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Jo Ann M. Burkholder - One of the best experts on this subject based on the ideXlab platform.
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The Standardized Fish Bioassay Procedure for Detecting and Culturing Actively Toxic Pfiesteria, Used by Two Reference Laboratories for Atlantic and Gulf Coast States
2013Co-Authors: Jo Ann M. Burkholder, Harold G. Marshall, Howard B. Glasgow, David W Seaborn, Nora J. Deamer-meliaAbstract:In the absence of purified standards of toxins from Pfiesteria species, appropriately conducted fish bioassays are the “gold standard ” that must be used to detect toxic strains of Pfiesteria spp. from natural estuarine water or sediment samples and to culture actively toxic Pfiesteria. In this article, we describe the standardized steps of our fish bioassay as an abbreviated term for a procedure that includes two sets of trials with fish, following the Henle-Koch postulates modified for toxic rather than infectious agents. This procedure was developed in 1991, and has been refined over more than 12 years of experience in research with toxic Pfiesteria. The steps involve isolating toxic strains of Pfiesteria (or other potentially, as-yet-undetected, toxic Pfiesteria or Pfiesteria-like species) from fish-killing bioassays with natural samples; growing the clones with axenic algal prey; and retesting the isolates in a second set of fish bioassays. The specific environmental conditions used (e.g., temperature, salinity, light, other factors) must remain flexible, given the wide range of conditions from which natural estuarine samples are derived. We present a comparison of information provided for fish culture conditions, reported in international science journals in which such research is routinely published, and we provide information from more than 2,000 fish bioassays with toxic Pfiesteria, along with recommendations for suitable ranges and frequency of monitoring o
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Articles Reporter Gene Assay for Fish-Killing Activity Produced by Pfiesteria piscicida
2013Co-Authors: Peter R. Moeller, Jo Ann M. Burkholder, John S. RamsdellAbstract:Collaborative studies were peormed to develop a finctional assay for fish-killing activity produced by If ia piscida Eight cell lines were used to screen organic fractions and residual water fraton by using a 3-[4,5-dimethyliazol-(2-4)1-diphenyltaolium bromide cytotoxicity asay. Diethyl ether and a residual water fraction were cytoc to several cell lines icl-uding rat pituitary (GH4C1) cells. Residual water as wdl as pre acted culture water continin P. piscicida cels induced c-fiwlucifre xr in GH4C, cells with a rapid time course of induction and sensitiv detection. The reporter gene assay detet activity in toxic isolates of P. pisciida from seral North Carolina estuaries in 1997 and 1998 and may also be suitable for detg toxic activity in human and serum. Key wordve assay c-for, GH4C1, Pfiestria pscici4da, pituitary, toxin. Enuron Heah Pmpc*t 107:711-714 (1999). [Online 28 July 1999] bttp://dpnetld. niehs.nibgwv/lds/l999/107p711-714fai"r/absstracthtml Pfiesteria piscicida is a toxic dinoflagellate that has been a causative agent of fish epizootics and mortalities in estuaries of th
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Current Progress in Isolation and Characterization of Toxins Isolated from Pfiesteria piscicida
2013Co-Authors: Peter D. R. Moeller, Jo Ann M. Burkholder, Nora J. Deamer-melia, Steve L. Morton, Brad A. Mitchell, Scott K. Sivertsen, Elizabeth R. Fairey, Tina M. Mikulski, Howard Glasgow, John S. RamsdellAbstract:The isolation and partial purification of toxic substances derived from Pfiesteria piscicida Steidinger & Burkholder extracts is described. Four distinct bioassay systems were used to monitor bioactivity of the P. piscicida extracts, including a high throughput cell cytotoxicity assay and a reporter gene assay as well as assays using brine shrimp and fish. Using these bioassays to guide fractionation, we have isolated