications of prenatal exposure to toxins. In chapter two, research on maternal consumption habits is presented, with an emphasis on commonly-consumed, potentially-teratogenic substances. Occurrences and frequencies of maternal intake of healthy and unhealthy foods, beverages, and medications in a population of predominantly Hispanic women in Southern California were assessed using the Food, Beverage, and Medication Intake Questionnaire (FBMIQ). The described study reveals that a proportion of pregnant women consumed BPA, MeHg, caffeine, and alcohol at varied levels during pregnancy. The following chapters provide an in-depth analysis of the postnatal effects of a particular neuroteratogen, nicotine, which has been shown to impart various detrimental postnatal effects on exposed offspring. A CD-1 mouse model of prenatal nicotine exposure (PNE) was used to analyze aspects of the brain and neocortex that may underly some of the cognitive and behavioral phenotypes seen with PNE. Analyses included postnatal measurements of brain weight, brain widths and lengths, development of neocortical circuitry, and cortical thickness measures. Exposed mice were found to exhibit reduced brain and body weights at birth, a phenotype that recovered by postnatal day 10. No changes in neocortical circuity or thickness in sensory and motor areas were found. PNE also resulted in persistent behavioral effects, including

  6. Sentinel Animals in a One Health Approach to Harmful Cyanobacterial and Algal Blooms

    PubMed Central

    Backer, Lorraine C.; Miller, Melissa

    2016-01-01

    People, domestic animals, and wildlife are all exposed to numerous environmental threats, including harmful algal blooms (HABs). However, because animals exhibit wide variations in diet, land use and biology, they are often more frequently or heavily exposed to HAB toxins than are people occupying the same habitat, making them sentinels for human exposures. Historically, we have taken advantage of unique physiological characteristics of animals, such as the sensitivity of canaries to carbon monoxide, to more quickly recognize threats and help protect human health. As HAB events become more severe and widespread worldwide, exposure and health outcome data for animals can be extremely helpful to predict, prevent, and evaluate human exposures and health outcomes. Applying a One Health approach to investigation of HABs means that lessons learned from animal sentinels can be applied to protect people, animals and our shared environment. PMID:27152315

  7. Synergistic effects on dopamine cell death in a Drosophila model of chronic toxin exposure

    PubMed Central

    Martin, Ciara A.; Barajas, Angel; Lawless, George; Lawal, Hakeem O.; Assani, Khadij; Lumintang, Yosephine P.; Nunez, Vanessa; Krantz, David E.

    2014-01-01

    The neurodegenerative effects of Parkinson’s disease (PD) are marked by a selective loss of dopaminergic (DA) neurons. Epidemiological studies suggest that chronic exposure to the pesticide paraquat may increase the risk for PD and DA cell loss. However, combined exposure with additional fungicide(s) including maneb and/or ziram may be required for pathogenesis. To explore potential pathogenic mechanisms, we have developed a Drosophila model of chronic paraquat exposure. We find that while chronic paraquat exposure alone decreased organismal survival and motor function, combined chronic exposure to both paraquat and maneb was required for DA cell death in the fly. To initiate mechanistic studies of this interaction, we used additional genetic reagents to target the ubiquitin proteasome system, implicated in some rare familial forms of PD and the toxic effects of ziram. Genetic inhibition of E1 ubiquitin ligase, but not the proteasome itself, increased DA cell death in combination with maneb but not paraquat. These studies establish a model for long-term exposure to multiple pesticides, and support the idea that pesticide interactions relevant to PD may involve inhibition of protein ubiquitination. PMID:25160001

  8. Centers for Oceans and Human Health: a unified approach to the challenge of harmful algal blooms

    PubMed Central

    Erdner, Deana L; Dyble, Julianne; Parsons, Michael L; Stevens, Richard C; Hubbard, Katherine A; Wrabel, Michele L; Moore, Stephanie K; Lefebvre, Kathi A; Anderson, Donald M; Bienfang, Paul; Bidigare, Robert R; Parker, Micaela S; Moeller, Peter; Brand, Larry E; Trainer, Vera L

    2008-01-01

    Background Harmful algal blooms (HABs) are one focus of the national research initiatives on Oceans and Human Health (OHH) at NIEHS, NOAA and NSF. All of the OHH Centers, from the east coast to Hawaii, include one or more research projects devoted to studying HAB problems and their relationship to human health. The research shares common goals for understanding, monitoring and predicting HAB events to protect and improve human health: understanding the basic biology of the organisms; identifying how chemistry, hydrography and genetic diversity influence blooms; developing analytical methods and sensors for cells and toxins; understanding health effects of toxin exposure; and developing conceptual, empirical and numerical models of bloom dynamics. Results In the past several years, there has been significant progress toward all of the common goals. Several studies have elucidated the effects of environmental conditions and genetic heterogeneity on bloom dynamics. New methods have been developed or implemented for the detection of HAB cells and toxins, including genetic assays for Pseudo-nitzschia and Microcystis, and a biosensor for domoic acid. There have been advances in predictive models of blooms, most notably for the toxic dinoflagellates Alexandrium and Karenia. Other work is focused on the future, studying the ways in which climate change may affect HAB incidence, and assessing the threat from emerging HABs and toxins, such as the cyanobacterial neurotoxin β-N-methylamino-L-alanine. Conclusion Along the way, many challenges have been encountered that are common to the OHH Centers and also echo those of the wider HAB community. Long-term field data and basic biological information are needed to develop accurate models. Sensor development is hindered by the lack of simple and rapid assays for algal cells and especially toxins. It is also critical to adequately understand the human health effects of HAB toxins. Currently, we understand best the effects of acute

  9. Exposure to the Paralytic Shellfish Toxin Producer Alexandrium catenella Increases the Susceptibility of the Oyster Crassostrea gigas to Pathogenic Vibrios

    PubMed Central

    Abi-Khalil, Celina; Lopez-Joven, Carmen; Abadie, Eric; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-Luc

    2016-01-01

    The multifactorial etiology of massive Crassostrea gigas summer mortalities results from complex interactions between oysters, opportunistic pathogens and environmental factors. In a field survey conducted in 2014 in the Mediterranean Thau Lagoon (France), we evidenced that the development of the toxic dinoflagellate Alexandrium catenella, which produces paralytic shellfish toxins (PSTs), was concomitant with the accumulation of PSTs in oyster flesh and the occurrence of C. gigas mortalities. In order to investigate the possible role of toxic algae in this complex disease, we experimentally infected C. gigas oyster juveniles with Vibrio tasmaniensis strain LGP32, a strain associated with oyster summer mortalities, after oysters were exposed to Alexandrium catenella. Exposure of oysters to A. catenella significantly increased the susceptibility of oysters to V. tasmaniensis LGP32. On the contrary, exposure to the non-toxic dinoflagellate Alexandrium tamarense or to the haptophyte Tisochrysis lutea used as a foraging alga did not increase susceptibility to V. tasmaniensis LGP32. This study shows for the first time that A. catenella increases the susceptibility of Crassostrea gigas to pathogenic vibrios. Therefore, in addition to complex environmental factors explaining the mass mortalities of bivalve mollusks, feeding on neurotoxic dinoflagellates should now be considered as an environmental factor that potentially increases the severity of oyster mortality events. PMID:26784228

  10. Exposure and Effect Assessment of Aerosolized Red Tide Toxins (Brevetoxins) and Asthma

    PubMed Central

    Fleming, Lora E.; Bean, Judy A.; Kirkpatrick, Barbara; Cheng, Yung Sung; Pierce, Richard; Naar, Jerome; Nierenberg, Kate; Backer, Lorraine C.; Wanner, Adam; Reich, Andrew; Zhou, Yue; Watkins, Sharon; Henry, Mike; Zaias, Julia; Abraham, William M.; Benson, Janet; Cassedy, Amy; Hollenbeck, Julie; Kirkpatrick, Gary; Clarke, Tainya; Baden, Daniel G

    2009-01-01

    Background In previous studies we demonstrated statistically significant changes in reported symptoms for lifeguards, general beach goers, and persons with asthma, as well as statistically significant changes in pulmonary function tests (PFTs) in asthmatics, after exposure to brevetoxins in Florida red tide (Karenia brevis bloom) aerosols. Objectives In this study we explored the use of different methods of intensive ambient and personal air monitoring to characterize these exposures to predict self-reported health effects in our asthmatic study population. Methods We evaluated health effects in 87 subjects with asthma before and after 1 hr of exposure to Florida red tide aerosols and assessed for aerosolized brevetoxin exposure using personal and ambient samplers. Results After only 1 hr of exposure to Florida red tide aerosols containing brevetoxin concentrations > 57 ng/m3, asthmatics had statistically significant increases in self-reported respiratory symptoms and total symptom scores. However, we did not see the expected corresponding changes in PFT results. Significant increases in self-reported symptoms were also observed for those not using asthma medication and those living ≥ 1 mile from the coast. Conclusions These results provide additional evidence of health effects in asthmatics from ambient exposure to aerosols containing very low concentrations of brevetoxins, possibly at the lower threshold for inducing a biologic response (i.e., toxicity). Consistent with the literature describing self-reported symptoms as an accurate measure of asthmatic distress, our results suggest that self-reported symptoms are a valuable measure of the extent of health effects from exposure to aerosolized brevetoxins in asthmatic populations. PMID:19654919

  11. MCEARD - CYANOBACTERIA AND THEIR TOXINS

    EPA Science Inventory

    Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Waterborne cyanobacteria and their highly potent toxins are a significant hazard for human health and the ecosystem....

  12. MCEARD - CYANOBACTERIA AND THEIR TOXINS

    EPA Science Inventory

    Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Waterborne cyanobacteria and their highly potent toxins are a significant hazard for human health and the ecosystem....

  13. Sublethal red tide toxin exposure in free-ranging manatees (Trichechus manatus) affects the immune system through reduced lymphocyte proliferation responses, inflammation, and oxidative stress.

    PubMed

    Walsh, Catherine J; Butawan, Matthew; Yordy, Jennifer; Ball, Ray; Flewelling, Leanne; de Wit, Martine; Bonde, Robert K

    2015-04-01

    The health of many Florida manatees (Trichechus manatus latirostris) is adversely affected by exposure to blooms of the toxic dinoflagellate, Karenia brevis. K. brevis blooms are common in manatee habitats of Florida's southwestern coast and produce a group of cyclic polyether toxins collectively referred to as red tide toxins, or brevetoxins. Although a large number of manatees exposed to significant levels of red tide toxins die, several manatees are rescued from sublethal exposure and are successfully treated and returned to the wild. Sublethal brevetoxin exposure may potentially impact the manatee immune system. Lymphocyte proliferative responses and a suite of immune function parameters in the plasma were used to evaluate effects of brevetoxin exposure on health of manatees rescued from natural exposure to red tide toxins in their habitat. Blood samples were collected from rescued manatees at Lowry Park Zoo in Tampa, FL and from healthy, unexposed manatees in Crystal River, FL. Peripheral blood leukocytes (PBL) isolated from whole blood were stimulated with T-cell mitogens, ConA and PHA. A suite of plasma parameters, including plasma protein electrophoresis profiles, lysozyme activity, superoxide dismutase (SOD) activity, and reactive oxygen/nitrogen (ROS/RNS) species, was also used to assess manatee health. Significant decreases (p<0.05) in lymphocyte proliferation were observed in ConA and PHA stimulated lymphocytes from rescued animals compared to non-exposed animals. Significant correlations were observed between oxidative stress markers (SOD, ROS/RNS) and plasma brevetoxin concentrations. Sublethal exposure to brevetoxins in the wild impacts some immune function components, and thus, overall health, in the Florida manatee.

  14. Toxin Release of Cyanobacterium Microcystis aeruginosa after Exposure to Typical Tetracycline Antibiotic Contaminants

    PubMed Central

    Ye, Jing; Du, Yuping; Wang, Lumei; Qian, Jingru; Chen, Jiejing; Wu, Qingwen; Hu, Xiaojun

    2017-01-01

    The global usage of veterinary antibiotics is significant. Antibiotics can be released into aquatic environments and elicit toxic effects on non-target organisms. In this study, the growth characteristics and toxin release of the cyanobacterium Microcystis aeruginosa (M. aeruginosa) were examined to investigate the physiological effects of tetracycline antibiotics on aquatic life. Results showed that the degree of toxicities of the following target antibiotics was TC (tetracycline hydrochloride) > CTC (chlortetracycline hydrochloride) > OTC (oxytetracycline hydrochloride) in terms of growth parameters, EC10 (0.63, 1.86, and 3.02 mg/L, respectively), and EC20 (1.58, 4.09, and 4.86 mg/L, respectively) values. These antibiotics inhibited the production of microcystin-LR (MC-LR) to varying degrees. CTC interfered M. aeruginosa cells and decreased their ability to release MC-LR, but this antibiotic stimulated the ability of these cells to synthesize MC-LR at 2 and 5 mg/L. OTC elicited a relatively weaker toxicity than CTC did and reduced MC-LR release. TC was the most toxic among the three antibiotics, and this antibiotic simultaneously reduced intracellular and extracellular MC-LR equivalents. Our results helped elucidate the effects of tetracycline antibiotics on M. aeruginosa, which is essential for environmental evaluation and protection. Our results are also helpful for guiding the application of veterinary antibiotics in agricultural settings. PMID:28230795

  15. Developmental exposure to T-2 toxin reversibly affects postnatal hippocampal neurogenesis and reduces neural stem cells and progenitor cells in mice.

    PubMed

    Tanaka, Takeshi; Abe, Hajime; Kimura, Masayuki; Onda, Nobuhiko; Mizukami, Sayaka; Yoshida, Toshinori; Shibutani, Makoto

    2016-08-01

    To determine the developmental exposure effects of T-2 toxin on postnatal hippocampal neurogenesis, pregnant ICR mice were provided a diet containing T-2 toxin at 0, 1, 3, or 9 ppm from gestation day 6 to day 21 on weaning after delivery. Offspring were maintained through postnatal day (PND) 77 without T-2 toxin exposure. In the hippocampal dentate gyrus of male PND 21 offspring, GFAP(+) and BLBP(+) type-1 stem cells and PAX6(+) and TBR2(+) type-2 progenitor cells decreased in the subgranular zone (SGZ) at 9 and ≥3 ppm, respectively, in parallel with increased apoptosis at ≥3 ppm. In the dentate hilus, reelin(+) γ-aminobutyric acid (GABA)-ergic interneurons increased at 9 ppm, suggesting reflection of neuronal mismigration. T-2 toxin decreased transcript levels of cholinergic and glutamate receptor subunits (Chrna4, Chrnb2 and Gria2) and glutamate transporter (Slc17a6) in the dentate gyrus, suggesting decreased cholinergic signals on hilar GABAergic interneurons innervating type-2 cells and decreased glutamatergic signals on type-1 and type-2 cells. T-2 toxin decreased SGZ cells expressing stem cell factor (SCF) and increased cells accumulating malondialdehydes. Neurogenesis-related changes disappeared on PND 77, suggesting that T-2 toxin reversibly affects neurogenesis by inducing apoptosis of type-1 and type-2 cells with different threshold levels. Decreased cholinergic and glutamatergic signals may decrease type-2 cells at ≥3 ppm. Additionally, decreased SCF/c-Kit interactions and increased oxidative stress may decrease type-1 and type-2 cells at 9 ppm. The no-observed-adverse-effect level for offspring neurogenesis was determined to be 1 ppm (0.14-0.49 mg/kg body weight/day).

  16. Neonatal exposure to the cyanobacterial toxin BMAA induces changes in protein expression and neurodegeneration in adult hippocampus.

    PubMed

    Karlsson, Oskar; Berg, Anna-Lena; Lindström, Anna-Karin; Hanrieder, Jörg; Arnerup, Gunnel; Roman, Erika; Bergquist, Jonas; Lindquist, Nils Gunnar; Brittebo, Eva B; Andersson, Malin

    2012-12-01

    The cyanobacterial toxin β-N-methylamino-L-alanine (BMAA) has been proposed to contribute to neurodegenerative disease. We have previously reported a selective uptake of BMAA in the mouse neonatal hippocampus and that exposure during the neonatal period causes learning and memory impairments in adult rats. The aim of this study was to characterize effects in the brain of 6-month-old rats treated neonatally (postnatal days 9-10) with the glutamatergic BMAA. Protein changes were examined using the novel technique Matrix-Assisted Laser Desorption Ionization (MALDI) imaging mass spectrometry (IMS) for direct imaging of proteins in brain cryosections, and histological changes were examined using immunohistochemistry and histopathology. The results showed long-term changes including a decreased expression of proteins involved in energy metabolism and intracellular signaling in the adult hippocampus at a dose (150 mg/kg) that gave no histopathological lesions in this brain region. Developmental exposure to a higher dose (460 mg/kg) also induced changes in the expression of S100β, histones, calcium- and calmodulin-binding proteins, and guanine nucleotide-binding proteins. At this dose, severe lesions in the adult hippocampus including neuronal degeneration, cell loss, calcium deposits, and astrogliosis were evident. The data demonstrate subtle, sometimes dose-dependent, but permanent effects of a lower neonatal dose of BMAA in the adult hippocampus suggesting that BMAA could potentially disturb many processes during the development. The detection of BMAA in seafood stresses the importance of evaluating the magnitude of human exposure to this neurotoxin.

  17. Trends in exposure to industrial air toxins for different racial and socioeconomic groups: A spatial and temporal examination of environmental inequality in the U.S. from 1995 to 2004.

    PubMed

    Ard, Kerry

    2015-09-01

    In recent decades there have been dramatic declines in industrial air toxins. However, there has yet to be a national study investigating if the drop has mitigated the unequal exposure to industrial toxins by race and social class. This paper addresses this by developing a unique dataset of air pollution exposure estimates, by aggregating the annual fall-out location of 415 air toxins, from 17,604 facilities, for the years 1995 to 2004 up to census block groups (N=216,159/year). These annual estimates of exposure were matched with census data to calculate trends in exposure for different racial and socioeconomic groups. Results show that exposure to air toxins has decreased for everyone, but African-Americans are consistently more exposed than Whites and Hispanics and socioeconomic status is not as protective for African-Americans. These results by race were further explored using spatially specified multilevel models which examine trends over time and across institutional boundaries.

  18. Increased Plasma Exposures of Conjugated Metabolites of Morinidazole in Renal Failure Patients: A Critical Role of Uremic Toxins.

    PubMed

    Kong, Fandi; Pang, Xiaoyan; Zhong, Kan; Guo, Zitao; Li, Xiuli; Zhong, Dafang; Chen, Xiaoyan

    2017-06-01

    Morinidazole is a 5-nitroimidazole drug. Its sulfate conjugate M7 was a sensitive substrate of organic anion transporter 1 (OAT1) and OAT3, whereas N(+)-glucuronides M8-1 and M8-2 were only OAT3 substrates. In chronic renal failure (CRF) patients, plasma exposures of the three conjugates increased by 15-fold, which were also found in 5/6 nephrectomized (5/6 Nx) rats in this study. Although the transcriptions of Oat1 and Oat3 in 5/6 Nx rat kidneys decreased by 50%, no difference was observed on the three conjugate uptakes between control and 5/6 Nx rat kidney slices. Thus, the highly elevated endogenous uremic toxins in 5/6 Nx rats and humans, namely, 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF), hippuric acid (HA), and indoxyl sulfate (IS), were considered as influential factors. In rat kidney slices, the uptake of M7, M8-1, and M8-2 was dose dependently reduced by HA and IS, whose plasma concentrations were elevated 5 times in 5/6 Nx rats. In OAT3-overexpressed cells, the three conjugate uptakes were inhibited by CMPF, HA, and IS with IC50 values of 19.2, 87.4, and 222 μM (M7); 8.53, 39.4, and 161 μM (M8-1); and 6.75, 24.1, and 78.3 μM (M8-2), respectively. In OAT1-overexpressed cells, CMPF, HA, and IS showed weak inhibition on M7 uptake with IC50 values of 187, 162, and 200 μM, correspondingly. Results suggest that the reduced mRNA expression of renal transporters in CRF patients may not influence the activities of these transporters. However, accumulated uremic toxins may inhibit the transporters, particularly OAT3, leading to plasma exposure changes of relevant substrates. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  19. The effects of in-utero tobacco-toxin exposure on the respiratory system in children.

    PubMed

    Stick, Stephen

    2006-10-01

    Promotion of cigarettes to children and women has resulted in unacceptably high rates of smoking during pregnancy in most developed countries and the potential to greatly increase smoking by mothers in developing countries. The risks of smoking during pregnancy to mothers and unborn children are well known and include growth retardation, respiratory diseases and sudden infant death syndrome. Determining the effects of exposure on the fetus depends upon accurate assessment of maternal smoking, both active and involuntary, and this can be done using self-reports and a variety of biomarkers in the mother and/or newborn. The evidence is clear that most of the excess respiratory morbidity in children born to smoking mothers is due to in-utero exposure and that deficits in lung function measured soon after birth persist in children and adults. Recent studies have also indicated that some children are genetically predisposed to adverse outcomes in response to in-utero exposure. Although many women attempt to quit during pregnancy and effective interventions are available, ultimately the respiratory health of future generations will depend upon effective public health and tobacco control measures designed to prevent smoking uptake by youth and in particular girls and young women.

  20. Glutathione transferase (GST) as a candidate molecular-based biomarker for soil toxin exposure in the earthworm Lumbricus rubellus.

    PubMed

    LaCourse, E James; Hernandez-Viadel, Mariluz; Jefferies, James R; Svendsen, Claus; Spurgeon, David J; Barrett, John; Morgan, A John; Kille, Peter; Brophy, Peter M

    2009-01-01

    The earthworm Lumbricus rubellus (Hoffmeister, 1843) is a terrestrial pollution sentinel. Enzyme activity and transcription of phase II detoxification superfamily glutathione transferases (GST) is known to respond in earthworms after soil toxin exposure, suggesting GST as a candidate molecular-based pollution biomarker. This study combined sub-proteomics, bioinformatics and biochemical assay to characterise the L. rubellus GST complement as pre-requisite to initialise assessment of the applicability of GST as a biomarker. L. rubellus possesses a range of GSTs related to known classes, with evidence of tissue-specific synthesis. Two affinity-purified GSTs dominating GST protein synthesis (Sigma and Pi class) were cloned, expressed and characterised for enzyme activity with various substrates. Electrospray ionisation mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS) following SDS-PAGE were superior in retaining subunit stability relative to two-dimensional gel electrophoresis (2-DE). This study provides greater understanding of Phase II detoxification GST superfamily status of an important environmental pollution sentinel organism.

  1. Crawling phagocytes recruited in the brain vasculature after pertussis toxin exposure through IL6, ICAM1 and ITGαM.

    PubMed

    Richard, Jean-François; Roy, Monica; Audoy-Rémus, Julie; Tremblay, Pierrot; Vallières, Luc

    2011-11-01

    The cerebral vasculature is constantly patrolled by rod-shaped leukocytes crawling on the luminal endothelial surface. These cells are recruited in greater numbers after exposure to bacterial lipopolysaccharide (LPS) by a mechanism involving tumor necrosis factor (TNF), interleukin-1β (IL1β) and angiopoietin-2 (Angpt2). Here, we report that the population of crawling leukocytes, consisting mainly of granulocytes, is also increased in the brains of mice suffering from experimental autoimmune encephalomyelitis (EAE) or injected with pertussis toxin (PTX), which is commonly used to induce EAE. However, this recruitment occurs through an alternative mechanism, independent of Angpt2. In a series of experiments using DNA microarrays, knockout mice and neutralizing antibodies, we found that PTX acts indirectly on the endothelium in part through IL6, which is essential for the post-transcriptional upregulation of intercellular adhesion molecule 1 (ICAM1) in response to PTX but not to LPS. We also found that phagocytes adhere to brain capillaries through the interaction of integrin αM (ITGαM) with ICAM1 and an unidentified ligand. In conclusion, this study supports the concept that PTX promotes EAE, at least in part, by inducing vascular changes necessary for the recruitment of patrolling leukocytes. © 2011 The Authors; Brain Pathology © 2011 International Society of Neuropathology.

  2. Acetalated Dextran Microparticulate Vaccine Formulated via Coaxial Electrospray Preserves Toxin Neutralization and Enhances Murine Survival Following Inhalational Bacillus Anthracis Exposure.

    PubMed

    Gallovic, Matthew D; Schully, Kevin L; Bell, Matthew G; Elberson, Margaret A; Palmer, John R; Darko, Christian A; Bachelder, Eric M; Wyslouzil, Barbara E; Keane-Myers, Andrea M; Ainslie, Kristy M

    2016-10-01

    Subunit formulations are regarded as the safest type of vaccine, but they often contain a protein-based antigen that can result in significant challenges, such as preserving antigenicity during formulation and administration. Many studies have demonstrated that encapsulation of protein antigens in polymeric microparticles (MPs) via emulsion techniques results in total IgG antibody titers comparable to alum formulations, however, the antibodies themselves are non-neutralizing. To address this issue, a coaxial electrohydrodynamic spraying (electrospray) technique is used to formulate a microparticulate-based subunit anthrax vaccine under conditions that minimize recombinant protective antigen (rPA) exposure to harsh solvents and high shear stress. rPA and the adjuvant resiquimod are encapsulated either in separate or the same acetalated dextran MPs. Using a murine model, the electrospray formulations lead to higher IgG2a subtype titers as well as comparable total IgG antibody titers and toxin neutralization relative to the FDA-approved vaccine (BioThrax). BioThrax provides no protection against a lethal inhalational challenge of the highly virulent Ames Bacillus anthracis anthrax strain, whereas 50% of the mice vaccinated with separately encapsulated electrospray MPs survive. Overall, this study demonstrates the potential use of electrospray for encapsulating protein antigens in polymeric MPs.

  3. Harmful Algal Blooms and Drinking Water Treatment Research

    EPA Science Inventory

    EPA has been conducting algal bloom research at multiple facilities around Lake Erie over the past few years to help communities confront the challenge of keeping cyanobacterial toxins from reaching consumers’ taps, while minimizing the financial burden. The first goal of this re...

  4. Harmful Algal Blooms and Drinking Water Treatment Research

    EPA Science Inventory

    EPA has been conducting algal bloom research at multiple facilities around Lake Erie over the past few years to help communities confront the challenge of keeping cyanobacterial toxins from reaching consumers’ taps, while minimizing the financial burden. The first goal of this re...

  5. Viability changes in human neutrophils and monocytes following exposure to toxin extracted from Aphanizomenon flos-aquae.

    PubMed

    Barton, L L; Foster, E W; Johnson, G V

    1980-02-01

    An in vitro method for detecting toxin produced by Aphanizomenon flos-aquae is described. This procedure is more sensitive than the mouse toxicity test and is based on viability changes in human leukocytes.

  6. Aerosolized Red-Tide Toxins (Brevetoxins) and Asthma

    PubMed Central

    Fleming, Lora E.; Kirkpatrick, Barbara; Backer, Lorraine C.; Bean, Judy A.; Wanner, Adam; Reich, Andrew; Zaias, Julia; Cheng, Yung Sung; Pierce, Richard; Naar, Jerome; Abraham, William M.; Baden, Daniel G.

    2009-01-01

    Background With the increasing incidence of asthma, there is increasing concern over environmental exposures that may trigger asthma exacerbations. Blooms of the marine microalgae, Karenia brevis, cause red tides (or harmful algal blooms) annually throughout the Gulf of Mexico. K brevis produces highly potent natural polyether toxins, called brevetoxins, which are sodium channel blockers, and possibly histamine activators. In experimental animals, brevetoxins cause significant bronchoconstriction. In humans, a significant increase in self-reported respiratory symptoms has been described after recreational and occupational exposures to Florida red-tide aerosols, particularly among individuals with asthma. Methods Before and after 1 h spent on beaches with and without an active K brevis red-tide exposure, 97 persons ≥ 12 years of age with physician-diagnosed asthma were evaluated by questionnaire and spirometry. Concomitant environmental monitoring, water and air sampling, and personal monitoring for brevetoxins were performed. Results Participants were significantly more likely to report respiratory symptoms after K brevis red-tide aerosol exposure than before exposure. Participants demonstrated small, but statistically significant, decreases in FEV1, midexpiratory phase of forced expiratory flow, and peak expiratory flow after exposure, particularly among those participants regularly using asthma medications. No significant differences were detected when there was no Florida red tide (ie, during nonexposure periods). Conclusions This study demonstrated objectively measurable adverse changes in lung function from exposure to aerosolized Florida red-tide toxins in asthmatic subjects, particularly among those requiring regular therapy with asthma medications. Future studies will assess these susceptible subpopulations in more depth, as well as the possible long-term effects of these toxins. PMID:17218574

  7. Effects of algal-derived carbon on sediment methane ...

    EPA Pesticide Factsheets

    Nutrient loading is known to have adverse consequences for aquatic ecosystems, particularly in the form of algal blooms that may result. These blooms pose problems for humans and wildlife, including harmful toxin release, aquatic hypoxia and increased costs for water treatment. Another potential disservice resulting from algal blooms is the enhanced production of methane (CH4), a potent greenhouse gas, in aquatic sediments. Laboratory experiments have shown that algal biomass additions to sediment cores increase rates of CH4 production, but it is unclear whether or not this effect occurs at the ecosystem scale. The goal of this research was to explore the link between algal-derived carbon and methane production in the sediment of a eutrophic reservoir located in southwest Ohio, using a sampling design that capitalized on spatial and temporal gradients in autochthonous carbon input to sediments. Specifically, we aimed to determine if the within-reservoir gradient of sediment algal-derived organic matter and sediment CH4 production rates correlate. This was done by retrieving sediment cores from 15 sites within the reservoir along a known gradient of methane emission rates, at two separate time points in 2016: late spring before the sediments had received large amounts of algal input and mid-summer after algal blooms had been prevalent in the reservoir. Potential CH4 production rates, sediment organic matter source, and microbial community composition were charac

  8. [Cyclic imine toxin gymnodimine: a review].

    PubMed

    Liu, Ren-yan; Liang, Yu-bo

    2009-09-01

    Gymnodimine (GYM), an algal toxin first detected from New Zealand oysters in 1994, is identified as a cyclic imine toxin and produced by Karenia selliformis, with imino nitrogen attached on loop-coil. Imine is the poisonous functional group of the toxin. GYM has a low oral toxicity, but its acute lethal toxicity of intra-peritoneal injection for mice is very high. Up to now, few reports have been published on the detailed information about the toxicity mechanism of GYM. Based on limited literatures, this paper reviewed the GYM's structure, producer, toxicity mechanism, carrying animals, geological distribution, degradation metabolism, dose-effect relation, and risk evaluation, and proposed the further research directions on algal toxin.

  9. Algal bloom response and risk management: On-site response tools.

    PubMed

    Watson, Susan B; Zastepa, Arthur; Boyer, Gregory L; Matthews, Eric

    2017-04-01

    Harmful algal blooms caused by cyanobacteria can present a risk to the safety of drinking- and recreational waters and beachfronts through the production of toxins, particularly microcystin, which are highly resilient to degradation. These blooms are difficult to predict, vary in appearance and toxicity, and can show significant spatial heterogeneity: wind- and current-borne scums can produce an order of magnitude range in toxin levels along shorelines. The growing demand for reliable, cost-effective and rapid methods to detect toxins in bloom material and reduce the risk of public exposure cannot be met by most analytical lab turnaround times. Commercial microcystin test kits are now available, but few have been rigorously field-tested or incorporated into monitoring programmes. Working with a local health agency, we evaluated two kits with different operative ranges of detection, applied to samples covering a wide range of water quality, sample matrices, and bloom composition. We compared their performance against lab analyses using Enzyme-Linked Immunosorbent and Protein Phosphatase Inhibition assays. Both kits could resolve samples with high (<10 μg/L microcystin equivalents (MCequiv)) and low/no toxins, but failed to reliably detect toxin levels between 1 and 5 μg/L, at which threshold there were few false negatives (8%) but ∼ one third of the samples (32%) yielded false positives. We conclude that these kits are potentially useful for screening and informed risk management decisions e.g. on beach closures, but should be followed up with more rigorous tests where needed. We describe how, based on these results, the kits have been successfully incorporated into the routine municipal beach monitoring and advisory programme by the Hamilton Public Health Services (Ontario).

  10. Immunodetection of T-2 Metabolites in Rat Urines after Dermal, Oral, or Intramuscular Exposure to T-2 Toxin

    DTIC Science & Technology

    1988-07-25

    were housed in plastic metabolh. cages (Nalgene. Inc. Rochester, N.Y.) with free access to food and water. Urine and feces were collected daily and...in swine bile and urine. J. Agric., Food Chem. 33, 1085-1089. ELLISON, R.A. and KOTSONIS, F.N. 1973. T-2 toxin as an emetic factor in meldy corn. AppL...fluids. J. Food Prot. 47, 964-967. FAN, T.S.. ZHANG, G.S., and CHU, F.S. 1987. Production and ’characterization of antibodies against HT-2 toxin and T-2

  11. Single and combined exposure to MC-LR and BMAA confirm suitability of Aegagropila linnaei for use in green liver systems(®)-A case study with cyanobacterial toxins.

    PubMed

    Contardo-Jara, Valeska; Kuehn, Sandra; Pflugmacher, Stephan

    2015-08-01

    The filamentous green algae Aegagropila linnaei was tested for its uptake capacity of the cyanobacterial toxins microcystin-LR (MC-LR) and β-N-methylamino-l-alanine (BMAA) in order to approve the suitability of its use in the Green Liver System(®). Uptake into the algae and toxin reduction in the medium were analyzed by LC-MS/MS after static exposure for one week to 20μgL(-1) MC-LR, 80μgL(-1) BMAA, and 20μgL(-1) MC-LR together with 80μgL(-1) BMAA, respectively. BMAA was effectively removed by A. linnaei within 5 days compared to only around 35% removal of the initial exposure concentration in the case of MC-LR, independent of the application mode, in single or in a mixture. However, differences were found for BMAA amounts taken up into the tissue in that it was higher if applied in combination with MC-LR. Additionally, physiological responses such as the activity of biotransformation enzyme glutathione S-transferase (GST), antioxidant enzymes peroxidase (POD) and catalase (CAT) as well as the development of the reactive oxygen species hydrogen peroxide (H2O2) were compared between the different treatment groups in order to determine possible harmful effects of the toxin exposure on the algae. In contrast to the toxin exposure to a single toxin with no significant enzymatic response, exposure to the toxin mixture provoked an immediate increase in GST and CAT activity after one day as well as after longer exposure for one week, hinting on an enhanced need for prevention against exposure derived reactive oxygen species as well as putative biotransformation attempts in a mixture exposure scenario.

  12. Kinetics and metabolism of the Fusarium toxin deoxynivalenol in farm animals: consequences for diagnosis of exposure and intoxication and carry over.

    PubMed

    Dänicke, Sven; Brezina, Ulrike

    2013-10-01

    The knowledge of factors influencing the kinetics, metabolism and bioavailability of the Fusarium toxin deoxynivalenol (DON) is a basic prerequisite for evaluation of the transfer (carry over) of the toxin and its metabolites into edible tissues, and for a physiological specimen-based diagnosis of intoxication. These aspects are addressed in the present review, and potentials and pitfalls of the suitability of analysis of physiological samples for evaluation of the DON exposure as a veterinary tool are discussed. For example, the farm animal species was shown to be a determining factor influencing the metabolic profile and the bioavailability of DON. Although linear relationships were derived between DON exposure of ad libitum and restrictively fed animals and DON or de-epoxy-DON concentration in the blood of pigs, dairy cows and sheep, it has to be considered that individual values might markedly deviate from these relationships, which makes interpretation of measured concentrations of DON and its metabolites difficult. The situation is further complicated by the lack of established relationships between DON residues in physiological matrices and the adverse effects of DON on the health and performance of farm animals.

  13. The Algal Revolution.

    PubMed

    Brodie, Juliet; Chan, Cheong Xin; De Clerck, Olivier; Cock, J Mark; Coelho, Susana M; Gachon, Claire; Grossman, Arthur R; Mock, Thomas; Raven, John A; Smith, Alison G; Yoon, Hwan Su; Bhattacharya, Debashish

    2017-08-01

    Algae are (mostly) photosynthetic eukaryotes that occupy multiple branches of the tree of life, and are vital for planet function and health. In this review, we highlight a transformative period in studies of the evolution and functioning of this extraordinary group of organisms and their potential for novel applications, wrought by high-throughput 'omic' and reverse genetic methods. We cover the origin and diversification of algal groups, explore advances in understanding the link between phenotype and genotype, consider algal sex determination, and review progress in understanding the roots of algal multicellularity. Experimental evolution studies to determine how algae evolve in changing environments are highlighted, as is their potential as production platforms for compounds of commercial interest, such as biofuel precursors, nutraceuticals, or therapeutics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Safety evaluation of Algal Oil from Schizochytrium sp.

    PubMed

    Fedorova-Dahms, I; Marone, P A; Bailey-Hall, E; Ryan, A S

    2011-01-01

    The safety of Algal Oil from Schizochytrium sp. was evaluated by testing for gene mutations, clastogenicity and aneugenicity, and in a subchronic 90-day Sprague-Dawley rat dietary study. The results of all genotoxicity tests were negative. The 90-day study involved dietary exposure to 0.5, 1.5, and 5 wt.% of Algal Oil and two control diets: a standard low-fat basal diet and a basal diet supplemented with 5 wt.% menhaden oil (the fish oil control). There were no treatment-related effects of Algal Oil on clinical observations, body weight, food consumption, behavior, hematology, clinical chemistry, coagulation, or urinalysis parameters. Increased mean liver weights and alveolar histiocytosis were observed in both the fish oil control and the high-dose Algal Oil-treated animals and were not considered to be adverse. Algal Oil was bioavailable as demonstrated by the dose-related increase of DHA and EPA levels in tissues and plasma. The no observable adverse effect level (NOAEL) for Algal Oil under the conditions of this study was 5 wt.% in the diet, equivalent to an overall average Algal Oil intake of 3250 mg/kg bw/day for male and female rats. Based on the body surface area, the human equivalent dose is about 30 g Algal Oil/day for a 60 kg adult.

  15. Algal Biofuels Fact Sheet

    SciTech Connect

    2009-10-27

    This fact sheet provides information on algal biofuels, which are generating considerable interest around the world. They may represent a sustainable pathway for helping to meet the U.S. biofuel production targets set by the Energy Independence and Security Act of 2007.

  16. Harmful Algal Blooms Research

    EPA Science Inventory

    This project represents the Agency’s first effort to unify harmful algal blooms (HABs) research that had been previously carried out in isolation within various laboratories. A unified program is the most efficient way generate useful results for the Agency’s decision...

  17. Harmful Algal Blooms Research

    EPA Science Inventory

    This project represents the Agency’s first effort to unify harmful algal blooms (HABs) research that had been previously carried out in isolation within various laboratories. A unified program is the most efficient way generate useful results for the Agency’s decision...

  18. DNA damage and DNA damage responses in THP-1 monocytes after exposure to spores of either Stachybotrys chartarum or Aspergillus versicolor or to T-2 toxin.

    PubMed

    Rakkestad, Kirsten E; Skaar, Ida; Ansteinsson, Vibeke E; Solhaug, Anita; Holme, Jørn A; Pestka, James J; Samuelsen, Jan T; Dahlman, Hans J; Hongslo, Jan K; Becher, Rune

    2010-05-01

    We have characterized cell death in THP-1 cells after exposure to heat-treated spores from satratoxin G-producing Stachybotrys chartarum isolate IBT 9631, atranone-producing S. chartarum isolate IBT 9634, and sterigmatocystin-producing Aspergillus versicolor isolate IBT 3781, as well as the trichothecenes T-2 and satratoxin G. Spores induced cell death within 3-6 h, with Stachybotrys appearing most potent. IBT 9631 induced both apoptosis and necrosis, while IBT 9634 and IBT 3781 induced mostly necrosis. T-2 toxin and satratoxin G caused mainly apoptosis. Comet assay +/- formamidopyrimidine DNA glycosylase showed that only the spore exposures induced early (3h) oxidative DNA damage. Likewise, only the spores increased the formation of reactive oxygen species (ROS), suggesting that spores as particles may induce ROS formation and oxidative DNA damage. Increased Ataxia Telangiectasia Mutated (ATM) phosphorylation, indicating DNA damage, was observed after all exposures. The DNA damage response induced by IBT 9631 as well as satratoxin G was characterized by rapid (15 min) activation of p38 and H2AX. The p38 inhibitor SB 202190 reduced IBT 9631-induced H2AX activation. Both IBT 9631 and T-2 induced activation of Chk2 and H2AX after 3 h. The ATM inhibitor KU 55933, as well as transfection of cells with ATM siRNA, reduced this activation, suggesting a partial role for ATM as upstream activator for Chk2 and H2AX. In conclusion, activation of Chk2 and H2AX correlated with spore- and toxin-induced apoptosis. For IBT 9631 and satratoxin G, additional factors may be involved in triggering apoptosis, most notably p38 activation.

  19. DNA Damage and DNA Damage Responses in THP-1 Monocytes after Exposure to Spores of either Stachybotrys chartarum or Aspergillus versicolor or to T-2 toxin

    PubMed Central

    Rakkestad, Kirsten E.; Skaar, Ida; Ansteinsson, Vibeke E.; Solhaug, Anita; Holme, Jørn A.; Pestka, James J.; Samuelsen, Jan T.; Dahlman, Hans J.; Hongslo, Jan K.; Becher, Rune

    2010-01-01

    We have characterized cell death in THP-1 cells after exposure to heat-treated spores from satratoxin G–producing Stachybotrys chartarum isolate IBT 9631, atranone-producing S. chartarum isolate IBT 9634, and sterigmatocystin-producing Aspergillus versicolor isolate IBT 3781, as well as the trichothecenes T-2 and satratoxin G. Spores induced cell death within 3–6 h, with Stachybotrys appearing most potent. IBT 9631 induced both apoptosis and necrosis, while IBT 9634 and IBT 3781 induced mostly necrosis. T-2 toxin and satratoxin G caused mainly apoptosis. Comet assay ± formamidopyrimidine DNA glycosylase showed that only the spore exposures induced early (3h) oxidative DNA damage. Likewise, only the spores increased the formation of reactive oxygen species (ROS), suggesting that spores as particles may induce ROS formation and oxidative DNA damage. Increased Ataxia Telangiectasia Mutated (ATM) phosphorylation, indicating DNA damage, was observed after all exposures. The DNA damage response induced by IBT 9631 as well as satratoxin G was characterized by rapid (15 min) activation of p38 and H2AX. The p38 inhibitor SB 202190 reduced IBT 9631–induced H2AX activation. Both IBT 9631 and T-2 induced activation of Chk2 and H2AX after 3 h. The ATM inhibitor KU 55933, as well as transfection of cells with ATM siRNA, reduced this activation, suggesting a partial role for ATM as upstream activator for Chk2 and H2AX. In conclusion, activation of Chk2 and H2AX correlated with spore- and toxin-induced apoptosis. For IBT 9631 and satratoxin G, additional factors may be involved in triggering apoptosis, most notably p38 activation. PMID:20150440

  20. Toxic Shock Syndrome Toxin-1-Mediated Toxicity Inhibited by Neutralizing Antibodies Late in the Course of Continual in Vivo and in Vitro Exposure

    PubMed Central

    Stich, Norbert; Model, Nina; Samstag, Aysen; Gruener, Corina S.; Wolf, Hermann M.; Eibl, Martha M.

    2014-01-01

    Toxic shock syndrome (TSS) results from the host’s overwhelming inflammatory response and cytokine storm mainly due to superantigens (SAgs). There is no effective specific therapy. Application of immunoglobulins has been shown to improve the outcome of the disease and to neutralize SAgs both in vivo and in vitro. However, in most experiments that have been performed, antiserum was either pre-incubated with SAg, or both were applied simultaneously. To mirror more closely the clinical situation, we applied a multiple dose (over five days) lethal challenge in a rabbit model. Treatment with toxic shock syndrome toxin 1 (TSST-1) neutralizing antibody was fully protective, even when administered late in the course of the challenge. Kinetic studies on the effect of superantigen toxins are scarce. We performed in vitro kinetic studies by neutralizing the toxin with antibodies at well-defined time points. T-cell activation was determined by assessing T-cell proliferation (3H-thymidine incorporation), determination of IL-2 release in the cell supernatant (ELISA), and IL-2 gene activation (real-time PCR (RT-PCR)). Here we show that T-cell activation occurs continuously. The application of TSST-1 neutralizing antiserum reduced IL-2 and TNFα release into the cell supernatant, even if added at later time points. Interference with the prolonged stimulation of proinflammatory cytokines is likely to be in vivo relevant, as postexposure treatment protected rabbits against the multiple dose lethal SAg challenge. Our results shed new light on the treatment of TSS by specific antibodies even at late stages of exposure. PMID:24887085

  1. Toxic shock syndrome toxin-1-mediated toxicity inhibited by neutralizing antibodies late in the course of continual in vivo and in vitro exposure.

    PubMed

    Stich, Norbert; Model, Nina; Samstag, Aysen; Gruener, Corina S; Wolf, Hermann M; Eibl, Martha M

    2014-05-30

    Toxic shock syndrome (TSS) results from the host's overwhelming inflammatory response and cytokine storm mainly due to superantigens (SAgs). There is no effective specific therapy. Application of immunoglobulins has been shown to improve the outcome of the disease and to neutralize SAgs both in vivo and in vitro. However, in most experiments that have been performed, antiserum was either pre-incubated with SAg, or both were applied simultaneously. To mirror more closely the clinical situation, we applied a multiple dose (over five days) lethal challenge in a rabbit model. Treatment with toxic shock syndrome toxin 1 (TSST-1) neutralizing antibody was fully protective, even when administered late in the course of the challenge. Kinetic studies on the effect of superantigen toxins are scarce. We performed in vitro kinetic studies by neutralizing the toxin with antibodies at well-defined time points. T-cell activation was determined by assessing T-cell proliferation (3H-thymidine incorporation), determination of IL-2 release in the cell supernatant (ELISA), and IL-2 gene activation (real-time PCR (RT-PCR)). Here we show that T-cell activation occurs continuously. The application of TSST-1 neutralizing antiserum reduced IL-2 and TNFα release into the cell supernatant, even if added at later time points. Interference with the prolonged stimulation of proinflammatory cytokines is likely to be in vivo relevant, as postexposure treatment protected rabbits against the multiple dose lethal SAg challenge. Our results shed new light on the treatment of TSS by specific antibodies even at late stages of exposure.

  2. Expression profile of eight glutathione S-transferase genes in Crassostrea ariakensis after exposure to DSP toxins producing dinoflagellate Prorocentrum lima.

    PubMed

    Zou, Ying; Wei, Xiao-Meng; Weng, Hui-Wen; Li, Hong-Ye; Liu, Jie-Sheng; Yang, Wei-Dong

    2015-10-01

    In this study, changes in eight GSTs mRNA level including GST-α, GST-σ, GST-ω, GST-π, GST-μ, GST-ρ, GST-θ and microsomal GST (mGST) in the oyster Crassostrea ariakensis after exposure to Prorocentrum lima have been evaluated by quantitative real-time PCR. Additionally, the contents of five GST isoforms were detected by ELISA. After exposure to P. lima at density of 2 × 10(5) cells/L, mGST mRNA significantly increased in gill, while GST-σ was induced in digestive gland. After exposure to P. lima at density of 2 × 10(6) cells/L, GST-ω and mGST expressions increased in gill, whereas GST-α and GST-σ were induced in digestive gland. The GST content and activity in oysters exposed to P. lima also showed a different pattern when the different isoforms and organs were compared. After exposure to P. lima (2 × 10(6) cell/L), GST-π increased in gill but decreased in digestive gland. The total GST enzyme activity increased in gill, while remained unchanged in digestive gland. These various regulation of GST gene expressions indicated that the GSTs isoenzymes might play divergent physiological roles in the detoxification of DSP toxins in C. ariakensis.

  3. Algal functional annotation tool

    SciTech Connect

    2012-07-12

    Abstract BACKGROUND: Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations to interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. DESCRIPTION: The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG

  4. Prolonged exposure to elevated CO(2) promotes growth of the algal symbiont Symbiodinium muscatinei in the intertidal sea anemone Anthopleura elegantissima.

    PubMed

    Towanda, Trisha; Thuesen, Erik V

    2012-07-15

    Some photosynthetic organisms benefit from elevated levels of carbon dioxide, but studies on the effects of elevated PCO(2) on the algal symbionts of animals are very few. This study investigated the impact of hypercapnia on a photosynthetic symbiosis between the anemone Anthopleura elegantissima and its zooxanthella Symbiodinium muscatinei. Anemones were maintained in the laboratory for 1 week at 37 Pa PCO(2) and pH 8.1. Clonal pairs were then divided into two groups and maintained for 6 weeks under conditions naturally experienced in their intertidal environment, 45 Pa PCO(2), pH 8.1 and 231 Pa PCO(2), pH 7.3. Respiration and photosynthesis were measured after the 1-week acclimation period and after 6 weeks in experimental conditions. Density of zooxanthellal cells, zooxanthellal cell size, mitotic index and chlorophyll content were compared between non-clonemate anemones after the 1-week acclimation period and clonal anemones at the end of the experiment. Anemones thrived in hypercapnia. After 6 weeks, A. elegantissima exhibited higher rates of photosynthesis at 45 Pa (4.2 µmol O(2) g(-1) h(-1)) and 231 Pa (3.30 µmol O(2) g(-1) h(-1)) than at the initial 37 Pa (1.53 µmol O(2) g(-1) h(-1)). Likewise, anemones at 231 Pa received more of their respiratory carbon from zooxanthellae (CZAR  = 78.2%) than those at 37 Pa (CZAR  = 66.6%) but less than anemones at 45 Pa (CZAR  = 137.3%). The mitotic index of zooxanthellae was significantly greater in the hypercapnic anemones than in anemones at lower PCO(2). Excess zooxanthellae were expelled by their hosts, and cell densities, cell diameters and chlorophyll contents were not significantly different between the groups. The response of A. elegantissima to hypercapnic acidification reveals the potential adaptation of an intertidal, photosynthetic symbiosis for high PCO(2).

  5. Prolonged exposure to elevated CO2 promotes growth of the algal symbiont Symbiodinium muscatinei in the intertidal sea anemone Anthopleura elegantissima

    PubMed Central

    Towanda, Trisha; Thuesen, Erik V.

    2012-01-01

    Summary Some photosynthetic organisms benefit from elevated levels of carbon dioxide, but studies on the effects of elevated PCO2 on the algal symbionts of animals are very few. This study investigated the impact of hypercapnia on a photosynthetic symbiosis between the anemone Anthopleura elegantissima and its zooxanthella Symbiodinium muscatinei. Anemones were maintained in the laboratory for 1 week at 37 Pa PCO2 and pH 8.1. Clonal pairs were then divided into two groups and maintained for 6 weeks under conditions naturally experienced in their intertidal environment, 45 Pa PCO2, pH 8.1 and 231 Pa PCO2, pH 7.3. Respiration and photosynthesis were measured after the 1-week acclimation period and after 6 weeks in experimental conditions. Density of zooxanthellal cells, zooxanthellal cell size, mitotic index and chlorophyll content were compared between non-clonemate anemones after the 1-week acclimation period and clonal anemones at the end of the experiment. Anemones thrived in hypercapnia. After 6 weeks, A. elegantissima exhibited higher rates of photosynthesis at 45 Pa (4.2 µmol O2 g−1 h−1) and 231 Pa (3.30 µmol O2 g−1 h−1) than at the initial 37 Pa (1.53 µmol O2 g−1 h−1). Likewise, anemones at 231 Pa received more of their respiratory carbon from zooxanthellae (CZAR  = 78.2%) than those at 37 Pa (CZAR  = 66.6%) but less than anemones at 45 Pa (CZAR  = 137.3%). The mitotic index of zooxanthellae was significantly greater in the hypercapnic anemones than in anemones at lower PCO2. Excess zooxanthellae were expelled by their hosts, and cell densities, cell diameters and chlorophyll contents were not significantly different between the groups. The response of A. elegantissima to hypercapnic acidification reveals the potential adaptation of an intertidal, photosynthetic symbiosis for high PCO2. PMID:23213455

  6. DETOXIFICATION OF CYANOBACTERIAL TOXIN - CONTAMINATED WATER USING TIO2 PHOTOCATALYTIC FILMS

    EPA Science Inventory

    Cyanobacterial harmfal algal blooms (CyanoHABs) often produce undesirable color, odor and taste and more importantly, potent toxins that can cause chronic, acute and acute letha poisonings to wild and domestic animals and humans

  7. Cyanobacterial Cells and Toxins:Evaluating Source Water Trends and Propagation through Lake Erie Treatment Facilities

    EPA Science Inventory

    Harmful algal blooms (HABs), and their associated toxins, in fresh water lakes and reservoirs are drawing the attention of utilities and state regulators nation-wide. Recognizing the potential health and economic consequences, the US Environmental Protection Agency, in partnersh...

  8. Cyanobacteria Toxin and Cell Propagation through Lake Erie Treatment Facilities - proceedings

    EPA Science Inventory

    Harmful algal blooms (HABs), and their associated toxins, in fresh water lakes and reservoirs are drawing the attention of utilities and state regulators nation-wide. Recognizing the potential health and economic consequences, the US Environmental Protection Agency, in partnersh...

  9. Cyanobacterial Cells and Toxins:Evaluating Source Water Trends and Propagation through Lake Erie Treatment Facilities

    EPA Science Inventory

    Harmful algal blooms (HABs), and their associated toxins, in fresh water lakes and reservoirs are drawing the attention of utilities and state regulators nation-wide. Recognizing the potential health and economic consequences, the US Environmental Protection Agency, in partnersh...

  10. Cyanobacteria Toxin and Cell Propagation through Lake Erie Treatment Facilities - proceedings

    EPA Science Inventory

    Harmful algal blooms (HABs), and their associated toxins, in fresh water lakes and reservoirs are drawing the attention of utilities and state regulators nation-wide. Recognizing the potential health and economic consequences, the US Environmental Protection Agency, in partnersh...

  11. Toxin-induced hepatic injury.

    PubMed

    Lopez, Annette M; Hendrickson, Robert G

    2014-02-01

    Toxins such as pharmaceuticals, herbals, foods, and supplements may lead to hepatic damage. This damage may range from nonspecific symptoms in the setting of liver test abnormalities to acute hepatic failure. The majority of severe cases of toxin-induced hepatic injury are caused by acetaminophen and ethanol. The most important step in the patient evaluation is to gather an extensive history that includes toxin exposure and exclude common causes of liver dysfunction. Patients whose hepatic dysfunction progresses to acute liver failure may benefit from transfer to a transplant service for further management. Currently, the mainstay in management for most exposures is discontinuing the offending agent. This manuscript will review the incidence, pathophysiology, diagnosis and management of the different forms of toxin-induced hepatic injury and exam in-depth the most common hepatic toxins.

  12. Monitoring for Harmful Algal Blooms in Influent Waters and Through Treatment on Lake Erie in the 2013 and 2014 Bloom Seasons 

    EPA Science Inventory

    Monitoring of Harmful Algal Blooms in Influent and Through Drinking Water Treatment Facilities Located on Lake Erie in the 2013 and 2014 Bloom SeasonsToby Sanan, Nicholas Dugan, Darren Lytle, Heath MashHarmful algal blooms (HABs) and their associated toxins are emerging as signif...

  13. Monitoring for Harmful Algal Blooms in Influent Waters and Through Treatment on Lake Erie in the 2013 and 2014 Bloom Seasons 

    EPA Science Inventory

    Monitoring of Harmful Algal Blooms in Influent and Through Drinking Water Treatment Facilities Located on Lake Erie in the 2013 and 2014 Bloom SeasonsToby Sanan, Nicholas Dugan, Darren Lytle, Heath MashHarmful algal blooms (HABs) and their associated toxins are emerging as signif...

  14. National Algal Biofuels Technology Roadmap

    SciTech Connect

    Ferrell, John; Sarisky-Reed, Valerie

    2010-05-01

    The framework for National Algal Biofuels Technology Roadmap was constructed at the Algal Biofuels Technology Roadmap Workshop, held December 9-10, 2008, at the University of Maryland-College Park. The Workshop was organized by the Biomass Program to discuss and identify the critical challenges currently hindering the development of a domestic, commercial-scale algal biofuels industry. This Roadmap presents information from a scientific, economic, and policy perspectives that can support and guide RD&D investment in algal biofuels. While addressing the potential economic and environmental benefits of using algal biomass for the production of liquid transportation fuels, the Roadmap describes the current status of algae RD&D. In doing so, it lays the groundwork for identifying challenges that likely need to be overcome for algal biomass to be used in the production of economically viable biofuels.

  15. Advanced Algal Systems Fact Sheet

    SciTech Connect

    2016-06-01

    Research and development (R&D) on advanced algal biofuels and bioproducts presents an opportunity to sustainably expand biomass resource potential in the United States. The Bioenergy Technologies Office’s (BETO’s) Advanced Algal Systems Program is carrying out a long-term, applied R&D strategy to lower the costs of algal biofuel production by working with partners to develop revolutionary technologies and conduct crosscutting analyses to better understand the potential

  16. Marine Toxin Okadaic Acid Affects the Immune Function of Bay Scallop (Argopecten irradians).

    PubMed

    Chi, Cheng; Giri, Sib Sankar; Jun, Jin Woo; Kim, Hyoun Joong; Yun, Saekil; Kim, Sang Guen; Park, Se Chang

    2016-08-24

    Okadaic acid (OA) is produced by dinoflagellates during harmful algal blooms and is a diarrhetic shellfish poisoning toxin. This toxin is particularly problematic for bivalves that are cultured for human consumption. This study aimed to reveal the effects of exposure to OA on the immune responses of bay scallop, Argopecten irradians. Various immunological parameters were assessed (total hemocyte counts (THC), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), lactate dehydrogenase (LDH), and nitric oxide (NO) in the hemolymph of scallops at 3, 6, 12, 24, and 48 h post-exposure (hpe) to different concentrations of OA (50, 100, and 500 nM). Moreover, the expression of immune-system-related genes (CLT-6, FREP, HSP90, MT, and Cu/ZnSOD) was also measured. Results showed that ROS, MDA, and NO levels and LDH activity were enhanced after exposure to different concentrations of OA; however, both THC and GSH decreased between 24-48 hpe. The expression of immune-system-related genes was also assessed at different time points during the exposure period. Overall, our results suggest that exposure to OA had negative effects on immune system function, increased oxygenic stress, and disrupted metabolism of bay scallops.

  17. Genomics Study of the Exposure Effect of Gymnodinium catenatum, a Paralyzing Toxin Producer, on Crassostrea gigas' Defense System and Detoxification Genes

    PubMed Central

    García-Lagunas, Norma; Romero-Geraldo, Reyna; Hernández-Saavedra, Norma Y.

    2013-01-01

    Background Crassostrea gigas accumulates paralytic shellfish toxins (PST) associated with red tide species as Gymnodinium catenatum. Previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in C. gigas stress response. Principal Findings We found that 24 h feeding on toxic dinoflagellate cells (acute exposure) induced a significant decrease in clearance rate and expression level changes of the genes involved in antioxidant defense (copper/zinc superoxide dismutase, Cu/Zn-SOD), cell detoxification (glutathione S-transferase, GST and cytochrome P450, CPY450), intermediate immune response activation (lipopolysaccharide and beta glucan binding protein, LGBP), and stress responses (glutamine synthetase, GS) in Pacific oysters compared to the effects with the non-toxic microalga Isochrysis galbana. A sub-chronic exposure feeding on toxic dinoflagellate cells for seven and fourteen days (30×103 cells mL−1) showed higher gene expression levels. A significant increase was observed in Cu/Zn-SOD, GST, and LGBP at day 7 and a major increase in GS and CPY450 at day 14. We also observed that oysters fed only with G. catenatum (3×103 cells mL−1) produced a significant increase on the transcription level than in a mixed diet (3×103 cells mL−1 of G. catenatum+0.75×106 cells mL−1 I. galbana) in all the analyzed genes. Conclusions Our results provide gene expression data of PST producer dinoflagellate G. catenatum toxic effects on C. gigas, a commercially important bivalve. Over expressed genes indicate the activation of a potent protective mechanism, whose response depends on both cell concentration and exposure time against these toxic microalgae. Given the importance of dinoflagellate blooms in coastal environments, these results provide a more comprehensive overview of how oysters respond to stress generated by

  18. Toxins of filamentous fungi.

    PubMed

    Bhatnagar, Deepak; Yu, Jiujiang; Ehrlich, Kenneth C

    2002-01-01

    Mycotoxins are low-molecular-weight secondary metabolites of fungi. The most significant mycotoxins are contaminants of agricultural commodities, foods and feeds. Fungi that produce these toxins do so both prior to harvest and during storage. Although contamination of commodities by toxigenic fungi occurs frequently in areas with a hot and humid climate (i.e. conditions favorable for fungal growth), they can also be found in temperate conditions. Production of mycotoxins is dependent upon the type of producing fungus and environmental conditions such as the substrate, water activity (moisture and relative humidity), duration of exposure to stress conditions and microbial, insect or other animal interactions. Although outbreaks of mycotoxicoses in humans have been documented, several of these have not been well characterized, neither has a direct correlation between the mycotoxin and resulting toxic effect been well established in vivo. Even though the specific modes of action of most of the toxins are not well established, acute and chronic effects in prokaryotic and eukaryotic systems, including humans have been reported. The toxicity of the mycotoxins varies considerably with the toxin, the animal species exposed to it, and the extent of exposure, age and nutritional status. Most of the toxic effects of mycotoxins are limited to specific organs, but several mycotoxins affect many organs. Induction of cancer by some mycotoxins is a major concern as a chronic effect of these toxins. It is nearly impossible to eliminate mycotoxins from the foods and feed in spite of the regulatory efforts at the national and international levels to remove the contaminated commodities. This is because mycotoxins are highly stable compounds, the producing fungi are ubiquitous, and food contamination can occur both before and after harvest. Nevertheless, good farm management practices and adequate storage facilities minimize the toxin contamination problems. Current research is

  19. Pertussis toxin

    SciTech Connect

    Sekura, R.D.; Moss, J.; Vaughan, M.

    1985-01-01

    This book contains 13 selections. Some of the titles are: Genetic and Functional Studies of Pertussis Toxin Substrates; Effect of Pertussis Toxin on the Hormonal Responsiveness of Different Tissues; Extracellular Adenylate Cyclase of Bordetella pertussis; and GTP-Regulatory Proteins are Introcellular Messagers: A Model for Hormone Action.

  20. Nicotine, Carcinogen, and Toxin Exposure in Long-Term E-Cigarette and Nicotine Replacement Therapy Users: A Cross-sectional Study.

    PubMed

    Shahab, Lion; Goniewicz, Maciej L; Blount, Benjamin C; Brown, Jamie; McNeill, Ann; Alwis, K Udeni; Feng, June; Wang, Lanqing; West, Robert

    2017-03-21

    Given the rapid increase in the popularity of e-cigarettes and the paucity of associated longitudinal health-related data, the need to assess the potential risks of long-term use is essential. To compare exposure to nicotine, tobacco-related carcinogens, and toxins among smokers of combustible cigarettes only, former smokers with long-term e-cigarette use only, former smokers with long-term nicotine replacement therapy (NRT) use only, long-term dual users of both combustible cigarettes and e-cigarettes, and long-term users of both combustible cigarettes and NRT. Cross-sectional study. United Kingdom. The following 5 groups were purposively recruited: combustible cigarette-only users, former smokers with long-term (≥6 months) e-cigarette-only or NRT-only use, and long-term dual combustible cigarette-e-cigarette or combustible cigarette-NRT users (n = 36 to 37 per group; total n = 181). Sociodemographic and smoking characteristics were assessed. Participants provided urine and saliva samples and were analyzed for biomarkers of nicotine, tobacco-specific N-nitrosamines (TSNAs), and volatile organic compounds (VOCs). After confounders were controlled for, no clear between-group differences in salivary or urinary biomarkers of nicotine intake were found. The e-cigarette-only and NRT-only users had significantly lower metabolite levels for TSNAs (including the carcinogenic metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol [NNAL]) and VOCs (including metabolites of the toxins acrolein; acrylamide; acrylonitrile; 1,3-butadiene; and ethylene oxide) than combustible cigarette-only, dual combustible cigarette-e-cigarette, or dual combustible cigarette-NRT users. The e-cigarette-only users had significantly lower NNAL levels than all other groups. Combustible cigarette-only, dual combustible cigarette-NRT, and dual combustible cigarette-e-cigarette users had largely similar levels of TSNA and VOC metabolites. Cross-sectional design with self-selected sample. Former

  1. Algal biofuels from wastewater treatment high rate algal ponds.

    PubMed

    Craggs, R J; Heubeck, S; Lundquist, T J; Benemann, J R

    2011-01-01

    This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (∼10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (∼30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO(2) has, under suitable climatic conditions, the potential to double production (to ∼60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest.

  2. Cyanobacteria toxins in the Salton Sea

    PubMed Central

    Carmichael, Wayne W; Li, RenHui

    2006-01-01

    Background The Salton Sea (SS) is the largest inland body of water in California: surface area 980 km2, volume 7.3 million acre-feet, 58 km long, 14–22 km wide, maximum depth 15 m. Located in the southeastern Sonoran desert of California, it is 85 m below sea level at its lowest point. It was formed between 1905 and 1907 from heavy river flows of the Colorado River. Since its formation, it has attracted both people and wildlife, including flocks of migratory birds that have made the Salton Sea a critical stopover on the Pacific flyway. Over the past 15 years wintering populations of eared grebe (Podiceps nigricollis) at the Salton Sea, have experienced over 200,000 mortalities. The cause of these large die-offs remains unknown. The unique environmental conditions of the Salton Sea, including salinities from brackish freshwater at river inlets to hypersaline conditions, extreme daily summer temperatures (>38°C), and high nutrient loading from rivers and agricultural drainage favor eutrophic conditions that encourage algal blooms throughout the year. A significant component of these algal blooms are the prokaryotic group – the Cyanophyta or blue-green algae (also called Cyanobacteria). Since many Cyanobacteria produce toxins (the cyanotoxins) it became important to evaluate their presence and to determine if they are a contributing factor in eared-grebe mortalities at the Salton Sea. Results From November 1999 to April 2001, 247 water and sediment samples were received for phytoplankton identification and cyanotoxin analyses. Immunoassay (ELISA) screening of these samples found that eighty five percent of all water samples contained low but detectable levels of the potent cyclic peptide liver toxin called microcystins. Isolation and identification of cyanobacteria isolates showed that the picoplanktonic Synechococcus and the benthic filamentous Oscillatoria were dominant. Both organisms were found to produce microcystins dominated by microcystin-LR and YR. A

  3. Female college student awareness of exposures to environmental toxins in personal care products and their effect on preconception health.

    PubMed

    Chan, Lisa M; Chalupka, Stephanie M; Barrett, Roseann

    2015-02-01

    This research study investigated college women's usage of personal care products and their views on health effects from exposures during the preconception period. Many personal care products and cosmetics contain chemical ingredients that have been known to disrupt human endocrine and neurological systems, and contribute to infertility and adverse birth outcomes. Seventy-two female college students from a single, medium-sized university campus completed a researcher-developed questionnaire. Findings provide insight into the daily exposures young women experience during their reproductive years. Results can inform occupational and environmental health nurses about the personal daily exposures of young women when conducting risk assessments in the workplace or at a school, and can aid in developing interventions that support the environmental health of employees or future employees. © 2015 The Author(s).

  4. Effects of algal-derived carbon on sediment methane production in a eutrophic Ohio reservoir

    EPA Science Inventory

    Nutrient loading is known to have adverse consequences for aquatic ecosystems, particularly in the form of algal blooms that may result. These blooms pose problems for humans and wildlife, including harmful toxin release, aquatic hypoxia and increased costs for water treatment. A...

  5. THE TRPV1 RECEPTOR: THE INTERAGENCY, INTERNATION SYMPOSIUM ON CYANOBACTERIAL HARMFUL ALGAL BLOOMS.

    EPA Science Inventory

    Background and Significance

    Evidence indicates that the frequency of occurrence of cyanobacterial harmful algal blooms (CHABs) is increasing in spatial and temporal extent in the US and worldwide. Cyanotoxins are among the most potent toxins known, causing death through ...

  6. THE TRPV1 RECEPTOR: THE INTERAGENCY, INTERNATION SYMPOSIUM ON CYANOBACTERIAL HARMFUL ALGAL BLOOMS.

    EPA Science Inventory

    Background and Significance

    Evidence indicates that the frequency of occurrence of cyanobacterial harmful algal blooms (CHABs) is increasing in spatial and temporal extent in the US and worldwide. Cyanotoxins are among the most potent toxins known, causing death through ...

  7. Effects of algal-derived carbon on sediment methane production in a eutrophic Ohio reservoir

    EPA Science Inventory

    Nutrient loading is known to have adverse consequences for aquatic ecosystems, particularly in the form of algal blooms that may result. These blooms pose problems for humans and wildlife, including harmful toxin release, aquatic hypoxia and increased costs for water treatment. A...

  8. Naturally Occurring Food Toxins

    PubMed Central

    Dolan, Laurie C.; Matulka, Ray A.; Burdock, George A.

    2010-01-01

    Although many foods contain toxins as a naturally-occurring constituent or, are formed as the result of handling or processing, the incidence of adverse reactions to food is relatively low. The low incidence of adverse effects is the result of some pragmatic solutions by the US Food and Drug Administration (FDA) and other regulatory agencies through the creative use of specifications, action levels, tolerances, warning labels and prohibitions. Manufacturers have also played a role by setting limits on certain substances and developing mitigation procedures for process-induced toxins. Regardless of measures taken by regulators and food producers to protect consumers from natural food toxins, consumption of small levels of these materials is unavoidable. Although the risk for toxicity due to consumption of food toxins is fairly low, there is always the possibility of toxicity due to contamination, overconsumption, allergy or an unpredictable idiosyncratic response. The purpose of this review is to provide a toxicological and regulatory overview of some of the toxins present in some commonly consumed foods, and where possible, discuss the steps that have been taken to reduce consumer exposure, many of which are possible because of the unique process of food regulation in the United States. PMID:22069686

  9. Naturally occurring food toxins.

    PubMed

    Dolan, Laurie C; Matulka, Ray A; Burdock, George A

    2010-09-01

    Although many foods contain toxins as a naturally-occurring constituent or, are formed as the result of handling or processing, the incidence of adverse reactions to food is relatively low. The low incidence of adverse effects is the result of some pragmatic solutions by the US Food and Drug Administration (FDA) and other regulatory agencies through the creative use of specifications, action levels, tolerances, warning labels and prohibitions. Manufacturers have also played a role by setting limits on certain substances and developing mitigation procedures for process-induced toxins. Regardless of measures taken by regulators and food producers to protect consumers from natural food toxins, consumption of small levels of these materials is unavoidable. Although the risk for toxicity due to consumption of food toxins is fairly low, there is always the possibility of toxicity due to contamination, overconsumption, allergy or an unpredictable idiosyncratic response. The purpose of this review is to provide a toxicological and regulatory overview of some of the toxins present in some commonly consumed foods, and where possible, discuss the steps that have been taken to reduce consumer exposure, many of which are possible because of the unique process of food regulation in the United States.

  10. Detecting exposure to environmental organic toxins in individual cells: towards development of a micro-fabricated device

    SciTech Connect

    Holman, Hoi-Ying N.; Zhang, Miqin; Goth-Goldstein, Regine; Martin, Michael C.; Russell, Marion; McKinney, Wayne R.; Ferrari, Mauro; Hunter-Cevera, Jennie C.

    1999-01-10

    A new method is being developed to quickly screen for the human exposure potential to polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs). The development involves two key elements: identifying suitable signals that represent intracellular changes that are specific to PAH and OC exposure, and constructing a device to guide the biological cell growth so that signals from individual cells are consistent and reproducible. We are completing the identification of suitable signals by using synchrotron radiation-based (SR) Fourier-transform infrared (FTIR) spectromicroscopy in the mid-infrared region (4000-400 cm-1). Distinct changes have been observed in the IR spectra after treatment of human cells in culture medium with PAHs and OCs. The potential use of this method for detecting exposure to PAHs and OCs has been tested and compared to a reverse transcription polymerase chain reaction (RT-PCR) assay that quantifies increased expression of the CYP1A1 gene in response to exposu re to PAHs or OCs.

  11. Climate Change and Algal Blooms =

    NASA Astrophysics Data System (ADS)

    Lin, Shengpan

    Algal blooms are new emerging hazards that have had important social impacts in recent years. However, it was not very clear whether future climate change causing warming waters and stronger storm events would exacerbate the algal bloom problem. The goal of this dissertation was to evaluate the sensitivity of algal biomass to climate change in the continental United States. Long-term large-scale observations of algal biomass in inland lakes are challenging, but are necessary to relate climate change to algal blooms. To get observations at this scale, this dissertation applied machine-learning algorithms including boosted regression trees (BRT) in remote sensing of chlorophyll-a with Landsat TM/ETM+. The results show that the BRT algorithm improved model accuracy by 15%, compared to traditional linear regression. The remote sensing model explained 46% of the total variance of the ground-measured chlorophyll- a in the first National Lake Assessment conducted by the US Environmental Protection Agency. That accuracy was ecologically meaningful to study climate change impacts on algal blooms. Moreover, the BRT algorithm for chlorophyll- a would not have systematic bias that is introduced by sediments and colored dissolved organic matter, both of which might change concurrently with climate change and algal blooms. This dissertation shows that the existing atmospheric corrections for Landsat TM/ETM+ imagery might not be good enough to improve the remote sensing of chlorophyll-a in inland lakes. After deriving long-term algal biomass estimates from Landsat TM/ETM+, time series analysis was used to study the relations of climate change and algal biomass in four Missouri reservoirs. The results show that neither temperature nor precipitation was the only factor that controlled temporal variation of algal biomass. Different reservoirs, even different zones within the same reservoir, responded differently to temperature and precipitation changes. These findings were further

  12. Collection and conversion of algal lipid

    NASA Astrophysics Data System (ADS)

    Lin, Ching-Chieh

    Sustainable economic activities mandate a significant replacement of fossil energy by renewable forms. Algae-derived biofuels are increasingly seen as an alternative source of energy with potential to supplement the world's ever increasing demand. Our primary objective is, once the algae were cultivated, to eliminate or make more efficient energy-intensive processing steps of collection, drying, grinding, and solvent extraction prior to conversion. To overcome the processing barrier, we propose to streamline from cultivated algae to biodiesel via algal biomass collection by sand filtration, cell rupturing with ozone, and immediate transesterification. To collect the algal biomass, the specific Chlorococcum aquaticum suspension was acidified to pH 3.3 to promote agglomeration prior to sand filtration. The algae-loaded filter bed was drained of free water and added with methanol and ozonated for 2 min to rupture cell membrane to accelerate release of the cellular contents. The methanol solution now containing the dissolved lipid product was collected by draining, while the filter bed was regenerated by further ozonation when needed. The results showed 95% collection of the algal biomass from the suspension and a 16% yield of lipid from the algae, as well as restoration of filtration velocity of the sand bed via ozonation. The results further showed increased lipid yield upon cell rupturing and transesterified products composed entirely of fatty acid methyl ester (FAME) compounds, demonstrating that the rupture and transesterification processes could proceed consecutively in the same medium, requiring no separate steps of drying, extraction, and conversion. The FAME products from algae without exposure to ozone were mainly of 16 to 18 carbons containing up to 3 double bonds, while those from algae having been ozonated were smaller, highly saturated hydrocarbons. The new technique streamlines individual steps from cultivated algal lipid to transesterified products and

  13. Occurrence of Harmful Algal Species and Shellfish Toxicity in Sardinia (Italy)

    PubMed Central

    Bazzoni, Anna Maria; Mudadu, Alessandro Graziano; Lorenzoni, Giuseppa; Arras, Igor; Lugliè, Antonella; Vivaldi, Barbara; Cicotelli, Valentina; Sanna, Giovanna; Tedde, Giuseppe; Ledda, Salvatore; Alesso, Enrico; Marongiu, Edoardo; Virgilio, Sebastiano

    2016-01-01

    Sardinia (Italy, north-western Mediterranean) is a commercially important producer of edible bivalve molluscs. Since the early 2000s, it was subjected to recurring cases of mussel farm closures due to toxic algal poison. Here, we present the studies on toxin concentrations and the associated potentially toxic phytoplankton distribution and abundances carried out by a regular monitoring programme in Sardinian shellfish areas, from January to May 2015. Diarrheic shellfish poisoning (DSP) toxins were detected in several bivalve molluscs samples, while paralytic shellfish poisoning (PSP) and paralytic shellfish poisoning toxins were present just once, without exceeding the legal limits. Potentially toxic algal species have been constantly present. Pseudo-nitzschia species were present during the entire study often with high abundances, while Dinophysis species reached high densities sporadically. Among PSP phytoplankton, only Alexandrium minutum Halim was found. The data obtained in this study showed an increase in the DSP toxicity in mussels in Sardinia. No clear relation between the occurrence of toxins in shellfish and the presence of potentially toxic algal species was found, although a slight correlation between DSP toxins and Dinophysis species could be supported. PMID:28058244

  14. Algal functional annotation tool

    SciTech Connect

    Lopez, D.; Casero, D.; Cokus, S. J.; Merchant, S. S.; Pellegrini, M.

    2012-07-01

    The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG pathway maps and batch gene identifier conversion.

  15. Continuous real-time in vivo measurement of cerebral nitric oxide supports theoretical predictions of an irreversible switching in cerebral ROS after sufficient exposure to external toxins.

    PubMed

    Finnerty, Niall J; O'Riordan, Saidhbhe L; Lowry, John P; Cloutier, Mathieu; Wellstead, Peter

    2013-01-01

    Mathematical models of the interactions between alphasynuclein (αS) and reactive oxygen species (ROS) predict a systematic and irreversible switching to damagingly high levels of ROS after sufficient exposure to risk factors associated with Parkinson's disease (PD). We tested this prediction by continuously monitoring real-time changes in neurochemical levels over periods of several days in animals exposed to a toxin known to cause Parkinsonian symptoms. Nitric oxide (NO) sensors were implanted in the brains of freely moving rats and the NO levels continuously recorded while the animals were exposed to paraquat (PQ) injections of various amounts and frequencies. Long-term, real-time measurement of NO in a cohort of animals showed systematic switching in levels when PQ injections of sufficient size and frequency were administered. The experimental observations of changes in NO imply a corresponding switching in endogenous ROS levels and support theoretical predictions of an irreversible change to damagingly high levels of endogenous ROS when PD risks are sufficiently large. Our current results only consider one form of PD risk, however, we are sufficiently confident in them to conclude that: (i) continuous long-term measurement of neurochemical dynamics provide a novel way to measure the temporal change and system dynamics which determine Parkinsonian damage, and (ii) the bistable feedback switching predicted by mathematical modelling seems to exist and that a deeper analysis of its characteristics would provide a way of understanding the pathogenic mechanisms that initiate Parkinsonian cell damage.

  16. Influence of Exposure to Single versus Multiple Toxins of Bacillus thuringiensis subsp. israelensis on Development of Resistance in the Mosquito Culex quinquefasciatus (Diptera: Culicidae)

    PubMed Central

    Georghiou, G. P.; Wirth, M. C.

    1997-01-01

    The impending widespread use of transgenic crop plants encoding a single insecticidal toxin protein of Bacillus thuringiensis has focused attention on the perceived risk of rapid selection of resistance in target insects. We have used Bacillus thuringiensis subsp. israelensis toxins as a model system and determined the speed and magnitude of evolution of resistance in colonies of the mosquito Culex quinquefasciatus during selection for 28 consecutive generations with single or multiple toxins. The parental strain was synthesized by combining approximately 500 larvae from each of 19 field collections obtained from the states of California, Oregon, Louisiana, and Tennessee. At least 10,000 larvae were selected in each generation of each line at an average mortality level of 84%. The susceptibilities of the parental and selected lines were compared in parallel tests in every third generation by using fresh suspensions of toxin powders. The normal toxin complement of B. thuringiensis subsp. israelensis consists of four toxins, CryIVA, CryIVB, CryIVD, and CytA. Resistance became evident first in the line that was selected with a single toxin (CryIVD), attaining the highest level (resistance ratio [RR], >913 at 95% lethal concentration) by generation F(inf28) when the study was completed. Resistance evolved more slowly and to a lower level (RR, >122 by F(inf25)) in the line selected with two toxins (CryIVA+CryIVB) and lower still (RR, 91 by F(inf28)) in the line selected with three toxins (CryIVA+CryIVB+ CryIVD). Resistance was remarkably low (RR, 3.2) in the line selected with all four toxins. The results reveal the importance of the full complement of toxins found in natural populations of B. thuringiensis subsp. israelensis as an effective approach to resistance management. PMID:16535542

  17. Algal Biofuels; Algal Biofuels R&D at NREL (Brochure)

    SciTech Connect

    Not Available

    2010-09-01

    An overview of NREL's algal biofuels projects, including U.S. Department of Energy-funded work, projects with U.S. and international partners, and Laboratory Directed Research and Development projects.

  18. High resolution metabolite imaging in the hippocampus following neonatal exposure to the environmental toxin BMAA using ToF-SIMS.

    PubMed

    Hanrieder, Jörg; Gerber, Lorenz; Persson Sandelius, Åsa; Brittebo, Eva B; Ewing, Andrew G; Karlsson, Oskar

    2014-07-16

    The environmental neurotoxin β-N-methylamino-L-alanine (BMAA) is suggested to be linked with neurodegenerative disease. In a rat model, neonatal exposure to BMAA induced selective uptake in the hippocampus and caused cell loss, mineralization and astrogliosis as well as learning and memory impairments in adulthood. Moreover, neonatal exposure resulted in increased protein ubiquitination in the cornus ammonis 1 (CA1) region of the adult hippocampus indicating that BMAA may induce protein aggregation. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) based imaging is a powerful technology for spatial profiling of small molecular weight compounds in biological tissues with high chemical specificity and high spatial resolution. The aim of this study was to characterize neurochemical changes in the hippocampus of six month-old rats treated neonatally (postnatal days 9-10) with BMAA. Multivariate data analysis of whole section ToF-SIMS scans was performed to delineate anatomical regions of interest based on their chemical distribution pattern. Further analysis of spectral data obtained from the outlined anatomical regions, including CA1 and dentate gyrus (DG) revealed BMAA-induced long-term changes. Increased levels of phospholipids and protein fragments in the histopathologically altered CA1 region as well as phosphate depletion in the DG were observed. Moreover, high resolution SIMS imaging revealed a specific localization of phosphatidylcholine lipids, protein signals and potassium in the histopathologically altered CA1. These findings demonstrate that ToF-SIMS based imaging is a powerful approach for probing biochemical changes in situ and might serve as promising technique for investigating neurotoxin-induced brain pathology.

  19. High Resolution Metabolite Imaging in the Hippocampus Following Neonatal Exposure to the Environmental Toxin BMAA Using ToF-SIMS

    PubMed Central

    2014-01-01

    The environmental neurotoxin β-N-methylamino-l-alanine (BMAA) is suggested to be linked with neurodegenerative disease. In a rat model, neonatal exposure to BMAA induced selective uptake in the hippocampus and caused cell loss, mineralization and astrogliosis as well as learning and memory impairments in adulthood. Moreover, neonatal exposure resulted in increased protein ubiquitination in the cornus ammonis 1 (CA1) region of the adult hippocampus indicating that BMAA may induce protein aggregation. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) based imaging is a powerful technology for spatial profiling of small molecular weight compounds in biological tissues with high chemical specificity and high spatial resolution. The aim of this study was to characterize neurochemical changes in the hippocampus of six month-old rats treated neonatally (postnatal days 9–10) with BMAA. Multivariate data analysis of whole section ToF-SIMS scans was performed to delineate anatomical regions of interest based on their chemical distribution pattern. Further analysis of spectral data obtained from the outlined anatomical regions, including CA1 and dentate gyrus (DG) revealed BMAA-induced long-term changes. Increased levels of phospholipids and protein fragments in the histopathologically altered CA1 region as well as phosphate depletion in the DG were observed. Moreover, high resolution SIMS imaging revealed a specific localization of phosphatidylcholine lipids, protein signals and potassium in the histopathologically altered CA1. These findings demonstrate that ToF-SIMS based imaging is a powerful approach for probing biochemical changes in situ and might serve as promising technique for investigating neurotoxin-induced brain pathology. PMID:24779349

  20. Fueling Future with Algal Genomics

    SciTech Connect

    Grigoriev, Igor

    2012-07-05

    Algae constitute a major component of fundamental eukaryotic diversity, play profound roles in the carbon cycle, and are prominent candidates for biofuel production. The US Department of Energy Joint Genome Institute (JGI) is leading the world in algal genome sequencing (http://jgi.doe.gov/Algae) and contributes of the algal genome projects worldwide (GOLD database, 2012). The sequenced algal genomes offer catalogs of genes, networks, and pathways. The sequenced first of its kind genomes of a haptophyte E.huxleyii, chlorarachniophyte B.natans, and cryptophyte G.theta fill the gaps in the eukaryotic tree of life and carry unique genes and pathways as well as molecular fossils of secondary endosymbiosis. Natural adaptation to conditions critical for industrial production is encoded in algal genomes, for example, growth of A.anophagefferens at very high cell densities during the harmful algae blooms or a global distribution across diverse environments of E.huxleyii, able to live on sparse nutrients due to its expanded pan-genome. Communications and signaling pathways can be derived from simple symbiotic systems like lichens or complex marine algae metagenomes. Collectively these datasets derived from algal genomics contribute to building a comprehensive parts list essential for algal biofuel development.

  1. Simultaneous removal of harmful algal blooms and microcystins using microorganism- and chitosan-modified local soil.

    PubMed

    Li, Hong; Pan, Gang

    2015-05-19

    Cyanobacterial harmful algal blooms (cyano-HAB) and microcystins (MCs) can cause a potential threat to public health. Here, a method for simultaneous removal of cyano-HAB and MCs was developed using chitosan-modified local soil (MLS) flocculation plus microorganism-modified soil capping. The experiment was conducted in simulated columns containing algal water collected from Lake Taihu (China). More than 90% of algal cells and intracellular MCs were flocculated and removed from water using chitosan-MLS and the sunken flocs were treated by different capping materials including Pseudomonas sp. An18 modified local soil. During 40 days of incubation, dissolved MC-LR and MC-RR showed 10-fold increase in the flocculation-only system. The increase of MC-LR and MC-RR in water was reduced by 30 and 70% in soil capping treatments; however, the total content of MCs in the sediment-water column remained similar to that in the control and flocculation only systems. In contrast, both dissolved MCs and total MCs were reduced by 90% in Pseudomonas sp. An18 modified soil capping treatment. The high performance of toxin decomposition was due to the combined effects of flocculation and MC-degrading bacteria that embedded in the capping material, which prevents dilution of bacteria biomass, concentrates algal cells, confines released toxins, and enhances toxin biodegradation.

  2. Botulinum Toxin for Rhinitis.

    PubMed

    Ozcan, Cengiz; Ismi, Onur

    2016-08-01

    Rhinitis is a common clinical entity. Besides nasal obstruction, itching, and sneezing, one of the most important symptoms of rhinitis is nasal hypersecretion produced by nasal glands and exudate from the nasal vascular bed. Allergic rhinitis is an IgE-mediated inflammatory reaction of nasal mucosa after exposure to environmental allergens. Idiopathic rhinitis describes rhinitis symptoms that occur after non-allergic, noninfectious irritants. Specific allergen avoidance, topical nasal decongestants, nasal corticosteroids, immunotherapy, and sinonasal surgery are the main treatment options. Because the current treatment modalities are not enough for reducing rhinorrhea in some patients, novel treatment options are required to solve this problem. Botulinum toxin is an exotoxin generated by Clostridium botulinum. It disturbs the signal transmission at the neuromuscular and neuroglandular junction by inhibiting the acetylcholine release from the presynaptic nerve terminal. It has been widely used in neuromuscular, hypersecretory, and autonomic nerve system disorders. There have been a lot of published articles concerning the effect of this toxin on rhinitis symptoms. Based on the results of these reports, intranasal botulinum toxin A administration appears to be a safe and effective treatment method for decreasing rhinitis symptoms in rhinitis patients with a long-lasting effect. Botulinum toxin type A will be a good treatment option for the chronic rhinitis patients who are resistant to other treatment methods.

  3. Institutional review board challenges related to community-based participatory research on human exposure to environmental toxins: A case study

    PubMed Central

    2010-01-01

    Background We report on the challenges of obtaining Institutional Review Board (IRB) coverage for a community-based participatory research (CBPR) environmental justice project, which involved reporting biomonitoring and household exposure results to participants, and included lay participation in research. Methods We draw on our experiences guiding a multi-partner CBPR project through university and state Institutional Review Board reviews, and other CBPR colleagues' written accounts and conference presentations and discussions. We also interviewed academics involved in CBPR to learn of their challenges with Institutional Review Boards. Results We found that Institutional Review Boards are generally unfamiliar with CBPR, reluctant to oversee community partners, and resistant to ongoing researcher-participant interaction. Institutional Review Boards sometimes unintentionally violate the very principles of beneficence and justice which they are supposed to uphold. For example, some Institutional Review Boards refuse to allow report-back of individual data to participants, which contradicts the CBPR principles that guide a growing number of projects. This causes significant delays and may divert research and dissemination efforts. Our extensive education of our university Institutional Review Board convinced them to provide human subjects protection coverage for two community-based organizations in our partnership. Conclusions IRBs and funders should develop clear, routine review guidelines that respect the unique qualities of CBPR, while researchers and community partners can educate IRB staff and board members about the objectives, ethical frameworks, and research methods of CBPR. These strategies can better protect research participants from the harm of unnecessary delays and exclusion from the research process, while facilitating the ethical communication of study results to participants and communities. PMID:20637068

  4. [Shiga toxin and tetanus toxin as a potential biologic weapon].

    PubMed

    Toczyska, Izabela; Płusa, Tadeusz

    2015-09-01

    Toxins produced by the bacteria are of particular interest as potential cargo combat possible for use in a terrorist attack or war. Shiga toxin is usually produced by shiga toxigenic strains of Escherichia coli (STEC - shigatoxigenic Escherichia coli). To infection occurs mostly after eating contaminated beef. Clinical syndromes associated with Shiga toxin diarrhea, hemorrhagic colitis, hemolytic uremic syndrome (HUS - hemolytic uremic syndrome) or thrombotic thrombocytopenic purpura. Treatment is symptomatic. In HUS, in which mortality during an epidemic reaches 20%, extending the kidney injury dialysis may be necessary. Exposure to tetanus toxin produced by Clostridium tetani, resulting in the most generalized tetanus, characterized by increased muscle tension and painful contractions of individual muscle groups. In the treatment beyond symptomatic behavior (among others spasticity medications, anticonvulsants, muscle relaxants) is used tetanus antitoxin and antibiotics (metronidazole choice). A common complication is acute respiratory failure - then it is necessary to implement mechanical ventilation. © 2015 MEDPRESS.

  5. Effects of In Vitro Exposure to Diarrheic Toxin Producer Prorocentrum lima on Gene Expressions Related to Cell Cycle Regulation and Immune Response in Crassostrea gigas

    PubMed Central

    de Jesús Romero-Geraldo, Reyna; García-Lagunas, Norma; Hernández-Saavedra, Norma Yolanda

    2014-01-01

    Background Crassostrea gigas accumulates diarrheic shellfish toxins (DSP) associated to Prorocentrum lima of which Okadaic acid (OA) causes specific inhibitions of serine and threonine phosphatases 1 and 2A. Its toxic effects have been extensively reported in bivalve mollusks at cellular and physiological levels, but genomic approaches have been scarcely studied. Methodology/Principal Findings Acute and sub-chronic exposure effects of P. lima were investigated on farmed juvenile C. gigas (3–5 mm). The Pacific oysters were fed with three dinoflagellate concentrations: 0.3, 3, and 30×103 cells mL−1 along with a nontoxic control diet of Isochrysis galbana. The effects of P. lima on C. gigas were followed by analyzing expression levels of a total of four genes, three involved in cell cycle regulation and one in immune response by polymerase chain reaction and real time quantitative PCR, where changes in time and cell concentration were found. The highest expression levels were found in oysters fed 3×103 cells mL−1 at 168 h for the cycle regulator p21 protein (9 fold), chromatin assembly factor 1 p55 subunit (8 fold), elongation factor 2 (2 fold), and lipopolysaccharide/β-1, 3 glucan binding protein (13 fold above base line). Additionally, the transcript level of all the genes decreased in oysters fed wich the mixed diet 30×103 cells mL−1 of dinoflagellate after 72 h and was lowest in the chromatin assembly factor 1 p55 subunit (0.9 fold below baseline). Conclusions On C. gigas the whole cell ingestion of P lima caused a clear mRNA modulation expression of the genes involved in cell cycle regulation and immune system. Over-expression could be related to DNA damage, disturbances in cell cycle continuity, probably a genotoxic effect, as well as an activation of its innate immune system as first line of defense. PMID:24825133

  6. Copepods induce paralytic shellfish toxin production in marine dinoflagellates

    PubMed Central

    Selander, Erik; Thor, Peter; Toth, Gunilla; Pavia, Henrik

    2006-01-01

    Among the thousands of unicellular phytoplankton species described in the sea, some frequently occurring and bloom-forming marine dinoflagellates are known to produce the potent neurotoxins causing paralytic shellfish poisoning. The natural function of these toxins is not clear, although they have been hypothesized to act as a chemical defence towards grazers. Here, we show that waterborne cues from the copepod Acartia tonsa induce paralytic shellfish toxin (PST) production in the harmful algal bloom-forming dinoflagellate Alexandrium minutum. Induced A. minutum contained up to 2.5 times more toxins than controls and was more resistant to further copepod grazing. Ingestion of non-toxic alternative prey was not affected by the presence of induced A. minutum. The ability of A. minutum to sense and respond to the presence of grazers by increased PST production and increased resistance to grazing may facilitate the formation of harmful algal blooms in the sea. PMID:16769640

  7. Algal culture studies for CELSS

    NASA Technical Reports Server (NTRS)

    Radmer, R.; Behrens, P.; Arnett, K.; Gladue, R.; Cox, J.; Lieberman, D.

    1987-01-01

    Microalgae are well-suited as a component of a Closed Environmental Life Support System (CELSS), since they can couple the closely related functions of food production and atmospheric regeneration. The objective was to provide a basis for predicting the response of CELSS algal cultures, and thus the food supply and air regeneration system, to changes in the culture parameters. Scenedesmus growth was measured as a function of light intensity, and the spectral dependence of light absorption by the algae as well as algal respiration in the light were determined as a function of cell concentration. These results were used to test and confirm a mathematical model that describes the productivity of an algal culture in terms of the competing processes of photosynthesis and respiration. The relationship of algal productivity to cell concentration was determined at different carbon dioxide concentrations, temperatures, and light intensities. The maximum productivity achieved by an air-grown culture was found to be within 10% of the computed maximum productivity, indicating that CO2 was very efficiently removed from the gas stream by the algal culture. Measurements of biomass productivity as a function of cell concentration at different light intensities indicated that both the productivity and efficiency of light utilization were greater at higher light intensities.