two distinct, active fractions from Pfiesteria culture medium and cell mass extracts on the basis of their solubility characteristics. We have identified and characterized a bioactive lipophilic substance from Pfiesteria-derived extracts as di(2-ethylhexyl)phthalate, a commonly used plasticizer. The source of this typically man-made substance has been identified as originating from Instant Ocean (Aquarium Systems, Mentor, OH, USA), a commercially available seawater salt mixture used to prepare our mass culture growth medium. We have developed chromatographic methodology to isolate a bioactive polar compound isolated from extracts of Pfiesteria culture and presently report the characterization of the activity of this substance. The molecular structural analysis of the polar active component(s) using mass spectrometry and nuclear magnetic resonance spectroscopy is currently under way. Key words: assay, chromatography, GH 4C 1, Pfiesteria piscicida, toxin bioassay. — Environ Health Perspect 109(suppl 5):739–743 (2001)
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Species of the Toxic Pfiesteria Complex, and the Importance of Functional Type in Data Interpretation
2013Co-Authors: Jo Ann M. Burkholder, Matthew W. Parrow, Howard B. Glasgow, Nora J. Deamer-melia, Jeffrey Springer, Cheng Zhang, Paul J. CancellieriAbstract:We describe the two species of the toxic Pfiesteria complex to date (Pfiesteria piscicida and Pfiesteria shumwayae), their complex life cycles, and the characteristics required for inclusion within this complex. These species resemble P. piscicida Steidinger & Burkholder and also have a) strong attraction to fresh fish tissues and excreta, b) toxic activity stimulated by live fish, and c) production of toxin that can cause fish death and disease. Amoeboid stages were verified in 1992–1997 by our laboratory (various stages from toxic cultures) and that of K. Steidinger and co-workers (filose amoebae in nontoxic cultures), and in 2000 by H. Marshall and co-workers (various stages from toxic cultures), from clonal Pfiesteria spp. cultures, using species-specific polymerase chain reaction-based molecular probes with cross-confirmation by an independent specialist. Data were provided from tests of the hypothesis that Pfiesteria strains differ in response to fresh fish mucus and excreta, algal prey, and inorganic nutrient (N, P) enrichment, depending on functional type or toxicity status. There are three functional types: TOX-A, in actively toxic, fish-killing mode; TOX-B, temporarily nontoxic, without access to live fish for days to weeks, but capable of toxic activity if fish are added; and NON-IND, noninducible with negligible toxicity in the presence of live fish. NON-IND Pfiesteria attained highest zoospore production on algal prey without or withou
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Use of Molecular Probes to Assess Geographic Distribution of Pfiesteria Species
2013Co-Authors: Parke A. Rublee, Jo Ann M. Burkholder, David W. Oldach, Torstein Tengs, Jason W. Kempton, Eric F. Schaefer, Coy Allen, Janera Harris, Holly Bowers, H. B. GlasgowAbstract:We have developed multiple polymerase chain reaction (PCR)-based methods for the detection of Pfiesteria sp. in cultures and environmental samples. More than 2,100 water and sediment samples from estuarine sites of the U.S. Atlantic and gulf coasts were assayed for the presence of Pfiesteria piscicida Steidinger & Burkholder and Pfiesteria shumwayae Glasgow & Burkholder by PCR probing of extracted DNA. Positive results were found in about 3 % of samples derived from routine monitoring of coastal waters and about 8 % of sediments. The geographic range of both species was the same, ranging from New York to Texas. Pfiesteria spp. are likely common and generally benign inhabitants of coastal areas, but their presence maintains a potential for fish and human health problems. Key words: molecular probes, PCR, Pfiesteria, toxic dinoflagellates. — Enviro
Howard B. Glasgow - One of the best experts on this subject based on the ideXlab platform.