  8. Fungal farmers or algal escorts: lichen adaptation from the algal perspective.

    PubMed

    Piercey-Normore, Michele D; Deduke, Christopher

    2011-09-01

    Domestication of algae by lichen-forming fungi describes the symbiotic relationship between the photosynthetic (green alga or cyanobacterium; photobiont) and fungal (mycobiont) partnership in lichen associations (Goward 1992). The algal domestication implies that the mycobiont cultivates the alga as a monoculture within its thallus, analogous to a farmer cultivating a food crop. However, the initial photobiont 'selection' by the mycobiont may be predetermined by the habitat rather than by the farmer. When the mycobiont selects a photobiont from the available photobionts within a habitat, the mycobiont may influence photobiont growth and reproduction (Ahmadjian & Jacobs 1981) only after the interaction has been initiated. The theory of ecological guilds (Rikkinen et al. 2002) proposes that habitat limits the variety of photobionts available to the fungal partner. While some studies provide evidence to support the theory of ecological guilds in cyanobacterial lichens (Rikkinen et al. 2002), other studies propose models to explain variation in symbiont combinations in green algal lichens (Ohmura et al. 2006; Piercey-Normore 2006; Yahr et al. 2006) hypothesizing the existence of such guilds. In this issue of Molecular Ecology, Peksa & Škaloud (2011) test the theory of ecological guilds and suggest a relationship between algal habitat requirements and lichen adaptation in green algal lichens of the genus Lepraria. The environmental parameters examined in this study, exposure to rainfall, altitude and substratum type, are integral to lichen biology. Lichens have a poikilohydric nature, relying on the availability of atmospheric moisture for metabolic processes. Having no known active mechanism to preserve metabolic thallus moisture in times of drought, one would expect a strong influence of the environment on symbiont adaptation to specific habitats. Adaptation to changes in substrata and its properties would be expected with the intimate contact between crustose

  9. Identifying Historical Occurrences of HABs Using Sedimentary Algal Pigments

    NASA Astrophysics Data System (ADS)

    Smoak, J. M.; Waters, M. N.

    2008-12-01

    Algal blooms are a common feature of many coastal areas. Under some environmental conditions, these develop into Harmful Algal Blooms (HABs) and present an environmental hazard and a health risk for humans and wildlife due to toxin production. While monitoring programs track the development of contemporary HABs, data are lacking for historical blooms. We use sedimentary algal pigments to identify the occurrence of Karenia Brevis (Florida Red Tide) in sediment cores collected from mangrove environments along the west coast of Florida. Karenia Brevis has a unique pigment, gyroxanthin-diester, that is routinely used to identify red tide in the water column. Gyroxanthin-diester and other carotenoid pigments associated with red tide taxa are analyzed using HPLC techniques. Identification of gyroxanthan-diester is based on comparison with HPLC analysis of gyroxanthin standard, a monoculture sample of K. Brevis and with published spectra of Gyroxanthin-diester in water samples. We track the timing of the K. Brevis using Pb-210 dating models which allows an examination over the last 100 years.

  10. Human Illnesses and Animal Deaths Associated with Freshwater Harmful Algal Blooms—Kansas

    PubMed Central

    Trevino-Garrison, Ingrid; DeMent, Jamie; Ahmed, Farah S.; Haines-Lieber, Patricia; Langer, Thomas; Ménager, Henri; Neff, Janet; van der Merwe, Deon; Carney, Edward

    2015-01-01

    Freshwater harmful algal bloom (FHAB) toxins can cause morbidity and mortality in both humans and animals, and the incidence of FHABs in the United States and Kansas has increased. In 2010, the Kansas Department of Health and Environment (KDHE) developed a FHAB policy and response plan. We describe the epidemiology of FHAB-associated morbidity and mortality in humans and animals in Kansas. Healthcare providers and veterinarians voluntarily reported FHAB-associated cases to KDHE. An investigation was initiated for each report to determine the source of exposure and to initiate public health mitigation actions. There were 38 water bodies with a confirmed FHAB in 2011. There were 34 reports of human and animal FHAB-associated health events in 2011, which included five dog deaths and hospitalization of two human case patients. Five confirmed human illnesses, two dog illnesses and five dog deaths were associated with one lake. Four human and seven dog cases were exposed to the lake after a public health alert was issued. Public health officials and FHAB partners must ensure continued awareness of the risks to the public, educate healthcare providers and veterinarians on FHAB-related health events and encourage timely reporting to public health authorities. PMID:25647780

  11. Human illnesses and animal deaths associated with freshwater harmful algal blooms-Kansas.

    PubMed

    Trevino-Garrison, Ingrid; DeMent, Jamie; Ahmed, Farah S; Haines-Lieber, Patricia; Langer, Thomas; Ménager, Henri; Neff, Janet; van der Merwe, Deon; Carney, Edward

    2015-01-30

    Freshwater harmful algal bloom (FHAB) toxins can cause morbidity and mortality in both humans and animals, and the incidence of FHABs in the United States and Kansas has increased. In 2010, the Kansas Department of Health and Environment (KDHE) developed a FHAB policy and response plan. We describe the epidemiology of FHAB-associated morbidity and mortality in humans and animals in Kansas. Healthcare providers and veterinarians voluntarily reported FHAB-associated cases to KDHE. An investigation was initiated for each report to determine the source of exposure and to initiate public health mitigation actions. There were 38 water bodies with a confirmed FHAB in 2011. There were 34 reports of human and animal FHAB-associated health events in 2011, which included five dog deaths and hospitalization of two human case patients. Five confirmed human illnesses, two dog illnesses and five dog deaths were associated with one lake. Four human and seven dog cases were exposed to the lake after a public health alert was issued. Public health officials and FHAB partners must ensure continued awareness of the risks to the public, educate healthcare providers and veterinarians on FHAB-related health events and encourage timely reporting to public health authorities.

  12. Evaluation of Harmful Algal Bloom Outreach Activities

    PubMed Central

    Fleming, Lora E.; Jerez, Eva; Stephan, Wendy Blair; Cassedy, Amy; Bean, Judy A; Reich, Andrew; Kirkpatrick, Barbara; Backer, Lorraine; Nierenberg, Kate; Watkins, Sharon; Hollenbeck, Julie; Weisman, Richard

    2007-01-01

    With an apparent increase of harmful algal blooms (HABs) worldwide, healthcare providers, public health personnel and coastal managers are struggling to provide scientifically-based appropriately-targeted HAB outreach and education. Since 1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year free Aquatic Toxins Hotline (1–888–232–8635) available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-related illness among callers are reported to the Florida Health Department. This pilot study evaluated an automated call processing menu system that allows callers to access bilingual HAB information, and to speak directly with a trained Poison Information Specialist. The majority (68%) of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials. PMID:18463727

  13. Evaluation of harmful algal bloom outreach activities.

    PubMed

    Fleming, Lora E; Jerez, Eva; Stephan, Wendy Blair; Cassedy, Amy; Bean, Judy A; Reich, Andrew; Kirkpatrick, Barbara; Backer, Lorraine; Nierenberg, Kate; Watkins, Sharon; Hollenbeck, Julie; Weisman, Richard

    2007-12-14

    With an apparent increase of harmful algal blooms (HABs) worldwide, healthcare providers, public health personnel and coastal managers are struggling to provide scientifically-based appropriately-targeted HAB outreach and education. Since 1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year free Aquatic Toxins Hotline (1-888-232-8635) available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-related illness among callers are reported to the Florida Health Department. This pilot study evaluated an automated call processing menu system that allows callers to access bilingual HAB information, and to speak directly with a trained Poison Information Specialist. The majority (68%) of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials.

  14. Sapphire Energy - Integrated Algal Biorefinery

    SciTech Connect

    White, Rebecca L.; Tyler, Mike

    2015-07-22

    Sapphire Energy, Inc. (SEI) is a leader in large-scale photosynthetic algal biomass production, with a strongly cohesive research, development, and operations program. SEI takes a multidiscipline approach to integrate lab-based strain selection, cultivation and harvest and production scale, and extraction for the production of Green Crude oil, a drop in replacement for traditional crude oil.. SEI’s technical accomplishments since 2007 have produced a multifunctional platform that can address needs for fuel, feed, and other higher value products. Figure 1 outlines SEI’s commercialization process, including Green Crude production and refinement to drop in fuel replacements. The large scale algal biomass production facility, the SEI Integrated Algal Biorefinery (IABR), was built in Luna County near Columbus, New Mexico (see fig 2). The extraction unit was located at the existing SEI facility in Las Cruces, New Mexico, approximately 95 miles from the IABR. The IABR facility was constructed on time and on budget, and the extraction unit expansion to accommodate the biomass output from the IABR was completed in October 2012. The IABR facility uses open pond cultivation with a proprietary harvesting method to produce algal biomass; this biomass is then shipped to the extraction facility for conversion to Green Crude. The operation of the IABR and the extraction facilities has demonstrated the critical integration of traditional agricultural techniques with algae cultivation knowledge for algal biomass production, and the successful conversion of the biomass to Green Crude. All primary unit operations are de-risked, and at a scale suitable for process demonstration. The results are stable, reliable, and long-term cultivation of strains for year round algal biomass production. From June 2012 to November 2014, the IABR and extraction facilities produced 524 metric tons (MT) of biomass (on a dry weight basis), and 2,587 gallons of Green Crude. Additionally, the IABR

  15. Botulinum Toxin

    DTIC Science & Technology

    2009-01-01

    1980) and the other in gibbons (Hylobates lar) (Smith et aI., 1985). In addition to nonhuman primates , most other animal species that show some...nonhuman primate species are known to be susceptible to type Cl and D toxins both in nature and as experimental models. A large natural outbreak of... primates were previously reported, one in squirrel monkeys (Saimiri sciureus) and capuchin monkeys (Cebus capucinus and Cebus olivaceus) (Smart et al

  16. Legionella Toxin.

    DTIC Science & Technology

    1981-04-29

    of a cytotoxin produced by Legionella pneumophila. Infect. Immun. 29:271-274. Fumarola, D. (1978) Legionnaires ’ disease agent and Limulus endotoxin... Legionnaires ’ disease bacterium in the AKR/J mouse. Ann. intern. Med. 90:676-679. Hedlund, K. W. and Larson, R. (1981) Legionella pneumophila toxin, isolation... Legionella Species New Name Old Name Lpneumophila Legionnaires ’ disease organism, OLDA L. bozemanil WIGA, MI 15 L. dumoffii NY 23, TEX-KL *L. micdadei

  17. Specific Caleosin/Peroxygenase and Lipoxygenase Activities Are Tissue-Differentially Expressed in Date Palm (Phoenix dactylifera L.) Seedlings and Are Further Induced Following Exposure to the Toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Hanano, Abdulsamie; Almousally, Ibrahem; Shaban, Mouhnad; Rahman, Farzana; Hassan, Mehedi; Murphy, Denis J

    2016-01-01

    Two caleosin/peroxygenase isoforms from date palm, Phoenix dactylifera L., PdCLO2 and PdCLO4, were characterized with respect to their tissue expression, subcellular localization, and oxylipin pathway substrate specificities in developing seedlings. Both PdCLO2 and PdCLO4 had peroxygenase activities that peaked at the mid-stage (radicle length of 2.5 cm) of seedling growth and were associated with the lipid droplet (LD) and microsomal fractions. Recombinant PdCLO2 and PdCLO4 proteins heterologously expressed in yeast cells were localized in both LD and microsomal fractions. Each of the purified recombinant proteins exhibited peroxygenase activity but they were catalytically distinct with respect to their specificity and product formation from fatty acid epoxide and hydroxide substrates. We recently showed that date palm CLO genes were upregulated following exposure to the potent toxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (Hanano et al., 2016), and we show here that transcripts of 9- and 13-lipoxygenase (LOX) genes were also induced by TCDD exposure. At the enzyme level, 9-LOX and 13-LOX activities were present in a range of seedling tissues and responded differently to TCDD exposure, as did the 9- and 13-fatty acid hydroperoxide reductase activities. This demonstrates that at least two branches of the oxylipin pathway are involved in responses to the environmental organic toxin, TCDD in date palm.

  18. Specific Caleosin/Peroxygenase and Lipoxygenase Activities Are Tissue-Differentially Expressed in Date Palm (Phoenix dactylifera L.) Seedlings and Are Further Induced Following Exposure to the Toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin

    PubMed Central

    Hanano, Abdulsamie; Almousally, Ibrahem; Shaban, Mouhnad; Rahman, Farzana; Hassan, Mehedi; Murphy, Denis J.

    2017-01-01

    Two caleosin/peroxygenase isoforms from date palm, Phoenix dactylifera L., PdCLO2 and PdCLO4, were characterized with respect to their tissue expression, subcellular localization, and oxylipin pathway substrate specificities in developing seedlings. Both PdCLO2 and PdCLO4 had peroxygenase activities that peaked at the mid-stage (radicle length of 2.5 cm) of seedling growth and were associated with the lipid droplet (LD) and microsomal fractions. Recombinant PdCLO2 and PdCLO4 proteins heterologously expressed in yeast cells were localized in both LD and microsomal fractions. Each of the purified recombinant proteins exhibited peroxygenase activity but they were catalytically distinct with respect to their specificity and product formation from fatty acid epoxide and hydroxide substrates. We recently showed that date palm CLO genes were upregulated following exposure to the potent toxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (Hanano et al., 2016), and we show here that transcripts of 9- and 13-lipoxygenase (LOX) genes were also induced by TCDD exposure. At the enzyme level, 9-LOX and 13-LOX activities were present in a range of seedling tissues and responded differently to TCDD exposure, as did the 9- and 13-fatty acid hydroperoxide reductase activities. This demonstrates that at least two branches of the oxylipin pathway are involved in responses to the environmental organic toxin, TCDD in date palm. PMID:28111588

  19. A Geospatial Analysis of Harmful Algal Blooms along the California Coast

    NASA Astrophysics Data System (ADS)

    Jensen, C.; Rothwell, R.; Johnson, E.; Condamoor, M.; Patil, M.; Largier, J. L.; Schmidt, C.

    2012-12-01

    Algal blooms are natural phenomena consisting of the rapid growth of phytoplankton populations. Some blooms have negative ecological or public health effects due to toxin production and removal of oxygen from the water column. In recent years, such "harmful algal blooms" (HABs) have been linked to human illness, economic loss from decreased fishing, and ecological damage related to marine life mortality as well as eutrophication. A notable HAB event occurred along the coast of northern California in August 2011, resulting in economic and ecological impacts of approximately $82 million. This was one of several algal blooms that occurred in fall 2011, with similar northward propagating algal blooms occurring in autumn of other years. Although the scale of the bloom impact is well-known, the spatial and temporal extent of the bloom boundary is still unclear. This study tracked the space-time pattern of numerous blooms during August-October 2011 using multiple NASA Earth observing systems in an effort to quantify and understand the structure of these recurrent bloom events. Aqua MODIS images were used to quantify surface chlorophyll-α levels, and thus to map the extent and development of all autumn algal blooms. The relation between sea surface temperature, ocean surface topography, and algal blooms was further explored with AVHRR and Jason-2 satellite data. A Generalized Additive Model (GAM) was used to identify the environmental factors most statistically influential in algal blooms and specifically in HAB events. Results from this study will assist California's Departments of Public Health and Fish & Game in mitigating and managing the impact of future harmful algal blooms.

  20. Effect of the endoparasite Amoebophrya sp. on toxin content and composition in the paralytic shellfish poisoning dinoflagellate Alexandrium fundyense (Dinophyceae).

    PubMed

    Kim, Sunju; Park, Myung Gil

    2016-01-01

    Members of the Amoebophrya ceratii complex are endoparasitic dinoflagellates that parasitize a number of their dinoflagellate relatives, including toxic and/or harmful algal bloom-forming species. Despite many studies on the occurrence, prevalence, biology and molecular phylogeny of Amoebophrya spp., little attention has been given to toxin dynamics of host population following parasitism. Using Amoebophrya sp. infecting the paralytic shellfish toxin (PSP)-producing dinoflagellate Alexandrium fundyense, we addressed the following questions: (1) does parasitism by Amoebophrya sp. alter toxin content and toxin profiles of the dinoflagellate A. fundyense over the infection cycle? and (2) do parasite dinospores produced at the end of the infection cycle retain host toxins and thus potentially act as a vector to convey PSP toxin through the marine microbial food-web? Toxin time-course experiments showed that the PSP toxin contents did not vary significantly over the infection cycle, but mean toxin content for infected cultures was significantly higher than that for uninfected cultures. Host toxins were not detected in the free-living, dinospore stage of the parasite. Therefore, our results indicate that Amoebophrya sp. does not function as a vector for transferring PSP toxins to higher trophic levels. Rather, Amoebophrya infections appear to play an important role in maintaining healthy ecosystems by transforming potent toxins-producing dinoflagellates into non-toxic dinospores, representing "edible food" for consumers of the marine microbial food-web during toxic algal bloom event. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Endangered North Atlantic right whales (Eubalaena glacialis) experience repeated, concurrent exposure to multiple environmental neurotoxins produced by marine algae.

    PubMed

    Doucette, Gregory J; Mikulski, Christina M; King, Kristen L; Roth, Patricia B; Wang, Zhihong; Leandro, Luis F; DeGrasse, Stacey L; White, Kevin D; De Biase, Daniela; Gillett, Roxanne M; Rolland, Rosalind M

    2012-01-01

    The western North Atlantic population of right whales (Eubalaena glacialis) is one of the most critically endangered of any whale population in the world. Among the factors considered to have potentially adverse effects on the health and reproduction of E. glacialis are biotoxins produced by certain microalgae responsible for causing harmful algal blooms. The worldwide incidence of these events has continued to increase dramatically over the past several decades and is expected to remain problematic under predicted climate change scenarios. Previous investigations have demonstrated that N. Atlantic right whales are being exposed to at least two classes of algal-produced environmental neurotoxins-paralytic shellfish toxins (PSTs) and domoic acid (DA). Our primary aims during this six-year study (2001-2006) were to assess whether the whales' exposure to these algal biotoxins occurred annually over multiple years, and to what extent individual whales were exposed repeatedly and/or concurrently to one or both toxin classes. Approximately 140 right whale fecal samples obtained across multiple habitats in the western N. Atlantic were analyzed for PSTs and DA. About 40% of these samples were attributed to individual whales in the North Atlantic Right Whale Catalog, permitting analysis of biotoxin exposure according to sex, age class, and reproductive status/history. Our findings demonstrate clearly that right whales are being exposed to both of these algal biotoxins on virtually an annual basis in multiple habitats for periods of up to six months (April through September), with similar exposure rates for females and males (PSTs: ∼70-80%; DA: ∼25-30%). Notably, only one of 14 lactating females sampled did not contain either PSTs or DA, suggesting the potential for maternal toxin transfer and possible effects on neonatal animals. Moreover, 22% of the fecal samples tested for PSTs and DA showed concurrent exposure to both neurotoxins, leading to questions of interactive

  2. Algal Systems for Hydrogen Photoproduction

    SciTech Connect

    Ghirardi, Maria L

    2015-10-08

    The National Renewable Energy Laboratory (NREL), under the guidance of Drs. Michael Seibert (retired, Fellow Emeritus) and Maria Ghirardi (Fellow), led 15 years of research addressing the issue of algal H2 photoproduction. This project resulted in greatly increased rates and yields of algal hydrogen production; increased understanding of the H2 metabolism in the green alga, Chlamydomonas reinhardtii; expanded our knowledge of other physiological aspects relevant to sustained algal photosynthetic H2 production; led to the genetic identification, cloning and manipulation of algal hydrogenase genes; and contributed to a broader, fundamental understanding of the technical and scientific challenges to improving the conversion efficiencies in order to reach the U.S. Department of Energy’s Fuel Cell Technologies Office’s targets. Some of the tangible results are: (i) 64 publications and 6 patents, (ii) international visibility to NREL, (iii) reinvigoration of national and international biohydrogen research, and (iv) research progress that helped stimulate new funding from other DOE and non-DOE programs, including the AFOSR and the DOE Office of Science.

  3. Stool C. difficile toxin

    MedlinePlus

    ... test detects harmful substances produced by the bacterium Clostridium difficile ( C difficile) . This infection is a common ... toxin; Necrotizing colitis - toxin; C difficile - toxin Images Clostridium difficile organism References Beavis KG, Charnot-Katsikas A. ...

  4. The Course of Toxicity in the Pregnant Mouse after Exposure to the Cyanobacterial Toxin, Cylindrospermopsin: Clinical Effects, Serum Chemistries, Hematology and Histopathology

    EPA Science Inventory

    Cylindrospermopsin (CYN) is a toxin produced by a wide variety of fresh water cyanobacterial species worldwide and induces significant adverse effects in both livestock and humans. This study investigated the course of CYN-induced toxicity in pregnant mice exposed during either t...

  5. The Course of Toxicity in the Pregnant Mouse after Exposure to the Cyanobacterial Toxin, Cylindrospermopsin: Clinical Effects, Serum Chemistries, Hematology and Histopathology

    EPA Science Inventory

    Cylindrospermopsin (CYN) is a toxin produced by a wide variety of fresh water cyanobacterial species worldwide and induces significant adverse effects in both livestock and humans. This study investigated the course of CYN-induced toxicity in pregnant mice exposed during either t...

  6. Effects of solar ultraviolet radiation on tropical algal communities

    SciTech Connect

    Santas, R.

    1989-01-01

    This study assessed some of the effects of solar ultraviolet (UV) radiation ion coral reef algal assemblages. The first part of the investigation was carried out under controlled laboratory conditions in the coral reef microcosm at the National Museum of Natural History in Washington, D.C., while a field counterpart was completed at the Smithsonian Institution's marine station on Grand Turk, Turks and Caicos Islands, in the eastern Caribbean. The study attempted to separate the effects of UV-A from those of UV-B. In the laboratory, algal turf assemblages exposed to simulated solar UV radiation produced 55.1% less biomass than assemblages that were not exposed to UV. Assemblages not exposed to UV were dominated by Ectocarpus rhodochondroides, whereas in the assemblage developing under high UV radiation, Enteromorpha prolifera and eventually Schizothrix calcicola dominated. Lower UV-B irradiances caused a proportional reduction in biomass production and had less pronounced effects on species composition. UV-A did not have any significant effects on either algal turf productivity or community structure. In the field, assemblages exposed to naturally occurring solar UV supported a biomass 40% lower than that of assemblages protected from UV-B exposure. Once again, UV-A did not inhibit algal turf productivity.

  7. Clostridium difficile toxin B is more potent than toxin A in damaging human colonic epithelium in vitro.

    PubMed Central

    Riegler, M; Sedivy, R; Pothoulakis, C; Hamilton, G; Zacherl, J; Bischof, G; Cosentini, E; Feil, W; Schiessel, R; LaMont, J T

    1995-01-01

    Toxin A but not toxin B, appears to mediate intestinal damage in animal models of Clostridium difficile enteritis. The purpose of this study was to investigate the electrophysiologic and morphologic effects of purified C. difficile toxins A and B on human colonic mucosa in Ussing chambers. Luminal exposure of tissues to 16-65 nM of toxin A and 0.2-29 nM of toxin B for 5 h caused dose-dependent epithelial damage. Potential difference, short-circuit current and resistance decreased by 76, 58, and 46%, respectively, with 32 nM of toxin A and by 76, 55, and 47%, respectively, with 3 nM of toxin B, when compared with baseline (P < 0.05). 3 nM of toxin A did not cause electrophysiologic changes. Permeability to [3H]mannitol increased 16-fold after exposure to 32 nM of toxin A and to 3 nM of toxin B when compared with controls (P < 0.05). Light and scanning electron microscopy after exposure to either toxin revealed patchy damage and exfoliation of superficial epithelial cells, while crypt epithelium remained intact. Fluorescent microscopy of phalloidin-stained sections showed that both toxins caused disruption and condensation of cellular F-actin. Our results demonstrate that the human colon is approximately 10 times more sensitive to the damaging effects of toxin B than toxin A, suggesting that toxin B may be more important than toxin A in the pathogenesis of C. difficile colitis in man. Images PMID:7738167

  8. Algal taxonomy forum: Algal Taxonomist, Let Serendipity Reign!

    PubMed

    Druehl, Louis

    2013-04-01

    The publication of a mini-review by Olivier De Clerck et al. in this issue of the Journal of Phycology presented an opportunity to open a dialogue on challenges faced by contemporary algal taxonomists. The Editorial Office solicited the following two additional contributions in response to De Clerck et al.'s paper; the responses were edited solely for clarity, space and format. © 2013 Phycological Society of America.

  9. Mycoplasma pneumoniae CARDS toxin elicits a functional IgE response in Balb/c mice

    PubMed Central

    Medina, Jorge L.; Brooks, Edward G.; Chaparro, Adriana

    2017-01-01

    Mycoplasma pneumoniae is strongly associated with new onset asthma and asthma exacerbations. Until recently, the molecular mechanisms utilized by M. pneumoniae to influence asthma symptoms were unknown. However, we recently reported that an ADP-ribosylating and vacuolating toxin called the Community Acquired Respiratory Distress Syndrome toxin, CARDS toxin, produced by M. pneumoniae was sufficient to promote allergic inflammation and asthma-like disease in mice. A mouse model of CARDS toxin exposure was used to evaluate total and CARDS-toxin specific serum IgE responses. Mast cell sensitization, challenge, and degranulation studies determined functionality of the CARDS toxin-specific IgE. In the current study, we report that a single mucosal exposure to CARDS toxin was sufficient to increase total serum IgE and CARDS toxin-specific IgE in mice. Mice given a second mucosal challenge of CARDS toxin responded with significant increases in total and CARDS toxin-specific IgE. CARDS toxin-specific IgE bound to an N-terminal peptide of CARDS toxin but not the C-terminal peptide. Likewise, full-length CARDS toxin and the N-terminal peptide induced mast cell degranulation. Altogether, these data demonstrate that exposure to CARDS toxin is sufficient to generate functional IgE in mice. M. pneumoniae and CARDS toxin are strongly associated with asthma exacerbations raising the possibility that the CARDS toxin-specific IgE-mast cell axis contributes to disease pathogenesis. PMID:28199385

  10. Mycoplasma pneumoniae CARDS toxin elicits a functional IgE response in Balb/c mice.

    PubMed

    Medina, Jorge L; Brooks, Edward G; Chaparro, Adriana; Dube, Peter H

    2017-01-01

    Mycoplasma pneumoniae is strongly associated with new onset asthma and asthma exacerbations. Until recently, the molecular mechanisms utilized by M. pneumoniae to influence asthma symptoms were unknown. However, we recently reported that an ADP-ribosylating and vacuolating toxin called the Community Acquired Respiratory Distress Syndrome toxin, CARDS toxin, produced by M. pneumoniae was sufficient to promote allergic inflammation and asthma-like disease in mice. A mouse model of CARDS toxin exposure was used to evaluate total and CARDS-toxin specific serum IgE responses. Mast cell sensitization, challenge, and degranulation studies determined functionality of the CARDS toxin-specific IgE. In the current study, we report that a single mucosal exposure to CARDS toxin was sufficient to increase total serum IgE and CARDS toxin-specific IgE in mice. Mice given a second mucosal challenge of CARDS toxin responded with significant increases in total and CARDS toxin-specific IgE. CARDS toxin-specific IgE bound to an N-terminal peptide of CARDS toxin but not the C-terminal peptide. Likewise, full-length CARDS toxin and the N-terminal peptide induced mast cell degranulation. Altogether, these data demonstrate that exposure to CARDS toxin is sufficient to generate functional IgE in mice. M. pneumoniae and CARDS toxin are strongly associated with asthma exacerbations raising the possibility that the CARDS toxin-specific IgE-mast cell axis contributes to disease pathogenesis.

  11. Harmful Algal Bloom Hotspots Really Are Hot: A Case Study from Monterey Bay, California

    NASA Astrophysics Data System (ADS)

    Kudela, R. M.; Anderson, C.; Birch, J. M.; Bowers, H.; Caron, D. A.; Chao, Y.; Doucette, G.; Farrara, J. D.; Gellene, A. G.; Negrey, K.; Howard, M. D.; Ryan, J. P.; Scholin, C. A.; Smith, J.; Sukhatme, G.

    2015-12-01

    Monterey Bay, California is one of several recognized hotspots for harmful algal blooms along the US west coast, particularly for the toxigenic diatom Pseudo-nitzschia, which produces domoic acid and is responsible for Amnesic Shellfish Poisoning. Historical observations have linked bloom activity to anomalously warm conditions with weak and sporadic upwelling. In particular, blooms appear to be associated with El Niño conditions. Monterey, as with much of the US west coast, experienced unusual warm conditions in spring and summer 2014, leading to multiple ecosystem effects including massive algal blooms, concentration of apex predators nearshore, and unusually high levels of domoic acid. As the warm anomalies continued and strengthened into 2015, Monterey (and much of the west coast) has been experiencing the largest and most toxic algal bloom recorded in the last 15 years, as well as unprecedented coccolithophore blooms associated with warm, nutrient-depleted waters. With the strengthening El Niño conditions developing in summer 2015, it is possible that 2016 will result in a third consecutive year of unusually toxic algal blooms. Using a combination of historical observations, intensive field studies, and predictive models we explore the hypothesis that these warm anomalies lead to shifts in the typical upwelling-dominated food web leading to a collapse of the ecosystem towards the coast, unusual algal blooms, and enhanced trophic transfer of toxins, resulting in magnified negative impacts to wildlife and, potentially, humans.

  12. Algal blooms and public health

    SciTech Connect

    Epstein, P.R. . Harvard Medical School)

    1993-06-01

    Alterations in coastal ecology are expanding the geographic extent, frequency, magnitude, and species complexity'' of algal blooms throughout the world, increasing the threat of fish and shellfish poisonings, anoxia in marine nurseries, and of cholera. The World Health Organization and members of the medical profession have described the potential health effects of global climate change. They warn of the consequences of increased ultraviolet-B (UV-B) rays and of warming: the possible damage to agriculture and nutrition, and the impact on habitats which may alter the distribution of vector-borne and water-based infectious diseases. Algal growth due to increased nitrogen (N) and phosphorus (P) and warming are already affecting marine microflora and aquatic plants; and there is now clear evidence that marine organisms are a reservoir for enteric pathogens. The pattern of cholera in the Western Hemisphere suggests that environmental changes have already begun to influence the epidemiology of this infectious disease. 106 refs.

  13. Algal biofuels: challenges and opportunities.

    PubMed

    Leite, Gustavo B; Abdelaziz, Ahmed E M; Hallenbeck, Patrick C

    2013-10-01

    Biodiesel production using microalgae is attractive in a number of respects. Here a number of pros and cons to using microalgae for biofuels production are reviewed. Algal cultivation can be carried out using non-arable land and non-potable water with simple nutrient supply. In addition, algal biomass productivities are much higher than those of vascular plants and the extractable content of lipids that can be usefully converted to biodiesel, triacylglycerols (TAGs) can be much higher than that of the oil seeds now used for first generation biodiesel. On the other hand, practical, cost-effective production of biofuels from microalgae requires that a number of obstacles be overcome. These include the development of low-cost, effective growth systems, efficient and energy saving harvesting techniques, and methods for oil extraction and conversion that are environmentally benign and cost-effective. Promising recent advances in these areas are highlighted.

  14. Potential natural exposure of endangered red-crowned crane (Grus japonensis) to mycotoxins aflatoxin B1, deoxynivalenol, zearalenone, T-2 toxin, and ochratoxin A*

    PubMed Central

    Liu, Da-wei; Liu, Hong-yi; Zhang, Hai-bin; Cao, Ming-chang; Sun, Yong; Wu, Wen-da; Lu, Chang-hu

    2016-01-01

    A survey was conducted to determine whether mycotoxins were present in the foods consumed by red-crowned cranes (Grus japonensis) in the Yancheng Biosphere Reserve, China. Collected in the reserve’s core, buffer, and experimental zones during overwintering periods of 2013 to 2015, a total of 113 food samples were analyzed for aflatoxin B1, deoxynivalenol, zearalenone, T-2 toxin, and ochratoxin A using high performance liquid chromatography (HPLC). The contamination incidences vary among different zones and the mycotoxins levels of different food samples also presented disparity. Average mycotoxin concentration from rice grain was greater than that from other food types. Among mycotoxin-positive samples, 59.3% were simultaneously contaminated with more than one toxin. This study demonstrated for the first time that red-crowned cranes were exposed to mycotoxins in the Yancheng Biosphere Reserve and suggested that artificial wetlands could not be considered good habitats for the birds in this reserve, especially rice fields. PMID:26834016

  15. Potential natural exposure of endangered red-crowned crane (Grus japonensis) to mycotoxins aflatoxin B1, deoxynivalenol, zearalenone, T-2 toxin, and ochratoxin A.

    PubMed

    Liu, Da-wei; Liu, Hong-yi; Zhang, Hai-bin; Cao, Ming-chang; Sun, Yong; Wu, Wen-da; Lu, Chang-hu

    2016-02-01

    A survey was conducted to determine whether mycotoxins were present in the foods consumed by red-crowned cranes (Grus japonensis) in the Yancheng Biosphere Reserve, China. Collected in the reserve's core, buffer, and experimental zones during overwintering periods of 2013 to 2015, a total of 113 food samples were analyzed for aflatoxin B1, deoxynivalenol, zearalenone, T-2 toxin, and ochratoxin A using high performance liquid chromatography (HPLC). The contamination incidences vary among different zones and the mycotoxins levels of different food samples also presented disparity. Average mycotoxin concentration from rice grain was greater than that from other food types. Among mycotoxin-positive samples, 59.3% were simultaneously contaminated with more than one toxin. This study demonstrated for the first time that red-crowned cranes were exposed to mycotoxins in the Yancheng Biosphere Reserve and suggested that artificial wetlands could not be considered good habitats for the birds in this reserve, especially rice fields.

  16. Exposure of Lycopersicon Esculentum to Microcystin-LR: Effects in the Leaf Proteome and Toxin Translocation from Water to Leaves and Fruits

    PubMed Central

    Gutiérrez-Praena, Daniel; Campos, Alexandre; Azevedo, Joana; Neves, Joana; Freitas, Marisa; Guzmán-Guillén, Remédios; Cameán, Ana María; Renaut, Jenny; Vasconcelos, Vitor

    2014-01-01

    Natural toxins such as those produced by freshwater cyanobacteria have been regarded as an emergent environmental threat. However, the impact of these water contaminants in agriculture is not yet fully understood. The aim of this work was to investigate microcystin-LR (MC-LR) toxicity in Lycopersicon esculentum and the toxin accumulation in this horticultural crop. Adult plants (2 month-old) grown in a greenhouse environment were exposed for 2 weeks to either pure MC-LR (100 μg/L) or Microcystis aeruginosa crude extracts containing 100 μg/L MC-LR. Chlorophyll fluorescence was measured, leaf proteome investigated with two-dimensional gel electrophoresis and Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF)/TOF, and toxin bioaccumulation assessed by liquid chromatography-mass spectrometry (LC-MS)/MS. Variations in several protein markers (ATP synthase subunits, Cytochrome b6-f complex iron-sulfur, oxygen-evolving enhancer proteins) highlight the decrease of the capacity of plants to synthesize ATP and to perform photosynthesis, whereas variations in other proteins (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit and ribose-5-phosphate isomerase) suggest an increase of carbon fixation and decrease of carbohydrate metabolism reactions in plants exposed to pure MC-LR and cyanobacterial extracts, respectively. MC-LR was found in roots (1635.21 μg/kg fw), green tomatoes (5.15–5.41 μg/kg fw), mature tomatoes (10.52–10.83 μg/kg fw), and leaves (12,298.18 μg/kg fw). The results raise concerns relative to food safety and point to the necessity of monitoring the bioaccumulation of water toxins in agricultural systems affected by cyanotoxin contamination. PMID:24921194

  17. Exposure of Lycopersicon esculentum to microcystin-LR: effects in the leaf proteome and toxin translocation from water to leaves and fruits.

    PubMed

    Gutiérrez-Praena, Daniel; Campos, Alexandre; Azevedo, Joana; Neves, Joana; Freitas, Marisa; Guzmán-Guillén, Remédios; Cameán, Ana María; Renaut, Jenny; Vasconcelos, Vitor

    2014-06-11

    Natural toxins such as those produced by freshwater cyanobacteria have been regarded as an emergent environmental threat. However, the impact of these water contaminants in agriculture is not yet fully understood. The aim of this work was to investigate microcystin-LR (MC-LR) toxicity in Lycopersicon esculentum and the toxin accumulation in this horticultural crop. Adult plants (2 month-old) grown in a greenhouse environment were exposed for 2 weeks to either pure MC-LR (100 μg/L) or Microcystis aeruginosa crude extracts containing 100 μg/L MC-LR. Chlorophyll fluorescence was measured, leaf proteome investigated with two-dimensional gel electrophoresis and Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF)/TOF, and toxin bioaccumulation assessed by liquid chromatography-mass spectrometry (LC-MS)/MS. Variations in several protein markers (ATP synthase subunits, Cytochrome b6-f complex iron-sulfur, oxygen-evolving enhancer proteins) highlight the decrease of the capacity of plants to synthesize ATP and to perform photosynthesis, whereas variations in other proteins (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit and ribose-5-phosphate isomerase) suggest an increase of carbon fixation and decrease of carbohydrate metabolism reactions in plants exposed to pure MC-LR and cyanobacterial extracts, respectively. MC-LR was found in roots (1635.21 μg/kg fw), green tomatoes (5.15-5.41 μg/kg fw), mature tomatoes (10.52-10.83 μg/kg fw), and leaves (12,298.18 μg/kg fw). The results raise concerns relative to food safety and point to the necessity of monitoring the bioaccumulation of water toxins in agricultural systems affected by cyanotoxin contamination.

  18. Beach-goer behavior during a retrospectively detected algal ...

    EPA Pesticide Factsheets

    Algal blooms occur among nutrient rich, warm surface waters and may adversely impact recreational beaches. During July – September 2003, a prospective study of beachgoers was conducted on weekends at a public beach on a Great Lake in the United States. We measured each beachgoer’s activity at the start and end of their beach visit and the environmental factors: water and air temperature, wind speed and wave height at the study site each day. At the time, there was no notification of algal blooms; we retrospectively evaluated the presence of algal blooms using MERIS data from the Envisat-1 satellite. A total of 2840 people participated in the study over 16 study days. The majority (55%) were female, and 751 (26%) were < 18 years of age. An algal bloom was detected retrospectively by remotely sensed satellite imagery during August 16 – 24. This peak bloom period (PB) included 4 study days. During PB study days, more study participants 226/742 (31%) reported body contact with the water compared to contact 531/2098 (25%) on non-peak days. During the 4 PB days, of the environmental factors, only mean water temperature was significantly different, 250 C vs. 230 C (p<0.05) from other days.These results suggest that beachgoer body contact with water was not deterred by the presence of an algal bloom, and that interventions to actively discourage water contact during a bloom are needed to reduce exposure to blooms. This is an abstract of a proposed presentation and

  19. Beach-goer behavior during a retrospectively detected algal ...

    EPA Pesticide Factsheets

    Algal blooms occur among nutrient rich, warm surface waters and may adversely impact recreational beaches. During July – September 2003, a prospective study of beachgoers was conducted on weekends at a public beach on a Great Lake in the United States. We measured each beachgoer’s activity at the start and end of their beach visit and the environmental factors: water and air temperature, wind speed and wave height at the study site each day. At the time, there was no notification of algal blooms; we retrospectively evaluated the presence of algal blooms using MERIS data from the Envisat-1 satellite. A total of 2840 people participated in the study over 16 study days. The majority (55%) were female, and 751 (26%) were < 18 years of age. An algal bloom was detected retrospectively by remotely sensed satellite imagery during August 16 – 24. This peak bloom period (PB) included 4 study days. During PB study days, more study participants 226/742 (31%) reported body contact with the water compared to contact 531/2098 (25%) on non-peak days. During the 4 PB days, of the environmental factors, only mean water temperature was significantly different, 250 C vs. 230 C (p<0.05) from other days.These results suggest that beachgoer body contact with water was not deterred by the presence of an algal bloom, and that interventions to actively discourage water contact during a bloom are needed to reduce exposure to blooms. This is an abstract of a proposed presentation and

  20. Targeting bacterial toxins.

    PubMed

    Ivarsson, Mattias E; Leroux, Jean-Christophe; Castagner, Bastien

    2012-04-23

    Protein toxins constitute the main virulence factors of several species of bacteria and have proven to be attractive targets for drug development. Lead candidates that target bacterial toxins range from small molecules to polymeric binders, and act at each of the multiple steps in the process of toxin-mediated pathogenicity. Despite recent and significant advances in the field, a rationally designed drug that targets toxins has yet to reach the market. This Review presents the state of the art in bacterial toxin targeted drug development with a critical consideration of achieved breakthroughs and withstanding challenges. The discussion focuses on A-B-type protein toxins secreted by four species of bacteria, namely Clostridium difficile (toxins A and B), Vibrio cholerae (cholera toxin), enterohemorrhagic Escherichia coli (Shiga toxin), and Bacillus anthracis (anthrax toxin), which are the causative agents of diseases for which treatments need to be improved. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A Revealing Exposure.

    ERIC Educational Resources Information Center

    Evans, Kenneth H.

    1992-01-01

    Describes an activity in which students examine hypothetical exposure to toxins by being showered by different colored pieces of confetti over several visits to exposure sites. Students record quantities of confetti that stick to packing tape. Colors correspond to different toxins posing different health problems. Students process their findings…

  2. Multiplex biotoxin surface plasmon resonance method for marine biotoxins in algal and seawater samples.

    PubMed

    McNamee, Sara E; Elliott, Christopher T; Delahaut, Philippe; Campbell, Katrina

    2013-10-01

    A multiplex surface plasmon resonance (SPR) biosensor method for the detection of paralytic shellfish poisoning (PSP) toxins, okadaic acid (and analogues) and domoic acid was developed. This method was compared to enzyme-linked immunosorbent assay (ELISA) methods. Seawater samples (n=256) from around Europe were collected by the consortia of an EU project MIcroarrays for the Detection of Toxic Algae (MIDTAL) and evaluated using each method. A simple sample preparation procedure was developed which involved lysing and releasing the toxins from the algal cells with glass beads followed by centrifugation and filtering the extract before testing for marine biotoxins by both multi-SPR and ELISA. Method detection limits based on IC20 values for PSP, okadaic acid and domoic acid toxins were 0.82, 0.36 and 1.66 ng/ml, respectively, for the prototype multiplex SPR biosensor. Evaluation by SPR for seawater samples has shown that 47, 59 and 61 % of total seawater samples tested positive (result greater than the IC20) for PSP, okadaic acid (and analogues) and domoic acid toxins, respectively. Toxic samples were received mainly from Spain and Ireland. This work has demonstrated the potential of multiplex analysis for marine biotoxins in algal and seawater samples with results available for 24 samples within a 7 h period for three groups of key marine biotoxins. Multiplex immunological methods could therefore be used as early warning monitoring tools for a variety of marine biotoxins in seawater samples.

  3. A novel algal toxicity testing technique for assessing the toxicity of both metallic and organic toxicants.

    PubMed

    Lin, Jui-Ho; Kao, Wei-Chen; Tsai, Kuo-Pei; Chen, Chung-Yuan

    2005-05-01

    This study presents a closed-system algal toxicity test technique that is capable of detecting the effects of both organic and metallic toxicants. Toxicity testing was conducted by transferring adequate amounts of algal suspension, dilution water (with culture growth medium), and toxicants into 300-mL BOD bottles. The BOD bottles were completely filled up with no head-space left. The initial cell density and the exposure time were 15,000 cells/mL and 48 h, respectively. The performance of the above test method was evaluated using three heavy metals and six organic toxicants based on three different test endpoints, i.e., dissolved oxygen production, algal growth rate, and cell density. The proposed test revealed excellent test sensitivity and reproducibility. Currently, none of the existing algal toxicity test protocols is adequate for assessing the toxicity of organic chemicals. The closed-system algal toxicity tests developed by previous researchers also may not be ideal because the enlarged headspace and/or enriched bicarbonate buffer may result in either underestimations of the exposure concentrations or insensitive responses to both heavy metals and organic toxicants. Compared to the aforementioned algal toxicity test methods, the proposed technique in the present study has a more general applicability under conditions such as effluent samples containing both metals and organic toxicants or samples with unknown compositions.

  4. Simultaneous detection of antibodies against Apx toxins ApxI, ApxII, ApxIII, and ApxIV in pigs with known and unknown Actinobacillus pleuropneumoniae exposure using a multiplexing liquid array platform.

    PubMed

    Giménez-Lirola, Luis G; Jiang, Yong-Hou; Sun, Dong; Hoang, Hai; Yoon, Kyoung-Jin; Halbur, Patrick G; Opriessnig, Tanja

    2014-01-01

    Surveillance for the presence of Actinobacillus pleuropneumoniae infection in a population plays a central role in controlling the disease. In this study, a 4-plex fluorescent microbead-based immunoassay (FMIA), developed for the simultaneous detection of IgG antibodies to repeat-in-toxin (RTX) toxins (ApxI, ApxII, ApxIII, and ApxIV) of A. pleuropneumoniae, was evaluated using (i) blood serum samples from pigs experimentally infected with each of the 15 known A. pleuropneumoniae serovars or with Actinobacillus suis, (ii) blood serum samples from pigs vaccinated with a bacterin containing A. pleuropneumoniae serovar 1, 3, 5, or 7, and (iii) blood serum samples from pigs with an unknown A. pleuropneumoniae exposure status. The results were compared to those obtained in a previous study where a dual-plate complement fixation test (CFT) and three commercially available enzyme-linked immunosorbent assays (ELISAs) were conducted on the same sample set. On samples from experimentally infected pigs, the 4-plex Apx FMIA detected specific seroconversion to Apx toxins as early as 7 days postinfection in a total of 29 pigs inoculated with 14 of the 15 A. pleuropneumoniae serovars. Seroconversion to ApxII and ApxIII was detected by FMIA in pigs inoculated with A. suis. The vaccinated pigs showed poor humoral responses against ApxI, ApxII, ApxIII, and ApxIV. In the field samples, the humoral response to ApxIV and the A. pleuropneumoniae seroprevalence increased with age. This novel FMIA (with a sensitivity of 82.7% and a specificity of 100% for the anti-ApxIV antibody) was found to be more sensitive and accurate than current tests (sensitivities, 9.5 to 56%; specificity, 100%) and is potentially an improved tool for the surveillance of disease and for monitoring vaccination compliance.

  5. Simultaneous Detection of Antibodies against Apx Toxins ApxI, ApxII, ApxIII, and ApxIV in Pigs with Known and Unknown Actinobacillus pleuropneumoniae Exposure Using a Multiplexing Liquid Array Platform

    PubMed Central

    Giménez-Lirola, Luis G.; Jiang, Yong-Hou; Sun, Dong; Hoang, Hai; Yoon, Kyoung-Jin; Halbur, Patrick G.

    2014-01-01

    Surveillance for the presence of Actinobacillus pleuropneumoniae infection in a population plays a central role in controlling the disease. In this study, a 4-plex fluorescent microbead-based immunoassay (FMIA), developed for the simultaneous detection of IgG antibodies to repeat-in-toxin (RTX) toxins (ApxI, ApxII, ApxIII, and ApxIV) of A. pleuropneumoniae, was evaluated using (i) blood serum samples from pigs experimentally infected with each of the 15 known A. pleuropneumoniae serovars or with Actinobacillus suis, (ii) blood serum samples from pigs vaccinated with a bacterin containing A. pleuropneumoniae serovar 1, 3, 5, or 7, and (iii) blood serum samples from pigs with an unknown A. pleuropneumoniae exposure status. The results were compared to those obtained in a previous study where a dual-plate complement fixation test (CFT) and three commercially available enzyme-linked immunosorbent assays (ELISAs) were conducted on the same sample set. On samples from experimentally infected pigs, the 4-plex Apx FMIA detected specific seroconversion to Apx toxins as early as 7 days postinfection in a total of 29 pigs inoculated with 14 of the 15 A. pleuropneumoniae serovars. Seroconversion to ApxII and ApxIII was detected by FMIA in pigs inoculated with A. suis. The vaccinated pigs showed poor humoral responses against ApxI, ApxII, ApxIII, and ApxIV. In the field samples, the humoral response to ApxIV and the A. pleuropneumoniae seroprevalence increased with age. This novel FMIA (with a sensitivity of 82.7% and a specificity of 100% for the anti-ApxIV antibody) was found to be more sensitive and accurate than current tests (sensitivities, 9.5 to 56%; specificity, 100%) and is potentially an improved tool for the surveillance of disease and for monitoring vaccination compliance. PMID:24226091

  6. Biofilm-based algal cultivation systems.

    PubMed

    Gross, Martin; Jarboe, Darren; Wen, Zhiyou

    2015-07-01

    Biofilm-based algal cultivation has received increased attention as a potential platform for algal production and other applications such as wastewater treatment. Algal biofilm cultivation systems represent an alternative to the suspension-based systems that have yet to become economically viable. One major advantage of algal biofilm systems is that algae can be simply harvested through scraping and thus avoid the expensive harvesting procedures used in suspension-based harvesting such as flocculation and centrifugation. In recent years, an assortment of algal biofilm systems have been developed with various design configurations and biomass production capacities. This review summarizes the state of the art of different algal biofilm systems in terms of their design and operation. Perspectives for future research needs are also discussed to provide guidance for further development of these unique cultivation systems.

  7. Air pollutant production by algal cell cultures

    NASA Technical Reports Server (NTRS)

    Fong, F.; Funkhouser, E. A.

    1982-01-01

    The production of phytotoxic air pollutants by cultures of Chlorella vulgaris and Euglena gracilis is considered. Algal and plant culture systems, a fumigation system, and ethylene, ethane, cyanide, and nitrogen oxides assays are discussed. Bean, tobacco, mustard green, cantaloupe and wheat plants all showed injury when fumigated with algal gases for 4 hours. Only coleus plants showed any resistance to the gases. It is found that a closed or recycled air effluent system does not produce plant injury from algal air pollutants.

  8. Methods for removing contaminants from algal oil

    SciTech Connect

    Lupton, Francis Stephen

    2016-09-27

    Methods for removing contaminants from algal oil are provided. In an embodiment, a method comprises the steps of combining a sulfuric acid-aqueous solution that has a pH of about 1 or less with a contaminant-containing algal oil at treatment conditions effective to form an effluent. The effluent comprises a treated algal oil phase and contaminants in an acidic aqueous phase. The contaminants comprise metals, phosphorus, or combinations thereof. The acidic aqueous phase is removed from the effluent to form a contaminant-depleted algal oil.

  9. Adult Exposure to Bt Toxin Cry1Ac Reduces Life Span and Reproduction of Resistant and Susceptible Pink Bollworm (Lepidoptera: Gelechiidae).

    PubMed

    Wang, Ling; Wan, Peng; Cong, Shengbo; Wang, Jintao; Huang, Minsong; Tabashnik, Bruce E; Li, Xianchun; Wu, Kongming

    2016-05-01

    Insecticidal proteins from Bacillus thuringiensis (Bt) are used widely in sprays and transgenic plants to control insect pests. Although much research has elucidated the effects of Bt toxins on larvae, relatively little is known about their effects on adults. Here, we evaluated the effects of exposing adults to Bt toxin Cry1Ac on the life span and reproduction of two strains of pink bollworm (Pectinophora gossypiella (Saunders)). In larval diet bioassays, the concentration of Cry1Ac killing 50% of larvae (LC50) was 640 times higher for the laboratory-selected resistant strain (AZP-R) than the susceptible strain (APHIS-S). In experiments with adults, the highest concentrations of Cry1Ac tested (160 and 640 µg Cry1Ac per ml of 5% honey water) reduced life span for both strains. Treatments with 10, 40, and 160 µg Cry1Ac per ml reduced the duration of the oviposition period as well as the number of eggs laid by both strains, but did not affect the percentage of pairs producing eggs, the duration of the preoviposition period, or the percentage of eggs hatching for either strain. Adult life span did not differ between strains at low to moderate concentrations of Cry1Ac, but it was significantly greater for the resistant strain than the susceptible strain at the two highest concentrations of Cry1Ac tested. The reduced susceptibility to high concentrations of Cry1Ac in adults of the AZP-R strain relative to the APHIS-S strain provides the first evidence of expression of resistance to a Bt toxin in adult Lepidoptera. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. From genome-wide to candidate gene: an investigation of variation at the major histocompatibility complex in common bottlenose dolphins exposed to harmful algal blooms.

    PubMed

    Cammen, Kristina M; Wilcox, Lynsey A; Rosel, Patricia E; Wells, Randall S; Read, Andrew J

    2015-02-01

    The role the major histocompatibility complex (MHC) plays in response to exposure to environmental toxins is relatively poorly understood, particularly in comparison to its well-described role in pathogen immunity. We investigated associations between MHC diversity and resistance to brevetoxins in common bottlenose dolphins (Tursiops truncatus). A previous genome-wide association study investigating an apparent difference in harmful algal bloom (HAB) resistance among dolphin populations in the Gulf of Mexico identified genetic variation associated with survival in close genomic proximity to multiple MHC class II loci. Here, we characterized genetic variation at DQA, DQB, DRA, and DRB loci in dolphins from central-west Florida and the Florida Panhandle, including dolphins that died during HABs and dolphins presumed to have survived HAB exposure. We found that DRB and DQB exhibited patterns of genetic differentiation among geographic regions that differed from neutral microsatellite loci. In addition, genetic differentiation at DRB across multiple pairwise comparisons of live and dead dolphins was greater than differentiation observed at neutral loci. Our findings at these MHC loci did not approach the strength of association with survival previously described for a nearby genetic variant. However, the results provide evidence that selective pressures at the MHC vary among dolphin populations that differ in the frequency of HAB exposure and that the overall composition of DRB variants differs between dolphin survivors and non-survivors of HABs. These results may suggest a potential role of MHC diversity in variable survival of bottlenose dolphins exposed to HABs.

  11. Cyanobacteria and Algae Blooms: Review of Health and Environmental Data from the Harmful Algal Bloom-Related Illness Surveillance System (HABISS) 2007–2011

    PubMed Central

    Backer, Lorraine C.; Manassaram-Baptiste, Deana; LePrell, Rebecca; Bolton, Birgit

    2015-01-01

    Algae and cyanobacteria are present in all aquatic environments. We do not have a good sense of the extent of human and animal exposures to cyanobacteria or their toxins, nor do we understand the public health impacts from acute exposures associated with recreational activities or chronic exposures associated with drinking water. We describe the Harmful Algal Bloom-related Illness Surveillance System (HABISS) and summarize the collected reports describing bloom events and associated adverse human and animal health events. For the period of 2007–2011, Departments of Health and/or Environment from 11 states funded by the National Center for Environmental Health (NCEH), Centers for Disease Control and Prevention contributed reports for 4534 events. For 2007, states contributed 173 reports from historical data. The states participating in the HABISS program built response capacity through targeted public outreach and prevention activities, including supporting routine cyanobacteria monitoring for public recreation waters. During 2007–2010, states used monitoring data to support196 public health advisories or beach closures. The information recorded in HABISS and the application of these data to develop a wide range of public health prevention and response activities indicate that cyanobacteria and algae blooms are an environmental public health issue that needs continuing attention. PMID:25826054

  12. Seasonal synchronicity of algal assemblages in three Midwestern agricultural streams having varying concentrations of atrazine, nutrients, and sediment.

    PubMed

    Andrus, J Malia; Winter, Diane; Scanlan, Michael; Sullivan, Sean; Bollman, Wease; Waggoner, J B; Hosmer, Alan J; Brain, Richard A

    2013-08-01

    Numerous studies characterizing the potential effects of atrazine on algal assemblages have been conducted using micro- or mesocosms; however, few evaluations focused on in situ lotic algal communities, potentially confounding risk assessment conclusions. This exploratory study, conducted at several sites in the midwestern United States where atrazine is commonly used, presents in situ observations of native algal communities relative to atrazine exposure and other parameters. Planktonic and periphytic algae from three streams in three Midwestern states, having historically differing atrazine levels, were sampled over a 16-week period in 2011 encompassing atrazine applications and the summer algal growth period at each site. Changes in abundance, diversity, and composition of algal communities were placed in the context of hydrological, climatic, and water quality parameters (including components sometimes present in agricultural runoff) also collected during the study. Diatoms dominated communities at each of the three sites and periphyton was much more abundant than phytoplankton. As expected, significant variations in algal community and environmental parameters were observed between sites. However, correspondence analysis plots revealed that patterns of temporal variation in algal communities at each site and in periphyton or phytoplankton were dominated by seasonal environmental gradients. Significant concordance in these seasonal patterns was detected among sites and between phytoplankton and periphyton communities (via procrustes Protest analysis), suggesting synchronicity of algal communities across a regional scale. While atrazine concentrations generally exhibited seasonal trends at the study watersheds; no effects on algal abundance, diversity or assemblage structure were observed as a result of atrazine pulses. This lack of response may be due to exposure events of insufficient concentration or duration (consistent with previously reported results) or

  13. Algal Bloom Detection from HICO

    NASA Astrophysics Data System (ADS)

    Amin, Ruhul; Gould, Richard

    2014-05-01

    Ocean color satellites provide daily, global views of marine bio-optical properties in the upper ocean at various spatial scales. The most productive area of the global ocean is the coastal zone which is heavily impacted by urban and agricultural runoff, transportation, recreation, and oil and gas production. In recent years, harmful algal blooms (HABs) have become one of the serious environmental problems in the coastal areas on a global scale. The global nature of the problem has expanded in its frequency, severity, and extent over the last several decades. Human activities and population increases have contributed to an increase in various toxic and noxious algal species in the coastal regions worldwide. Eutrophication in estuaries and coastal waters is believed to be the major factor causing HABs. In this study, we assess the applicability of the Red Band Difference (RBD) HAB detection algorithm on data from the Hyperspectral Imager for the Coastal Ocean (HICO). Our preliminary results show that due to various uncertainties such as atmospheric correction, calibration and possibly also the relatively low signal-to-noise ratio of HICO for fluorescence detection, it is difficult to extract the fluorescence portion of the reflectance spectrum that RBD uses for bloom detection. We propose an improved bloom detection technique for HICO using red and NIR bands. Our results are validated using other space-borne and ground based measurements.

  14. NREL Algal Biofuels Projects and Partnerships

    SciTech Connect

    2016-10-01

    This fact sheet highlights several algal biofuels research and development projects focused on improving the economics of the algal biofuels production process. These projects should serve as a foundation for the research efforts toward algae as a source of fuels and other chemicals.

  15. *CYANOBACTERIA AND THEIR TOXINS

    EPA Science Inventory

    Cyanobacteria, or blue-green algae, are naturally-occurring contaminants of surface waters worldwide. These photosynthesizing prokaryotes thrive in warm, shallow, nutrient-rich waters. Many produce potent toxins as secondary metabolites. Cyanobacteria toxins have been document...

  16. *CYANOBACTERIA AND THEIR TOXINS

    EPA Science Inventory

    Cyanobacteria, or blue-green algae, are naturally-occurring contaminants of surface waters worldwide. These photosynthesizing prokaryotes thrive in warm, shallow, nutrient-rich waters. Many produce potent toxins as secondary metabolites. Cyanobacteria toxins have been document...

  17. The role of selective predation in harmful algal blooms

    NASA Astrophysics Data System (ADS)

    Solé, Jordi; Garcia-Ladona, Emilio; Estrada, Marta

    2006-08-01

    A feature of marine plankton communities is the occurrence of rapid population explosions. When the blooming species are directly or indirectly noxious for humans, these proliferations are denoted as harmful algal blooms (HAB). The importance of biological interactions for the appearance of HABs, in particular when the proliferating microalgae produce toxins that affect other organisms in the food web, remains still poorly understood. Here we analyse the role of toxins produced by a microalgal species and affecting its predators, in determining the success of that species as a bloom former. A three-species predator-prey model is used to define a criterion that determines whether a toxic microalga will be able to initiate a bloom in competition against a non-toxic one with higher growth rate. Dominance of the toxic species depends on a critical parameter that defines the degree of feeding selectivity by grazers. The criterion is applied to a particular simplified model and to numerical simulations of a full marine ecosystem model. The results suggest that the release of toxic compounds affecting predators may be a plausible biological factor in allowing the development of HABs.

  18. The course of toxicity in the pregnant mouse after exposure to the cyanobacterial toxin cylindrospermopsin: clinical effects, serum chemistries, hematology, and histopathology.

    PubMed

    Chernoff, N; Rogers, E H; Zehr, R D; Gage, M I; Travlos, G S; Malarkey, D E; Brix, A; Schmid, J E; Hill, D

    2014-01-01

    Cylindrospermopsin (CYN) is a toxin produced by a variety of fresh-water cyanobacterial species worldwide and induces significant adverse effects in both livestock and humans. This study investigated the course of CYN-induced toxicity in pregnant mice exposed daily during either the period of major organogenesis (gestation days [GD] 8-12) or fetal growth (GD13-17). Endpoints include clinical signs of toxicity, serum analyses to evaluate hepatic and renal function, histopathology of liver and kidney, and hematology. Study animals were administered 50 μg/kg CYN once daily by ip route and euthanized 24 h after 1, 2, 3, 4, or 5 consecutive doses, or 6 or 13 d after the dosing period. The course of the CYN-induced effects was determined at all euthanasia times for the endpoints just outlined. Results indicated that CYN is a toxin, producing lethality in dams during the early part of gestation, significant weight loss, and bleeding in the gastrointestinal tract, tail tip, and peri-orbital tissues. Effects also included alterations in serum markers for liver function, histopathological changes in liver and kidney tissues, electrolyte abnormalities, leukocytosis, and posttreatment thrombocytopenia and reticulocytosis. The onset of symptoms was rapid, producing reductions in weight gain in GD8-12 animals, bleeding in the vaginal area in GD13-17 animals, and significant increases in sorbitol dehydrogenase (SDH) in both groups after a single dose. Although the GD8-12 dams displayed a 50% lethality, in GD13-17 animals only a single death occurred. Alterations seen in hepatic and renal function or histopathology do not appear to be of sufficient severity to produce death. Evidence indicates that bleeding may play a critical role in the onset of symptoms and eventually, in the observed lethality.

  19. Safety evaluation of DHA-rich Algal Oil from Schizochytrium sp.

    PubMed

    Fedorova-Dahms, I; Marone, P A; Bauter, M; Ryan, A S

    2011-12-01

    The safety of DHA-rich Algal Oil from Schizochytrium sp. containing 40-45 wt% DHA and up to 10 wt% EPA was evaluated by testing for gene mutations, clastogenicity and aneugenicity, and in a subchronic 90-day Sprague-Dawley rat dietary study with in utero exposure, followed by a 4-week recovery phase. The results of all genotoxicity tests were negative. In the 90-day study, DHA-rich Algal Oil was administered at dietary levels of 0.5, 1.5, and 5 wt% along with two control diets: a standard low-fat basal diet and a basal diet supplemented with 5 wt% of concentrated Fish Oil. There were no treatment-related effects of DHA-rich Algal Oil on clinical observations, body weight, food consumption, behavior, hematology, clinical chemistry, coagulation, or urinalysis. Increases in absolute and relative weights of the liver, kidney, spleen and adrenals (adrenals and spleen with histological correlates) were observed in both the Fish Oil- and the high-dose of DHA-rich Algal Oil-treated females and were not considered to be adverse. The no observed adverse effect level (NOAEL) for DHA-rich Algal Oil under the conditions of this study was 5 wt% in the diet, equivalent to an overall average DHA-rich Algal Oil intake of 4260 mg/kg bw/day for male and female rats. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Constraints to commercialization of algal fuels.

    PubMed

    Chisti, Yusuf

    2013-09-10

    Production of algal crude oil has been achieved in various pilot scale facilities, but whether algal fuels can be produced in sufficient quantity to meaningfully displace petroleum fuels, has been largely overlooked. Limitations to commercialization of algal fuels need to be understood and addressed for any future commercialization. This review identifies the major constraints to commercialization of transport fuels from microalgae. Algae derived fuels are expensive compared to petroleum derived fuels, but this could change. Unfortunately, improved economics of production are not sufficient for an environmentally sustainable production, or its large scale feasibility. A low-cost point supply of concentrated carbon dioxide colocated with the other essential resources is necessary for producing algal fuels. An insufficiency of concentrated carbon dioxide is actually a major impediment to any substantial production of algal fuels. Sustainability of production requires the development of an ability to almost fully recycle the phosphorous and nitrogen nutrients that are necessary for algae culture. Development of a nitrogen biofixation ability to support production of algal fuels ought to be an important long term objective. At sufficiently large scale, a limited supply of freshwater will pose a significant limitation to production even if marine algae are used. Processes for recovering energy from the algal biomass left after the extraction of oil, are required for achieving a net positive energy balance in the algal fuel oil. The near term outlook for widespread use of algal fuels appears bleak, but fuels for niche applications such as in aviation may be likely in the medium term. Genetic and metabolic engineering of microalgae to boost production of fuel oil and ease its recovery, are essential for commercialization of algal fuels. Algae will need to be genetically modified for improved photosynthetic efficiency in the long term. Copyright © 2013 Elsevier B.V. All

  1. Responding to Harmful Algal Blooms: Treatment Optimization

    EPA Science Inventory

    This presentation discusses: (1) analytical methods for toxins and cyanobacteria within the context of monitoring a treatment process, (2) toxin and cell removal capacities for common drinking water treatment processes, (3) issues to consider when evaluating a treatment facility...

  2. Responding to Harmful Algal Blooms: Treatment Optimization

    EPA Science Inventory

    This presentation discusses: (1) analytical methods for toxins and cyanobacteria within the context of monitoring a treatment process, (2) toxin and cell removal capacities for common drinking water treatment processes, (3) issues to consider when evaluating a treatment facility...

  3. Detection of Protein Toxins

    USDA-ARS?s Scientific Manuscript database

    We have focused on ricin, shiga-like toxin, botulinum neurotoxin (BoNT), and staphylococcal enterotoxin A (SEA), developing sensitive test methods for toxins and marker compounds in food matrices. Although animal models provide the best means for risk assessment, especially for crude toxins in compl...

  4. Cyanobacterial toxins: risk management for health protection

    SciTech Connect

    Codd, Geoffrey A.; Morrison, Louise F.; Metcalf, James S

    2005-03-15

    This paper reviews the occurrence and properties of cyanobacterial toxins, with reference to the recognition and management of the human health risks which they may present. Mass populations of toxin-producing cyanobacteria in natural and controlled waterbodies include blooms and scums of planktonic species, and mats and biofilms of benthic species. Toxic cyanobacterial populations have been reported in freshwaters in over 45 countries, and in numerous brackish, coastal, and marine environments. The principal toxigenic genera are listed. Known sources of the families of cyanobacterial toxins (hepato-, neuro-, and cytotoxins, irritants, and gastrointestinal toxins) are briefly discussed. Key procedures in the risk management of cyanobacterial toxins and cells are reviewed, including derivations (where sufficient data are available) of tolerable daily intakes (TDIs) and guideline values (GVs) with reference to the toxins in drinking water, and guideline levels for toxigenic cyanobacteria in bathing waters. Uncertainties and some gaps in knowledge are also discussed, including the importance of exposure media (animal and plant foods), in addition to potable and recreational waters. Finally, we present an outline of steps to develop and implement risk management strategies for cyanobacterial cells and toxins in waterbodies, with recent applications and the integration of Hazard Assessment Critical Control Point (HACCP) principles.

  5. Metabolic systems analysis to advance algal biotechnology.

    PubMed

    Schmidt, Brian J; Lin-Schmidt, Xiefan; Chamberlin, Austin; Salehi-Ashtiani, Kourosh; Papin, Jason A

    2010-07-01

    Algal fuel sources promise unsurpassed yields in a carbon neutral manner that minimizes resource competition between agriculture and fuel crops. Many challenges must be addressed before algal biofuels can be accepted as a component of the fossil fuel replacement strategy. One significant challenge is that the cost of algal fuel production must become competitive with existing fuel alternatives. Algal biofuel production presents the opportunity to fine-tune microbial metabolic machinery for an optimal blend of biomass constituents and desired fuel molecules. Genome-scale model-driven algal metabolic design promises to facilitate both goals by directing the utilization of metabolites in the complex, interconnected metabolic networks to optimize production of the compounds of interest. Network analysis can direct microbial development efforts towards successful strategies and enable quantitative fine-tuning of the network for optimal product yields while maintaining the robustness of the production microbe. Metabolic modeling yields insights into microbial function, guides experiments by generating testable hypotheses, and enables the refinement of knowledge on the specific organism. While the application of such analytical approaches to algal systems is limited to date, metabolic network analysis can improve understanding of algal metabolic systems and play an important role in expediting the adoption of new biofuel technologies.

  6. Harmful algal blooms and eutrophication: "strategies" for nutrient uptake and growth outside the Redfield comfort zone

    NASA Astrophysics Data System (ADS)

    Glibert, Patricia M.; Burkholder, Joann M.

    2011-07-01

    While many harmful algal blooms have been associated with increasing eutrophication, not all species respond similarly and the increasing challenge, especially for resource managers, is to determine which blooms are related to eutrophication and to understand why particular species proliferate under specific nutrient conditions. The overall goal of this brief review is to describe why nutrient loads are not changing in stoichiometric proportion to the "Redfield ratio", and why this has important consequences for algal growth. Many types of harmful algae appear to be able to thrive, and/or increase their production of toxins, when nutrient loads are not in proportion classically identified as Redfield ratios. Here we also describe some of the physiological mechanisms of different species to take up nutrients and to thrive under conditions of nutrient imbalance.

  7. Application of Multispectral and Hyperspectral Remote Sensing For Detection of Freshwater Harmful Algal Blooms

    NASA Astrophysics Data System (ADS)

    Kudela, R. M.; Accorsi, E.; Austerberry, D.; Palacios, S. L.

    2013-12-01

    Freshwater Cyanobacterial Harmful algal blooms (CHABs) represent a pressing and apparently increasing threat to both human and environmental health. In California, toxin producing blooms of several species, including Aphanizomenon, Microcystis, Lyngbya, and Anabaena are common; toxins from these blooms have been linked to impaired drinking water, domestic and wild animal deaths, and increasing evidence for toxin transfer to coastal marine environments, including the death of several California sea otters, a threatened marine species. California scientists and managers are under increasing pressure to identify and mitigate these potentially toxic blooms, but point-source measurements and grab samples have been less than effective. There is increasing awareness that these toxic events are both spatially widespread and ephememeral, leading to the need for better monitoring methods applicable to large spatial and temporal scales. Based on monitoring in several California water bodies, it appears that Aphanizomenon blooms frequently precede dangerous levels of toxins from Microcystis. We are exploring new detection methods for identifying CHABs and potentially distinguishing between blooms of the harmful cyanobacteria Aphanizomenon and Microcystis using remote sensing reflectance from a variety of airborne and satellite sensors. We suggest that Aphanizomenon blooms could potentially be used as an early warning of more highly toxic subsequent blooms, and that these methods, combined with better toxin monitoring, can lead to improved understanding and prediction of CHABs by pinpointing problematic watersheds.

  8. Bioterrorism: toxins as weapons.

    PubMed

    Anderson, Peter D

    2012-04-01

    The potential for biological weapons to be used in terrorism is a real possibility. Biological weapons include infectious agents and toxins. Toxins are poisons produced by living organisms. Toxins relevant to bioterrorism include ricin, botulinum, Clostridium perfrigens epsilson toxin, conotoxins, shigatoxins, saxitoxins, tetrodotoxins, mycotoxins, and nicotine. Toxins have properties of biological and chemical weapons. Unlike pathogens, toxins do not produce an infection. Ricin causes multiorgan toxicity by blocking protein synthesis. Botulinum blocks acetylcholine in the peripheral nervous system leading to muscle paralysis. Epsilon toxin damages cell membranes. Conotoxins block potassium and sodium channels in neurons. Shigatoxins inhibit protein synthesis and induce apoptosis. Saxitoxin and tetrodotoxin inhibit sodium channels in neurons. Mycotoxins include aflatoxins and trichothecenes. Aflatoxins are carcinogens. Trichothecenes inhibit protein and nucleic acid synthesis. Nicotine produces numerous nicotinic effects in the nervous system.

  9. Bacterial toxins as immunomodulators.

    PubMed

    Donaldson, David S; Williams, Neil A

    2009-01-01

    Bacterial toxins are the causative agent at pathology in a variety of diseases. Although not always the primary target of these toxins, many have been shown to have potent immunomodulatory effects, for example, inducing immune responses to co-administered antigens and suppressing activation of immune cells. These abilities of bacterial toxins can be harnessed and used in a therapeutic manner, such as in vaccination or the treatment of autoimmune diseases. Furthermore, the ability of toxins to gain entry to cells can be used in novel bacterial toxin based immuno-therapies in order to deliver antigens into MHC Class I processing pathways. Whether the immunomodulatory properties of these toxins arose in order to enhance bacterial survival within hosts, to aid spread within the population or is pure serendipity, it is interesting to think that these same toxins potentially hold the key to preventing or treating human disease.

  10. Sustainable Algal Energy Production and Environmental Remediation

    SciTech Connect

    Cooke, William E.

    2012-07-14

    Overall, our results confirm that wild algal species sequester a wide range of organic and metal contaminants and excess nutrients (PAHs, trace metals, and nutrients) from natural waters, and suggest parameters that could be useful in predicting uptake rates for algae growing on an algal floway or other algal growth systems in the environment or in industrial processes. The implication for various fuel production processes differ with the detailed unit operations involved, and these results will be of use in the developing of scaling experiments for various types of engineering process designs.

  11. Exploring the Utilization of Complex Algal Communities to Address Algal Pond Crash and Increase Annual Biomass Production for Algal Biofuels

    SciTech Connect

    Hamilton, Cyd E.

    2014-03-25

    This white paper briefly reviews the research literature exploring complex algal communities as a means of increasing algal biomass production via increased tolerance, resilience, and resistance to a variety of abiotic and biotic perturbations occurring within harvesting timescales. This paper identifies what data are available and whether more research utilizing complex communities is needed to explore the potential of complex algal community stability (CACS) approach as a plausible means to increase biomass yields regardless of ecological context and resulting in decreased algal-based fuel prices by reducing operations costs. By reviewing the literature for what we do and do not know, in terms of CACS methodologies, this report will provide guidance for future research addressing pond crash phenomena.

  12. Variable toxicity of silver nanoparticles to Daphnia magna: effects of algal particles and animal nutrition.

    PubMed

    Conine, Andrea L; Frost, Paul C

    2017-01-01

    Aquatic environments vary widely in aspects other than their physicochemical properties that could alter the toxicity of novel contaminants. One factor that could affect chemical toxicity to aquatic consumers is their nutritional environment as it can strongly affect their physiology and life history. Nutrition has the potential to alter an organism's response to the toxin or how the toxin interacts with the consumer through its food. Here we determined how growth and survival responses of Daphnia to an emerging contaminant, silver nanoparticles (AgNPs), are affected by the presence of food and its stoichiometric food quality. We used a series of survival tests, each slightly modified, to determine whether variable toxicity in different nutritional environments resulted from algal sequestration of AgNPs in a nontoxic form or from changes to the nutritional status of the test animals. We found that the presence of algae, of good or poor quality, reduced the toxicity of AgNPs on animal growth and survival. However, the decrease in AgNP toxicity was greater for animals consuming P-rich compared to P-poor food. We found evidence that this effect of food quality was due to greater algal uptake of AgNPs by P-rich than by P-stressed algae. However, we also found animal nutrition, in the absence of algal AgNP binding, could affect toxicity with P-nourished animals surviving slightly better when exposed to AgNPs compared to their P-stressed counterparts. Our results show an important role for algal particles and their P content in determining the toxicity of AgNPs in natural waters primarily due to their binding and uptake abilities and, less so, to their effects on animal nutrition.

  13. Free ammonia offers algal crop protection from predators in dairy wastewater and ammonium-rich media.

    PubMed

    Thomas, Patrick K; Dunn, Gary P; Passero, Maxine; Feris, Kevin P

    2017-11-01

    Cost-effective methods for protecting crops from grazing organisms like rotifers are needed to reduce the risk of pond crashes in mass algal cultures. We present a novel strategy to optimize the exposure time to free ammonia, via control of media pH, in both defined media and dairy anaerobic digester effluent to suppress rotifers and maintain algal productivity. We tested five different free ammonia exposure times (0, 1, 2, 6, and 12h) and found a significant nonlinear effect of exposure time (p<0.0001) but not pH (p>0.9) on rotifer survival. In both media types, 6-12h of elevated free ammonia significantly reduced Brachionus plicatilis rotifer survival with no negative effects on Nannochloropsis oculata, while shorter exposure times were insufficient to inhibit rotifers, leading to severe algal culture crashes. These results suggest that algal crops can be protected from rotifers, without productivity loss, by elevating free ammonia for 6 or more hours. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Effect of exposure time and organic matter on efficacy of antimicrobial compounds against Shiga Toxin-producing Escherichia coli and Salmonella

    USDA-ARS?s Scientific Manuscript database

    Several antimicrobial compounds are in commercial meat processing plants for the purpose of pathogens control on beef carcasses. However, the efficacy of the method used is influenced by a number of factors such as spray pressure, temperature, type of chemical and concentration, exposure time, metho...

  15. Factsheet: Climate Change and Harmful Algal Blooms

    EPA Pesticide Factsheets

    Climate change is predicted to change many environmental conditions that could affect the properties of fresh and marine waters. These changes could favor the growth of harmful algal blooms and habitat changes.

  16. Eukaryotic algal phytochromes span the visible spectrum

    PubMed Central

    Rockwell, Nathan C.; Duanmu, Deqiang; Martin, Shelley S.; Bachy, Charles; Price, Dana C.; Bhattacharya, Debashish; Worden, Alexandra Z.; Lagarias, J. Clark

    2014-01-01

    Plant phytochromes are photoswitchable red/far-red photoreceptors that allow competition with neighboring plants for photosynthetically active red light. In aquatic environments, red and far-red light are rapidly attenuated with depth; therefore, photosynthetic species must use shorter wavelengths of light. Nevertheless, phytochrome-related proteins are found in recently sequenced genomes of many eukaryotic algae from aquatic environments. We examined the photosensory properties of seven phytochromes from diverse algae: four prasinophyte (green algal) species, the heterokont (brown algal) Ectocarpus siliculosus, and two glaucophyte species. We demonstrate that algal phytochromes are not limited to red and far-red responses. Instead, different algal phytochromes can sense orange, green, and even blue light. Characterization of these previously undescribed photosensors using CD spectroscopy supports a structurally heterogeneous chromophore in the far-red–absorbing photostate. Our study thus demonstrates that extensive spectral tuning of phytochromes has evolved in phylogenetically distinct lineages of aquatic photosynthetic eukaryotes. PMID:24567382

  17. Environmental performance of algal biofuel technology options.

    PubMed

    Vasudevan, Venkatesh; Stratton, Russell W; Pearlson, Matthew N; Jersey, Gilbert R; Beyene, Abraham G; Weissman, Joseph C; Rubino, Michele; Hileman, James I

    2012-02-21

    Considerable research and development is underway to produce fuels from microalgae, one of several options being explored for increasing transportation fuel supplies and mitigating greenhouse gas emissions (GHG). This work models life-cycle GHG and on-site freshwater consumption for algal biofuels over a wide technology space, spanning both near- and long-term options. The environmental performance of algal biofuel production can vary considerably and is influenced by engineering, biological, siting, and land-use considerations. We have examined these considerations for open pond systems, to identify variables that have a strong influence on GHG and freshwater consumption. We conclude that algal biofuels can yield GHG reductions relative to fossil and other biobased fuels with the use of appropriate technology options. Further, freshwater consumption for algal biofuels produced using saline pond systems can be comparable to that of petroleum-derived fuels.

  18. Climate Adaptation and Harmful Algal Blooms

    EPA Pesticide Factsheets

    EPA supports local, state and tribal efforts to maintain water quality. A key element of its efforts is to reduce excess nutrient pollution and the resulting adverse impacts, including harmful algal blooms.

  19. Recent Advances in Algal Genetic Tool Development

    SciTech Connect

    R. Dahlin, Lukas; T. Guarnieri, Michael

    2016-06-24

    The goal of achieving cost-effective biofuels and bioproducts derived from algal biomass will require improvements along the entire value chain, including identification of robust, high-productivity strains and development of advanced genetic tools. Though there have been modest advances in development of genetic systems for the model alga Chlamydomonas reinhardtii, progress in development of algal genetic tools, especially as applied to non-model algae, has generally lagged behind that of more commonly utilized laboratory and industrial microbes. This is in part due to the complex organellar structure of algae, including robust cell walls and intricate compartmentalization of target loci, as well as prevalent gene silencing mechanisms, which hinder facile utilization of conventional genetic engineering tools and methodologies. However, recent progress in global tool development has opened the door for implementation of strain-engineering strategies in industrially-relevant algal strains. Here, we review recent advances in algal genetic tool development and applications in eukaryotic microalgae.

  20. Recent Advances in Algal Genetic Tool Development

    SciTech Connect

    R. Dahlin, Lukas; T. Guarnieri, Michael

    2016-06-24

    The goal of achieving cost-effective biofuels and bioproducts derived from algal biomass will require improvements along the entire value chain, including identification of robust, high-productivity strains and development of advanced genetic tools. Though there have been modest advances in development of genetic systems for the model alga Chlamydomonas reinhardtii, progress in development of algal genetic tools, especially as applied to non-model algae, has generally lagged behind that of more commonly utilized laboratory and industrial microbes. This is in part due to the complex organellar structure of algae, including robust cell walls and intricate compartmentalization of target loci, as well as prevalent gene silencing mechanisms, which hinder facile utilization of conventional genetic engineering tools and methodologies. However, recent progress in global tool development has opened the door for implementation of strain-engineering strategies in industrially-relevant algal strains. Here, we review recent advances in algal genetic tool development and applications in eukaryotic microalgae.

  1. Direct conversion of algal biomass to biofuel

    DOEpatents

    Deng, Shuguang; Patil, Prafulla D; Gude, Veera Gnaneswar

    2014-10-14

    A method and system for providing direct conversion of algal biomass. Optionally, the method and system can be used to directly convert dry algal biomass to biodiesels under microwave irradiation by combining the reaction and combining steps. Alternatively, wet algae can be directly processed and converted to fatty acid methyl esters, which have the major components of biodiesels, by reacting with methanol at predetermined pressure and temperature ranges.

  2. Algal and fungal diversity in Antarctic lichens.

    PubMed

    Park, Chae Haeng; Kim, Kyung Mo; Elvebakk, Arve; Kim, Ok-Sun; Jeong, Gajin; Hong, Soon Gyu

    2015-01-01

    The composition of lichen ecosystems except mycobiont and photobiont has not been evaluated intensively. In addition, recent studies to identify algal genotypes have raised questions about the specific relationship between mycobiont and photobiont. In the current study, we analyzed algal and fungal community structures in lichen species from King George Island, Antarctica, by pyrosequencing of eukaryotic large subunit (LSU) and algal internal transcribed spacer (ITS) domains of the nuclear rRNA gene. The sequencing results of LSU and ITS regions indicated that each lichen thallus contained diverse algal species. The major algal operational taxonomic unit (OTU) defined at a 99% similarity cutoff of LSU sequences accounted for 78.7-100% of the total algal community in each sample. In several cases, the major OTUs defined by LSU sequences were represented by two closely related OTUs defined by 98% sequence similarity of ITS domain. The results of LSU sequences indicated that lichen-associated fungi belonged to the Arthoniomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, and Sordariomycetes of the Ascomycota, and Tremellomycetes and Cystobasidiomycetes of the Basidiomycota. The composition of major photobiont species and lichen-associated fungal community were mostly related to the mycobiont species. The contribution of growth forms or substrates on composition of photobiont and lichen-associated fungi was not evident.

  3. Vertical profile of algal distribution during aeration prior to intake tower for safe drinking water.

    PubMed

    Kim, H K; Kim, J M; Lee, Y J; Kim, B I; Lee, B C; Chang, N I

    2007-01-01

    Blue-green algae or cyanobacteria comprise a diverse group of organisms, all of which generate potent natural toxins, as well as characteristic odours. In particular, blue-green algae, such as Microcystis and Anabaena, are often detected abundantly in surface water used as a drinking water resource. In order to confirm our ability to provide safe drinking water even during a water bloom, we have conducted an investigation into the vertical distribution of algae during aeration prior to entry into the intake tower at a dam site. Our analysis of the vertical algal distribution during aeration indicated that aeration occurring at the intake tower exerts a significant influence on the safety of the drinking water. It was determined that the discontinuation of aeration and an increase in the depth at which water intake is conducted, constitutes a viable strategy for the maintenance of toxin- and odour-free drinking water, particularly during water bloom events.

  4. [Intoxication of botulinum toxin].

    PubMed

    Chudzicka, Aleksandra

    2015-09-01

    Botulinum toxin is an egzotoxin produced by Gram positive bacteria Clostridium botulinum. It is among the most potent toxins known. The 3 main clinical presentations of botulism are as follows: foodborne botulism, infant botulism and wound botulism. The main symptom of intoxication is flat muscles paralysis. The treatment is supportive care and administration of antitoxin. In prevention the correct preparing of canned food is most important. Botulinum toxin is accepted as a biological weapon.

  5. Effects of interactions between algal densities and cadmium concentrations on Ceriodaphnia dubia fecundity and survival.

    PubMed

    Rodgher, Suzelei; Luiz Gaeta Espíndola, Evaldo

    2008-11-01

    The influence of different densities of the algae Pseudokirchneriella subcapitata on the chronic toxicity of cadmium to Ceriodaphnia dubia was investigated. The importance of algal cells as a source of metal to zooplankton was studied by exposing P. subcapitata cells to free cadmium ions and supplying the algae as food to C. dubia. The results of a bifactorial analysis (metal versus food levels) showed that metal toxicity to zooplankton was dependent on food level. Significant toxic effects on the fecundity and survival of C. dubia were observed at low metal concentrations with high algal density. Algae contaminated with Cd(2+) were less toxic to cladoceran than was the Cd(2+) in solution. Green algae retained cadmium and released low metal concentration in the test medium. We concluded that algal cells are an important route of exposure to metal and a factor that has an appreciable influence on the expression of metal toxicity to daphnids.

  6. Botulinum toxin injection - larynx

    MedlinePlus

    Injection laryngoplasty; Botox - larynx: spasmodic dysphonia-BTX; Essential voice tremor (EVT)-btx; Glottic insufficiency; Percutaneous electromyography - guided botulinum toxin treatment; Percutaneous indirect laryngoscopy - ...

  7. Chorea caused by toxins.

    PubMed

    Miyasaki, Janis M

    2011-01-01

    Chorea is uncommonly caused by toxins. Anecdotal evidence from cases of toxin-induced chorea assists in our understanding of neurodegenerative diseases associated with chorea. Beginning in medieval Europe with ergotism and the "fire that twisted people," spanning to crack dancing in contemporary times and the coexistence of alcohol abuse with chorea, toxins may exert direct effects to enhance mesolimbic dopamine transmission or indirect effects through gamma-aminobutyric acid modulation. The following chapter will discuss toxins associated with chorea and the presumed pathophysiology underlying the movement disorders in these case series. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Extremely Low Frequency Magnetic Field (ELF-MF) Exposure Sensitizes SH-SY5Y Cells to the Pro-Parkinson's Disease Toxin MPP(.).

    PubMed

    Benassi, Barbara; Filomeni, Giuseppe; Montagna, Costanza; Merla, Caterina; Lopresto, Vanni; Pinto, Rosanna; Marino, Carmela; Consales, Claudia

    2016-08-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by dopaminergic neuron loss, with an etiopathogenesis involving both genetic and environmental factors. The occupational/residential exposure to the electromagnetic fields has been recently associated with an increased risk of neurodegenerative diseases; it has been thus proposed that the extremely low frequency magnetic field (ELF-MF) may contribute to neurodegenerative etiopathogenesis, as its interaction with biological systems directly impairs redox homeostasis in specific areas of the brain. The molecular mechanisms elicited by ELF-MF, and their potential involvement in PD onset, still remain unclear. To this end, we set up a generator of ELF-MF able to stably and homogeneously reproduce environmental prolonged exposure to ELF-MF (50 Hz, 1 mT). Results obtained indicate that ELF-MF exposure alters cell response of SH-SY5Y cells to MPP(+). We demonstrate that ELF-MF does not affect per se survival, shape, and morphology of both proliferating and differentiated SH-SY5Y cells but significantly impairs redox homeostasis and thiol content, triggering an increase in protein carbonylation. As a result, toxicity of MPP(+), even at low doses, is highly enhanced in ELF-MF-exposed cells due to a significant increase in ROS levels, potentiation of oxidative damage, and induction of a caspase-dependent apoptosis. Pre-incubation with the thiol antioxidants N-acetyl-L-cysteine and GSH ethyl-ester significantly reduces the extent of oxidative damage and protects cells from death induced by the combined treatment ELF-MF/MPP(+). Taken overall, our results demonstrate the redox-based molecular interaction between ELF-MF and PD neurotoxins in vitro, and open a new scenario for defining the synergy of environmental factors in PD onset.

  9. Community Needs Assessment After Microcystin Toxin Contamination of a Municipal Water Supply - Lucas County, Ohio, September 2014.

    PubMed

    McCarty, Carolyn L; Nelson, Leigh; Eitniear, Samantha; Zgodzinski, Eric; Zabala, Amanda; Billing, Laurie; DiOrio, Mary

    2016-09-09

    On August 1, 2014, routine testing at the Collins Park Water Treatment Plant in Lucas County, Ohio, revealed microcystin toxin levels in drinking water had reached 3.19 μg/L, surpassing the Ohio Environmental Protection Agency (EPA) drinking water advisory threshold of 1.0 μg/L. Microcystin is a hepatoxin released by cyanobacteria in certain harmful algal blooms. Exposure to microcystin has been associated with gastrointestinal and hepatic illness in both humans and animals (1-3). On August 2, a do-not-drink advisory was issued, warning community members not to drink, boil, or use the water for cooking or brushing teeth. Public health officials used traditional and social media outlets to disseminate public health messages to affected communities. On August 4, 2014, the advisory was lifted after multiple water samples confirmed microcystin toxin levels had dropped below the advisory threshold. To assess communication strategies, water exposure, and household needs, the Ohio Department of Health (ODH) and Toledo-Lucas County Health Department (TLCHD) conducted a Community Assessment for Public Health Emergency Response (CASPER) in Lucas County. Most households (88.1%) reported hearing about the advisory the morning it was issued, but 11% reported drinking and 21% reported brushing teeth with municipal water during the advisory. Household members reported physical (16%) and mental (10%) health concerns that they believed were related to the advisory and activity disruptions including temporarily staying outside of the home (6%) during the advisory and continued use of alternative water sources after the advisory was lifted (82%). During a do-not-drink advisory, governmental agencies and community partners need to engage in joint prevention and response efforts to decrease water exposure and prevent activity disruptions.

  10. Wastewater treatment and algal production in high rate algal ponds with carbon dioxide addition.

    PubMed

    Park, J B K; Craggs, R J

    2010-01-01

    High rate algal ponds (HRAPs) provide improved wastewater treatment over conventional wastewater stabilisation ponds; however, algal production and recovery of wastewater nutrients as algal biomass is limited by the low carbon:nitrogen ratio of wastewater. This paper investigates the influence of CO(2) addition (to augment daytime carbon availability) on wastewater treatment performance and algal production of two pilot-scale HRAPs operated with different hydraulic retention times (4 and 8 days) over a New Zealand Summer (November-March, 07/08). Weekly measurements were made of influent and effluent flow rate and water qualities, algal and bacterial biomass production, and the percentage of algae biomass harvested in gravity settling units. This research shows that the wastewater treatment HRAPs with CO(2) addition achieved a mean algal productivity of 16.7 g/m(2)/d for the HRAP(4d) (4 d HRT, maximum algae productivity of 24.7 g/m(2)/d measured in January 08) and 9.0 g/m(2)/d for the HRAP(8d) (8 d HRT)). Algae biomass produced in the HRAPs was efficiently harvested by simple gravity settling units (mean harvested algal productivity: 11.5 g/m(2)/d for the HRAP(4d) and 7.5 g/m(2)/d for the HRAP(8d) respectively). Higher bacterial composition and the larger size of algal/bacterial flocs of the HRAP(8d) biomass increased harvestability (83%) compared to that of HRAP(4d) biomass (69%).

  11. Diarrhetic Shellfish Toxins and Other Lipophilic Toxins of Human Health Concern in Washington State

    PubMed Central

    Trainer, Vera L.; Moore, Leslie; Bill, Brian D.; Adams, Nicolaus G.; Harrington, Neil; Borchert, Jerry; da Silva, Denis A. M.; Eberhart, Bich-Thuy L.

    2013-01-01

    The illness of three people in 2011 after their ingestion of mussels collected from Sequim Bay State Park, Washington State, USA, demonstrated the need to monitor diarrhetic shellfish toxins (DSTs) in Washington State for the protection of human health. Following these cases of diarrhetic shellfish poisoning, monitoring for DSTs in Washington State became formalized in 2012, guided by routine monitoring of Dinophysis species by the SoundToxins program in Puget Sound and the Olympic Region Harmful Algal Bloom (ORHAB) partnership on the outer Washington State coast. Here we show that the DSTs at concentrations above the guidance level of 16 μg okadaic acid (OA) + dinophysistoxins (DTXs)/100 g shellfish tissue were widespread in sentinel mussels throughout Puget Sound in summer 2012 and included harvest closures of California mussel, varnish clam, manila clam and Pacific oyster. Concentrations of toxins in Pacific oyster and manila clam were often at least half those measured in blue mussels at the same site. The primary toxin isomer in shellfish and plankton samples was dinophysistoxin-1 (DTX-1) with D. acuminata as the primary Dinophysis species. Other lipophilic toxins in shellfish were pectenotoxin-2 (PTX-2) and yessotoxin (YTX) with azaspiracid-2 (AZA-2) also measured in phytoplankton samples. Okadaic acid, azaspiracid-1 (AZA-1) and azaspiracid-3 (AZA-3) were all below the levels of detection by liquid chromatography tandem mass spectrometry (LC-MS/MS). A shellfish closure at Ruby Beach, Washington, was the first ever noted on the Washington State Pacific coast due to DSTs. The greater than average Fraser River flow during the summers of 2011 and 2012 may have provided an environment conducive to dinoflagellates and played a role in the prevalence of toxigenic Dinophysis in Puget Sound. PMID:23760013

  12. Diarrhetic shellfish toxins and other lipophilic toxins of human health concern in Washington State.

    PubMed

    Trainer, Vera L; Moore, Leslie; Bill, Brian D; Adams, Nicolaus G; Harrington, Neil; Borchert, Jerry; da Silva, Denis A M; Eberhart, Bich-Thuy L

    2013-05-28

    The illness of three people in 2011 after their ingestion of mussels collected from Sequim Bay State Park, Washington State, USA, demonstrated the need to monitor diarrhetic shellfish toxins (DSTs) in Washington State for the protection of human health. Following these cases of diarrhetic shellfish poisoning, monitoring for DSTs in Washington State became formalized in 2012, guided by routine monitoring of Dinophysis species by the SoundToxins program in Puget Sound and the Olympic Region Harmful Algal Bloom (ORHAB) partnership on the outer Washington State coast. Here we show that the DSTs at concentrations above the guidance level of 16 μg okadaic acid (OA) + dinophysistoxins (DTXs)/100 g shellfish tissue were widespread in sentinel mussels throughout Puget Sound in summer 2012 and included harvest closures of California mussel, varnish clam, manila clam and Pacific oyster. Concentrations of toxins in Pacific oyster and manila clam were often at least half those measured in blue mussels at the same site. The primary toxin isomer in shellfish and plankton samples was dinophysistoxin-1 (DTX-1) with D. acuminata as the primary Dinophysis species. Other lipophilic toxins in shellfish were pectenotoxin-2 (PTX-2) and yessotoxin (YTX) with azaspiracid-2 (AZA-2) also measured in phytoplankton samples. Okadaic acid, azaspiracid-1 (AZA-1) and azaspiracid-3 (AZA-3) were all below the levels of detection by liquid chromatography tandem mass spectrometry (LC-MS/MS). A shellfish closure at Ruby Beach, Washington, was the first ever noted on the Washington State Pacific coast due to DSTs. The greater than average Fraser River flow during the summers of 2011 and 2012 may have provided an environment conducive to dinoflagellates and played a role in the prevalence of toxigenic Dinophysis in Puget Sound.