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The Standardized Fish Bioassay Procedure for Detecting and Culturing Actively Toxic Pfiesteria, Used by Two Reference Laboratories for Atlantic and Gulf Coast States
2013Co-Authors: Jo Ann M. Burkholder, Harold G. Marshall, Howard B. Glasgow, David W Seaborn, Nora J. Deamer-meliaAbstract:In the absence of purified standards of toxins from Pfiesteria species, appropriately conducted fish bioassays are the “gold standard ” that must be used to detect toxic strains of Pfiesteria spp. from natural estuarine water or sediment samples and to culture actively toxic Pfiesteria. In this article, we describe the standardized steps of our fish bioassay as an abbreviated term for a procedure that includes two sets of trials with fish, following the Henle-Koch postulates modified for toxic rather than infectious agents. This procedure was developed in 1991, and has been refined over more than 12 years of experience in research with toxic Pfiesteria. The steps involve isolating toxic strains of Pfiesteria (or other potentially, as-yet-undetected, toxic Pfiesteria or Pfiesteria-like species) from fish-killing bioassays with natural samples; growing the clones with axenic algal prey; and retesting the isolates in a second set of fish bioassays. The specific environmental conditions used (e.g., temperature, salinity, light, other factors) must remain flexible, given the wide range of conditions from which natural estuarine samples are derived. We present a comparison of information provided for fish culture conditions, reported in international science journals in which such research is routinely published, and we provide information from more than 2,000 fish bioassays with toxic Pfiesteria, along with recommendations for suitable ranges and frequency of monitoring o
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Species of the Toxic Pfiesteria Complex, and the Importance of Functional Type in Data Interpretation
2013Co-Authors: Jo Ann M. Burkholder, Matthew W. Parrow, Howard B. Glasgow, Nora J. Deamer-melia, Jeffrey Springer, Cheng Zhang, Paul J. CancellieriAbstract:We describe the two species of the toxic Pfiesteria complex to date (Pfiesteria piscicida and Pfiesteria shumwayae), their complex life cycles, and the characteristics required for inclusion within this complex. These species resemble P. piscicida Steidinger & Burkholder and also have a) strong attraction to fresh fish tissues and excreta, b) toxic activity stimulated by live fish, and c) production of toxin that can cause fish death and disease. Amoeboid stages were verified in 1992–1997 by our laboratory (various stages from toxic cultures) and that of K. Steidinger and co-workers (filose amoebae in nontoxic cultures), and in 2000 by H. Marshall and co-workers (various stages from toxic cultures), from clonal Pfiesteria spp. cultures, using species-specific polymerase chain reaction-based molecular probes with cross-confirmation by an independent specialist. Data were provided from tests of the hypothesis that Pfiesteria strains differ in response to fresh fish mucus and excreta, algal prey, and inorganic nutrient (N, P) enrichment, depending on functional type or toxicity status. There are three functional types: TOX-A, in actively toxic, fish-killing mode; TOX-B, temporarily nontoxic, without access to live fish for days to weeks, but capable of toxic activity if fish are added; and NON-IND, noninducible with negligible toxicity in the presence of live fish. NON-IND Pfiesteria attained highest zoospore production on algal prey without or withou
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Re-evaluation of the Relationship between Pfiesteria and Estuarine Fish Kills
Ecosystems, 2003Co-Authors: Cavell Brownie, Jo Ann M. Burkholder, Howard B. Glasgow, Robert E. Reed, Yongqiang TangAbstract:In recent years, fish kills along the mid-Atlantic US coast have become an increasing problem, with important economic, environmental, and public health implications (Glasgow and others 1995; Burkholder 1998; Grattan and others 1998; Haselow and others 2001; Shoemaker and Hudnell 2001). Research into the causes of these fish kills is ongoing, and monitoring and surveillance programs have been instituted to investigate (among other factors) the role of actively toxic forms of two known species within the dinoflagellate genus Pfiesteria (Burkholder and others 1995, 2001a; Steidinger and others 1996; Burkholder and Glasgow 1997; Glasgow and others 2001b). In their recent analyses of the relationship between Pfiesteria and fish kills, Burkholder and others (1999) and Stow (1999) stated, as others have noted previously (Meyer and Barclay 1990), that it is difficult to establish the causes of estuarine fish kills at the ecosystem level. The evaluation of Burkholder and others (1999) was based on the biology and toxic behavior of Pfiesteria, as well as empirical sampling of field fish kill events then in progress, as supported by laboratory analyses of samples collected from each fish kill. In contrast, Stow (1999) conducted theoretical probability calculations and argued that information demonstrating the presence of toxic Pfiesteria during fish kills was insufficient to prove that there was a cause-and-effect
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Learning impairment caused by a toxin produced by Pfiesteria piscicida infused into the hippocampus of rats.