  13. Algal Supply System Design - Harmonized Version

    SciTech Connect

    Abodeely, Jared; Stevens, Daniel; Ray, Allison; Newby, Deborah; Schaller, Kastli

    2013-03-01

    The objective of this design report is to provide an assessment of current technologies used for production, dewatering, and converting microalgae cultivated in open-pond systems to biofuel. The original draft design was created in 2011 and has subsequently been brought into agreement with the DOE harmonized model. The design report extends beyond this harmonized model to discuss some of the challenges with assessing algal production systems, including the ability to (1) quickly assess alternative algal production system designs, (2) assess spatial and temporal variability, and (3) perform large-scale assessments considering multiple scenarios for thousands of potential sites. The Algae Logistics Model (ALM) was developed to address each of these limitations of current modeling efforts to enable assessment of the economic feasibility of algal production systems across the United States. The (ALM) enables (1) dynamic assessments using spatiotemporal conditions, (2) exploration of algal production system design configurations, (3) investigation of algal production system operating assumptions, and (4) trade-off assessments with technology decisions and operating assumptions. The report discusses results from the ALM, which is used to assess the baseline design determined by harmonization efforts between U.S. DOE national laboratories. Productivity and resource assessment data is provided by coupling the ALM with the Biomass Assessment Tool developed at PNNL. This high-fidelity data is dynamically passed to the ALM and used to help better understand the impacts of spatial and temporal constraints on algal production systems by providing a cost for producing extracted algal lipids annually for each potential site.

  14. Decrease of marine toxin content in bivalves by industrial processes.

    PubMed

    Reboreda, Antonio; Lago, Jorge; Chapela, María-José; Vieites, Juan M; Botana, Luis M; Alfonso, Amparo; Cabado, Ana G

    2010-01-01

    Harmful algal blooms cause important economical losses due to the accumulation of toxins in shellfish. Natural detoxification occurs but this mechanism is very slow in most cases. The achievement of a method for the rapid detoxification of commercial bivalves would be very interesting for the shellfish harvesting sector in order to diminish economical losses due to harvesting areas closure. In this work, four different methods easily applicable in the food industry (freezing, evisceration, ozonization and thermal processing) were studied to gain the detoxification of four species of bivalves (mussels, scallops, clams and cockles) contaminated with the three main types of toxins (ASP, DSP, PSP). Results show that for ASP a significant decrease of the toxin levels below the legal limit (20 microg/g) is achieved by using hepatopancreas ablation or combination of simple steps (evisceration and/or thermal processing/and or freezing). In our hands, PSP toxin levels are sharply decreased under the limit of detection (35 microg STX eq/100g) after a thermal processing, inducing percentages of detoxification higher than 50%. The effect of freezing on the levels of PSP is very dependent on the matrix studied. DSP toxins are not significantly reduced with none of these methods. Copyright 2009 Elsevier Ltd. All rights reserved.

  15. Effects of Algal-Derived Carbon on Sediment Methane Production in a Eutrophic Ohio Reservoir

    NASA Astrophysics Data System (ADS)

    Berberich, M.; Buffam, I. D.; Beaulieu, J. J.; Hamilton, T. L.; Waldo, S.; Li, X.

    2016-12-01

    Nutrient loading is known to have adverse consequences for aquatic ecosystems, particularly in the form of algal blooms that may result. These blooms pose problems for humans and wildlife, including harmful toxin release, aquatic hypoxia and increased costs for water treatment. Another potential disservice resulting from algal blooms is the enhanced production of methane (CH4), a potent greenhouse gas, in aquatic sediments. Laboratory experiments have shown that algal biomass additions to sediment cores increase rates of CH4 production, but it is unclear whether or not this effect occurs at the ecosystem scale. The goal of this research was to explore the link between algal-derived carbon and methane production in the sediment of a eutrophic reservoir located in southwest Ohio, using a sampling design that capitalized on spatial and temporal gradients in autochthonous carbon input to sediments. Specifically, we aimed to determine if the within-reservoir gradient of sediment algal-derived organic matter and sediment CH4 production rates correlate. This was done by retrieving sediment cores from 15 sites within the reservoir along a known gradient of methane emission rates, at two separate time points in 2016: late spring before the sediments had received large amounts of algal input and mid-summer after algal blooms had been prevalent in the reservoir. Potential CH4 production rates, sediment organic matter source, and microbial community composition were characterized from each of the sites during both sampling periods. Sediment organic matter was characterized by source using a combination of C/N ratios, C and N stable isotopes, and excitation emission matrix spectroscopy (EEMs). Potential CH4 production rates were highest from sediments near the main reservoir tributary, with the four highest potential CH4 production rates corresponding to four sampling sites located near this main inlet. These high CH4 potential production rates also correspond to the highest

  16. Algal Energy Conversion and Capture

    NASA Astrophysics Data System (ADS)

    Hazendonk, P.

    2015-12-01

    We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

  17. Satellite Monitoring of Cyanobacterial Harmful Algal Bloom Frequency in Recreational Waters and Drinking Water Sources

    NASA Technical Reports Server (NTRS)

    Clark, John M.; Schaeffer, Blake A.; Darling, John A.; Urquhart, Erin A.; Johnston, John M.; Ignatius, Amber R.; Myer, Mark H.; Loftin, Keith A.; Werdell, P. Jeremy; Stumpf, Richard P.

    2017-01-01

    Cyanobacterial harmful algal blooms (cyanoHAB) cause extensive problems in lakes worldwide, including human and ecological health risks, anoxia and sh kills, and taste and odor problems. CyanoHABs are a particular concern in both recreational waters and drinking water sources because of their dense biomass and the risk of exposure to toxins. Successful cyanoHAB assessment using satellites may provide an indicator for human and ecological health protection. In this study, methods were developed to assess the utility of satellite technology for detecting cyanoHAB frequency of occurrence at locations of potential management interest. The European Space Agency's MEdium Resolution Imaging Spectrometer (MERIS) was evaluated to prepare for the equivalent series of Sentinel-3 Ocean and Land Colour Imagers (OLCI) launched in 2016 as part of the Copernicus program. Based on the 2012 National Lakes Assessment site evaluation guidelines and National Hydrography Dataset, the continental United States contains 275,897 lakes and reservoirs greater than 1 ha in area. Results from this study show that 5.6% of waterbodies were resolvable by satellites with 300 m single-pixel resolution and 0.7% of waterbodies were resolvable when a three by three pixel (3 x 3-pixel) array was applied based on minimum Euclidian distance from shore. Satellite data were spatially joined to U.S. public water surface intake (PWSI) locations, where single-pixel resolution resolved 57% of the PWSI locations and a 3 x 3-pixel array resolved 33% of the PWSI locations. Recreational and drinking water sources in Florida and Ohio were ranked from 2008 through 2011 by cyanoHAB frequency above the World Health Organizations (WHO) high threshold for risk of 100,000 cells m/L. The ranking identified waterbodies with values above the WHO high threshold, where Lake Apopka, FL (99.1%) and Grand Lake St. Marys, OH (83%) had the highest observed bloom frequencies per region. The method presented here may indicate

  18. Supported liquid membrane-liquid chromatography-mass spectrometry analysis of cyanobacterial toxins in fresh water systems

    NASA Astrophysics Data System (ADS)

    Mbukwa, Elbert A.; Msagati, Titus A. M.; Mamba, Bhekie B.

    Harmful algal blooms (HABs) are increasingly becoming of great concern to water resources worldwide due to indiscriminate waste disposal habits resulting in water pollution and eutrophication. When cyanobacterial cells lyse (burst) they release toxins called microcystins (MCs) that are well known for their hepatotoxicity (causing liver damage) and have been found in eutrophic lakes, rivers, wastewater ponds and other water reservoirs. Prolonged exposure to low concentrated MCs are equally of health importance as they are known to be bioaccumulative and even at such low concentration do exhibit toxic effects to aquatic animals, wildlife and human liver cells. The application of common treatment processes for drinking water sourced from HABs infested reservoirs have the potential to cause algal cell lyses releasing low to higher amounts of MCs in finished water. Trace microcystins in water/tissue can be analyzed and quantified using Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) following solid-phase extraction (SPE) sample clean-up procedures. However, extracting MCs from algal samples which are rich in chlorophyll pigments and other organic matrices the SPE method suffers a number of drawbacks, including cartridge clogging, long procedural steps and use of larger volumes of extraction solvents. We applied a supported liquid membrane (SLM) based technique as an alternative sample clean-up method for LC-ESI-MS analysis of MCs from both water and algal cells. Four (4) MC variants (MC-RR, -YR, -LR and -WR) from lyophilized cells of Microcystis aeruginosa and water collected from a wastewater pond were identified) and quantified using LC-ESI-MS following a SLM extraction and liquid partitioning step, however, MC-WR was not detected from water extracts. Within 45 min of SLM extraction all studied MCs were extracted and pre-concentrated in approximately 15 μL of an acceptor phase at an optimal pH 2.02 of the donor phase (sample). The highest

  19. Resistance of ovine, caprine and bovine endothelial cells to Clostridium perfringens type D epsilon toxin in vitro.

    PubMed

    Uzal, F A; Rolfe, B E; Smith, N J; Thomas, A C; Kelly, W R

    1999-08-01

    Ovine, caprine and bovine endothelial cells were grown in vitro and challenged with Clostridium perfringens type D epsilon toxin to compare their susceptibility to this toxin. Madin Darby canine kidney (MDCK) cells, which are known to be susceptible to epsilon toxin, were used as a positive control. No morphological alterations were observed in any of the endothelial cell cultures tested, even after challenging with doses as high as 1200 MLD50/ml of epsilon toxin. MDCK cells showed contour rounding and nuclear condensation as early as 30 min after exposure to 100 MLD50/ml of epsilon toxin and after 60 min of exposure to 12.5 MLD50/ml of the same toxin. All the MDCK cells were dead after 3 h of exposure to all concentrations of epsilon toxin. The results indicate that ovine, caprine and bovine endothelial cells are not morphologically responsive to the action of epsilon toxin in vitro.

  20. Platy algal banks: Modern and ancient

    SciTech Connect

    Brinton, L. )

    1990-05-01

    Plaly algal banks and associated cycles in the lower Ismay zone of the Paradox Formation are exposed along the walls of the San Juan River canyon, southeastern Utah. These complexes closely resemble algal bank reservoirs in the lower Ismay zone of Ismay and Cache, and possibly other Paradox basin fields. Similarities include facies relationships, lateral and vertical textural variations, and early diagenesis. Extensive algal banks exposed along the San Juan canyon generally have flat bases and mound and swale topographic surfaces, and are separated by interbank channels. The surficial mounds have a regular amplitude and wavelength suggesting a hydrologic rather than biologic influence on topography. The banks themselves, however, are believed to be thick, predominantly in-situ accumulations of platy algae. Distribution of algal banks can be mapped on a field scale; mound and swale topographic features may be identified in core on the basis of depositional and early diagenetic characteristics. Halimeda bioherms (Holocene) cover large areas behind the Great Barrier Reef, developing adjacent to the deep passes that separate the individual reefs. These large in-situ accumulations (20-50 m deep) display similar bank geometries, interbank features, topographic features, vertical textural sequence (including porosity type and distribution), and facies relationships to algal banks observed in the outcropping and subsurface Paradox Formation. Although the hydrodynamic and paleobathymetric settings differ markedly between these two examples, analogies between the mounds themselves are very close. The resemblance lends relevance to exploration and development drilling.

  1. Algal swimming velocities signal fatty acid accumulation.

    PubMed

    Hansen, Travis J; Hondzo, Miki; Mashek, Mara T; Mashek, Douglas G; Lefebvre, Paul A

    2013-01-01

    The use of microalgae for biofuel production will be beneficial to society if we can produce biofuels at large scales with minimal mechanical energy input in the production process. Understanding micro-algal physiological responses under variable environmental conditions in bioreactors is essential for the optimization of biofuel production. We demonstrate that measuring micro-algal swimming speed provides information on culture health and total fatty acid accumulation. Three strains of Chlamydomonas reinhardtii were grown heterotrophically on acetate and subjected to various levels of nitrogen starvation. Other nutrient levels were explored to determine their effect on micro-algal kinetics. Swimming velocities were measured with two-dimensional micro-particle tracking velocimetry. The results show an inverse linear relationship between normalized total fatty acid mass versus swimming speed of micro-algal cells. Analysis of RNA sequencing data confirms these results by demonstrating that the biological processes of cell motion and the generation of energy precursors are significantly down-regulated. Experiments demonstrate that changes in nutrient concentration in the surrounding media also affect swimming speed. The findings have the potential for the in situ and indirect assessment of lipid content by measuring micro-algal swimming kinetics.

  2. Defense against toxin weapons

    SciTech Connect

    Franz, D.R.

    1994-01-01

    The purpose of this manual is to provide basic information on biological toxins to military leaders and health-care providers at all levels to help them make informed decisions on protecting their troops from toxins. Much of the information contained herein will also be of interest to individuals charged with countering domestic and international terrorism. We typically fear what we do not understand.

  3. Eosinophilia and biotoxin exposure in bottlenose dolphins (Tursiops truncatus) from a coastal area impacted by repeated mortality events

    SciTech Connect

    Schwacke, Lori H.; Twiner, Michael J.; De Guise, Sylvain; Balmer, Brian C.; Wells, Randall S.; Rotstein, David C.; Varela, Rene A.; Hansen, Larry J.; Zolman, Eric S.; Spradlin, Trevor R.; and others

    2010-08-15

    Bottlenose dolphins (Tursiops truncatus) inhabiting coastal waters in the northern Gulf of Mexico have been impacted by recurrent unusual mortality events over the past few decades. Several of these mortality events along the Florida panhandle have been tentatively attributed to poisoning from brevetoxin produced by the dinoflagellate Karenia brevis. While dolphins in other regions of the Florida coast are often exposed to K. brevis blooms, large-scale dolphin mortality events are relatively rare and the frequency and magnitude of die-offs along the Panhandle raise concern for the apparent vulnerability of dolphins in this region. We report results from dolphin health assessments conducted near St. Joseph Bay, Florida, an area impacted by 3 unusual die-offs within a 7-year time span. An eosinophilia syndrome, manifested as an elevated blood eosinophil count without obvious cause, was observed in 23% of sampled dolphins. Elevated eosinophil counts were associated with decreased T-lymphocyte proliferation and increased neutrophil phagocytosis. In addition, indication of chronic low-level exposure to another algal toxin, domoic acid produced by the diatom Pseudo-nitzschia spp., was determined. Previous studies of other marine mammal populations exposed recurrently to Pseudo-nitzschia blooms have suggested a possible link between the eosinophilia and domoic acid exposure. While the chronic eosinophilia syndrome could over the long-term produce organ damage and alter immunological status and thereby increase vulnerability to other challenges, the significance of the high prevalence of the syndrome to the observed mortality events in the St. Joseph Bay area is unclear. Nonetheless, the unusual immunological findings and concurrent evidence of domoic acid exposure in this sentinel marine species suggest a need for further investigation to elucidate potential links between chronic, low-level exposure to algal toxins and immune health.

  4. Protection against Shiga Toxins

    PubMed Central

    Kavaliauskiene, Simona; Dyve Lingelem, Anne Berit; Skotland, Tore; Sandvig, Kirsten

    2017-01-01

    Shiga toxins consist of an A-moiety and five B-moieties able to bind the neutral glycosphingolipid globotriaosylceramide (Gb3) on the cell surface. To intoxicate cells efficiently, the toxin A-moiety has to be cleaved by furin and transported retrogradely to the Golgi apparatus and to the endoplasmic reticulum. The enzymatically active part of the A-moiety is then translocated to the cytosol, where it inhibits protein synthesis and in some cell types induces apoptosis. Protection of cells can be provided either by inhibiting binding of the toxin to cells or by interfering with any of the subsequent steps required for its toxic effect. In this article we provide a brief overview of the interaction of Shiga toxins with cells, describe some compounds and conditions found to protect cells against Shiga toxins, and discuss whether they might also provide protection in animals and humans. PMID:28165371

  5. A synopsis of research needs identified at the Interagency, International Symposium on Cyanobacterial Harmful Algal Blooms (ISOC-HAB).

    PubMed

    Hudnell, H Kenneth; Dortch, Quay

    2008-01-01

    Evidence indicates that the incidence of cyanobacterial harmful algal blooms (CHABs) is increasing in spatial extent and temporal frequency worldwide. Cyanobacterial blooms produce highly potent toxins and huge, noxious biomasses in surface Waters used for recreation, commerce, and as drinking water sources. The Interagency, International Symposium on Cyanobacterial Harmful Algal Blooms (ISOC-HAB) characterized the state of the science and identified research needed to address the risks posed by CHABs to human health and ecosystem sustainability. This chapter provides a synopsis of CHAB research needs that were identified by workgroups that addressed charges in major topic areas. The research and infrastructure needed are listed under nine categories: 1) Analytical Methods; 2) CHAB Occurrence; 3) CHAB Causes; 4) Human Health; 5) Ecosystem Sustainability; 6) CHAB Prevention; 7) CHAB Control and Mitigation; 8) Risk Assessment and; 9) Infrastructure. A number of important issues must be addressed to successfully confront the health, ecologic, and economic challenges presented by CHABs. Near-term research goals include the development of field-ready tests to identify and quantify cells and toxins, the production of certified reference standards and bulk toxins, formal assessments of CHAB incidence, improved understanding of toxin effects, therapeutic interventions, ecologically benign means to prevent and control CHABs, supplemental drinking water treatment techniques, and the development of risk assessment and management strategies. Long-term goals include the assimilation of CHAB databases into emerging U.S. and international observing systems, the development of quantitative models to predict CHAB occurrence, effects, and management outcomes, and economic analyses of CAHB costs and management benefits. Accomplishing further infrastructure development and freshwater HAB research is discussed in relationship to the Harmful Algal Blooms and Hypoxia Research and Control

  6. Monitoring Algal Blooms in a Southwestern U.S. Reservoir System

    NASA Astrophysics Data System (ADS)

    Tarrant, Philip; Neuer, Susanne

    2009-02-01

    In recent years, several studies have explored the potential of higher-resolution sensor data for monitoring phytoplankton primary production in coastal areas and lakes. Landsat data have been used to monitor algal blooms [Chang et al., 2004; Vincent et al., 2004], and Moderate Resolution Imaging Spectroradiometer (MODIS) 250-meter and Medium Resolution Imaging Spectrometer (MERIS) full-resolution (300-meter) bands have been utilized to detect cyanobacterial blooms [Reinart and Kutser, 2006] as well as to monitor water quality [Koponen et al., 2004]. Field sampling efforts and MODIS 250-meter data are now being combined to develop a cost-effective method for monitoring water quality in a southwestern U.S. reservoir system. In the Phoenix, Ariz., metropolitan area, the Salt River reservoirs supply more than 3.5 million people, a population expected to rise to more than 6 million by 2030. Given that reservoir capacities have physical limitations, maintaining water quality will become critical as the population expands. Potentially noxious algal blooms that can release toxins and may affect water quality by modifying taste and odor have become a major concern in recent years. While frequent field sampling regimes are expensive, satellite imagery can be applied cost-effectively to monitor algal biomass trends remotely, and this information could provide early warning of blooms in these reservoirs.

  7. Algal Biology Toolbox Workshop Summary Report

    SciTech Connect

    None, None

    2016-08-01

    DOE-EERE's Bioenergy Technologies Office (BETO) works to accelerate the development of a sustainable, cost-competitive, advanced biofuel industry that can strengthen U.S. energy security, environmental quality, and economic vitality, through research, development, and demonstration projects in partnership with industry, academia, and national laboratory partners. BETO’s Advanced Algal Systems Program (also called the Algae Program) has a long-term applied research and development (R&D) strategy to increase the yields and lower the costs of algal biofuels. The team works with partners to develop new technologies, to integrate technologies at commercially relevant scales, and to conduct crosscutting analyses to better understand the potential and challenges of the algal biofuels industry. Research has indicated that this industry is capable of producing billions of gallons of renewable diesel, gasoline, and jet fuels annually. R&D activities are integrated with BETO’s longstanding effort to accelerate the commercialization of lignocellulosic biofuels.

  8. Critical evaluation and modeling of algal harvesting using dissolved air flotation. DAF Algal Harvesting Modeling

    DOE PAGES

    Zhang, Xuezhi; Hewson, John C.; Amendola, Pasquale; ...

    2014-07-14

    In our study, Chlorella zofingiensis harvesting by dissolved air flotation (DAF) was critically evaluated with regard to algal concentration, culture conditions, type and dosage of coagulants, and recycle ratio. Harvesting efficiency increased with coagulant dosage and leveled off at 81%, 86%, 91%, and 87% when chitosan, Al3+, Fe3+, and cetyl trimethylammonium bromide (CTAB) were used at dosages of 70, 180, 250, and 500 mg g-1, respectively. The DAF efficiency-coagulant dosage relationship changed with algal culture conditions. In evaluating the influence of the initial algal concentration and recycle ratio revealed that, under conditions typical for algal harvesting, we found that itmore » is possible that the number of bubbles is insufficient. A DAF algal harvesting model was developed to explain this observation by introducing mass-based floc size distributions and a bubble limitation into the white water blanket model. Moreover, the model revealed the importance of coagulation to increase floc-bubble collision and attachment, and the preferential interaction of bubbles with larger flocs, which limited the availability of bubbles to the smaller sized flocs. The harvesting efficiencies predicted by the model agree reasonably with experimental data obtained at different Al3+ dosages, algal concentrations, and recycle ratios. Based on this modeling, critical parameters for efficient algal harvesting were identified.« less

  9. Critical evaluation and modeling of algal harvesting using dissolved air flotation. DAF Algal Harvesting Modeling

    SciTech Connect

    Zhang, Xuezhi; Hewson, John C.; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton; Chen, Yongsheng; Hu, Qiang

    2014-07-14

    In our study, Chlorella zofingiensis harvesting by dissolved air flotation (DAF) was critically evaluated with regard to algal concentration, culture conditions, type and dosage of coagulants, and recycle ratio. Harvesting efficiency increased with coagulant dosage and leveled off at 81%, 86%, 91%, and 87% when chitosan, Al3+, Fe3+, and cetyl trimethylammonium bromide (CTAB) were used at dosages of 70, 180, 250, and 500 mg g-1, respectively. The DAF efficiency-coagulant dosage relationship changed with algal culture conditions. In evaluating the influence of the initial algal concentration and recycle ratio revealed that, under conditions typical for algal harvesting, we found that it is possible that the number of bubbles is insufficient. A DAF algal harvesting model was developed to explain this observation by introducing mass-based floc size distributions and a bubble limitation into the white water blanket model. Moreover, the model revealed the importance of coagulation to increase floc-bubble collision and attachment, and the preferential interaction of bubbles with larger flocs, which limited the availability of bubbles to the smaller sized flocs. The harvesting efficiencies predicted by the model agree reasonably with experimental data obtained at different Al3+ dosages, algal concentrations, and recycle ratios. Based on this modeling, critical parameters for efficient algal harvesting were identified.

  10. Algal recycling enhances algal productivity and settleability in Pediastrum boryanum pure cultures.

    PubMed

    Park, Jason B K; Craggs, Rupert J; Shilton, Andy N

    2015-12-15

    Recycling a portion of gravity harvested algae (i.e. algae and associated bacteria biomass) has been shown to improve both algal biomass productivity and harvest efficiency by maintaining the dominance of a rapidly-settleable colonial alga, Pediastrum boryanum in both pilot-scale wastewater treatment High Rate Algal Ponds (HRAP) and outdoor mesocosms. While algal recycling did not change the relative proportions of algae and bacteria in the HRAP culture, the contribution of the wastewater bacteria to the improved algal biomass productivity and settleability with the recycling was not certain and still required investigation. P. boryanum was therefore isolated from the HRAP and grown in pure culture on synthetic wastewater growth media under laboratory conditions. The influence of recycling on the productivity and settleability of the pure P. boryanum culture was then determined without wastewater bacteria present. Six 1 L P. boryanum cultures were grown over 30 days in a laboratory growth chamber simulating New Zealand summer conditions either with (Pr) or without (Pc) recycling of 10% of gravity harvested algae. The cultures with recycling (Pr) had higher algal productivity than the controls (Pc) when the cultures were operated at both 4 and 3 d hydraulic retention times by 11% and 38% respectively. Furthermore, algal recycling also improved 1 h settleability from ∼60% to ∼85% by increasing the average P. boryanum colony size due to the extended mean cell residence time and promoted formation of large algal bio-flocs (>500 μm diameter). These results demonstrate that the presence of wastewater bacteria was not necessary to improve algal productivity and settleability with algal recycling. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Copepod Trajectory Characteristics in Thin Layers of Toxic Algal Exudates

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; True, A. C.; Weissburg, M. J.; Yen, J.

    2013-11-01

    Recently documented thin layers of toxic phytoplankton (``cryptic blooms'') are modeled in a custom flume system for copepod behavioral assays. Planar laser-induced fluorescence (LIF) measurements quantify the spatiotemporal structure of the chemical layers ensuring a close match to in situ bloom conditions and allowing for quantification of threshold dissolved toxin levels that induce behavioral responses. Assays with the copepods Acartia tonsa (hop-sinker) and Temora longicornis (cruiser) in thin layers of toxic exudates from the common dinoflagellate Karenia brevis (cell equivalent ~ 1 - 10,000 cells/mL) examine the effects of dissolved toxic compounds and copepod species on swimming trajectory characteristics. Computation of parameters such as swimming speed and the fractal dimension of the two-dimensional trajectory (F2D) allows for statistical evaluation of copepod behavioral responses to dissolved toxic compounds associated with harmful algal blooms (HABs). Changes in copepod swimming behavior caused by toxic compounds can significantly influence predator, prey, and mate encounter rates by altering the fracticality (``diffuseness'' or ``volume-fillingness'') of a copepod's trajectory. As trophic mediators linking primary producers and higher trophic levels, copepods can significantly influence HAB dynamics and modulate large scale ecological effects through their behavioral interactions with toxic blooms.

  12. Eutrophication and Harmful Algal Blooms: A Scientific Consensus

    PubMed Central

    Heisler, J.; Glibert, P.; Burkholder, J.; Anderson, D.; Cochlan, W.; Dennison, W.; Gobler, C.; Dortch, Q.; Heil, C.; Humphries, E.; Lewitus, A.; Magnien, R.; Marshall, H.; Sellner, K.; Stockwell, D.; Stoecker, D.; Suddleson, M.

    2017-01-01

    In January 2003, the US Environmental Protection Agency sponsored a “roundtable discussion” to develop a consensus on the relationship between eutrophication and harmful algal blooms (HABs), specifically targeting those relationships for which management actions may be appropriate. Academic, federal, and state agency representatives were in attendance. The following seven statements were unanimously adopted by attendees based on review and analysis of current as well as pertinent previous data: 1) Degraded water quality from increased nutrient pollution promotes the development and persistence of many HABs and is one of the reasons for their expansion in the U.S. and the world; 2) The composition – not just the total quantity – of the nutrient pool impacts HABs; 3) High biomass blooms must have exogenous nutrients to be sustained; 4) Both chronic and episodic nutrient delivery promote HAB development; 5) Recently developed tools and techniques are already improving the detection of some HABs, and emerging technologies are rapidly advancing toward operational status for the prediction of HABs and their toxins; 6) Experimental studies are critical to further the understanding of the role of nutrients in HAB expression, and will strengthen prediction and mitigation of HABs; and 7) Management of nutrient inputs to the watershed can lead to significant reduction in HABs. Supporting evidence and pertinent examples for each consensus statement is provided herein. PMID:28781587

  13. Harmful Algal Blooms – Special Sampling and Response Actions

    EPA Pesticide Factsheets

    The Harmful Algal Blooms – Special Sampling and Response Actions webpage contains information about Background on Harmful Algae in Surface Waters and What to Do if Your System Has Indicators of an Algal Bloom.

  14. Quantifying Phycocyanin Concentration in Cyanobacterial Algal Blooms from Remote Sensing Reflectance-A Quasi Analytical Approach

    NASA Astrophysics Data System (ADS)

    Mishra, S.; Mishra, D. R.; Tucker, C.

    2011-12-01

    Cyanobacterial harmful algal blooms (CHAB) are notorious for depleting dissolved oxygen level, producing various toxins, causing threats to aquatic life, altering the food-web dynamics and the overall ecosystem functioning in inland lakes, estuaries, and coastal waters. Most of these algal blooms produce various toxins that can damage cells, tissues and even cause mortality of living organisms. Frequent monitoring of water quality in a synoptic scale has been possible by the virtue of remote sensing techniques. In this research, we present a novel technique to monitor CHAB using remote sensing reflectance products. We have modified a multi-band quasi analytical algorithm that determines phytoplankton absorption coefficients from above surface remote sensing reflectance measurements using an inversion method. In situ hyperspectral remote sensing reflectance data were collected from several highly turbid and productive aquaculture ponds. A novel technique was developed to further decompose the phytoplankton absorption coefficients at 620 nm and obtain phycocyanin absorption coefficient at the same wavelength. An empirical relationship was established between phycocyanin absorption coefficients at 620 nm and measured phycocyanin concentrations. Model calibration showed strong relationship between phycocyanin absorption coefficients and phycocyanin pigment concentration (r2=0.94). Validation of the model in a separate dataset produced a root mean squared error of 167 mg m-3 (phycocyanin range: 26-1012 mg m-3). Results demonstrate that the new approach will be suitable for quantifying phycocyanin concentration in cyanobacteria dominated turbid productive waters. Band architecture of the model matches with the band configuration of the Medium Resolution Imaging Spectrometer (MERIS) and assures that MERIS reflectance products can be used to quantify phycocyanin in cyanobacterial harmful algal blooms in optically complex waters.

  15. Understanding malarial toxins.

    PubMed

    Starkl Renar, Katarina; Iskra, Jernej; Križaj, Igor

    2016-09-01

    Recognized since antiquity, malaria is one of the most infamous and widespread infectious diseases in humans and, although the death rate during the last century has been diminishing, it still accounts for more than a half million deaths annually. It is caused by the Plasmodium parasite and typical symptoms include fever, shivering, headache, diaphoresis and nausea, all resulting from an excessive inflammatory response induced by malarial toxins released into the victim's bloodstream. These toxins are hemozoin and glycosylphosphatidylinositols. The former is the final product of the parasite's detoxification of haeme, a by-product of haemoglobin catabolism, while the latter anchor proteins to the Plasmodium cell surface or occur as free molecules. Currently, only two groups of antimalarial toxin drugs exist on the market, quinolines and artemisinins. As we describe, they both target biosynthesis of hemozoin. Other substances, currently in various phases of clinical trials, are directed towards biosynthesis of glycosylphosphatidylinositol, formation of hemozoin, or attenuation of the inflammatory response of the patient. Among the innovative approaches to alleviating the effects of malarial toxins, is the development of antimalarial toxin vaccines. In this review the most important lessons learned from the use of treatments directed against the action of malarial toxins in antimalarial therapy are emphasized and the most relevant and promising directions for future research in obtaining novel antimalarial agents acting on malarial toxins are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Uptake, transfer and elimination kinetics of paralytic shellfish toxins in common octopus (Octopus vulgaris).

    PubMed

    Lopes, Vanessa M; Baptista, Miguel; Repolho, Tiago; Rosa, Rui; Costa, Pedro Reis

    2014-01-01

    Marine phycotoxins derived from harmful algal blooms are known to be associated with mass mortalities in the higher trophic levels of marine food webs. Bivalve mollusks and planktivorous fish are the most studied vectors of marine phycotoxins. However, field surveys recently showed that cephalopod mollusks also constitute potential vectors of toxins. Thus, here we determine, for the first time, the time course of accumulation and depuration of paralytic shellfish toxins (PSTs) in the common octopus (Octopus vulgaris). Concomitantly, the underlying kinetics of toxin transfer between tissue compartments was also calculated. Naturally contaminated clams were used to orally expose the octopus to PSTs during 6 days. Afterwards, octopus specimens were fed with non-contaminated shellfish during 10 days of depuration period. Toxins reached the highest concentrations in the digestive gland surpassing the levels in the kidney by three orders of magnitude. PSTs were not detected in any other tissue analyzed. Net accumulation efficiencies of 42% for GTX5, 36% for dcSTX and 23% for C1+2 were calculated for the digestive gland. These compounds were the most abundant toxins in both digestive gland and the contaminated shellfish diet. The small differences in relative abundance of each toxin observed between the prey and the cephalopod predator indicates low conversion rates of these toxins. The depuration period was better described using an exponential decay model comprising a single compartment - the entire viscera. It is worth noting that since octopuses' excretion and depuration rates are low, the digestive gland is able to accumulate very high toxin concentrations for long periods of time. Therefore, the present study clearly shows that O. vulgaris is a high-potential vector of PSTs during and even after the occurrence of these toxic algal blooms.

  17. Transcriptomic signatures in whole blood of patients who acquire a chronic inflammatory response syndrome (CIRS) following an exposure to the marine toxin ciguatoxin.

    PubMed

    Ryan, James C; Wu, Qingzhong; Shoemaker, Ritchie C

    2015-04-02

    Ciguatoxins (CTXs) are polyether marine neurotoxins found in multiple reef-fish species and are potent activators of voltage-gated sodium channels. It is estimated that up to 500,000 people annually experience acute ciguatera poisoning from consuming toxic fish and a small percentage of these victims will develop a chronic, multisymptom, multisystem illness, which can last years, termed a Chronic Inflammatory Response Syndrome (CIRS). Symptoms of ciguatera CIRS include fatigue, cognitive deficits, neurologic deficits, pain and sensitivity to light. There are few treatment options for ciguatera CIRS since little is known about its pathophysiology. This study characterizes the transcriptional profile in whole blood of 11 patients with ciguatera-induced CIRS and 11 normal controls run in duplicate using Agilent one color whole genome microarrays. Differential expression was determined by using a combination of moderated t-test p-value and fold change (FC). Significant genes were subjected to gene ontology, principal component analysis and SVM classification. Seven significant genes found by microarray were validated by PCR. Using a low stringency (p < 0.05 and FC > 1.4) and a high stringency (p < 0.01 and FC > 1.5) filter, the resulting gene sets of 185 and 55, respectively, showed clear separation of cases and controls by PCA as well as 100% classification accuracy by SVM, indicating that the gene profiles can separate patients from controls. PCR results of 7 genes showed a 95% correlation to microarray data. Several genes identified by microarray are important in wound healing (CD9, CD36, vWF and Factor XIII), adaptive immunity (HLA-DQB1, DQB2, IL18R1 and IL5RA) and innate immunity (GZMK, TOLLIP, SIGIRR and VIPR2), overlapping several areas shown to be disrupted in a mouse model of acute exposure to ciguatoxin. Another area of interest was differential expression of long, non-coding sequences, or lncRNA. Disruptions of innate and adaptive immune

  18. Crystal structure of Clostridium difficile toxin A

    SciTech Connect

    Chumbler, Nicole M.; Rutherford, Stacey A.; Zhang, Zhifen; Farrow, Melissa A.; Lisher, John P.; Farquhar, Erik; Giedroc, David P.; Spiller, Benjamin W.; Melnyk, Roman A.; Lacy, D. Borden

    2016-01-11

    Clostridium difficile infection is the leading cause of hospital-acquired diarrhoea and pseudomembranous colitis. Disease is mediated by the actions of two toxins, TcdA and TcdB, which cause the diarrhoea, as well as inflammation and necrosis within the colon. The toxins are large (308 and 270 kDa, respectively), homologous (47% amino acid identity) glucosyltransferases that target small GTPases within the host. The multidomain toxins enter cells by receptor-mediated endocytosis and, upon exposure to the low pH of the endosome, insert into and deliver two enzymatic domains across the membrane. Eukaryotic inositol-hexakisphosphate (InsP6) binds an autoprocessing domain to activate a proteolysis event that releases the N-terminal glucosyltransferase domain into the cytosol. Here, we report the crystal structure of a 1,832-amino-acid fragment of TcdA (TcdA1832), which reveals a requirement for zinc in the mechanism of toxin autoprocessing and an extended delivery domain that serves as a scaffold for the hydrophobic α-helices involved in pH-dependent pore formation. A surface loop of the delivery domain whose sequence is strictly conserved among all large clostridial toxins is shown to be functionally important, and is highlighted for future efforts in the development of vaccines and novel therapeutics.

  19. Crystal structure of Clostridium difficile toxin A.

    PubMed

    Chumbler, Nicole M; Rutherford, Stacey A; Zhang, Zhifen; Farrow, Melissa A; Lisher, John P; Farquhar, Erik; Giedroc, David P; Spiller, Benjamin W; Melnyk, Roman A; Lacy, D Borden

    2016-01-11

    Clostridium difficile infection is the leading cause of hospital-acquired diarrhoea and pseudomembranous colitis. Disease is mediated by the actions of two toxins, TcdA and TcdB, which cause the diarrhoea, as well as inflammation and necrosis within the colon. The toxins are large (308 and 270 kDa, respectively), homologous (47% amino acid identity) glucosyltransferases that target small GTPases within the host. The multidomain toxins enter cells by receptor-mediated endocytosis and, upon exposure to the low pH of the endosome, insert into and deliver two enzymatic domains across the membrane. Eukaryotic inositol-hexakisphosphate (InsP6) binds an autoprocessing domain to activate a proteolysis event that releases the N-terminal glucosyltransferase domain into the cytosol. Here, we report the crystal structure of a 1,832-amino-acid fragment of TcdA (TcdA1832), which reveals a requirement for zinc in the mechanism of toxin autoprocessing and an extended delivery domain that serves as a scaffold for the hydrophobic α-helices involved in pH-dependent pore formation. A surface loop of the delivery domain whose sequence is strictly conserved among all large clostridial toxins is shown to be functionally important, and is highlighted for future efforts in the development of vaccines and novel therapeutics.

  20. Crystal structure of Clostridium difficile toxin A.

    PubMed

    Chumbler, Nicole M; Rutherford, Stacey A; Zhang, Zhifen; Farrow, Melissa A; Lisher, John P; Farquhar, Erik; Giedroc, David P; Spiller, Benjamin W; Melnyk, Roman A; Lacy, D Borden

    Clostridium difficile infection is the leading cause of hospital-acquired diarrhoea and pseudomembranous colitis. Disease is mediated by the actions of two toxins, TcdA and TcdB, which cause the diarrhoea, as well as inflammation and necrosis within the colon(1,2). The toxins are large (308 and 270 kDa, respectively), homologous (47% amino acid identity) glucosyltransferases that target small GTPases within the host(3,4). The multidomain toxins enter cells by receptor-mediated endocytosis and, upon exposure to the low pH of the endosome, insert into and deliver two enzymatic domains across the membrane. Eukaryotic inositol-hexakisphosphate (InsP6) binds an autoprocessing domain to activate a proteolysis event that releases the N-terminal glucosyltransferase domain into the cytosol. Here, we report the crystal structure of a 1,832-amino-acid fragment of TcdA (TcdA1832), which reveals a requirement for zinc in the mechanism of toxin autoprocessing and an extended delivery domain that serves as a scaffold for the hydrophobic α-helices involved in pH-dependent pore formation. A surface loop of the delivery domain whose sequence is strictly conserved among all large clostridial toxins is shown to be functionally important, and is highlighted for future efforts in the development of vaccines and novel therapeutics.

  1. Crystal structure of Clostridium difficile toxin A

    PubMed Central

    Chumbler, Nicole M.; Rutherford, Stacey A.; Zhang, Zhifen; Farrow, Melissa A.; Lisher, John P.; Farquhar, Erik; Giedroc, David P.; Spiller, Benjamin W.; Melnyk, Roman A.; Lacy, D. Borden

    2016-01-01

    Clostridium difficile infection is the leading cause of hospital-acquired diarrhoea and pseudomembranous colitis. Disease is mediated by the actions of two toxins, TcdA and TcdB, which cause the diarrhoea, as well as inflammation and necrosis within the colon1,2. The toxins are large (308 and 270 kDa, respectively), homologous (47% amino acid identity) glucosyltransferases that target small GTPases within the host3,4. The multidomain toxins enter cells by receptor-mediated endocytosis and, upon exposure to the low pH of the endosome, insert into and deliver two enzymatic domains across the membrane. Eukaryotic inositol-hexakisphosphate (InsP6) binds an autoprocessing domain to activate a proteolysis event that releases the N-terminal glucosyltransferase domain into the cytosol. Here, we report the crystal structure of a 1,832-amino-acid fragment of TcdA (TcdA1832), which reveals a requirement for zinc in the mechanism of toxin autoprocessing and an extended delivery domain that serves as a scaffold for the hydrophobic α-helices involved in pH-dependent pore formation. A surface loop of the delivery domain whose sequence is strictly conserved among all large clostridial toxins is shown to be functionally important, and is highlighted for future efforts in the development of vaccines and novel therapeutics. PMID:27571750

  2. Quality measures of imaging mass spectrometry aids in revealing long-term striatal protein changes induced by neonatal exposure to the cyanobacterial toxin β-N-methylamino-L-alanine (BMAA).

    PubMed

    Karlsson, Oskar; Bergquist, Jonas; Andersson, Malin

    2014-01-01

    Many pathological processes are not directly correlated to dramatic alterations in protein levels. The changes in local concentrations of important proteins in a subset of cells or at specific loci are likely to play a significant role in disease etiologies, but the precise location might be unknown, or the concentration might be too small to be adequately sampled for traditional proteomic techniques. Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS) is a unique analytical method that combines analysis of multiple molecular species and of their distribution in a single platform. As reproducibility is essential for successful biomarker discovery, it is important to systematically assess data quality in biologically relevant MALDI IMS experiments. In the present study, we applied four simple tools to study the reproducibility for individual sections, within-group variation, and between-group variation of data acquired from brain sections of 21 animals divided into three treatment groups. We also characterized protein changes in distinct regions of the striatum from six-month-old rats treated neonatally (postnatal days 9-10) with the cyanobacterial toxin β-N-methylamino-l-alanine (BMAA), which has been implicated in neurodegenerative diseases. The results showed that optimized experimental settings can yield high-quality MALDI IMS data with relatively low variation (14% to 15% coefficient of variance) that allow the characterization of subtle changes in protein expression in various subregions of the brain. This was further exemplified by the dose-dependent reduction of myelin basic protein in the caudate putamen and the nucleus accumbens of adult rats neonatally treated with BMAA (150 and 460 mg/kg). The reduction in myelin basic protein was confirmed through immunohistochemistry and indicates that developmental exposure to BMAA may induce structural effects on axonal growth and/or directly on the proliferation of oligodendrocytes

  3. About lipids and toxins.

    PubMed

    Reig, Núria; van der Goot, F Gisou

    2006-10-09

    Many mono or multicellular organisms secrete soluble proteins, referred to as protein toxins, which alter the behavior of foreign, or target cells, possibly leading to their death. These toxins affect either the cell membrane by forming pores or modifying lipids, or some intracellular target. To reach this target, they must cross one of the cellular membranes, generally that of an intracellular organelle. As described in this minireview, lipids play crucial roles in the intoxication process of most if not all toxins, by allowing/promoting binding, endocytosis, trafficking and/or translocation into the cytoplasm.

  4. Designing Inhibitors of Anthrax Toxin

    PubMed Central

    Nestorovich, Ekaterina M.; Bezrukov, Sergey M.

    2014-01-01

    Introduction Present-day rational drug design approaches are based on exploiting unique features of the target biomolecules, small- or macromolecule drug candidates, and physical forces that govern their interactions. The 2013 Nobel Prize in chemistry awarded “for the development of multiscale models for complex chemical systems” once again demonstrated the importance of the tailored drug discovery that reduces the role of the trial and error approach to a minimum. The “rational drug design” term is rather comprehensive as it includes all contemporary methods of drug discovery where serendipity and screening are substituted by the information-guided search for new and existing compounds. Successful implementation of these innovative drug discovery approaches is inevitably preceded by learning the physics, chemistry, and physiology of functioning of biological structures under normal and pathological conditions. Areas covered This article provides an overview of the recent rational drug design approaches to discover inhibitors of anthrax toxin. Some of the examples include small-molecule and peptide-based post-exposure therapeutic agents as well as several polyvalent compounds. The review also directs the reader to the vast literature on the recognized advances and future possibilities in the field. Expert opinion Existing options to combat anthrax toxin lethality are limited. With the only anthrax toxin inhibiting therapy (PA-targeting with a monoclonal antibody, raxibacumab) approved to treat inhalational anthrax, in our view, the situation is still insecure. The FDA’s animal rule for drug approval, which clears compounds without validated efficacy studies on humans, creates a high level of uncertainty, especially when a well-characterized animal model does not exist. Besides, unlike PA, which is known to be unstable, LF remains active in cells and in animal tissues for days. Therefore, the effectiveness of the post-exposure treatment of the individuals

  5. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Algistatic means having the property of inhibiting algal growth. (3) ECx means the experimentally derived chemical concentration that is calculated to effect X percent of the test criterion. (4) Growth means a relative measure of the viability of an algal population based on the number and/or weight of algal cells...

  6. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Algistatic means having the property of inhibiting algal growth. (3) ECx means the experimentally derived chemical concentration that is calculated to effect X percent of the test criterion. (4) Growth means a relative measure of the viability of an algal population based on the number and/or weight of algal cells...

  7. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Algistatic means having the property of inhibiting algal growth. (3) ECx means the experimentally derived chemical concentration that is calculated to effect X percent of the test criterion. (4) Growth means a relative measure of the viability of an algal population based on the number and/or weight of algal cells...

  8. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Algistatic means having the property of inhibiting algal growth. (3) ECx means the experimentally derived chemical concentration that is calculated to effect X percent of the test criterion. (4) Growth means a relative measure of the viability of an algal population based on the number and/or weight of algal cells...

  9. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Algistatic means having the property of inhibiting algal growth. (3) ECx means the experimentally derived chemical concentration that is calculated to effect X percent of the test criterion. (4) Growth means a relative measure of the viability of an algal population based on the number and/or weight of algal cells...

  10. Immunoassays and biosensors for the detection of cyanobacterial toxins in water.

    PubMed

    Weller, Michael G

    2013-11-05

    Algal blooms are a frequent phenomenon in nearly all kinds of fresh water. Global warming and eutrophication by waste water, air pollution and fertilizers seem to lead to an increased frequency of occurrence. Many cyanobacteria produce hazardous and quite persistent toxins, which can contaminate the respective water bodies. This may limit the use of the raw water for many purposes. The purification of the contaminated water might be quite costly, which makes a continuous and large scale treatment economically unfeasible in many cases. Due to the obvious risks of algal toxins, an online or mobile detection method would be highly desirable. Several biosensor systems have been presented in the literature for this purpose. In this review, their mode of operation, performance and general suitability for the intended purpose will be described and critically discussed. Finally, an outlook on current developments and future prospects will be given.

  11. Immunoassays and Biosensors for the Detection of Cyanobacterial Toxins in Water

    PubMed Central

    Weller, Michael G.

    2013-01-01

    Algal blooms are a frequent phenomenon in nearly all kinds of fresh water. Global warming and eutrophication by waste water, air pollution and fertilizers seem to lead to an increased frequency of occurrence. Many cyanobacteria produce hazardous and quite persistent toxins, which can contaminate the respective water bodies. This may limit the use of the raw water for many purposes. The purification of the contaminated water might be quite costly, which makes a continuous and large scale treatment economically unfeasible in many cases. Due to the obvious risks of algal toxins, an online or mobile detection method would be highly desirable. Several biosensor systems have been presented in the literature for this purpose. In this review, their mode of operation, performance and general suitability for the intended purpose will be described and critically discussed. Finally, an outlook on current developments and future prospects will be given. PMID:24196435

  12. Alga-PrAS (Algal Protein Annotation Suite): A Database of Comprehensive Annotation in Algal Proteomes

    PubMed Central

    Kurotani, Atsushi; Yamada, Yutaka

    2017-01-01

    Algae are smaller organisms than land plants and offer clear advantages in research over terrestrial species in terms of rapid production, short generation time and varied commercial applications. Thus, studies investigating the practical development of effective algal production are important and will improve our understanding of both aquatic and terrestrial plants. In this study we estimated multiple physicochemical and secondary structural properties of protein sequences, the predicted presence of post-translational modification (PTM) sites, and subcellular localization using a total of 510,123 protein sequences from the proteomes of 31 algal and three plant species. Algal species were broadly selected from green and red algae, glaucophytes, oomycetes, diatoms and other microalgal groups. The results were deposited in the Algal Protein Annotation Suite database (Alga-PrAS; http://alga-pras.riken.jp/), which can be freely accessed online. PMID:28069893

  13. Alga-PrAS (Algal Protein Annotation Suite): A Database of Comprehensive Annotation in Algal Proteomes.

    PubMed

    Kurotani, Atsushi; Yamada, Yutaka; Sakurai, Tetsuya

    2017-01-01

    Algae are smaller organisms than land plants and offer clear advantages in research over terrestrial species in terms of rapid production, short generation time and varied commercial applications. Thus, studies investigating the practical development of effective algal production are important and will improve our understanding of both aquatic and terrestrial plants. In this study we estimated multiple physicochemical and secondary structural properties of protein sequences, the predicted presence of post-translational modification (PTM) sites, and subcellular localization using a total of 510,123 protein sequences from the proteomes of 31 algal and three plant species. Algal species were broadly selected from green and red algae, glaucophytes, oomycetes, diatoms and other microalgal groups. The results were deposited in the Algal Protein Annotation Suite database (Alga-PrAS; http://alga-pras.riken.jp/), which can be freely accessed online. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  14. Recent Advances in Algal Genetic Tool Development

    DOE PAGES

    R. Dahlin, Lukas; T. Guarnieri, Michael

    2016-06-24

    The goal of achieving cost-effective biofuels and bioproducts derived from algal biomass will require improvements along the entire value chain, including identification of robust, high-productivity strains and development of advanced genetic tools. Though there have been modest advances in development of genetic systems for the model alga Chlamydomonas reinhardtii, progress in development of algal genetic tools, especially as applied to non-model algae, has generally lagged behind that of more commonly utilized laboratory and industrial microbes. This is in part due to the complex organellar structure of algae, including robust cell walls and intricate compartmentalization of target loci, as well asmore » prevalent gene silencing mechanisms, which hinder facile utilization of conventional genetic engineering tools and methodologies. However, recent progress in global tool development has opened the door for implementation of strain-engineering strategies in industrially-relevant algal strains. Here, we review recent advances in algal genetic tool development and applications in eukaryotic microalgae.« less

  15. Algal production in wastewater treatment high rate algal ponds for potential biofuel use.

    PubMed

    Park, J B K; Craggs, R J

    2011-01-01

    Wastewater treatment High Rate Algal Ponds with CO2 addition could provide cost-effective and efficient tertiary-level wastewater treatment with the co-benefit of algal biomass production for biofuel use. Wastewater grown algal biomass can have a lipid content of 10-30% of dry weight, which could be used to make biodiesel. This research investigated algal biomass and total lipid production by two pilot-scale wastewater treatment HRAP(S) (4-day HRT) with and without CO2 addition under New Zealand mid summer (Nov-Jan) conditions. The influence of CO2 addition on wastewater treatment performance was also determined. CO2 was added to one of the HRAPs (the HRAP(E)) by maintaining the maximum pH of the pond below 8. Measurements of HRAP influent and effluent water qualities, total lipid content and algal biomass production were made twice a week over the experimental period. Both HRAP(S) achieved high levels of organic compound and nutrient removal, with >85% SBOD5, >92 NH4(+)-N and >70% DRP removal. Algal/bacterial biomass production in the HRAP(E) (15.2 g/m2/d) was improved by CO2 addition by approximately 30% compared with that of the control HRAP(W) (10.6 g/m2/d). Total lipid content of the biomass grown on both HRAP(S) was slightly reduced (from 25% to 20%) with CO2 addition and the maximum total lipid content of approximately 40% was observed in the HRAP(W) when low NH4(+)-N concentration (<0.5 mg/L) and high maximum pH (>10.0) occurred. Total lipid content of the biomass increased by approximately 15% under nitrogen limiting conditions, however, overall algal/bacterial biomass production was reduced by half during the period of nitrogen limitation. More research is required to maintain algal production under near nitrogen-limiting conditions.

  16. Staphylococcus aureus toxins.

    PubMed

    Otto, Michael

    2014-02-01

    Staphylococcus aureus is a dangerous pathogen that causes a variety of severe diseases. The virulence of S. aureus is defined by a large repertoire of virulence factors, among which secreted toxins play a preeminent role. Many S. aureus toxins damage biological membranes, leading to cell death. In particular, S. aureus produces potent hemolysins and leukotoxins. Among the latter, some were recently identified to lyse neutrophils after ingestion, representing an especially powerful weapon against bacterial elimination by innate host defense. Furthermore, S. aureus secretes many factors that inhibit the complement cascade or prevent recognition by host defenses. Several further toxins add to this multi-faceted program of S. aureus to evade elimination in the host. This review will give an overview over S. aureus toxins focusing on recent advances in our understanding of how leukotoxins work in receptor-mediated or receptor-independent fashions. Published by Elsevier Ltd.

  17. Wallpaper May Breed Toxins

    MedlinePlus

    ... toxins are likely to be located on fungal spores, but we also demonstrated that part of the ... News Related MedlinePlus Health Topics Indoor Air Pollution Molds About MedlinePlus Site Map FAQs Customer Support Get ...

  18. Oxygen sensitivity of algal H{sub 2}-production

    SciTech Connect

    Ghirardi, M.L.; Seibert, M.; Togasaki, R.K.

    1997-12-31

    Photoproduction of H{sub 2} by green algae utilizes electrons originating from the photosynthetic oxidation of water and does not require metabolic intermediates. However, algal hydrogenases are extremely sensitive to O{sub 2}, which limits their usefulness in future commercial H{sub 2}-production systems. We designed an experimental technique for the selection of O{sub 2}tolerant, H{sub 2}-producing variants of Chlamydomonas reinhardtii based on the ability of wild-type cells to survive a short (20 min) exposure to metronidazole in the presence of controlled concentrations of O{sub 2}. The number of survivors depends on the metronidazole concentration, light intensity, preinduction of the hydrogenase, and the presence or absence of O{sub 2}. Finally, we demonstrate that some of the selected survivors in fact exhibit H{sub 2}-production capacity that is less sensitive to O{sub 2} than the original wild-type population. 17 refs., 1 tab.

  19. [Natural toxin poisoning].

    PubMed

    Tsunematsu, Satoshi

    2012-08-01

    Natural toxin poisoning often occurs when amateur who has no expert knowledge of food collects and cooks the wrong material. In many cases, the symptoms of natural toxin poisoning are mild and the patients recover from illness within a day. However, if the patients have respiratory or neurological symptoms after several hours of intake, the patients must go to hospital immediately. Mushroom poisoning is often reported and puffer fish poisoning is sometimes reported in Japan.

  20. The cyanobacteria toxins, microcystins – emerging risks to human health

    EPA Science Inventory

    Dialysis patients appear to be at increased risk for exposure to cyanobacteria toxins; episodes of microcystin (MCYST) exposure via dialysate during 1996 and 2001 have been previously reported. During 2001, as many as 44 renal insufficiency patients were exposed to contaminated d...

  1. The cyanobacteria toxins, microcystins – emerging risks to human health

    EPA Science Inventory

    Dialysis patients appear to be at increased risk for exposure to cyanobacteria toxins; episodes of microcystin (MCYST) exposure via dialysate during 1996 and 2001 have been previously reported. During 2001, as many as 44 renal insufficiency patients were exposed to contaminated d...

  2. Competition for one nutrient with internal storage and toxin mortality.

    PubMed

    Grover, James P; Wang, Feng-Bin

    2013-08-01

    This study presents a mathematical model of two species competing in a chemostat for one resource that is stored internally, and who also compete through allelopathy. Each species produces a toxin to that increases mortality rate of its competitor. The two species system and its single species subsystem follow mass conservation constraints characteristic of chemostat models. Persistence of a single species occurs if the nutrient supply of an empty habitat allows it to acquire a threshold of stored nutrient quota, sufficient to overcome loss to outflow after accounting for the cost of toxin production. For the two-species system, a semitrivial equilibrium with one species resident is unstable to invasion by the missing species according to a similar threshold condition. The invader increases if acquires a stored nutrient quota sufficient to overcome loss to outflow and toxin-induced mortality, after accounting for the cost of the invader's own toxin production. If both semitrivial equilibria for the two-species system are invasible then there is at least one coexistence equilibrium. Numerical analyses indicate another possibility: bistability in which both semitrivial equilibria are stable against invasion. In such a case there is competitive exclusion of one species, whose identity depends on initial conditions. When there is a tradeoff between abilities to compete for the nutrient and to compete through toxicity, the more toxic species can dominate only under nutrient-rich conditions. Bistability under such conditions could contribute to the unpredictability of toxic algal blooms. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Dihydropyridine Receotprs: Possible Allosteric Regulation by Tremorgenic Toxins.

    DTIC Science & Technology

    1986-11-01

    and three treatment groups. The three treatment groups received either a mildly tremaorgenic dose of verruculogen, aflatrem, or cyclopiazonic acid (I my... treatment groups were injected as described and decapitated 1 hr after injection. Rats designated for the in vitro exposure to toxin were decapi- tated on...Y., and Yasumoto, T. Ca+ 2 Channel Activating Function of Maitotoxin, the Most Potent Marine Toxin Known, in Clonal Rat Pheochromocytoma Cells. J

  4. Multiplex detection of protein toxins using MALDI-TOF-TOF tandem mass spectrometry: application in unambiguous toxin detection from bioaerosol.

    PubMed

    Alam, Syed Imteyaz; Kumar, Bhoj; Kamboj, Dev Vrat

    2012-12-04

    Protein toxins, such as botulinum neurotoxins (BoNTs), Clostridium perfringens epsilon toxin (ETX), staphylococcal enterotoxin B (SEB), shiga toxin (STX), and plant toxin ricin, are involved in a number of diseases and are considered as potential agents for bioterrorism and warfare. From a bioterrorism and warfare perspective, these agents are likely to cause maximum damage to a civilian or military population through an inhalational route of exposure and aerosol is considered the envisaged mode of delivery. Unambiguous detection of toxin from aerosol is of paramount importance, both for bringing mitigation protocols into operation and for implementation of effective medical countermeasures, in case a "biological cloud" is seen over a population. A multiplex, unambiguous, and qualitative detection of protein toxins is reported here using tandem mass spectrometry with MALDI-TOF-TOF. The methodology involving simple sample processing steps was demonstrated to identify toxins (ETX, Clostridium perfringes phospholipase C, and SEB) from blind spiked samples. The novel directed search approach using a list of unique peptides was used to identify toxins from a complex protein mixture. The bioinformatic analysis of seven protein toxins for elucidation of unique peptides with conservation status across all known sequences provides a high confidence for detecting toxins originating from any geographical location and source organism. Use of tandem MS data with peptide sequence information increases the specificity of the method. A prototype for generation of aerosol using a nebulizer and collection using a cyclone collector was used to provide a proof of concept for unambiguous detection of toxin from aerosol using precursor directed tandem mass spectrometry combined with protein database searching. ETX prototoxin could be detected from aerosol at 0.2 ppb concentration in aerosol.

  5. An analytical perspective on detection, screening, and confirmation in phycology, with particular reference to toxins and toxin-producing species.

    PubMed

    de la Iglesia, Pablo; Fernández-Tejedor, Margarita; Trobajo, Rosa; Diogène, Jorge

    2013-12-01

    Knowledge concerning the ability of microalgae to produce metabolites of interest such as toxins or high-value secondary metabolites requires exhaustive details to be supplied on how the research was conducted. These should include the microalgal species and strain characterization, the culture conditions, the cell density, and physiological state at the time of harvesting, the harvesting method, the sample pre-treatment protocol, and the subsequent instrumental analytical separation/detection system. In this comment, we discuss issues that affect algal research from an analytical chemistry perspective, particularly (i) the need to specify detection capabilities of the entire method (i.e., limits of detection or threshold detection levels), which we illustrate in relation to classification of a species or strain as being "toxin producing" or "non-toxin producing"; and (ii) the requirements that have to be satisfied to confirm a microalgal species (new or not) as a producer of a particular chemical of interest for phycologists, which again we illustrate in relation to toxins. A successful collaboration among phycologists and analytical chemists will only be achieved as a result of a synergistic collaboration between the two disciplines, with a reciprocal understanding at least at a background level. © 2013 Phycological Society of America.

  6. Mycosporine-like amino acids and marine toxins--the common and the different.

    PubMed

    Klisch, Manfred; Häder, Donat-P

    2008-05-22

    Marine microorganisms harbor a multitude of secondary metabolites. Among these are toxins of different chemical classes as well as the UV-protective mycosporine-like amino acids (MAAs). The latter form a group of water-soluble, low molecular-weight (generally < 400) compounds composed of either an aminocyclohexenone or an aminocyclohexenimine ring, carrying amino acid or amino alcohol substituents. So far there has been no report of toxicity in MAAs but nevertheless there are some features they have in common with marine toxins. Among the organisms producing MAAs are cyanobacteria, dinoflagellates and diatoms that also synthesize toxins. As in cyclic peptide toxins found in cyanobacteria, amino acids are the main building blocks of MAAs. Both, MAAs and some marine toxins are transferred to other organisms e.g. via the food chains, and chemical modifications can take place in secondary consumers. In contrast to algal toxins, the physiological role of MAAs is clearly the protection from harmful UV radiation by physical screening. However, other roles, e.g. as osmolytes and antioxidants, are also considered. In this paper the common characteristics of MAAs and marine toxins are discussed as well as the differences.

  7. Apparent bioaccumulation of cylindrospermopsin and paralytic shellfish toxins by finfish in Lake Catemaco (Veracruz, Mexico).

    PubMed

    Berry, J P; Jaja-Chimedza, A; Dávalos-Lind, L; Lind, O

    2012-01-01

    Compared to the well-characterized health threats associated with contamination of fish and shellfish by algal toxins in marine fisheries, the toxicological relevance of the bioaccumulation of toxins from cyanobacteria (blue-green algae), as the primary toxigenic algae in freshwater systems, remains relatively unknown. Lake Catemaco (Veracruz, Mexico) is a small, tropical lake system specifically characterized by a year-round dominance of the known toxigenic cyanobacterial genus, Cylindrospermopsis, and by low, but detectable, levels of both a cyanobacterial hepatotoxin, cylindrospermopsin (CYN), and paralytic shellfish toxins (PSTs). In the present study, we evaluated, using enzyme-linked immunoassay (ELISA), levels of both toxins in several species of finfish caught and consumed locally in the region to investigate the bioaccumulation of, and possible health threats associated with, these toxins as potential foodborne contaminants. ELISA detected levels of both CYN and PSTs in fish tissues from the lake. Levels were generally low (≤ 1 ng g(-1) tissue); however, calculated bioaccumulation factors (BAFs) indicate that toxin levels exceed the rather low levels in the water column and, consequently, indicated bioaccumulation (BAF >1). A reasonable correlation was observed between measured bioaccumulation of CYN and PSTs, possibly indicating a mutual source of both toxins, and most likely cells of Cylindrospermopsis, the dominant cyanobacteria in the lake, and a known producer of both metabolites. The potential roles of trophic transport in the system, as well as possible implications for human health with regards to bioaccumulation, are discussed.

  8. Mycosporine-Like Amino Acids and Marine Toxins - The Common and the Different

    PubMed Central

    Klisch, Manfred; Häder, Donat-P.

    2008-01-01

    Marine microorganisms harbor a multitude of secondary metabolites. Among these are toxins of different chemical classes as well as the UV-protective mycosporine-like amino acids (MAAs). The latter form a group of water-soluble, low molecular-weight (generally < 400) compounds composed of either an aminocyclohexenone or an aminocyclohexenimine ring, carrying amino acid or amino alcohol substituents. So far there has been no report of toxicity in MAAs but nevertheless there are some features they have in common with marine toxins. Among the organisms producing MAAs are cyanobacteria, dinoflagellates and diatoms that also synthesize toxins. As in cyclic peptide toxins found in cyanobacteria, amino acids are the main building blocks of MAAs. Both, MAAs and some marine toxins are transferred to other organisms e.g. via the food chains, and chemical modifications can take place in secondary consumers. In contrast to algal toxins, the physiological role of MAAs is clearly the protection from harmful UV radiation by physical screening. However, other roles, e.g. as osmolytes and antioxidants, are also considered. In this paper the common characteristics of MAAs and marine toxins are discussed as well as the differences. PMID:18728764

  9. Uptake and bioaccumulation of Cry toxins by an aphidophagous predator.

    PubMed

    Paula, Débora P; Andow, David A

    2016-02-01

    Uptake of Cry toxins by insect natural enemies has rarely been considered and bioaccumulation has not yet been demonstrated. Uptake can be demonstrated by the continued presence of Cry toxin after exposure has stopped and gut contents eliminated. Bioaccumulation can be demonstrated by showing uptake and that the concentration of Cry toxin in the natural enemy exceeds that in its food. We exposed larvae of the aphidophagous predator, Harmonia axyridis, to Cry1Ac and Cry1F through uniform and constant tritrophic exposure via an aphid, Myzus persicae, and looked for toxin presence in the pupae. We repeated the experiment using only Cry1F and tested newly emerged adults. Both Cry toxins were detected in pupae, and Cry1F was detected in recently emerged, unfed adults. Cry1Ac was present 2.05 times and Cry1F 3.09 times higher in predator pupae than in the aphid prey. Uptake and bioaccumulation in the third trophic level might increase the persistence of Cry toxins in the food web and mediate new exposure routes to natural enemies.

  10. Biosecurity of Select Agents and Toxins

    DTIC Science & Technology

    2005-03-01

    cholerae , Cryptosporidium parvum) Category C) Emerging infectious diseases such as Nipah virus and hantavirus Source: Centers for Disease Control http...and Toxin Weapons Convention CDC US Department of Health and Human Services, Centers for Disease Control CFR Code of Federal Regulations HHS US...nuclear weapon, strikes silently and has a delayed presentation. Days or weeks may elapse between exposure and the actual presentation of disease . Yet

  11. Investigation of diarrhetic shellfish toxins in Lingshan Bay, Yellow Sea, China, using solid-phase adsorption toxin tracking (SPATT).

    PubMed

    Li, Feng-Ling; Li, Zhao-Xin; Guo, Meng-Meng; Wu, Hai-Yan; Zhang, Ting-Ting; Song, Cai-Hu

    2016-08-01

    Early detection of toxin contamination in shellfish (i.e., prior to harvest) would be of considerable advantage to fish farmers, researchers and food safety administrators. In 2004, a solid-phase adsorption toxin tracking (SPATT) technique was developed to study algal toxins in New Zealand shellfish harvesting areas. In subsequent years, the basic idea have been further developed. Using a SPATT method, an investigation into diarrhetic shellfish toxins (DSTs) was conducted over a 10.5-month period in 2012 in shellfish farming areas in Lingshan Bay (Yellow Sea, China). This paper discusses the relationship among DSTs in toxic algae, seawater and contaminated shellfish. OA, DTX1 and PTX2 toxins were found in this shellfish farming area from summer to autumn. In shellfish the maximum concentrations of OA and DTX1 were 81 and 41 ng g(-1) respectively. PTX2 was very low. The maximum levels of OA and DTX1 in seawater were 165 and 56 ng g(-1) respectively, and were detected on June, separated by a 14-day period. Shellfish had accumulated the highest levels of OA and DTX1 recorded in this study. Comparison of the variations in DST levels in seawater showed there to be about 2 weeks for administrators to warn of the potential for toxin contamination in shellfish. Further research to explore the relationship between the variables of seawater temperature, sunlight and salinity, and DSTs in shellfish may help to establish a more suitable model for forecasting DST contamination in shellfish.

  12. Targeted Silencing of Anthrax Toxin Receptors Protects against Anthrax Toxins*

    PubMed Central

    Arévalo, Maria T.; Navarro, Ashley; Arico, Chenoa D.; Li, Junwei; Alkhatib, Omar; Chen, Shan; Diaz-Arévalo, Diana; Zeng, Mingtao

    2014-01-01

    Anthrax spores can be aerosolized and dispersed as a bioweapon. Current postexposure treatments are inadequate at later stages of infection, when high levels of anthrax toxins are present. Anthrax toxins enter cells via two identified anthrax toxin receptors: tumor endothelial marker 8 (TEM8) and capillary morphogenesis protein 2 (CMG2). We hypothesized that host cells would be protected from anthrax toxins if anthrax toxin receptor expression was effectively silenced using RNA interference (RNAi) technology. Thus, anthrax toxin receptors in mouse and human macrophages were silenced using targeted siRNAs or blocked with specific antibody prior to challenge with anthrax lethal toxin. Viability assays were used to assess protection in macrophages treated with specific siRNA or antibody as compared with untreated cells. Silencing CMG2 using targeted siRNAs provided almost complete protection against anthrax lethal toxin-induced cytotoxicity and death in murine and human macrophages. The same results were obtained by prebinding cells with specific antibody prior to treatment with anthrax lethal toxin. In addition, TEM8-targeted siRNAs also offered significant protection against lethal toxin in human macrophage-like cells. Furthermore, silencing CMG2, TEM8, or both receptors in combination was also protective against MEK2 cleavage by lethal toxin or adenylyl cyclase activity by edema toxin in human kidney cells. Thus, anthrax toxin receptor-targeted RNAi has the potential to be developed as a life-saving, postexposure therapy against anthrax. PMID:24742682

  13. Targeted silencing of anthrax toxin receptors protects against anthrax toxins.

    PubMed

    Arévalo, Maria T; Navarro, Ashley; Arico, Chenoa D; Li, Junwei; Alkhatib, Omar; Chen, Shan; Diaz-Arévalo, Diana; Zeng, Mingtao

    2014-05-30

    Anthrax spores can be aerosolized and dispersed as a bioweapon. Current postexposure treatments are inadequate at later stages of infection, when high levels of anthrax toxins are present. Anthrax toxins enter cells via two identified anthrax toxin receptors: tumor endothelial marker 8 (TEM8) and capillary morphogenesis protein 2 (CMG2). We hypothesized that host cells would be protected from anthrax toxins if anthrax toxin receptor expression was effectively silenced using RNA interference (RNAi) technology. Thus, anthrax toxin receptors in mouse and human macrophages were silenced using targeted siRNAs or blocked with specific antibody prior to challenge with anthrax lethal toxin. Viability assays were used to assess protection in macrophages treated with specific siRNA or antibody as compared with untreated cells. Silencing CMG2 using targeted siRNAs provided almost complete protection against anthrax lethal toxin-induced cytotoxicity and death in murine and human macrophages. The same results were obtained by prebinding cells with specific antibody prior to treatment with anthrax lethal toxin. In addition, TEM8-targeted siRNAs also offered significant protection against lethal toxin in human macrophage-like cells. Furthermore, silencing CMG2, TEM8, or both receptors in combination was also protective against MEK2 cleavage by lethal toxin or adenylyl cyclase activity by edema toxin in human kidney cells. Thus, anthrax toxin receptor-targeted RNAi has the potential to be developed as a life-saving, postexposure therapy against anthrax.

  14. Are harmful algal blooms becoming the greatest inland water quality threat to public health and aquatic ecosystems?

    PubMed

    Brooks, Bryan W; Lazorchak, James M; Howard, Meredith D A; Johnson, Mari-Vaughn V; Morton, Steve L; Perkins, Dawn A K; Reavie, Euan D; Scott, Geoffrey I; Smith, Stephanie A; Steevens, Jeffery A

    2016-01-01

    In this Focus article, the authors ask a seemingly simple question: Are harmful algal blooms (HABs) becoming the greatest inland water quality threat to public health and aquatic ecosystems? When HAB events require restrictions on fisheries, recreation, and drinking water uses of inland water bodies significant economic consequences result. Unfortunately, the magnitude, frequency, and duration of HABs in inland waters are poorly understood across spatiotemporal scales and differentially engaged among states, tribes, and territories. Harmful algal bloom impacts are not as predictable as those from conventional chemical contaminants, for which water quality assessment and management programs were primarily developed, because interactions among multiple natural and anthropogenic factors determine the likelihood and severity to which a HAB will occur in a specific water body. These forcing factors can also affect toxin production. Beyond site-specific water quality degradation caused directly by HABs, the presence of HAB toxins can negatively influence routine surface water quality monitoring, assessment, and management practices. Harmful algal blooms present significant challenges for achieving water quality protection and restoration goals when these toxins confound interpretation of monitoring results and environmental quality standards implementation efforts for other chemicals and stressors. Whether HABs presently represent the greatest threat to inland water quality is debatable, though in inland waters of developed countries they typically cause more severe acute impacts to environmental quality than conventional chemical contamination events. The authors identify several timely research needs. Environmental toxicology, environmental chemistry, and risk-assessment expertise must interface with ecologists, engineers, and public health practitioners to engage the complexities of HAB assessment and management, to address the forcing factors for HAB formation, and

  15. Therapy After Exposure to Toxins (I)

    DTIC Science & Technology

    2005-09-01

    increments, brighter bands at 200bp and 500bp) was used. Real Time PCR Real Time PCR amplification was performed in the LightCycler with a variable amount...20bp increments, brighter bands at 200bp and 500bp). TNO report I TNO-DV2 2005 A061 11/24 3.1.2 Real Time PCR Real Time PCR amplification was performed

  16. Coupling of algal biofuel production with wastewater.

    PubMed

    Bhatt, Neha Chamoli; Panwar, Amit; Bisht, Tara Singh; Tamta, Sushma

    2014-01-01

    Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area.

  17. Phototaxis and chemotaxis of brown algal swarmers.

    PubMed

    Kinoshita, Nana; Nagasato, Chikako; Motomura, Taizo

    2017-05-01

    Brown algae exhibit three patterns of sexual reproduction: isogamy, anisogamy, and oogamy. Unicellular swarmers including gametes and zoospores bear two heterogenous flagella, an anterior flagellum with mastigonemes (fine tripartite hairs) and a posterior one. In seawater, these flagellates usually receive physico-chemical signals for finding partners and good habitats. It is well known that brown algal swarmers change their swimming direction depending on blue light (phototaxis), and male gametes do so, based on the sex pheromones from female gametes (chemotaxis). In recent years, the comparative analysis of chemotaxis in isogamy, anisogamy, and oogamy has been conducted. In this paper, we focused on the phototaxis and chemotaxis of brown algal gametes comparing the current knowledge with our recent studies.

  18. Coupling of Algal Biofuel Production with Wastewater

    PubMed Central

    Panwar, Amit; Bisht, Tara Singh; Tamta, Sushma

    2014-01-01

    Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area. PMID:24982930

  19. Algal diseases: spotlight on a black box.

    PubMed

    Gachon, Claire M M; Sime-Ngando, Télesphore; Strittmatter, Martina; Chambouvet, Aurélie; Kim, Gwang Hoon

    2010-11-01

    Like any other living organisms, algae are plagued by diseases caused by fungi, protists, bacteria or viruses. As aquaculture continues to rise worldwide, pathogens of nori or biofuel sources are becoming a significant economic burden. Parasites are also increasingly being considered of equal importance with predators for ecosystem functioning. Altered disease patterns in disturbed environments are blamed for sudden extinctions, regime shifts, and spreading of alien species. Here we review the biodiversity and impact of pathogens and parasites of aquatic primary producers in freshwater and marine systems. We also cover recent advances on algal defence reactions, and discuss how emerging technologies can be used to reassess the profound, multi-faceted, and so far broadly-overlooked influence of algal diseases on ecosystem properties.

  20. Climate change impacts on natural toxins in food production systems, exemplified by deoxynivalenol in wheat and diarrhetic shellfish toxins.

    PubMed

    van der Fels-Klerx, H J; Olesen, J E; Naustvoll, L-J; Friocourt, Y; Mengelers, M J B; Christensen, J H

    2012-01-01

    Climate change is expected to affect food and feed safety, including the occurrence of natural toxins in primary crop and seafood production; however, to date, quantitative estimates are scarce. This study aimed to estimate the impact of climate change effects on mycotoxin contamination of cereal grains cultivated in the terrestrial area of north west Europe, and on the frequency of harmful algal blooms and contamination of shellfish with marine biotoxins in the North Sea coastal zone. The study focused on contamination of wheat with deoxynivalenol, and on abundance of Dinophysis spp. and the possible relationship with diarrhetic shellfish toxins. The study used currently available data and models. Global and regional climate models were combined with models of crop phenology, mycotoxin prediction models, hydrodynamic models and ecological models, with the output of one model being used as input for the other. In addition, statistical data analyses using existing national datasets from the study area were performed to obtain information on the relationships between Dinophysis spp. cell counts and contamination of shellfish with diarrhetic shellfish toxins as well as on frequency of cereal cropping. In this paper, a summary of the study is presented, and overall conclusions and recommendations are given. Climate change projections for the years 2031-2050 were used as the starting point of the analyses relative to a preceding 20-year baseline period from which the climate change signal was calculated. Results showed that, in general, climate change effects lead to advanced flowering and harvest of wheat, and increased risk of contamination of wheat with deoxynivalenol. Blooms of dinoflagellates were estimated to occur more often. If the group of Dinophysis spp. behaves similarly to other flagellates in the future then frequency of harmful algal blooms of Dinophysis spp. may also increase, but consequences for contamination of shellfish with diarrhetic shellfish

  1. Microbial bioenergetics of coral-algal interactions

    PubMed Central

    Abieri, Maria L.; George, Emma E.; Knowles, Ben; Naliboff, Douglas S.; Smurthwaite, Cameron A.; Kelly, Linda Wegley; Haas, Andreas F.

    2017-01-01

    Human impacts are causing ecosystem phase shifts from coral- to algal-dominated reef systems on a global scale. As these ecosystems undergo transition, there is an increased incidence of coral-macroalgal interactions. Mounting evidence indicates that the outcome of these interaction events is, in part, governed by microbially mediated dynamics. The allocation of available energy through different trophic levels, including the microbial food web, determines the outcome of these interactions and ultimately shapes the benthic community structure. However, little is known about the underlying thermodynamic mechanisms involved in these trophic energy transfers. This study utilizes a novel combination of methods including calorimetry, flow cytometry, and optical oxygen measurements, to provide a bioenergetic analysis of coral-macroalgal interactions in a controlled aquarium setting. We demonstrate that the energetic demands of microbial communities at the coral-algal interaction interface are higher than in the communities associated with either of the macroorganisms alone. This was evident through higher microbial power output (energy use per unit time) and lower oxygen concentrations at interaction zones compared to areas distal from the interface. Increases in microbial power output and lower oxygen concentrations were significantly correlated with the ratio of heterotrophic to autotrophic microbes but not the total microbial abundance. These results suggest that coral-algal interfaces harbor higher proportions of heterotrophic microbes that are optimizing maximal power output, as opposed to yield. This yield to power shift offers a possible thermodynamic mechanism underlying the transition from coral- to algal-dominated reef ecosystems currently being observed worldwide. As changes in the power output of an ecosystem are a significant indicator of the current state of the system, this analysis provides a novel and insightful means to quantify microbial impacts on

  2. Microbial bioenergetics of coral-algal interactions.

    PubMed

    Roach, Ty N F; Abieri, Maria L; George, Emma E; Knowles, Ben; Naliboff, Douglas S; Smurthwaite, Cameron A; Kelly, Linda Wegley; Haas, Andreas F; Rohwer, Forest L

    2017-01-01

    Human impacts are causing ecosystem phase shifts from coral- to algal-dominated reef systems on a global scale. As these ecosystems undergo transition, there is an increased incidence of coral-macroalgal interactions. Mounting evidence indicates that the outcome of these interaction events is, in part, governed by microbially mediated dynamics. The allocation of available energy through different trophic levels, including the microbial food web, determines the outcome of these interactions and ultimately shapes the benthic community structure. However, little is known about the underlying thermodynamic mechanisms involved in these trophic energy transfers. This study utilizes a novel combination of methods including calorimetry, flow cytometry, and optical oxygen measurements, to provide a bioenergetic analysis of coral-macroalgal interactions in a controlled aquarium setting. We demonstrate that the energetic demands of microbial communities at the coral-algal interaction interface are higher than in the communities associated with either of the macroorganisms alone. This was evident through higher microbial power output (energy use per unit time) and lower oxygen concentrations at interaction zones compared to areas distal from the interface. Increases in microbial power output and lower oxygen concentrations were significantly correlated with the ratio of heterotrophic to autotrophic microbes but not the total microbial abundance. These results suggest that coral-algal interfaces harbor higher proportions of heterotrophic microbes that are optimizing maximal power output, as opposed to yield. This yield to power shift offers a possible thermodynamic mechanism underlying the transition from coral- to algal-dominated reef ecosystems currently being observed worldwide. As changes in the power output of an ecosystem are a significant indicator of the current state of the system, this analysis provides a novel and insightful means to quantify microbial impacts on

  3. Copper desorption from Gelidium algal biomass.

    PubMed

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2007-04-01

    Desorption of divalent copper from marine algae Gelidium sesquipedale, an algal waste (from agar extraction industry) and a composite material (the algal waste immobilized in polyacrylonitrile) was studied in a batch system. Copper ions were first adsorbed until saturation and then desorbed by HNO(3) and Na(2)EDTA solutions. Elution efficiency using HNO(3) increases as pH decreases. At pH=1, for a solid to liquid ratio S/L=4gl(-1), elution efficiency was 97%, 95% and 88%, the stoichiometric coefficient for the ionic exchange, 0.70+/-0.02, 0.73+/-0.05 and 0.76+/-0.06 and the selectivity coefficient, 0.93+/-0.07, 1.0+/-0.3 and 1.1+/-0.3, respectively, for algae Gelidium, algal waste and composite material. Complexation of copper ions by EDTA occurs in a molar proportion of 1:1 and the elution efficiency increases with EDTA concentration. For concentrations of 1.4, 0.88 and 0.57 mmoll(-1), the elution efficiency for S/L=4gl(-1), was 91%, 86% and 78%, respectively, for algae Gelidium, algal waste and composite material. The S/L ratio, in the range 1-20gl(-1), has little influence on copper recovery by using 0.1M HNO(3). Desorption kinetics was very fast for all biosorbents. Kinetic data using HNO(3) as eluant were well described by the mass transfer model, considering the average metal concentration in the solid phase and the equilibrium relationship given by the mass action law. The homogeneous diffusion coefficient varied between 1.0 x 10(-7)cm(2)s(-1) for algae Gelidium and 3.0 x 10(-7)cm(2)s(-1) for the composite material.

  4. Algal Cell Response to Pulsed Waved Stimulation and Its Application to Increase Algal Lipid Production

    PubMed Central

    Savchenko, Oleksandra; Xing, Jida; Yang, Xiaoyan; Gu, Quanrong; Shaheen, Mohamed; Huang, Min; Yu, Xiaojian; Burrell, Robert; Patra, Prabir; Chen, Jie

    2017-01-01

    Generating renewable energy while sequestering CO2 using algae has recently attracted significant research attention, mostly directing towards biological methods such as systems biology, genetic engineering and bio-refining for optimizing algae strains. Other approaches focus on chemical screening to adjust culture conditions or culture media. We report for the first time the physiological changes of algal cells in response to a novel form of mechanical stimulation, or a pulsed wave at the frequency of 1.5 MHz and the duty cycle of 20%. We studied how the pulsed wave can further increase algal lipid production on top of existing biological and chemical methods. Two commonly used algal strains, fresh-water Chlorella vulgaris and seawater Tetraselmis chuii, were selected. We have performed the tests in shake flasks and 1 L spinner-flask bioreactors. Conventional Gravimetric measurements show that up to 20% increase for algal lipid could be achieved after 8 days of stimulation. The total electricity cost needed for the stimulations in a one-liter bioreactor is only one-tenth of a US penny. Gas liquid chromatography shows that the fatty acid composition remains unchanged after pulsed-wave stimulation. Scanning electron microscope results also suggest that pulsed wave stimulation induces shear stress and thus increases algal lipid production. PMID:28186124

  5. Algal Cell Response to Pulsed Waved Stimulation and Its Application to Increase Algal Lipid Production

    NASA Astrophysics Data System (ADS)

    Savchenko, Oleksandra; Xing, Jida; Yang, Xiaoyan; Gu, Quanrong; Shaheen, Mohamed; Huang, Min; Yu, Xiaojian; Burrell, Robert; Patra, Prabir; Chen, Jie

    2017-02-01

    Generating renewable energy while sequestering CO2 using algae has recently attracted significant research attention, mostly directing towards biological methods such as systems biology, genetic engineering and bio-refining for optimizing algae strains. Other approaches focus on chemical screening to adjust culture conditions or culture media. We report for the first time the physiological changes of algal cells in response to a novel form of mechanical stimulation, or a pulsed wave at the frequency of 1.5 MHz and the duty cycle of 20%. We studied how the pulsed wave can further increase algal lipid production on top of existing biological and chemical methods. Two commonly used algal strains, fresh-water Chlorella vulgaris and seawater Tetraselmis chuii, were selected. We have performed the tests in shake flasks and 1 L spinner-flask bioreactors. Conventional Gravimetric measurements show that up to 20% increase for algal lipid could be achieved after 8 days of stimulation. The total electricity cost needed for the stimulations in a one-liter bioreactor is only one-tenth of a US penny. Gas liquid chromatography shows that the fatty acid composition remains unchanged after pulsed-wave stimulation. Scanning electron microscope results also suggest that pulsed wave stimulation induces shear stress and thus increases algal lipid production.

  6. Algal Cell Response to Pulsed Waved Stimulation and Its Application to Increase Algal Lipid Production.

    PubMed

    Savchenko, Oleksandra; Xing, Jida; Yang, Xiaoyan; Gu, Quanrong; Shaheen, Mohamed; Huang, Min; Yu, Xiaojian; Burrell, Robert; Patra, Prabir; Chen, Jie

    2017-02-10

    Generating renewable energy while sequestering CO2 using algae has recently attracted significant research attention, mostly directing towards biological methods such as systems biology, genetic engineering and bio-refining for optimizing algae strains. Other approaches focus on chemical screening to adjust culture conditions or culture media. We report for the first time the physiological changes of algal cells in response to a novel form of mechanical stimulation, or a pulsed wave at the frequency of 1.5 MHz and the duty cycle of 20%. We studied how the pulsed wave can further increase algal lipid production on top of existing biological and chemical methods. Two commonly used algal strains, fresh-water Chlorella vulgaris and seawater Tetraselmis chuii, were selected. We have performed the tests in shake flasks and 1 L spinner-flask bioreactors. Conventional Gravimetric measurements show that up to 20% increase for algal lipid could be achieved after 8 days of stimulation. The total electricity cost needed for the stimulations in a one-liter bioreactor is only one-tenth of a US penny. Gas liquid chromatography shows that the fatty acid composition remains unchanged after pulsed-wave stimulation. Scanning electron microscope results also suggest that pulsed wave stimulation induces shear stress and thus increases algal lipid production.

  7. Anti-Idiotype Probes for Toxin Detection

    DTIC Science & Technology

    1991-09-13

    enterotoxins A and B, the exfoliative toxins A and B and toxic shock syndrome syndrome toxin-1 to activate macrophages. All the toxins tested had the...Staphylococcal enterotoxin A, toxic shock syndrome toxin-1 and both exfoliative toxins triggered C3HeB/FeJ macrophages to secrete tumor necrosis...toxins A and B and toxic shock syndrome toxin-1 to activate macrophages. All the toxins tested had the potential to stimulate tumoricidal activity in

  8. Liquid transportation fuels from algal oils

    NASA Astrophysics Data System (ADS)

    Chen, Daichuan

    Liquid transportation fuels from renewable sources are becoming more prominent and important in modem society. Processing of hydrocarbon oils from algae has not been studied in detail in the past, so components which have been proposed for incorporation in algal oils via genetic engineering, such as cuparene, farnesene, phytol and squalene, have been subjected to processing via catalytic cracking in a pulse reactor at different temperatures. The cracking results showed that liquid products contained numerous high octane molecules which make it feasible for use in automobiles. Additionally, canola oil, chosen as an algal oil model compound, was studied as a feed for catalytic cracking in a fixed-bed reactor at atmospheric pressure over different types of zeolites. The results showed that MFI catalysts gave the highest yield of gasoline range products and lowest coke formation. Gallium loaded MFI zeolites increased the total aromatics yield for the canola oil cracking relative to the acid form of the zeolite. Finally, algal oils were cracked on several selected zeolites, and the results showed the same trend as canola oil cracking. MFI gave the highest gasoline yield (43.8 wt%) and lowest coke (4.7 wt%). The total aromatics yield from algae oil cracking is improved 7.8 wt% when MFI is loaded with gallium.

  9. Caspase Activation as a Versatile Assay Platform for Detection of Cytotoxic Bacterial Toxins

    PubMed Central

    Zorman, Julie; Horton, Melanie; Dubey, Sheri; ter Meulen, Jan

    2013-01-01

    Pathogenic bacteria produce several virulence factors that help them establish infection in permissive hosts. Bacterial toxins are a major class of virulence factors and hence are attractive therapeutic targets for vaccine development. Here, we describe the development of a rapid, sensitive, and high-throughput assay that can be used as a versatile platform to measure the activities of bacterial toxins. We have exploited the ability of these toxins to cause cell death via apoptosis of sensitive cultured cell lines as a readout for measuring toxin activity. Caspases (cysteine-aspartic proteases) are induced early in the apoptotic pathway, and so we used their induction to measure the activities of Clostridium difficile toxins A (TcdA) and B (TcdB) and binary toxin (CDTa-CDTb), Corynebacterium diphtheriae toxin (DT), and Pseudomonas aeruginosa exotoxin A (PEA). Caspase induction in the cell lines, upon exposure to toxins, was optimized by toxin concentration and intoxication time, and the specificity of caspase activity was established using a genetically mutated toxin and a pan-caspase inhibitor. In addition, we demonstrate the utility of the caspase assay for measuring toxin potency, as well as neutralizing antibody (NAb) activity against C. difficile toxins. Furthermore, the caspase assay showed excellent correlation with the filamentous actin (F-actin) polymerization assay for measuring TcdA and TcdB neutralization titers upon vaccination of hamsters. These results demonstrate that the detection of caspase induction due to toxin exposure using a chemiluminescence readout can support potency and clinical immunogenicity testing for bacterial toxin vaccine candidates in development. PMID:23824772

  10. Caspase activation as a versatile assay platform for detection of cytotoxic bacterial toxins.

    PubMed

    Payne, Angela M; Zorman, Julie; Horton, Melanie; Dubey, Sheri; ter Meulen, Jan; Vora, Kalpit A

    2013-09-01

    Pathogenic bacteria produce several virulence factors that help them establish infection in permissive hosts. Bacterial toxins are a major class of virulence factors and hence are attractive therapeutic targets for vaccine development. Here, we describe the development of a rapid, sensitive, and high-throughput assay that can be used as a versatile platform to measure the activities of bacterial toxins. We have exploited the ability of these toxins to cause cell death via apoptosis of sensitive cultured cell lines as a readout for measuring toxin activity. Caspases (cysteine-aspartic proteases) are induced early in the apoptotic pathway, and so we used their induction to measure the activities of Clostridium difficile toxins A (TcdA) and B (TcdB) and binary toxin (CDTa-CDTb), Corynebacterium diphtheriae toxin (DT), and Pseudomonas aeruginosa exotoxin A (PEA). Caspase induction in the cell lines, upon exposure to toxins, was optimized by toxin concentration and intoxication time, and the specificity of caspase activity was established using a genetically mutated toxin and a pan-caspase inhibitor. In addition, we demonstrate the utility of the caspase assay for measuring toxin potency, as well as neutralizing antibody (NAb) activity against C. difficile toxins. Furthermore, the caspase assay showed excellent correlation with the filamentous actin (F-actin) polymerization assay for measuring TcdA and TcdB neutralization titers upon vaccination of hamsters. These results demonstrate that the detection of caspase induction due to toxin exposure using a chemiluminescence readout can support potency and clinical immunogenicity testing for bacterial toxin vaccine candidates in development.

  11. Marine Toxins: An Overview

    NASA Astrophysics Data System (ADS)

    Fusetani, Nobuhiro

    Oceans provide enormous and diverse space for marine life. Invertebrates are conspicuous inhabitants in certain zones such as the intertidal; many are soft-bodied, relatively immobile and lack obvious physical defenses. These animals frequently have evolved chemical defenses against predators and overgrowth by fouling organisms. Marine animals may accumulate and use a variety of toxins from prey organisms and from symbiotic microorganisms for their own purposes. Thus, toxic animals are particularly abundant in the oceans. The toxins vary from small molecules to high molecular weight proteins and display unique chemical and biological features of scientific interest. Many of these substances can serve as useful research tools or molecular models for the design of new drugs and pesticides. This chapter provides an initial survey of these toxins and their salient properties.

  12. Marine Neurotoxins: Envenomations and Contact Toxins.

    PubMed

    Watters, Michael R.; Stommel, Elijah W.

    2004-03-01

    Familiarity with the appearance and habitat of venomous sea creatures, the location of their stinging apparatus, and surveillance of population concentrations within recreational waters are essential in avoiding envenomations. Compared with the thermo-stable low molecular weighted ingestible seafood toxins, venomous toxins are often large molecular weight proteins and many are heat labile, which provides opportunity for therapeutic intervention. Heat therapy may denature the toxins, and provide immediate relief of pain in coelenterate and venomous fish envenomations. Injections of local anesthetic agents may also be used. First aid measures at the seashore may limit the spread of venom, and include immobilization of the affected sites, compression bandaging, and venous-lymphatic occlusive bandages. Measures to limit continued envenomation by attached stinging cells include topical vinegar for jellyfish tentacles and irrigation with debridment for spines of venomous fish. Antivenins are of limited availability and may be used for envenomations with sea snakes, Chironex box jellyfish, and some venomous fish. Sea snakes bites may be treated with antivenin from land snakes or with hemodialysis when antivenin is not available. Neuromuscular paralysis occurs with bites by sea snakes, cone snails, blue octopuses, and some jellyfish. Supportive treatment includes attention to cardiopulmonary resuscitation and intubation. Exposure to Pfeisteria may result in cognitive and behavioral abnormalities. Treatment with cholestyramine may be helpful in binding the toxin and improve recovery.

  13. Recent advances in ultrasonic treatment: Challenges and field applications for controlling harmful algal blooms (HABs).

    PubMed

    Park, Jungsu; Church, Jared; Son, Younggyu; Kim, Keug-Tae; Lee, Woo Hyoung

    2017-09-01

    Algal blooms are a naturally occurring phenomenon which can occur in both freshwater and saltwater. However, due to excess nutrient loading in water bodies (e.g. agricultural runoff and industrial activities), harmful algal blooms (HABs) have become an increasing issue globally, and can even cause health effects in humans due to the release of cyanotoxins. Among currently available treatment methods, sonication has received increasing attention for algal control because of its low impact on ecosystems and the environment. The effects of ultrasound on algal cells are well understood and operating parameter such as frequency, intensity, and duration of exposure has been well studied. However, most studies have been limited to laboratory data interpretation due to complicated environmental conditions in the field. Only a few field and pilot tests in small reservoirs were reported and the applicability of ultrasound for HABs prevention and control is still under question. There is a lack of information on the upscaling of ultrasonication devices for HAB control on larger water bodies, considering field influencing factors such as rainfall, light intensity/duration, temperature, water flow, nutrients loading, and turbidity. In this review article, we address the challenges and field considerations of ultrasonic applications for controlling algal blooms. An extensive literature survey, from the fundamentals of ultrasound techniques to recent ultrasound laboratory and field studies, has been thoroughly conducted and summarized to identify future technical expectations for field applications. Case studies investigating spatial distribution of frequency and pressure during sonication are highlighted with future implications. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Simultaneous screening for lipophilic and hydrophilic toxins in marine harmful algae using a serially coupled reversed-phase and hydrophilic interaction liquid chromatography separation system with high-resolution mass spectrometry.

    PubMed

    Chen, Junhui; Gao, Liyuan; Li, Zhaoyong; Wang, Shuai; Li, Jingxi; Cao, Wei; Sun, Chengjun; Zheng, Li; Wang, Xiaoru

    2016-03-31

    The presence of toxins in harmful algal blooms (HABs) poses considerable concerns because of their potential adverse effects on ecological environments and human health. When marine HABs occur, efficient screening and identification of toxins in different kinds of HAB algae remains a challenge. In this study, the applicability of serial coupling of reversed-phase liquid chromatography (RPLC) and hydrophilic interaction chromatography (HILIC) combined with high resolution mass spectrometry (HR-MS) for the simultaneous screening and identification of various kinds of known lipophilic and hydrophilic toxins in HAB algae was investigated for the first time. Ultrasound-assisted extraction (UAE) was explored to extract both lipophilic and hydrophilic toxins in algae simultaneously. As in most cases, toxin standards were not available; therefore, an identification procedure based on accurate mass data and chromatographic behavior was proposed. According to this procedure, eight known lipophilic toxins and 11 hydrophilic toxins were successfully detected in a single injection, and the proposed method was validated. Satisfactory sensitivity, repeatability (RSD <14.87%) and recovery (89.4-105.8%) of the method were achieved. A major advantage of the proposed method is that it can almost detect members of all eight groups of marine algal toxins in a single run. Using this method, several known toxins in different marine toxigenic algae including Alexandrium tamarense, Alexandrium minutum and Prorocentrum lima were successfully observed and identified. This work demonstrates that RPLC/HILIC-HR-MS combined with an accurate mass list of known marine algal toxins may be used as a powerful tool for screening of different classes of known toxins in marine harmful algae.

  15. [Toxins as a biological weapon].

    PubMed

    Płusa, Tadeusz

    2015-09-01

    The criteria for recognizing a chemical compound for the toxin are vague and gave it the possibility of inclusion in this group a number of biological agents. Toxins list is extensive, but the interest is focused on bacterial toxins, poisons derived from snake venoms, algae and plant proteins, and small molecules. Particular attention is focused on the so-called "sea" toxins, which include tetrodotoxin, brevetoxin and saxitoxin. This indicates the search for a new hitherto unknown potential bioterrorist threats. © 2015 MEDPRESS.

  16. Study of polyacrylamide grafted starch based algal flocculation towards applications in algal biomass harvesting.

    PubMed

    Banerjee, Chiranjib; Gupta, Pratibha; Mishra, Sumit; Sen, Gautam; Shukla, Pratyoosh; Bandopadhyay, Rajib

    2012-11-01

    Microalgae may be the source of high amount of lipid and protein. It has the property for carbon dioxide sequestration, recycling and also can remove pollutants from wastewater. Using traditional methods, collection of algal biomass is either cost effective, time consuming or may be toxic due to use of chemical salts. The aim of this study is to harvest freshwater microalgae (Chlorella sp. CB4) biomass by using polymer. Polyacrylamide grafted starch (St-g-PAM) has been synthesized by microwave assisted method involving a synergism of microwave radiation and ceric ammonium nitrate (CAN) to initiate the grafting reaction. The synthesis was optimized in terms of CAN and monomer (acrylamide) concentration. The algal flocculation efficacy of all the grades of this graft copolymer was studied through standard 'Jar test' procedure. Effects of percentage grafting, pH and zeta potential on percentage recovery of algal biomass were thoroughly investigated.

  17. Algal taxonomy: a road to nowhere?

    PubMed

    De Clerck, Olivier; Guiry, Michael D; Leliaert, Frederik; Samyn, Yves; Verbruggen, Heroen

    2013-04-01

    The widespread view of taxonomy as an essentially retrogressive and outmoded science unable to cope with the current biodiversity crisis stimulated us to analyze the current status of cataloguing global algal diversity. Contrary to this largely pessimistic belief, species description rates of algae through time and trends in the number of active taxonomists, as revealed by the web resource AlgaeBase, show a much more positive picture. More species than ever before are being described by a large community of algal taxonomists. The lack of any decline in the rate at which new species and genera are described, however, is indicative of the large proportion of undiscovered diversity and bears heavily on any prediction of global algal species diversity and the time needed to catalogue it. The saturation of accumulation curves of higher taxa (family, order, and classes) on the other hand suggest that at these taxonomic levels most diversity has been discovered. This reasonably positive picture does not imply that algal taxonomy does not face serious challenges in the near future. The observed levels of cryptic diversity in algae, combined with the shift in methods used to characterize them, have resulted in a rampant uncertainty about the status of many older species. As a consequence, there is a tendency in phycology to move gradually away from traditional names to a more informal system whereby clade-, specimen- or strain-based identifiers are used to communicate biological information. Whether these informal names for species-level clades represent a temporary situation stimulated by the lag between species discovery and formal description, or an incipient alternative or parallel taxonomy, will be largely determined by how well we manage to integrate historical collections into modern taxonomic research. Additionally, there is a pressing need for a consensus about the organizational framework to manage the information about algal species names. An eventual strategy

  18. Comprehensive computational model for combining fluid hydrodynamics, light transport and biomass growth in a Taylor vortex algal photobioreactor: Lagrangian approach.

    PubMed

    Gao, Xi; Kong, Bo; Vigil, R Dennis

    2017-01-01

    A comprehensive quantitative model incorporating the effects of fluid flow patterns, light distribution, and algal growth kinetics on biomass growth rate is developed in order to predict the performance of a Taylor vortex algal photobioreactor for culturing Chlorella vulgaris. A commonly used Lagrangian strategy for coupling the various factors influencing algal growth was employed whereby results from computational fluid dynamics and radiation transport simulations were used to compute numerous microorganism light exposure histories, and this information in turn was used to estimate the global biomass specific growth rate. The simulations provide good quantitative agreement with experimental data and correctly predict the trend in reactor performance as a key reactor operating parameter is varied (inner cylinder rotation speed). However, biomass growth curves are consistently over-predicted and potential causes for these over-predictions and drawbacks of the Lagrangian approach are addressed.

  19. Algal biomass production and wastewater treatment in high rate algal ponds receiving disinfected effluent.

    PubMed

    Santiago, Aníbal Fonseca; Calijuri, Maria Lucia; Assemany, Paula Peixoto; Calijuri, Maria do Carmo; dos Reis, Alberto José Delgado

    2013-01-01

    Algal biomass production associated with wastewater is usually carried out in high rate algal ponds (HRAPs), which are concomitantly used in the treatment of such effluent. However, most types of wastewater have high levels of bacteria that can inhibit the growth of algal biomass by competing for space and nutrients. The objective of this study was to assess the influence of ultraviolet (UV) pre-disinfection on the performance of HRAPs used for wastewater treatment and algal biomass production. Two HRAPs were tested: one received effluent from an upflow anaerobic sludge blanket (UASB) reactor- HRAP -and the second received UASB effluent pre-disinfected by UV radiation-(UV)HRAP. Physical, chemical and microbiological parameters were monitored, as well as algal biomass productivity and daily pH and dissolved oxygen (DO) variation. The (UV)HRAP presented highest DO and pH values, as well as greater percentage of chlorophyll a in the biomass, which indicates greater algal biomass productivity. The average percentages of chlorophyll a found in the biomass obtained from the HRAP and the (UV)HRAP were 0.95 +/- 0.65% and 1.58 +/- 0.65%, respectively. However, total biomass productivity was greater in the HRAP (11.4 gVSSm(-2) day(-1)) compared with the (UV)HRAP (9.3 gVSSm(-2) day(-1)). Mean pH values were 7.7 +/- 0.7 in the HRAP and 8.1 +/- 1.0 in the (UV)HRAP, and mean values of DO percent saturation were 87 +/- 26% and 112 +/- 31% for the HRAP and the (UV)HRAP, respectively. Despite these differences, removal efficiencies of organic carbon, chemical oxygen demand, ammoniacal nitrogen and soluble phosphorus were statistically equal at the 5% significance level.

  20. LYSOSOMAL DISRUPTION BY BACTERIAL TOXINS

    PubMed Central

    Bernheimer, Alan W.; Schwartz, Lois L.

    1964-01-01

    Bernheimer, Alan W. (New York University School of Medicine, New York), and Lois L. Schwartz. Lysosomal disruption by bacterial toxins. J. Bacteriol. 87:1100–1104. 1964.—Seventeen bacterial toxins were examined for capacity (i) to disrupt rabbit leukocyte lysosomes as indicated by decrease in turbidity of lysosomal suspensions, and (ii) to alter rabbit liver lysosomes as measured by release of β-glucuronidase and acid phosphatase. Staphylococcal α-toxin, Clostridium perfringens α-toxin, and streptolysins O and S affected lysosomes in both systems. Staphylococcal β-toxin, leucocidin and enterotoxin, Shiga neurotoxin, Serratia endotoxin, diphtheria toxin, tetanus neurotoxin, C. botulinum type A toxin, and C. perfringens ε-toxin were not active in either system. Staphylococcal δ-toxin, C. histolyticum collagenase, crude C. perfringens β-toxin, and crude anthrax toxin caused lysosomal damage in only one of the test systems. There is a substantial correlation between the hemolytic property of a toxin and its capacity to disrupt lysosomes, lending support to the concept that erythrocytes and lysosomes are bounded by similar membranes. PMID:5874534

  1. Wastewater treatment high rate algal ponds for biofuel production.

    PubMed

    Park, J B K; Craggs, R J; Shilton, A N

    2011-01-01

    While research and development of algal biofuels are currently receiving much interest and funding, they are still not commercially viable at today's fossil fuel prices. However, a niche opportunity may exist where algae are grown as a by-product of high rate algal ponds (HRAPs) operated for wastewater treatment. In addition to significantly better economics, algal biofuel production from wastewater treatment HRAPs has a much smaller environmental footprint compared to commercial algal production HRAPs which consume freshwater and fertilisers. In this paper the critical parameters that limit algal cultivation, production and harvest are reviewed and practical options that may enhance the net harvestable algal production from wastewater treatment HRAPs including CO(2) addition, species control, control of grazers and parasites and bioflocculation are discussed.

  2. Mechanism and challenges in commercialisation of algal biofuels.

    PubMed

    Singh, Anoop; Nigam, Poonam Singh; Murphy, Jerry D

    2011-01-01

    Biofuels made from algal biomass are being considered as the most suitable alternative energy in current global and economical scenario. Microalgae are known to produce and accumulate lipids within their cell mass which is similar to those found in many vegetable oils. The efficient lipid producer algae cell mass has been reported to contain more than 30% of their cell weight as lipids. According to US DOE microalgae have the potential to produce 100 times more oil per acre land than any terrestrial plants. This article reviews up to date literature on the composition of algae, mechanism of oil droplets, triacylglycerol (TAG) production in algal biomass, research and development made in the cultivation of algal biomass, harvesting strategies, and recovery of lipids from algal mass. The economical challenges in the production of biofuels from algal biomass have been discussed in view of the future prospects in the commercialisation of algal fuels.

  3. Effects of algal turfs and sediment on coral settlement.

    PubMed

    Birrell, Chico L; McCook, Laurence J; Willis, Bette L

    2005-01-01

    Successful settlement and recruitment of corals is critical to the resilience of coral reefs. Given that many degraded reefs are dominated by benthic algae, recovery of coral populations after bleaching and other disturbances requires successful settlement amidst benthic algae. Algal turfs often accumulate sediments, sediments are known to inhibit coral settlement, and reefs with high inputs of terrestrial sediments are often dominated by turfs. We investigated the impacts of two algal turf assemblages, and of sediment deposits, on settlement of the coral Acropora millepora (Ehrenberg). Adding sediment reduced coral settlement, but the effects of different algal turfs varied. In one case, algal turfs inhibited coral settlement, whereas the other turf only inhibited settlement when combined with sediments. These results provide the first direct, experimental evidence of effects of filamentous algal turfs on coral settlement, the variability in those effects, and the potential combined effects of algal turfs and trapped sediments.

  4. Relationships between primary production and irradiance in coral reef algal communities

    SciTech Connect

    Not Available

    1985-07-01

    Shallow water algal turf communities are the major primary producers on coral reefs. High rates of primary production are maintained despite extremely high light intensities and exposure to ultraviolet wavelengths. The relationships between the light intensity and primary production in these assemblages are typical of algae adapted to a high light environment (low ..cap alpha.. (initial slope), high I/sub k/ (saturating light intensity), and high I/sub c/ (compensation point light intensity)). Seasonal variations in algal standing crop due to herbivory and daylength result in some characteristic photoadaptive changes in ..cap alpha.. I/sub k/, and I/sub c/ and changes in Pnet/sub max/ rates (maximum net photosynthetic rate achieved at light saturation) on both a chlorophyll ..cap alpha.. and an areal basis. Exposure to UV wavelength results in significantly higher respiration rates but no changes in ..cap alpha.., Pnet/sub max/, or I/sub k/, when compared with these parameters for the same algal communities incubated at the same light intensities without UV wavelengths. The apparent lack of photoinhibition in these algae allows calculation of the daily integrated production from the P vs. I parameters. This integrated production is highest in July (3.1 +/- 0.2 g C m/sup -2/d/sup -1/) and is reduced by 30% from this maximum in December (2.1 +/- 0.1 g C m/sup -2/d/sup -1/).

  5. The Immunopathologic Effects of Mycoplasma Pneumoniae and CARDS Toxin: A Primate Model.

    PubMed

    Maselli, Diego J; Medina, Jorge L; Brooks, Edward G; Coalson, Jacqueline J; Kannan, Thirumalai R; Winter, Vicki T; Principe, Molly; Cagle, Marianna P; Baseman, Joel B; Dube, Peter H; Peters, Jay I

    2017-09-15

    Mycoplasma pneumoniae infection has been linked to poor asthma outcomes. M. pneumoniae produces an ADP-ribosylating and vacuolating toxin called Community Acquired Respiratory Distress Syndrome (CARDS) toxin that has a major role in inflammation and airway dysfunction. The objective was to evaluate the immunopathological effects in primates exposed to M. pneumoniae or CARDS toxin. Thirteen baboons were exposed to M. pneumoniae or CARDS toxin. At day 7 and 14, bronchoalveolar lavage fluid was collected and analyzed for cell count, percent of each type of cell, CARDS toxin by PCR, CARDS toxin by antigen capture, eosinophilic cationic protein, and cytokine profiles. Serum IgM, IgG and IgE responses to CARDS toxin were measured. All animals had a necropsy for analysis of the histopathological changes on lungs. No animal developed signs of infection. The serological responses to CARDS toxin were variable. At day 14, 4 of 7 animals exposed to M. pneumoniae and all 4 animals exposed to CARDS toxin developed histological "asthma-like" changes. T-cell intracellular cytokine analysis revealed an increasing ratio of IL-4/IFN-γ over time. Both M. pneumoniae and CARDS toxin exposure resulted in similar histopathological pulmonary changes suggesting that CARDS toxin plays a major role in the inflammatory response.

  6. Isolation, purification and spectrometric analysis of PSP toxins from moraxella sp., a bacterium associated with a toxic dinoflagellate

    SciTech Connect

    Boyce, S.D.; Doucette, G.J.

    1994-12-31

    Paralytic shellfish poisoning (PSP) is a seafood intoxication syndrome caused by the injestion of shellfish contaminated with toxins produced by algae known as dinoflagellates. The PSP toxins, saxitoxin and its derivatives, act to block voltage-dependent sodium channels and can cause paralysis and even death at higher doses. It is well documented that bacteria coexist with many harmful or toxic algal species, though the exact nature of the association in relation to toxin production is unknown. Recently, the bacterium Moraxella sp. was isolated from the PSP toxin producing dinoflagellate Alexandrium tamarense. Through HPLC analysis and saxitoxin receptor binding assays performed on crude bacterial extracts, it appears that Moraxella sp. is capable of producing saxitoxin and several of its derivatives. However, physical confirmation (e.g. mass spectrometry) of these results is still needed.

  7. Progress in understanding harmful algal blooms: paradigm shifts and new technologies for research, monitoring, and management.

    PubMed

    Anderson, Donald M; Cembella, Allan D; Hallegraeff, Gustaaf M

    2012-01-01

    The public health, tourism, fisheries, and ecosystem impacts from harmful algal blooms (HABs) have all increased over the past few decades. This has led to heightened scientific and regulatory attention, and the development of many new technologies and approaches for research and management. This, in turn, is leading to significant paradigm shifts with regard to, e.g., our interpretation of the phytoplankton species concept (strain variation), the dogma of their apparent cosmopolitanism, the role of bacteria and zooplankton grazing in HABs, and our approaches to investigating the ecological and genetic basis for the production of toxins and allelochemicals. Increasingly, eutrophication and climate change are viewed and managed as multifactorial environmental stressors that will further challenge managers of coastal resources and those responsible for protecting human health. Here we review HAB science with an eye toward new concepts and approaches, emphasizing, where possible, the unexpected yet promising new directions that research has taken in this diverse field.

  8. Progress in Understanding Harmful Algal Blooms: Paradigm Shifts and New Technologies for Research, Monitoring, and Management

    NASA Astrophysics Data System (ADS)

    Anderson, Donald M.; Cembella, Allan D.; Hallegraeff, Gustaaf M.

    2012-01-01

    The public health, tourism, fisheries, and ecosystem impacts from harmful algal blooms (HABs) have all increased over the past few decades. This has led to heightened scientific and regulatory attention, and the development of many new technologies and approaches for research and management. This, in turn, is leading to significant paradigm shifts with regard to, e.g., our interpretation of the phytoplankton species concept (strain variation), the dogma of their apparent cosmopolitanism, the role of bacteria and zooplankton grazing in HABs, and our approaches to investigating the ecological and genetic basis for the production of toxins and allelochemicals. Increasingly, eutrophication and climate change are viewed and managed as multifactorial environmental stressors that will further challenge managers of coastal resources and those responsible for protecting human health. Here we review HAB science with an eye toward new concepts and approaches, emphasizing, where possible, the unexpected yet promising new directions that research has taken in this diverse field.

  9. Involvement of Ras-related Rho proteins in the mechanisms of action of Clostridium difficile toxin A and toxin B.

    PubMed Central

    Dillon, S T; Rubin, E J; Yakubovich, M; Pothoulakis, C; LaMont, J T; Feig, L A; Gilbert, R J

    1995-01-01

    Toxins A and B of Clostridium difficile are responsible for pseudomembranous colitis, a disease that afflicts a substantial number of hospitalized patients treated with antibiotics. A major effect of these proteins is the disruption of the actin cytoskeleton. Recently, I. Just, G. Fritz, K. Aktories, M. Giry, M. R. Popoff, P. Boquet, S. Hegenbarth, and C. von Eichel-Streiber (J. Biol. Chem. 269:10706-10712, 1994) implicated Rho proteins as cellular targets of C. difficile toxin B, since pretreatment of cells or purified Rho with toxin prevented subsequent ADP-ribosylation of Rho by exoenzyme C3. Moreover, they showed that overexpression of Rho proteins in cells suppressed cell rounding normally associated with exposure of cells to C. difficile toxin B. Here we expand these findings by showing directly that Rho proteins are covalently modified by both C. difficile toxins A and B. In addition, we demonstrate that the stability of toxin-modified Rho in NIH 3T3 cells is dramatically reduced. Finally, we show that C. difficile toxins A and B do not have similar effects on the closely related Rac and CDC42 GTP-binding proteins. PMID:7890404

  10. Shiga toxin binds to activated platelets.

    PubMed

    Ghosh, S A; Polanowska-Grabowska, R K; Fujii, J; Obrig, T; Gear, A R L

    2004-03-01

    Hemolytic uremic syndrome (HUS) is associated with acute renal failure in children and can be caused by Shiga toxin (Stx)-producing Escherichia coli. Thrombocytopenia and formation of renal thrombi are characteristic of HUS, suggesting that platelet activation is involved in its pathogenesis. However, whether Shiga toxin directly activates platelets is controversial. The present study evaluates if potential platelet sensitization during isolation by different procedures influences platelet interaction with Shiga toxin. Platelets isolated from sodium citrate anticoagulated blood were exposed during washing to EDTA and higher g forces than platelets prepared from acid-citrate-dextrose (ACD) plasma. Platelet binding of Stx was significantly higher in EDTA-washed preparations relative to ACD-derived platelets. Binding of Stx was also increased with ACD-derived platelets when activated with thrombin (1 U mL-1) and exposure of the Gb3 Stx receptor was detected only on platelets subjected to EDTA, higher g forces or thrombin. EDTA-exposed platelets lost their normal discoid shape and were larger. P-selectin (CD62P) exposure was significantly increased in EDTA-washed preparations relative to ACD-derived platelets, suggesting platelet activation. Taken together, these results suggest that direct binding of Stx occurs only on 'activated' platelets rather than on resting platelets. The ability of Stx to interact with previously activated platelets may be an important element in understanding the pathogenesis of HUS.

  11. Diffusion of Botulinum Toxins

    PubMed Central

    Brodsky, Matthew A.; Swope, David M.; Grimes, David

    2012-01-01

    Background It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion. Methods This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method). It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB). Results Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others. Discussion Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected. PMID:23440162

  12. Optimizing algal cultivation & productivity : an innovative, multidiscipline, and multiscale approach.

    SciTech Connect

    Murton, Jaclyn K.; Hanson, David T.; Turner, Tom; Powell, Amy Jo; James, Scott Carlton; Timlin, Jerilyn Ann; Scholle, Steven; August, Andrew; Dwyer, Brian P.; Ruffing, Anne; Jones, Howland D. T.; Ricken, James Bryce; Reichardt, Thomas A.

    2010-04-01

    Progress in algal biofuels has been limited by significant knowledge gaps in algal biology, particularly as they relate to scale-up. To address this we are investigating how culture composition dynamics (light as well as biotic and abiotic stressors) describe key biochemical indicators of algal health: growth rate, photosynthetic electron transport, and lipid production. Our approach combines traditional algal physiology with genomics, bioanalytical spectroscopy, chemical imaging, remote sensing, and computational modeling to provide an improved fundamental understanding of algal cell biology across multiple cultures scales. This work spans investigations from the single-cell level to ensemble measurements of algal cell cultures at the laboratory benchtop to large greenhouse scale (175 gal). We will discuss the advantages of this novel, multidisciplinary strategy and emphasize the importance of developing an integrated toolkit to provide sensitive, selective methods for detecting early fluctuations in algal health, productivity, and population diversity. Progress in several areas will be summarized including identification of spectroscopic signatures for algal culture composition, stress level, and lipid production enabled by non-invasive spectroscopic monitoring of the photosynthetic and photoprotective pigments at the single-cell and bulk-culture scales. Early experiments compare and contrast the well-studied green algae chlamydomonas with two potential production strains of microalgae, nannochloropsis and dunnaliella, under optimal and stressed conditions. This integrated approach has the potential for broad impact on algal biofuels and bioenergy and several of these opportunities will be discussed.

  13. Conversion of Small Algal Oil Sample to JP-8

    DTIC Science & Technology

    2012-01-01

    9 Table 4. Wei ht Percent of n-Paraffins for Biofuels and JP-8 Fuel 7051 n-Decane ·n- ndecane n-Dodecane n-Tridecane W911NF -10-C-0021 Algal ...REPORT Conversion of Small Algal Oil Sample to JP-8 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: A small sample of Algal oil was received by UOP for...P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS Algal Oil, JP-8, SPK, MIL-DTL-83133G F. S. Lupton UOP LLC 25 East

  14. Assessing the potential of polyculture to accelerate algal biofuel production

    DOE PAGES

    Newby, Deborah T.; Mathews, Teresa J.; Pate, Ron C.; ...

    2016-10-24

    To date, the algal biofuel industry has focused on the cultivation of monocultures of highly productive algal strains, but scaling up production remains challenging. However, algal monocultures are difficult to maintain because they are easily contaminated by wild algal strains, grazers, and pathogens. In contrast, theory suggests that polycultures (multispecies assemblages) can promote both ecosystem stability and productivity. A greater understanding of species interactions and how communities change with time will need to be developed before polycultures can be successfully applied to large-scale algal production efforts. Here in this paper we review the agricultural and ecological literature to explore opportunitiesmore » for increased annual biomass production through the use of algal polycultures. We discuss case studies where algal polycultures have been successfully maintained for industries other than the biofuel industry, as well as the few studies that have compared biomass production of algal polycultures to that of monocultures. Assemblages that include species with complementary traits are of particular promise. These assemblages have the potential not only to increase crop productivity and stability, but they may also be capable of utilizing natural resources (e.g. light, nutrients, water) more efficiently via tighter niche packing. Therefore, algal polycultures show promise for enhancing biomass productivity, enabling sustainable production and reducing overall production costs.« less

  15. Assessing the potential of polyculture to accelerate algal biofuel production

    SciTech Connect

    Newby, Deborah T.; Mathews, Teresa J.; Pate, Ron C.; Huesemann, Michael H.; Lane, Todd W.; Wahlen, Bradley D.; Mandal, Shovon; Engler, Robert K.; Feris, Kevin P.; Shurin, Jon B.

    2016-10-24

    To date, the algal biofuel industry has focused on the cultivation of monocultures of highly productive algal strains, but scaling up production remains challenging. However, algal monocultures are difficult to maintain because they are easily contaminated by wild algal strains, grazers, and pathogens. In contrast, theory suggests that polycultures (multispecies assemblages) can promote both ecosystem stability and productivity. A greater understanding of species interactions and how communities change with time will need to be developed before polycultures can be successfully applied to large-scale algal production efforts. Here in this paper we review the agricultural and ecological literature to explore opportunities for increased annual biomass production through the use of algal polycultures. We discuss case studies where algal polycultures have been successfully maintained for industries other than the biofuel industry, as well as the few studies that have compared biomass production of algal polycultures to that of monocultures. Assemblages that include species with complementary traits are of particular promise. These assemblages have the potential not only to increase crop productivity and stability, but they may also be capable of utilizing natural resources (e.g. light, nutrients, water) more efficiently via tighter niche packing. Therefore, algal polycultures show promise for enhancing biomass productivity, enabling sustainable production and reducing overall production costs.

  16. Algal biodiesel economy and competition among bio-fuels.

    PubMed

    Lee, D H

    2011-01-01

    This investigation examines the possible results of policy support in developed and developing economies for developing algal biodiesel through to 2040. This investigation adopts the Taiwan General Equilibrium Model-Energy for Bio-fuels (TAIGEM-EB) to predict competition among the development of algal biodiesel, bioethanol and conventional crop-based biodiesel. Analytical results show that algal biodiesel will not be the major energy source in 2040 without strong support in developed economies. In contrast, bioethanol enjoys a development advantage relative to both forms of biodiesel. Finally, algal biodiesel will almost completely replace conventional biodiesel. CO(2) reduction benefits the development of the bio-fuels industry.

  17. Assessing the potential of polyculture to accelerate algal biofuel production

    SciTech Connect

    Newby, Deborah T.; Mathews, Teresa J.; Pate, Ron C.; Huesemann, Michael H.; Lane, Todd W.; Wahlen, Bradley D.; Mandal, Shovon; Engler, Robert K.; Feris, Kevin P.; Shurin, Jon B.

    2016-10-24

    To date, the algal biofuel industry has focused on the cultivation of monocultures of highly productive algal strains, but scaling up production remains challenging. However, algal monocultures are difficult to maintain because they are easily contaminated by wild algal strains, grazers, and pathogens. In contrast, theory suggests that polycultures (multispecies assemblages) can promote both ecosystem stability and productivity. A greater understanding of species interactions and how communities change with time will need to be developed before polycultures can be successfully applied to large-scale algal production efforts. Here in this paper we review the agricultural and ecological literature to explore opportunities for increased annual biomass production through the use of algal polycultures. We discuss case studies where algal polycultures have been successfully maintained for industries other than the biofuel industry, as well as the few studies that have compared biomass production of algal polycultures to that of monocultures. Assemblages that include species with complementary traits are of particular promise. These assemblages have the potential not only to increase crop productivity and stability, but they may also be capable of utilizing natural resources (e.g. light, nutrients, water) more efficiently via tighter niche packing. Therefore, algal polycultures show promise for enhancing biomass productivity, enabling sustainable production and reducing overall production costs.

  18. Assessing the potential of polyculture to accelerate algal biofuel production

    DOE PAGES

    Newby, Deborah T.; Mathews, Teresa J.; Pate, Ron C.; ...

    2016-10-24

    To date, the algal biofuel industry has focused on the cultivation of monocultures of highly productive algal strains, but scaling up production remains challenging. However, algal monocultures are difficult to maintain because they are easily contaminated by wild algal strains, grazers, and pathogens. In contrast, theory suggests that polycultures (multispecies assemblages) can promote both ecosystem stability and productivity. A greater understanding of species interactions and how communities change with time will need to be developed before polycultures can be successfully applied to large-scale algal production efforts. Here in this paper we review the agricultural and ecological literature to explore opportunitiesmore » for increased annual biomass production through the use of algal polycultures. We discuss case studies where algal polycultures have been successfully maintained for industries other than the biofuel industry, as well as the few studies that have compared biomass production of algal polycultures to that of monocultures. Assemblages that include species with complementary traits are of particular promise. These assemblages have the potential not only to increase crop productivity and stability, but they may also be capable of utilizing natural resources (e.g. light, nutrients, water) more efficiently via tighter niche packing. Therefore, algal polycultures show promise for enhancing biomass productivity, enabling sustainable production and reducing overall production costs.« less

  19. [Protein toxins of Staphylococcus aureus].

    PubMed

    Shamsutdinov, A F; Tiurin, Iu A

    2014-01-01

    Main scientific-research studies regarding protein bacterial toxins of the most widespread bacteria that belong to Staphylococcus spp. genus and in particular the most pathogenic species for humans--Staphylococcus aureus, are analyzed. Structural and biological properties of protein toxins that have received the name of staphylococcus pyrogenic toxins (PTSAg) are presented. Data regarding genetic regulation of secretion and synthesis of these toxins and 3 main regulatory genetic systems (agr--accessory gene regulator, xpr--extracellular protein regulator, sar--staphylococcal accessory regulator) that coordinate synthesis of the most important protein toxins and enzymes for virulence of S. aureus, are presented.

  20. Emergent toxins in North Atlantic temperate waters: a challenge for monitoring programs and legislation.

    PubMed

    Silva, Marisa; Pratheepa, Vijaya K; Botana, Luis M; Vasconcelos, Vitor

    2015-03-16

    Harmful Algal Blooms (HAB) are complex to manage due to their intermittent nature and their severe impact on the economy and human health. The conditions which promote HAB have not yet been fully explained, though climate change and anthropogenic intervention are pointed as significant factors. The rise of water temperature, the opening of new sea canals and the introduction of ship ballast waters all contribute to the dispersion and establishment of toxin-producing invasive species that promote the settling of emergent toxins in the food-chain. Tetrodotoxin, ciguatoxin, palytoxin and cyclic imines are commonly reported in warm waters but have also caused poisoning incidents in temperate zones. There is evidence that monitoring for these toxins exclusively in bivalves is simplistic and underestimates the risk to public health, since new vectors have been reported for these toxins and as well for regulated toxins such as PSTs and DSTs. In order to avoid public health impacts, there is a need for adequate monitoring programs, a need for establishing appropriate legislation, and a need for optimizing effective methods of analysis. In this review, we will compile evidence concerning emergent marine toxins and provide data that may indicate the need to restructure the current monitoring programs of HAB.

  1. Emergent Toxins in North Atlantic Temperate Waters: A Challenge for Monitoring Programs and Legislation

    PubMed Central

    Silva, Marisa; Pratheepa, Vijaya K.; Botana, Luis M.; Vasconcelos, Vitor

    2015-01-01

    Harmful Algal Blooms (HAB) are complex to manage due to their intermittent nature and their severe impact on the economy and human health. The conditions which promote HAB have not yet been fully explained, though climate change and anthropogenic intervention are pointed as significant factors. The rise of water temperature, the opening of new sea canals and the introduction of ship ballast waters all contribute to the dispersion and establishment of toxin-producing invasive species that promote the settling of emergent toxins in the food-chain. Tetrodotoxin, ciguatoxin, palytoxin and cyclic imines are commonly reported in warm waters but have also caused poisoning incidents in temperate zones. There is evidence that monitoring for these toxins exclusively in bivalves is simplistic and underestimates the risk to public health, since new vectors have been reported for these toxins and as well for regulated toxins such as PSTs and DSTs. In order to avoid public health impacts, there is a need for adequate monitoring programs, a need for establishing appropriate legislation, and a need for optimizing effective methods of analysis. In this review, we will compile evidence concerning emergent marine toxins and provide data that may indicate the need to restructure the current monitoring programs of HAB. PMID:25785464

  2. Removal of Algal Blooms in Freshwater by Meso-porous Composite Coagulant

    NASA Astrophysics Data System (ADS)

    Liu, Dan; Li, Fengting; Hui, Franck; Lédion, Jean

    2010-11-01

    Based on the concept of "using waste to treat waste and changing waste into valuables", this paper put forward a new meso-porous composite coagulant with good performance and low cost, and the removal effects of meso-porous composite coagulant on algae cells and toxins, dissolved organics in water was studied, the object of this research was to provide a new and effective way for emergency needs to clear up harmful algal blooms in freshwater. The results showed that meso-porous composite coagulant at optimal loadings (1g/L) could remove over 99% algal cells; meanwhile, the removal efficiency of COD, microcystin, total nitrogen and phosphorus was found to be 87.5%, 97.7%, 41.5% and 77.8% respectively, moreover, the forming speed of floccules was fast, and the dense floccules had good settling performance. Furthermore, the mechanism of algae removal was explored preliminarily by meso-porous composite coagulant which played a dual role in adsorption and flocculation.

  3. Autoproteolytic activation of bacterial toxins.

    PubMed

    Shen, Aimee

    2010-05-01

    Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD) in Multifunctional Autoprocessing RTX-like (MARTX) and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP(6)), which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins.

  4. Autoproteolytic Activation of Bacterial Toxins

    PubMed Central

    Shen, Aimee

    2010-01-01

    Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD) in Multifunctional Autoprocessing RTX-like (MARTX) and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP6), which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins. PMID:22069620

  5. Algal Lipids as Quantitative Paleosalinity Proxies

    NASA Astrophysics Data System (ADS)

    Maloney, A.; Shinneman, A.; Hemeon, K.; Sachs, J. P.

    2012-12-01

    The tropics play an important role in driving climate. However it is difficult to uncover past changes in tropical precipitation due to a lack of tree ring records and low accumulation rates of marine sediments. Hydrogen isotope ratios of algal lipids preserved in lacustrine and marine sediments have been used to qualitatively reconstruct tropical paleohydrology. Changes in the hydrologic balance are reflected in salinity and in lake water D/H ratios, which are closely tracked by lipid D/H ratios of algal biomarkers. While useful for determining past periods of "wetter" or "drier" conditions, variability in isotope fractionation in algal lipids during lipid biosynthesis can be exploited to more quantitatively determine how much wetter or drier conditions were in the past. The estuarine diatom, Thalassiosira pseudonnana, was grown in continuous cultures under controlled light, temperature, nutrient, and growth rate conditions to assess the influence of salinity (9-40 PSU) on D/H fractionation between lipids and source water. Three fatty acids, 24-methylcholesta-5,24(28)-dien-3B-ol, and phytol show decreasing fractionation between lipid and source water as salinity increases with 0.8-1.3‰ change in fractionation per salinity unit. These results compliment field-based empirical observations of dinosterol in Chesapeake Bay suspended particles that change 0.99‰ per salinity unit and lipid biomarkers from hyper-saline ponds on Christmas Island that change 0.7-1.1‰ per salinity unit. Biological pathways responsible for the inverse relationship between fractionation and salinity will be discussed.

  6. Addressing the challenges for sustainable production of algal biofuels: I. Algal strains and nutrient supply.

    PubMed

    Abdelaziz, Ahmed E M; Leite, Gustavo B; Hallenbeck, Patrick C

    2013-01-01

    Microalgae hold promise for the production of sustainable replacement of fossil fuels due to their high growth rates, ability to grow on non-arable land and their high content, under the proper conditions, of high energy compounds that can be relatively easily chemically converted to fuels using existing technology. However, projected large-scale algal production raises a number of sustainability concerns concerning land use, net energy return, water use and nutrient supply. The state-of-the-art of algal production of biofuels is presented with emphasis on some possible avenues to provide answers to the sustainability questions that have been raised. Here, issues concerning algal strains and supply of nutrients for large-scale production are discussed. Since sustainability concerns necessitate the use of wastewaters for supply of bulk nutrients, emphasis is placed on the composition and suitability of different wastewater streams. At the same time, algal cultivation has proven useful in waste treatment processes, and thus this aspect is also treated in some detail.

  7. Algal Attributes: An Autecological Classification of Algal Taxa Collected by the National Water-Quality Assessment Program

    USGS Publications Warehouse

    Porter, Stephen D.

    2008-01-01

    Algae are excellent indicators of water-quality conditions, notably nutrient and organic enrichment, and also are indicators of major ion, dissolved oxygen, and pH concentrations and stream microhabitat conditions. The autecology, or physiological optima and tolerance, of algal species for various water-quality contaminants and conditions is relatively well understood for certain groups of freshwater algae, notably diatoms. However, applications of autecological information for water-quality assessments have been limited because of challenges associated with compiling autecological literature from disparate sources, tracking name changes for a large number of algal species, and creating an autecological data base from which algal-indicator metrics can be calculated. A comprehensive summary of algal autecological attributes for North American streams and rivers does not exist. This report describes a large, digital data file containing 28,182 records for 5,939 algal taxa, generally species or variety, collected by the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program. The data file includes 37 algal attributes classified by over 100 algal-indicator codes or metrics that can be calculated easily with readily available software. Algal attributes include qualitative classifications based on European and North American autecological literature, and semi-quantitative, weighted-average regression approaches for estimating optima using regional and national NAWQA data. Applications of algal metrics in water-quality assessments are discussed and national quartile distributions of metric scores are shown for selected indicator metrics.

  8. Centriole asymmetry determines algal cell geometry

    PubMed Central

    Marshall, Wallace F.

    2012-01-01

    The mechanisms that determine the shape and organization of cells remain largely unknown. Green algae such as Chlamydomonas provide excellent model systems for studying cell geometry due to their highly reproducible cell organization. Structural and genetic studies suggest that asymmetry of the centriole (basal body) plays a critical determining role in organizing the internal organization of algal cells, through the attachment of microtubule rootlets and other large fiber systems to specific sets of microtubule triplets on the centriole. Thus to understand cell organization, it will be critical to understand how the different triplets of the centriole come to have distinct molecular identities. PMID:23026116

  9. Isolation and Characterization of a Double Stranded DNA Megavirus Infecting the Toxin-Producing Haptophyte Prymnesium parvum

    PubMed Central

    Wagstaff, Ben A.; Vladu, Iulia C.; Barclay, J. Elaine; Schroeder, Declan C.; Malin, Gill; Field, Robert A.

    2017-01-01

    Prymnesium parvum is a toxin-producing haptophyte that causes harmful algal blooms globally, leading to large-scale fish kills that have severe ecological and economic implications. For the model haptophyte, Emiliania huxleyi, it has been shown that large dsDNA viruses play an important role in regulating blooms and therefore biogeochemical cycling, but much less work has been done looking at viruses that infect P. parvum, or the role that these viruses may play in regulating harmful algal blooms. In this study, we report the isolation and characterization of a lytic nucleo-cytoplasmic large DNA virus (NCLDV) collected from the site of a harmful P. parvum bloom. In subsequent experiments, this virus was shown to infect cultures of Prymnesium sp. and showed phylogenetic similarity to the extended Megaviridae family of algal viruses. PMID:28282930

  10. Accelerating Commercialization of Algal Biofuels Through Partnerships (Brochure)

    SciTech Connect

    Not Available

    2011-10-01

    This brochure describes National Renewable Energy Laboratory's (NREL's) algal biofuels research capabilities and partnership opportunities. NREL is accelerating algal biofuels commercialization through: (1) Advances in applied biology; (2) Algal strain development; (3) Development of fuel conversion pathways; (4) Techno-economic analysis; and (5) Development of high-throughput lipid analysis methodologies. NREL scientists and engineers are addressing challenges across the algal biofuels value chain, including algal biology, cultivation, harvesting and extraction, and fuel conversion. Through partnerships, NREL can share knowledge and capabilities in the following areas: (1) Algal Biology - A fundamental understanding of algal biology is key to developing cost-effective algal biofuels processes. NREL scientists are experts in the isolation and characterization of microalgal species. They are identifying genes and pathways involved in biofuel production. In addition, they have developed a high-throughput, non-destructive technique for assessing lipid production in microalgae. (2) Cultivation - NREL researchers study algal growth capabilities and perform compositional analysis of algal biomass. Laboratory-scale photobioreactors and 1-m2 open raceway ponds in an on-site greenhouse allow for year-round cultivation of algae under a variety of conditions. A bioenergy-focused algal strain collection is being established at NREL, and our laboratory houses a cryopreservation system for long-term maintenance of algal cultures and preservation of intellectual property. (3) Harvesting and Extraction - NREL is investigating cost-effective harvesting and extraction methods suitable for a variety of species and conditions. Areas of expertise include cell wall analysis and deconstruction and identification and utilization of co-products. (4) Fuel Conversion - NREL's excellent capabilities and facilities for biochemical and thermochemical conversion of biomass to biofuels are being

  11. Analysis of the mechanisms that underlie absorption of botulinum toxin by the inhalation route.

    PubMed

    Al-Saleem, Fetweh H; Ancharski, Denise M; Joshi, Suresh G; Elias, M; Singh, Ajay; Nasser, Zidoon; Simpson, Lance L

    2012-12-01

    Botulinum toxin is a highly potent oral and inhalation poison, which means that the toxin must have an efficient mechanism for penetration of epithelial barriers. To date, three models for toxin passage across epithelial barriers have been proposed: (i) the toxin itself undergoes binding and transcytosis; (ii) an auxiliary protein, HA35, transports toxin from the apical to the basal side of epithelial cells; and (iii) an auxiliary protein, HA35, acts on the basal side of epithelial cells to disrupt tight junctions, and this permits paracellular flux of toxin. These models were evaluated by studying toxin absorption following inhalation exposure in mice. Three types of experiments were conducted. In the first, the potency of pure neurotoxin was compared with that of progenitor toxin complex, which contains HA35. The results showed that the rate and extent of toxin absorption, as well as the potency of absorbed toxin, did not depend upon, nor were they enhanced by, the presence of HA35. In the second type of experiment, the potencies of pure neurotoxin and progenitor toxin complex were compared in the absence or presence of antibodies on the apical side of epithelial cells. Antibodies directed against the neurotoxin protected against challenge, but antibodies against HA35 did not. In the final type of experiment, the potency of pure neurotoxin and toxin complex was compared in animals pretreated to deliver antibodies to the basal side of epithelial cells. Once again, antibodies directed against the neurotoxin provided resistance to challenge, but antibodies directed against HA35 did not. Taken collectively, the data indicate that the toxin by itself is capable of crossing epithelial barriers. The data do not support any hypothesis in which HA35 is essential for toxin penetration of epithelial barriers.

  12. Algal toxins in Upper Klamath Lake, Oregon: Linking water quality to juvenile sucker health

    USGS Publications Warehouse

    VanderKooi, S.P.; Burdick, S.M.; Echols, K.R.; Ottinger, C.A.; Rosen, B.H.; Wood, T.M.

    2010-01-01

    As the lead science agency for the Department of Interior, the U.S. Geological Survey is actively involved in resource issues in the Klamath River basin. Activities include research projects on endangered Lost River and shortnose suckers, threatened coho salmon, groundwater resources, seasonal runoff forecasting, water quality in Upper Klamath Lake and the Klamath River, nutrient cycling in wetlands, and assessment of land idling programs to reduce water consumption. Many of these studies are collaborations with various partners including Department of Interior agencies, Indian Tribes, and State agencies.

  13. POSSIBLE IMPORTANCE OF ALGAL TOXINS IN THE SALTON SEA, CALIFORNIA. (R826552)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. POSSIBLE IMPORTANCE OF ALGAL TOXINS IN THE SALTON SEA, CALIFORNIA. (R826552)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  15. Heteroduplex mobility assay-guided sequence discovery: elucidation of the small subunit (18S) rDNA sequences of Pfiesteria piscicida and related dinoflagellates from complex algal culture and environmental sample DNA pools.

    PubMed

    Oldach, D W; Delwiche, C F; Jakobsen, K S; Tengs, T; Brown, E G; Kempton, J W; Schaefer, E F; Bowers, H A; Glasgow, H B; Burkholder, J M; Steidinger, K A; Rublee, P A

    2000-04-11

    The newly described heterotrophic estuarine dinoflagellate Pfiesteria piscicida has been linked with fish kills in field and laboratory settings, and with a novel clinical syndrome of impaired cognition and memory disturbance among humans after presumptive toxin exposure. As a result, there is a pressing need to better characterize the organism and these associations. Advances in Pfiesteria research have been hampered, however, by the absence of genomic sequence data. We employed a sequencing strategy directed by heteroduplex mobility assay to detect Pfiesteria piscicida 18S rDNA "signature" sequences in complex pools of DNA and used those data as the basis for determination of the complete P. piscicida 18S rDNA sequence. Specific PCR assays for P. piscicida and other estuarine heterotrophic dinoflagellates were developed, permitting their detection in algal cultures and in estuarine water samples collected during fish kill and fish lesion events. These tools should enhance efforts to characterize these organisms and their ecological relationships. Heteroduplex mobility assay-directed sequence discovery is broadly applicable, and may be adapted for the detection of genomic sequence data of other novel or nonculturable organisms in complex assemblages.

  16. Algal Lectins as Potential HIV Microbicide Candidates

    PubMed Central

    Huskens, Dana; Schols, Dominique

    2012-01-01

    The development and use of topical microbicides potentially offers an additional strategy to reduce the spread of the Human Immunodeficiency Virus (HIV). Carbohydrate-binding agents (CBAs) that show specificity for high mannose carbohydrates on the surface of the heavily glycosylated envelope of HIV are endowed with potent anti-HIV activity. In fact, a number of algal lectins such as cyanovirin-N, microvirin, microcystis viridis lectin, scytovirin, Oscillatoria agardhii agglutinin and griffithsin are considered as potential microbicide candidates to prevent the sexual transmission of HIV through topical applications. They not only inhibit infection of cells by cell-free virus but they can also efficiently prevent virus transmission from virus-infected cells to uninfected CD4+ target T-lymphocytes and DC-SIGN-directed capture of HIV-1 and transmission to CD4+ T lymphocytes. This review focuses on the structural properties and carbohydrate specificity of these algal lectins, their antiviral activity against HIV and several other enveloped viruses, their safety profile and viral resistance patterns. PMID:22851920

  17. Exploiting algal NADPH oxidase for biophotovoltaic energy

    DOE PAGES

    Anderson, Alexander; Laohavisit, Anuphon; Blaby, Ian K.; ...

    2015-01-29

    Photosynthetic microbes exhibit light-dependent electron export across the cell membrane, which can generate electricity in biological photovoltaic (BPV) devices. How electrons are exported remains to be determined; the identification of mechanisms would help selection or generation of photosynthetic microbes capable of enhanced electrical output. We show that plasma membrane NADPH oxidase activity is a significant component of light-dependent generation of electricity by the unicellular green alga Chlamydomonas reinhardtii. NADPH oxidases export electrons across the plasma membrane to form superoxide anion from oxygen. The C. reinhardtii mutant lacking the NADPH oxidase encoded by RBO1 is impaired in both extracellular superoxide anionmore » production and current generation in a BPV device. Complementation with the wild-type gene restores both capacities, demonstrating the role of the enzyme in electron export. Monitoring light-dependent extracellular superoxide production with a colorimetric assay is shown to be an effective way of screening for electrogenic potential of candidate algal strains. Furthermore, the results show that algal NADPH oxidases are important for superoxide anion production and open avenues for optimizing the biological component of these devices.« less

  18. Exploiting algal NADPH oxidase for biophotovoltaic energy.

    PubMed

    Anderson, Alexander; Laohavisit, Anuphon; Blaby, Ian K; Bombelli, Paolo; Howe, Christopher J; Merchant, Sabeeha S; Davies, Julia M; Smith, Alison G

    2016-01-01

    Photosynthetic microbes exhibit light-dependent electron export across the cell membrane, which can generate electricity in biological photovoltaic (BPV) devices. How electrons are exported remains to be determined; the identification of mechanisms would help selection or generation of photosynthetic microbes capable of enhanced electrical output. We show that plasma membrane NADPH oxidase activity is a significant component of light-dependent generation of electricity by the unicellular green alga Chlamydomonas reinhardtii. NADPH oxidases export electrons across the plasma membrane to form superoxide anion from oxygen. The C. reinhardtii mutant lacking the NADPH oxidase encoded by RBO1 is impaired in both extracellular superoxide anion production and current generation in a BPV device. Complementation with the wild-type gene restores both capacities, demonstrating the role of the enzyme in electron export. Monitoring light-dependent extracellular superoxide production with a colorimetric assay is shown to be an effective way of screening for electrogenic potential of candidate algal strains. The results show that algal NADPH oxidases are important for superoxide anion production and open avenues for optimizing the biological component of these devices.

  19. Mechanical algal disruption for efficient biodiesel extraction

    NASA Astrophysics Data System (ADS)

    Krehbiel, Joel David

    Biodiesel from algae provides several benefits over current biodiesel feedstocks, but the energy requirements of processing algae into a useable fuel are currently so high as to be prohibitive. One route to improving this is via disruption of the cells prior to lipid extraction, which can significantly increase energy recovery. Unfortunately, several obvious disruption techniques require more energy than can be gained. This dissertation examines the use of microbubbles to improve mechanical disruption of algal cells using experimental, theoretical, and computational methods. New laboratory experiments show that effective ultrasonic disruption of algae is achieved by adding microbubbles to an algal solution. The configuration studied flows the solution through a tube and insonifies a small section with a high-pressure ultrasound wave. Previous biomedical research has shown effective cell membrane damage on animal cells with similar methods, but the present research is the first to extend such study to algal cells. Results indicate that disruption increases with peak negative pressure between 1.90 and 3.07 MPa and with microbubble concentration up to 12.5 x 107 bubbles/ml. Energy estimates of this process suggest that it requires only one-fourth the currently most-efficient laboratory-scale disruption process. Estimates of the radius near each bubble that causes disruption (i.e. the disruption radius) suggest that it increases with peak negative pressure and is near 9--20 microm for all cases tested. It is anticipated that these procedures can be designed for better efficiency and efficacy, which will be facilitated by identifying the root mechanisms of the bubble-induced disruption. We therefore examine whether bubble expansion alone creates sufficient cell deformation for cell rupture. The spherically-symmetric Marmottant model for bubble dynamics allows estimation of the flow regime under experimental conditions. Bubble expansion is modeled as a point source of

  20. Potential of carbon nanotubes in algal biotechnology.

    PubMed

    Lambreva, Maya Dimova; Lavecchia, Teresa; Tyystjärvi, Esa; Antal, Taras Kornelievich; Orlanducci, Silvia; Margonelli, Andrea; Rea, Giuseppina

    2015-09-01

    A critical mass of knowledge is emerging on the interactions between plant cells and engineered nanomaterials, revealing the potential of plant nanobiotechnology to promote and support novel solutions for the development of a competitive bioeconomy. This knowledge can foster the adoption of new methodological strategies to empower the large-scale production of biomass from commercially important microalgae. The present review focuses on the potential of carbon nanotubes (CNTs) to enhance photosynthetic performance of microalgae by (i) widening the spectral region available for the energy conversion reactions and (ii) increasing the tolerance of microalgae towards unfavourable conditions occurring in mass production. To this end, current understanding on the mechanisms of uptake and localization of CNTs in plant cells is discussed. The available ecotoxicological data were used in an attempt to assess the feasibility of CNT-based applications in algal biotechnology, by critically correlating the experimental conditions with the observed adverse effects. Furthermore, main structural and physicochemical properties of single- and multi-walled CNTs and common approaches for the functionalization and characterization of CNTs in biological environment are presented. Here, we explore the potential that nanotechnology can offer to enhance functions of algae, paving the way for a more efficient use of photosynthetic algal systems in the sustainable production of energy, biomass and high-value compounds.

  1. Luminescent Solar Concentrators in the Algal Industry

    NASA Astrophysics Data System (ADS)

    Hellier, Katie; Corrado, Carley; Carter, Sue; Detweiler, Angela; Bebout, Leslie

    2013-03-01

    Today's industry for renewable energy sources and highly efficient energy management systems is rapidly increasing. Development of increased efficiency Luminescent Solar Concentrators (LSCs) has brought about new applications for commercial interests, including greenhouses for agricultural crops. This project is taking first steps to explore the potential of LSCs to enhance production and reduce costs for algae and cyanobacteria used in biofuels and nutraceuticals. This pilot phase uses LSC filtered light for algal growth trials in greenhouses and laboratory experiments, creating specific wavelength combinations to determine effects of discrete solar light regimes on algal growth and the reduction of heating and water loss in the system. Enhancing the optimal spectra for specific algae will not only increase production, but has the potential to lessen contamination of large scale production due to competition from other algae and bacteria. Providing LSC filtered light will reduce evaporation and heating in regions with limited water supply, while the increased energy output from photovoltaic cells will reduce costs of heating and mixing cultures, thus creating a more efficient and cost effective production system.

  2. Dynamic metabolic exchange governs a marine algal-bacterial interaction

    PubMed Central

    Segev, Einat; Wyche, Thomas P; Kim, Ki Hyun; Petersen, Jörn; Ellebrandt, Claire; Vlamakis, Hera; Barteneva, Natasha; Paulson, Joseph N; Chai, Liraz; Clardy, Jon; Kolter, Roberto

    2016-01-01

    Emiliania huxleyi is a model coccolithophore micro-alga that generates vast blooms in the ocean. Bacteria are not considered among the major factors influencing coccolithophore physiology. Here we show through a laboratory model system that the bacterium Phaeobacter inhibens, a well-studied member of the Roseobacter group, intimately interacts with E. huxleyi. While attached to the algal cell, bacteria initially promote algal growth but ultimately kill their algal host. Both algal growth enhancement and algal death are driven by the bacterially-produced phytohormone indole-3-acetic acid. Bacterial production of indole-3-acetic acid and attachment to algae are significantly increased by tryptophan, which is exuded from the algal cell. Algal death triggered by bacteria involves activation of pathways unique to oxidative stress response and programmed cell death. Our observations suggest that bacteria greatly influence the physiology and metabolism of E. huxleyi. Coccolithophore-bacteria interactions should be further studied in the environment to determine whether they impact micro-algal population dynamics on a global scale. DOI: http://dx.doi.org/10.7554/eLife.17473.001 PMID:27855786

  3. Algal Lipid Extraction and Upgrading to Hydrocarbons Technology Pathway

    SciTech Connect

    Davis, R.; Biddy, M.; Jones, S.

    2013-03-01

    This technology pathway case investigates the cultivation of algal biomass followed by further lipid extraction and upgrading to hydrocarbon biofuels. Technical barriers and key research needs have been assessed in order for the algal lipid extraction and upgrading pathway to be competitive with petroleum-derived gasoline-, diesel-, and jet-range hydrocarbon blendstocks.

  4. Dynamic metabolic exchange governs a marine algal-bacterial interaction.

    PubMed

    Segev, Einat; Wyche, Thomas P; Kim, Ki Hyun; Petersen, Jörn; Ellebrandt, Claire; Vlamakis, Hera; Barteneva, Natasha; Paulson, Joseph N; Chai, Liraz; Clardy, Jon; Kolter, Roberto

    2016-11-18

    Emiliania huxleyi is a model coccolithophore micro-alga that generates vast blooms in the ocean. Bacteria are not considered among the major factors influencing coccolithophore physiology. Here we show through a laboratory model system that the bacterium Phaeobacter inhibens, a well-studied member of the Roseobacter group, intimately interacts with E. huxleyi. While attached to the algal cell, bacteria initially promote algal growth but ultimately kill their algal host. Both algal growth enhancement and algal death are driven by the bacterially-produced phytohormone indole-3-acetic acid. Bacterial production of indole-3-acetic acid and attachment to algae are significantly increased by tryptophan, which is exuded from the algal cell. Algal death triggered by bacteria involves activation of pathways unique to oxidative stress response and programmed cell death. Our observations suggest that bacteria greatly influence the physiology and metabolism of E. huxleyi. Coccolithophore-bacteria interactions should be further studied in the environment to determine whether they impact micro-algal population dynamics on a global scale.

  5. COMPARISON OF LARGE RIVER SAMPLING METHODS ON ALGAL METRICS

    EPA Science Inventory

    We compared the results of four methods used to assess the algal communities at 60 sites distributed among four rivers. Based on Principle Component Analysis of physical habitat data collected concomitantly with the algal data, sites were separated into those with a mean thalweg...

  6. Method and system of culturing an algal mat

    SciTech Connect

    Das, Keshav C; Cannon, Benjamin R; Bhatnagar, Ashish; Chinnasamy, Senthil

    2014-05-13

    A system and method for culturing algae are presented. The system and method utilize a fog of growth medium that is delivered to an algal mat generator along with a stream of CO.sub.2 to promote growth of algal cells contained in the generator.

  7. Near- and mid-infrared spectroscopic determination of algal composition

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to investigate the feasibility of using near-infrared reflectance spectroscopy (NIRS) and mid-infrared reflectance spectroscopy (MIRS) to determine the composition of algal samples. We assayed a set of algal biomass samples (n=117), collected from algae turf scrubber...

  8. COMPARISON OF LARGE RIVER SAMPLING METHODS ON ALGAL METRICS

    EPA Science Inventory

    We compared the results of four methods used to assess the algal communities at 60 sites distributed among four rivers. Based on Principle Component Analysis of physical habitat data collected concomitantly with the algal data, sites were separated into those with a mean thalweg...

  9. Toxins and drug discovery.

    PubMed

    Harvey, Alan L

    2014-12-15

    Components from venoms have stimulated many drug discovery projects, with some notable successes. These are briefly reviewed, from captopril to ziconotide. However, there have been many more disappointments on the road from toxin discovery to approval of a new medicine. Drug discovery and development is an inherently risky business, and the main causes of failure during development programmes are outlined in order to highlight steps that might be taken to increase the chances of success with toxin-based drug discovery. These include having a clear focus on unmet therapeutic needs, concentrating on targets that are well-validated in terms of their relevance to the disease in question, making use of phenotypic screening rather than molecular-based assays, and working with development partners with the resources required for the long and expensive development process. Copyright © 2014 The Author. Published by Elsevier Ltd.. All rights reserved.

  10. Evidence of paralytic shellfish poisoning toxin in milkfish in South Taiwan.

    PubMed

    Chou, H-N; Chung, Y-C; Cho, W-C; Chen, C-Y

    2003-06-01

    Natural phytoplankton blooms of the dinoflagellate Alexandrium minutum, milkfish (Chanos chanos) exposed to natural blooms, sediment and mangrove crab (Scylla serrata) were analysed for paralytic shellfish poisoning toxins by high-performance liquid chromatography. The toxin profiles of milkfish and mangrove crab were similar to that of A. minutum collected from blooming fishponds. In a laboratory A. minutum-blooming environment, the stomach and intestine of milkfish accumulated paralytic shellfish poisoning toxins during the exposure period. The non-visceral tissues were non-toxic. However, milkfish lost their entire body burden of toxin on the first day of transferring to a toxic algae-free environment. The result shows that milkfish concentrate paralytic shellfish poisoning toxins in digestive organs and did not retain toxins.

  11. Toxins as biological weapons for terror-characteristics, challenges and medical countermeasures: a mini-review.

    PubMed

    Berger, Tamar; Eisenkraft, Arik; Bar-Haim, Erez; Kassirer, Michael; Aran, Adi Avniel; Fogel, Itay

    2016-01-01

    Toxins are hazardous biochemical compounds derived from bacteria, fungi, or plants. Some have mechanisms of action and physical properties that make them amenable for use as potential warfare agents. Currently, some toxins are classified as potential biological weapons, although they have several differences from classic living bio-terror pathogens and some similarities to manmade chemical warfare agents. This review focuses on category A and B bio-terror toxins recognized by the Centers for Disease Control and Prevention: Botulinum neurotoxin, staphylococcal enterotoxin B, Clostridium perfringens epsilon toxin, and ricin. Their derivation, pathogenesis, mechanism of action, associated clinical signs and symptoms, diagnosis, and treatment are discussed in detail. Given their expected covert use, the primary diagnostic challenge in toxin exposure is the early detection of morbidity clusters, apart from background morbidity, after a relatively short incubation period. For this reason, it is important that clinicians be familiar with the clinical manifestations of toxins and the appropriate methods of management and countermeasures.

  12. Lektine, Toxine und Immunotoxine

    NASA Astrophysics Data System (ADS)

    Uhlenbruck, Gerhard

    1981-12-01

    A definition and classification of lectins (carbohydrate-binding (glyco)proteins) is given on the basis of new data and experimental results. Especially the biological role of bacterial, vertebrate and sponge lectins is discussed. The lectin-toxin combination offers an excellent model not only for studying adhesion to and penetration through the cell membrane, but also for hybridization with antibody fragments showing anti-tumor specificity.

  13. [Cytolethal distending toxins].

    PubMed

    Curová, K; Kmeťová, M; Siegfried, L

    2014-06-01

    Cytolethal distending toxins (CDT) are intracellularly acting proteins which interfere with the eukaryotic cell cycle. They are produced by Gram-negative bacteria with affinity to mucocutaneous surfaces and could play a role in the pathogenesis of various mammalian diseases. The functional toxin is composed of three proteins: CdtB entering the nucleus and by its nuclease activity inducing nuclear fragmentation and chromatin disintegration, CdtA, and CdtC, the two latter being responsible for toxin attachment to the surface of the target cell. Cytotoxic effect of CDT leads to the cell cycle arrest before the cell enters mitosis and to further changes (cell distension and death, apoptosis) depending on the cell type. Thus, CDT may function as a virulence factor in pathogenic bacteria that produce it and thus may contribute to the initiation of certain diseases. Most important are inflammatory bowel diseases caused by intestinal bacteria, periodontitis with Aggregatibacter actinomycetemcomitans as the aetiologic agent and ulcus molle where Haemophilus ducreyi is the causative agent.

  14. Phospholipid scramblase 1 mediates type i interferon-induced protection against staphylococcal α-toxin.

    PubMed

    Lizak, Miroslaw; Yarovinsky, Timur O

    2012-01-19

    The opportunistic gram-positive pathogen Staphylococcus aureus is a leading cause of pneumonia and sepsis. Staphylococcal α-toxin, a prototypical pore-forming toxin, is a major virulence factor of S. aureus clinical isolates, and lung epithelial cells are highly sensitive to α-toxin's cytolytic activity. Type I interferon (IFN) signaling activated in response to S. aureus increases pulmonary cell resistance to α-toxin, but the underlying mechanisms are uncharacterized. We show that IFNα protects human lung epithelial cells from α-toxin-induced intracellular ATP depletion and cell death by reducing extracellular ATP leakage. This effect depends on protein palmitoylation and induction of phospholipid scramblase 1 (PLSCR1). IFNα-induced PLSCR1 associates with the cytoskeleton after exposure to α-toxin, and cellular depletion of PLSCR1 negates IFN-induced protection from α-toxin. PLSCR1-deficient mice display enhanced sensitivity to inhaled α-toxin and an α-toxin-producing S. aureus strain. These results uncover PLSCR1 activity as part of an innate protective mechanism to a bacterial pore-forming toxin. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Phospholipid scramblase 1 mediates type I interferon-induced protection against staphylococcal α-toxin

    PubMed Central

    Lizak, Miroslaw; Yarovinsky, Timur O.

    2012-01-01

    Summary The opportunistic gram-positive pathogen Staphylococcus aureus is a leading cause of pneumonia and sepsis. Staphylococcal α-toxin, a prototypical pore-forming toxin, is a major virulence factor of S. aureus clinical isolates and lung epithelial cells are highly sensitive to α-toxin's cytolytic activity. Type I interferon (IFN) signaling activated in response to S. aureus increases pulmonary cell resistance to α-toxin but the underlying mechanisms are uncharacterized. We show that IFNα protects human lung epithelial cells from α-toxin-induced intracellular ATP depletion and cell death by reducing extracellular ATP leakage. This effect depends on protein palmitoylation and induction of phospholipid scramblase 1 (PLSCR1). IFNα-induced PLSCR1 associates with the cytoskeleton after exposure to α-toxin and cellular depletion of PLSCR1 negates IFN-induced protection from α-toxin. PLSCR1-deficient mice display enhanced sensitivity to inhaled α-toxin and an α-toxin-producing S. aureus strain. These results uncover PLSCR1 activity as part of an innate protective mechanism to a bacterial pore-forming toxin. PMID:22264514

  16. Evaluation of anticoagulant activity of two algal polysaccharides.

    PubMed

    Faggio, C; Pagano, M; Dottore, A; Genovese, G; Morabito, M

    2016-09-01

    Marine algae are important sources of phycocolloids like agar, carrageenans and alginates used in industrial applications. Algal polysaccharides have emerged as an important class of bioactive products showing interesting properties. The aim of our study was to evaluate the potential uses as anticoagulant drugs of algal sulphate polysaccharides extracted from Ulva fasciata (Chlorophyta) and Agardhiella subulata (Rhodophyta) collected in Ganzirri Lake (Cape Peloro Lagoon, north-eastern Sicily, Italy). Toxicity of algal extracts through trypan blue test and anticoagulant action measured by activated partial thromboplastin time (APTT), prothrombin time (PT) test has been evaluated. Algal extracts showed to prolong the PT and APTT during the coagulation cascade and to avoid the blood coagulation of samples. Furthermore, the algal extracts lack toxic effects towards cellular metabolism and their productions are relatively at low cost. This permits to consider the algae as the biological source of the future.

  17. Uniform algal growth in photobioreactors using surface scatterers

    NASA Astrophysics Data System (ADS)

    Ahsan, Syed S.; Pereyra, Brandon; Erickson, David

    2014-03-01

    Cultures of algae, such as cyanobacteria, are a promising source of renewable energy. However, algal growth is highly dependent on light intensity and standard photobioreactors do a poor job of distributing light uniformly for algal utilization due to shading effects in dense algal cultures. Engineered scattering schemes are already employed in current slab-waveguide technologies, like edge-lit LEDs. Stacking such slab-waveguides that uniformly distribute light could potentially yield photobioreactors to overcome the shading effect and grow extremely high densities of algal cultures that would lower monetary and energetic costs. Here, we characterize and design a scattering scheme for specific application within photobioreactors which employs a gradient distribution of surface scatterers with uniform lateral scattering intensity. This uniform scattering scheme is shown to be superior for algal cultivation.

  18. The contribution of bacteria to algal growth by carbon cycling.

    PubMed

    Bai, Xue; Lant, Paul; Pratt, Steven

    2015-04-01

    Algal mass production in open systems is often limited by the availability of inorganic carbon substrate. In this paper, we evaluate how bacterial driven carbon cycling mitigates carbon limitation in open algal culture systems. The contribution of bacteria to carbon cycling was determined by quantifying algae growth with and without supplementation of bacteria. It was found that adding heterotrophic bacteria to an open algal culture dramatically enhanced algae productivity. Increases in algal productivity due to supplementation of bacteria of 4.8 and 3.4 times were observed in two batch tests operating at two different pH values over 7 days. A kinetic model is proposed which describes carbon limited algal growth, and how the limitation could be overcome by bacterial activity to re-mineralize photosynthetic end products.

  19. Update on the Role of Environmental Toxins in Neurodevelopmental Disabilities

    ERIC Educational Resources Information Center

    Kouris, Steven

    2007-01-01

    Toxic exposures during pregnancy and early childhood continue to play an important role as a preventable cause of neurodevelopmental disabilities in the U.S. and around the world. Identifying and eliminating these toxins should be a priority, but the task is made exceedingly difficult due to the severe limits of scientific knowledge in this area…

  20. Update on the Role of Environmental Toxins in Neurodevelopmental Disabilities

    ERIC Educational Resources Information Center

    Kouris, Steven

    2007-01-01

    Toxic exposures during pregnancy and early childhood continue to play an important role as a preventable cause of neurodevelopmental disabilities in the U.S. and around the world. Identifying and eliminating these toxins should be a priority, but the task is made exceedingly difficult due to the severe limits of scientific knowledge in this area…

  1. Detection of surface algal blooms using the newly developed algorithm surface algal bloom index (SABI)

    NASA Astrophysics Data System (ADS)

    Alawadi, Fahad

    2010-10-01

    Quantifying ocean colour properties has evolved over the past two decades from being able to merely detect their biological activity to the ability to estimate chlorophyll concentration using optical satellite sensors like MODIS and MERIS. The production of chlorophyll spatial distribution maps is a good indicator of plankton biomass (primary production) and is useful for the tracing of oceanographic currents, jets and blooms, including harmful algal blooms (HABs). Depending on the type of HABs involved and the environmental conditions, if their concentration rises above a critical threshold, it can impact the flora and fauna of the aquatic habitat through the introduction of the so called "red tide" phenomenon. The estimation of chlorophyll concentration is derived from quantifying the spectral relationship between the blue and the green bands reflected from the water column. This spectral relationship is employed in the standard ocean colour chlorophyll-a (Chlor-a) product, but is incapable of detecting certain macro-algal species that float near to or at the water surface in the form of dense filaments or mats. The ability to accurately identify algal formations that sometimes appear as oil spill look-alikes in satellite imagery, contributes towards the reduction of false-positive incidents arising from oil spill monitoring operations. Such algal formations that occur in relatively high concentrations may experience, as in land vegetation, what is known as the "red-edge" effect. This phenomena occurs at the highest reflectance slope between the maximum absorption in the red due to the surrounding ocean water and the maximum reflectance in the infra-red due to the photosynthetic pigments present in the surface algae. A new algorithm termed the surface algal bloom index (SABI), has been proposed to delineate the spatial distributions of floating micro-algal species like for example cyanobacteria or exposed inter-tidal vegetation like seagrass. This algorithm was

  2. Responses of sympatric Karenia brevis, Prorocentrum minimum, and Heterosigma akashiwo to the exposure of crude oil.

    PubMed

    Ozhan, Koray; Bargu, Sibel

    2014-10-01

    Impacts of the Deepwater Horizon oil spill on phytoplankton, particularly, the tolerability and changes to the toxin profiles of harmful toxic algal species remain unknown. The degree to which oil-affected sympatric Karenia brevis, Prorocentrum minimum, and Heterosigma akashiwo, all of which are ecologically important species in the Gulf of Mexico, was investigated. Comparison of their tolerability to that of non-toxic species showed that the toxin-production potential of harmful species does not provide a selective advantage. Investigated toxin profiles for K. brevis and P. minimum demonstrated an increase in toxin productivity at the lowest crude oil concentration (0.66 mg L(-1)) tested in this study. Higher crude oil concentrations led to significant growth inhibition and a decrease in toxin production. Findings from this study could assist in the assessment of shellfish bed closures due to high risk of increased toxin potential of these phytoplankton species, especially during times of stressed conditions.

  3. Method for detecting biological toxins

    SciTech Connect

    Ligler, F.S.; Campbell, J.R.

    1992-01-01

    Biological toxins are indirectly detected by using polymerase chain reaction to amplify unique nucleic acid sequences coding for the toxins or enzymes unique to toxin synthesis. Buffer, primers coding for the unique nucleic acid sequences and an amplifying enzyme are added to a sample suspected of containing the toxin. The mixture is then cycled thermally to exponentially amplify any of these unique nucleic acid sequences present in the sample. The amplified sequences can be detected by various means, including fluorescence. Detection of the amplified sequences is indicative of the presence of toxin in the original sample. By using more than one set of labeled primers, the method can be used to simultaneously detect several toxins in a sample.

  4. Intracellular trafficking of bacterial toxins.

    PubMed

    Williams, Jeffrey M; Tsai, Billy

    2016-08-01

    Bacterial toxins often translocate across a cellular membrane to gain access into the host cytosol, modifying cellular components in order to exert their toxic effects. To accomplish this feat, these toxins traffic to a membrane penetration site where they undergo conformational changes essential to eject the toxin's catalytic subunit into the cytosol. In this brief review, we highlight recent findings that elucidate both the trafficking pathways and membrane translocation mechanisms of toxins that cross the plasma, endosomal, or endoplasmic reticulum (ER) membrane. These findings not only illuminate the specific nature of the host-toxin interactions during entry, but should also provide additional therapeutic strategies to prevent or alleviate the bacterial toxin-induced diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. [Today's threat of ricin toxin].

    PubMed

    From, Sławomir; Płusa, Tadeusz

    2015-09-01

    Since the late 70s of the last century there were more than 700 incidents related to the use of the ricin toxin. For this reason, CDC (Center of Disease Control and Prevention) recognized toxin as a biological weapon category B. The lethal dose of ricin toxin after parenteral administration is 0.0001 mg/kg and after oral administration 0.2 mg. The first symptoms of poisoning occur within a few hours after application of toxin as a nausea, vomiting and abdominal pain. In the final stage there are observed: cardiac arrhythmia, collapse and symptoms suggestive of involvement of the central nervous system. Stage immediately preceding death is a state of coma. The ricin toxin is still the substance against which action has no optimal antidote. Developed a vaccine called RiVax is waiting for its registration. It should be pointed out that the availability of a ricin toxin makes it possible to use it for real bioterrorists.

  6. Effect of algal recycling rate on the performance of Pediastrum boryanum dominated wastewater treatment high rate algal pond.

    PubMed

    Park, J B K; Craggs, R J

    2014-01-01

    Recycling a portion of gravity harvested algae promoted the dominance of a rapidly settling colonial alga, Pediastrum boryanum (P. boryanum) and improved both biomass productivity and settleability in High Rate Algal Pond (HRAP) treating domestic wastewater. The effect of algal recycling rate on HRAP performance was investigated using 12 replicate mesocosms (18 L) that were operated semi-continuously under ambient conditions. Three experiments were conducted during different seasons with each experiment lasting up to 36 days. Recycling 10%, 25%, and 50% of the 'mass' of daily algal production all increased total biomass concentration in the mesocosms. However, recycling >10% reduced the organic content (volatile suspended solids (VSS)) of the mesocosm biomass from 83% to 68% and did not further increase biomass productivity (based on VSS). This indicates that if a HRAP is operated with a low algal concentration and does not utilise all the available sunlight, algal recycling increases the algal concentration up to an optimum level, resulting in higher algal biomass productivity. Recycling 10% of the daily algal production not only increased biomass productivity by ∼40%, but increased biomass settleability by ∼25%, which was probably a consequence of the ∼30% increase in P. boryanum dominance in the mesocosms compared with controls without recycling.

  7. Polycystic ovary syndrome and environmental toxins.

    PubMed

    Rutkowska, Aleksandra Zofia; Diamanti-Kandarakis, Evanthia

    2016-09-15

    Polycystic ovary syndrome (PCOS) is the most common, heterogeneous, and multifactorial endocrine disorder in premenopausal women. The pathophysiology of this endocrinopathy is still unclear; however, the heterogeneity of its features within ethnic races, geographic location, and families suggests that environment and lifestyle are of prime importance. This work is mainly focused on the possible role of the most common and studied environmental toxins for this syndrome in the pathogenesis of PCOS. Plasticizers, such as bisphenol A (BPA) or phthalates, which belong to the categories of endocrine disrupting chemicals (EDCs) and advanced glycation end products (AGEs), affect humans' health in everyday, industrialized life; therefore special attention should be paid to such exposure. Timing of exposure to EDCs is crucial for the intensity of adverse health effects. It is now evident that fetuses, infants, and/or young children are the most susceptible groups, especially in the early development periods. Prenatal exposure to EDCs that mimic endogenous hormones may contribute to the altered fetal programming and in consequence lead to PCOS and other adverse health effects, potentially transgenerationally. Acute or prolonged exposure to EDCs and AGEs through different life cycle stages may result in destabilization of the hormonal homeostasis and lead to disruption of reproductive functions. They may also interfere with metabolic alterations such as obesity, insulin resistance, and compensatory hyperinsulinemia that can exacerbate the PCOS phenotype and contribute to PCOS consequences such as type 2 diabetes and cardiovascular disease. Since wide exposure to environmental toxins and their role in the pathophysiology of PCOS are supported by extensive data derived from diverse scientific models, protective strategies and strong recommendations should be considered to reduce human exposure to protect present and future generations from their adverse health effects. Copyright

  8. Arsenic (V) induces a fluidization of algal cell and liposome membranes.

    PubMed

    Tuan, Le Quoc; Huong, Tran Thi Thanh; Hong, Pham Thi Anh; Kawakami, Tomonori; Shimanouchi, Toshinori; Umakoshi, Hiroshi; Kuboi, Ryoichi

    2008-09-01

    Arsenate is one of the most poisonous elements for living cells. When cells are exposed to arsenate, their life activities are immediately affected by various biochemical reactions, such as the binding of arsenic to membranes and the substitution of arsenic for phosphate or the choline head of phospholipids in the biological membranes. The effects of arsenate on the life activities of algae Chlorella vulgaris were investigated at various concentrations and exposure times. The results demonstrated that the living activities of algal cells (10(10)cells/L) were seriously affected by arsenate at a concentration of more than 7.5mg As/L within 24h. Algal cells and the artificial membranes (liposomes) were exposed to arsenate to evaluate its effects on the membrane fluidization. In the presence of arsenate, the membranes were fluidized due to the binding and substitution of arsenate groups for phosphates or the choline head on the their membrane surface. This fluidization of the biological membranes was considered to enhance the transport of toxicants across the membrane of algal cells.

  9. Modelling long-term ecotoxicological effects on an algal population under dynamic nutrient stress.

    PubMed

    Bontje, D; Kooi, B W; Liebig, M; Kooijman, S A L M

    2009-07-01

    We study the effects of toxicants on the functioning of phototrophic unicellular organism (an algae) in a simple aquatic microcosm by applying a parameter-sparse model. The model allows us to study the interaction between ecological and toxicological effects. Nutrient stress and toxicant stress, together or alone, can cause extinction of the algal population. The modelled algae consume dissolved inorganic nitrogen (DIN) under surplus light and use it for growth and maintenance. Dead algal biomass is mineralized by bacterial activity, leading to nutrient recycling. The ecological model is coupled with a toxicity-module that describes the dependency of the algal growth and death rate on the toxicant concentration. Model parameter fitting is performed on experimental data from Liebig, M., Schmidt, G., Bontje, D., Kooi, B.W., Streck, G., Traunspurger, W., Knacker, T. [2008. Direct and indirect effects of pollutants on algae and algivorous ciliates in an aquatic indoor microcosm. Aquatic Toxicology 88, 102-110]. These experiments were especially designed to include nutrient limitation, nutrient recycling and long-term exposure to toxicants. The flagellate species Cryptomonas sp. was exposed to the herbicide prometryn and insecticide methyl parathion in semi-closed Erlenmeyers. Given the total limiting amount of nitrogen in the system, the estimated toxicant concentration at which a long-term steady population of algae goes extinct will be derived. We intend to use the results of this study to investigate the effects of ecological (environmental) and toxicological stresses on more realistic ecosystem structure and functioning.

  10. Effects of co-existing microalgae and grazers on the production of hemolytic toxins in Karenia mikimotoi

    NASA Astrophysics Data System (ADS)

    Yang, Weidong; Zhang, Naisheng; Cui, Weimin; Xu, Yanyan; Li, Hongye; Liu, Jiesheng

    2011-11-01

    Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup is associated with harmful algal blooms in temperate and subtropical zones of the world. The hemolytic substances produced by K. mikimotoi are thought to cause mortality in fishes and invertebrates. We evaluated the composition of the hemolytic toxin produced by K. mikimotoi cultured in the laboratory using thin-layer chromatography. In addition, we evaluated the effect of co-occuring algae ( Prorocentrum donghaiense and Alexandrium tamarense) and the cladoceran grazer Moina mongolica on hemolytic toxin production in K. mikimotoi. The hemolytic toxins from K. mikimotoi were a mixture of 2 liposaccharides and 1 lipid. Waterborne clues from P. donghaiense and A. tamarense inhibited the growth of K. mikimotoi but increased the production of hemolytic toxins. Conversely, K. mikimotoi strongly inhibited the growth of caged P. donghaiense and A. tamarense. In addition, the ingestion of K. mikimotoi by M. mongolica induced the production of hemolytic toxins in K. mikimotoi. Taken together, our results suggest that the presence of other microalgae and grazers may be as important as environmental factors for controlling the production of hemolytic substances. K. mikimotoi secreted allelochemicals other than unstable fatty acids with hemolytic activity. The production of hemolytic toxins in dinoflagellates was not only dependent on resource availability, but also on the risk of predation. Hemolytic toxins likely play an important role as chemical deterrents secreted by K. mikimotoi.

  11. Studies in the Use of Magnetic Microspheres for Immunoaffinity Extraction of Paralytic Shellfish Poisoning Toxins from Shellfish

    PubMed Central

    Devlin, Raymond; Campbell, Katrina; Kawatsu, Kentaro; Elliott, Christopher

    2011-01-01

    Paralytic shellfish poisoning (PSP) is a potentially fatal human health condition caused by the consumption of shellfish containing high levels of PSP toxins. Toxin extraction from shellfish and from algal cultures for use as standards and analysis by alternative analytical monitoring methods to the mouse bioassay is extensive and laborious. This study investigated whether a selected MAb antibody could be coupled to a novel form of magnetic microsphere (hollow glass magnetic microspheres, brand name Ferrospheres-N) and whether these coated microspheres could be utilized in the extraction of low concentrations of the PSP toxin, STX, from potential extraction buffers and spiked mussel extracts. The feasibility of utilizing a mass of 25 mg of Ferrospheres-N, as a simple extraction procedure for STX from spiked sodium acetate buffer, spiked PBS buffer and spiked mussel extracts was determined. The effects of a range of toxin concentrations (20-300 ng/mL), incubation times and temperature on the capability of the immuno-capture of the STX from the spiked mussel extracts were investigated. Finally, the coated microspheres were tested to determine their efficiency at extracting PSP toxins from naturally contaminated mussel samples. Toxin recovery after each experiment was determined by HPLC analysis. This study on using a highly novel immunoaffinity based extraction procedure, using STX as a model, has indicated that it could be a convenient alternative to conventional extraction procedures used in toxin purification prior to sample analysis. PMID:22069687

  12. Toxin Plasmids of Clostridium perfringens

    PubMed Central

    Li, Jihong; Adams, Vicki; Bannam, Trudi L.; Miyamoto, Kazuaki; Garcia, Jorge P.; Uzal, Francisco A.; Rood, Julian I.

    2013-01-01

    SUMMARY In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ∼16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ∼45 kb to ∼140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ∼35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract. PMID:23699255

  13. Recombinant Toxins for Cancer Treatment

    NASA Astrophysics Data System (ADS)

    Pastan, Ira; Fitzgerald, David

    1991-11-01

    Recombinant toxins target cell surface receptors and antigens on tumor cells. They kill by mechanisms different from conventional chemotherapy, so that cross resistance to conventional chemotherapeutic agents should not be a problem. Furthermore, they are not mutagens and should not induce secondary malignancies or accelerate progression of benign malignancies. They can be mass-produced cheaply in bacteria as homogeneous proteins. Either growth factor-toxin fusions or antibody-toxin fusions can be chosen, depending on the cellular target.

  14. Pore formation by Cry toxins.

    PubMed

    Soberón, Mario; Pardo, Liliana; Muñóz-Garay, Carlos; Sánchez, Jorge; Gómez, Isabel; Porta, Helena; Bravo, Alejandra

    2010-01-01

    Bacillus thuringiensis (Bt) bacteria produce insecticidal Cry and Cyt proteins used in the biological control of different insect pests. In this review, we will focus on the 3d-Cry toxins that represent the biggest group of Cry proteins and also on Cyt toxins. The 3d-Cry toxins are pore-forming toxins that induce cell death by forming ionic pores into the membrane of the midgut epithelial cells in their target insect. The initial steps in the mode of action include ingestion of the protoxin, activation by midgut proteases to produce the toxin fragment and the interaction with the primary cadherin receptor. The interaction of the monomeric CrylA toxin with the cadherin receptor promotes an extra proteolytic cleavage, where helix alpha-1 of domain I is eliminated and the toxin oligomerization is induced, forming a structure of 250 kDa. The oligomeric structure binds to a secondary receptor, aminopeptidase N or alkaline phosphatase. The secondary receptor drives the toxin into detergent resistant membrane microdomains formingpores that cause osmotic shock, burst of the midgut cells and insect death. Regarding to Cyt toxins, these proteins have a synergistic effect on the toxicity of some Cry toxins. Cyt proteins are also proteolytic activated in the midgut lumen of their target, they bind to some phospholipids present in the mosquito midgut cells. The proposed mechanism of synergism between Cry and Cyt toxins is that Cyt1Aa function as a receptor for Cry toxins. The Cyt1A inserts into midgut epithelium membrane and exposes protein regions that are recognized by Cry11Aa. It was demonstrated that this interaction facilitates the oligomerization of Cry11Aa and also its pore formation activity.

  15. Ricin detection: tracking active toxin.

    PubMed

    Bozza, William P; Tolleson, William H; Rosado, Leslie A Rivera; Zhang, Baolin

    2015-01-01

    Ricin is a plant toxin with high bioterrorism potential due to its natural abundance and potency in inducing cell death. Early detection of the active toxin is essential for developing appropriate countermeasures. Here we review concepts for designing ricin detection methods, including mechanism of action of the toxin, advantages and disadvantages of current detection assays, and perspectives on the future development of rapid and reliable methods for detecting ricin in environmental samples.

  16. Quantification and profiling of lipophilic marine toxins in microalgae by UHPLC coupled to high-resolution orbitrap mass spectrometry.

    PubMed

    Orellana, Gabriel; Van Meulebroek, Lieven; Van Vooren, Sarah; De Rijcke, Maarten; Vandegehuchte, Michiel; Janssen, Colin R; Vanhaecke, Lynn

    2015-08-01

    During the last decade, a significant increase in the occurrence of harmful algal blooms (HABs), linked to repetitive cases of shellfish contamination has become a public health concern and therefore, accurate methods to detect marine toxins in different matrices are required. In this study, we developed a method for profiling lipophilic marine microalgal toxins based on ultra-high-performance liquid chromatography coupled to high-resolution Orbitrap mass spectrometry (UHPLC-HR-Orbitrap MS). Extraction of selected toxins (okadaic acid (OA), dinophysistoxin-1 (DTX-1), pectenotoxin-2 (PTX-2), azaspiracid-1 (AZA-1), yessotoxin (YTX) and 13-desmethyl spirolide C (SPX-1)) was optimized using a Plackett-Burman design. Three key algal species, i.e., Prorocentrum lima, Protoceratium reticulatum and Alexandrium ostenfeldii were used to test the extraction efficiency of OA, YTXs and SPXs, respectively. Prorocentrum micans, fortified with certified reference solutions, was used for recovery studies. The quantitative and confirmatory performance of the method was evaluated according to CD 2002/657/EC. Limits of detection and quantification ranged between 0.006 and 0.050 ng mL(-1) and 0.018 to 0.227 ng mL(-1), respectively. The intra-laboratory reproducibility ranged from 6.8 to 11.7 %, repeatability from 6.41 to 11.5 % and mean corrected recoveries from 81.9 to 119.6 %. In addition, algae cultures were retrospectively screened for analogues and metabolites through a homemade database. Using the ToxID software programme, 18 toxin derivates were detected in the extract of three toxin producing microalgae species. In conclusion, the generic extraction and full-scan HRMS approach offers an excellent quantitative performance and simultaneously allows to profile analogues and metabolites of marine toxins in microalgae. Graphical Abstract Optimization of extraction, detection and quantification of lipophilic marine toxins in microalgae by UHPLC-HR Orbitrap MS.

  17. THE SYNERGY OF BACTERIAL TOXINS,

    DTIC Science & Technology

    TOXINS AND ANTITOXINS, STRENGTH(PHYSIOLOGY), BACTERIA , CLOSTRIDIUM PERFRINGENS, CLOSTRIDIUM TETANI, CLOSTRIDIUM, STAPHYLOCOCCUS, ESCHERICHIA COLI, PROTEUS, ETIOLOGY, ANTIGENS, ANTIBODIES, AMINO ACIDS.

  18. NVC-422 inactivates Staphylococcus aureus toxins.

    PubMed

    Jekle, Andreas; Yoon, Jungjoo; Zuck, Meghan; Najafi, Ramin; Wang, Lu; Shiau, Timothy; Francavilla, Charles; Rani, Suriani Abdul; Eitzinger, Christian; Nagl, Markus; Anderson, Mark; Debabov, Dmitri

    2013-02-01

    Bacterial pathogens have specific virulence factors (e.g., toxins) that contribute significantly to the virulence and infectivity of microorganisms within the human hosts. Virulence factors are molecules expressed by pathogens that enable colonization, immunoevasion, and immunosuppression, obtaining nutrients from the host or gaining entry into host cells. They can cause pathogenesis by inhibiting or stimulating certain host functions. For example, in systemic Staphylococcus aureus infections, virulence factors such as toxic shock syndrome toxin 1 (TSST-1), staphylococcal enterotoxin A (SEA), and staphylococcal enterotoxin B (SEB) cause sepsis or toxic shock by uncontrolled stimulation of T lymphocytes and by triggering a cytokine storm. In vitro, these superantigens stimulate the proliferation of human peripheral blood mononuclear cells (PBMC) and the release of many cytokines. NVC-422 (N,N-dichloro-2,2-dimethyltaurine) is a broad-spectrum, fast-acting topical anti-infective agent against microbial pathogens, including antibiotic-resistant microbes. Using mass spectrometry, we demonstrate here that NVC-422 oxidizes methionine residues of TSST-1, SEA, SEB, and exfoliative toxin A (ETA). Exposure of virulence factors to 0.1% NVC-422 for 1 h prevented TSST-1-, SEA-, SEB-, and ETA-induced cell proliferation and cytokine release. Moreover, NVC-422 also delayed and reduced the protein A- and clumping factor-associated agglutination of S. aureus cultures. These results show that, in addition to its well-described direct microbicidal activity, NVC-422 can inactivate S. aureus virulence factors through rapid oxidation of methionines.

  19. Lifespan extension of rotifers by treatment with red algal extracts

    PubMed Central

    Snare, David J.; Fields, Allison M.; Snell, Terry W.; Kubanek, Julia

    2013-01-01

    Aging results from an accumulation of damage to macromolecules inhibiting cellular replication, repair, and other necessary functions. Damage may be due to environmental stressors such as metal toxicity, oxidative stress caused by imperfections in electron transfer reactions, or other metabolic processes. In an effort to discover medical treatments that counteract this damage, we initiated a search for small molecule drugs from natural sources using life table experiments which, through their unbiased approach, present the opportunity to discover first-in-class molecules. We have identified marine red algae as a source of natural products that slow aging of the invertebrate rotifer Brachionus manjavacas. Rotifers are a promising model organism for life extension studies as they maintain a short, measurable lifespan while also having an extensive literature related to aging. Rotifer lifespan was increased 9–14% by exposure to three of a total of 200 screened red algal extracts. Bioassay guided fractionation led to semi-purified extracts composed primarily of lipids responsible for rotifer life extension. The life extending mixture from the red alga Acanthophora spicifera contained eicosanoic, octadecanoic, and hexadecanoic acids as well as several unidentified unsaturated fatty acids. The life extending effects of these small molecule mixtures are not a result of their direct antioxidant capacity; other unknown mechanisms of action are likely involved. An understanding of how these natural products interact with their molecular targets could lead to selective and effective treatments for slowing aging and reducing age related diseases. PMID:24120568

  20. Algal-bacterial treatment facility removes selenium from drainage water

    SciTech Connect

    Quinn, Nigel W.T.; Lundquist, Tryg J.; Green, F. Bailey; Zarate, Max A.; Oswald, William J.; Leighton, Terrance

    2000-01-25

    A demonstration algal-bacterial selenium removal (ABSR) facility has been treating agricultural drainage water in the Panoche Drainage District on the west side of the San Joaquin Valley since 1997. The project goals are to demonstrate the effectiveness of the ABSR technology for selenium removal, to investigate potential wildlife exposure to selenium at full-scale facilities, and to develop an operational plant configuration that will minimize the life-cycle cost for each pound of selenium removed. The facility consists of a series of ponds designed to promote native microorganisms that remove nitrate and selenium. Previous treatment research efforts sought to reduce selenium concentrations to less than 5 mu g/L, but the ABSR Facility demonstration focuses on providing affordable reduction of the selenium load that is discharged to the San Joaquin River. During 1997 and 1998, the best-performing ABSR plant configuration reduced nitrate by more than 95 percent and reduced total soluble selenium mass by 80 percent. Ongoing investigations focus on optimizing operational parameters and determining operational costs and scale-up engineering requirements. The preliminary total cost estimate for a 10-acre-foot per day ABSR facility is less than $200 per acre-foot of treated drainage water.