Neurotoxicology and teratology, 2003Co-Authors: Edward D. Levin, Jo Ann M. Burkholder, Howard B. Glasgow, Peter D. R. Moeller, W.paul Blackwelder, John S. RamsdellAbstract:Pfiesteria piscicida, an estuarine dinoflagellate, which has been shown to kill fish, has also been associated with neurocognitive deficits in humans. With a rat model, we have demonstrated the cause-and-effect relationship between Pfiesteria exposure and learning impairment. In several studies, we have replicated the finding in Sprague-Dawley rats that exposure to fixed acute doses of Pfiesteria cells or filtrates caused radial-arm maze learning impairment. Recently, this finding of Pfiesteria-induced learning impairment in rats has been independently replicated in another laboratory as well. We have demonstrated significant Pfiesteria-induced learning impairment in both the win-shift and repeated-acquisition tasks in the radial-arm maze and in reversal learning in a visual operant signal detection task. These learning impairments have been seen as long as 10 weeks after a single acute exposure to Pfiesteria. In the current study, we used a hydrophilic toxin isolated from clonal P. piscicida cultures (PfTx) and tested its effect when applied locally to the ventral hippocampus on repeated acquisition of rats in the radial-arm maze. Toxin exposure impaired choice accuracy in the radial-arm maze repeated acquisition procedure. The PfTx-induced impairment was seen at the beginning of the session and the early learning deficit was persistent across 6 weeks of testing after a single administration of the toxin. Eventually, with enough practice, in each session, the PfTx-exposed rats did learn that session's problem as did control rats. This model has demonstrated the cause-and-effect relationship between exposure to a hydrophilic toxin produced by P. piscicida and learning impairment, and specifically that the ventral hippocampus was critically involved.
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Low abundance of the dinoflagellates,Pfiesteria piscicida, P. shumwayae, andCryptoperidiniopsis spp., in South Carolina tidal creeks and open estuaries
Estuaries, 2002Co-Authors: Alan J. Lewitus, Parke A. Rublee, Jo Ann M. Burkholder, Howard B. Glasgow, Kenneth C. Hayes, Bonnie M. Willis, A. Fred Holland, Philip P. Maier, Robert MagnienAbstract:The toxic Pfiesteria complex are a group of dinoflagellates that have received considerable attention in recent years as causative factors in fish kill or lesion events in North Carolina estuaries and in the Pocomoke River of Chesapeake Bay. In response to the potential Pfiesteria threat, the South Carolina Task Group on Harmful Algae was formed in late 1997 and implemented programs to monitor harmful algal blooms and respond to fish kills or lesion events with particular emphasis on the Bushy Park (Cooper River, Charleston) region, a site of annually recurrent menhaden lesion events. Pfiesteria piscicida, Pfiesteria shumwayae , and Cryptoperidiniopsis spp. were documented in South Carolina estuaries. Routine monitoring and fish kill or lesion event sampling consistently indicated low abundances compared to estimates from similar programs in North Carolina and Maryland that sampled areas with a history of Pfiesteria toxic activity. The finding that Pfiesteria -like organism (PLO) abundances were always low in samples collected during menhaden lesion events in Bushy Park suggested other causes for lesion progression, although Pfiesteria spp. could not be ruled out as a factor in lesion initiation. Based on the previously demonstrated positive relationship between PLO abundance, chlorophyll a , and inorganic nutrient concentrations (in laboratory experiments and North Carolina field observations), we hypothesized that the relatively low abundance of Pfiesteria spp. and other PLO (e.g., Cryptoperidiniopsis ) in South Carolina estuaries is related to the relatively low supply of phytoplankton prey, as supported by interstate comparisons in chlorophyll a concentrations. Nitrate concentrations were generally much lower in South Carolina estuaries. Estuarine eutrophication may be an important consideration in explaining interstate differences in susceptibility to Pfiesteria -related toxic events.
Harold G. Marshall - One of the best experts on this subject based on the ideXlab platform.
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The Standardized Fish Bioassay Procedure for Detecting and Culturing Actively Toxic Pfiesteria, Used by Two Reference Laboratories for Atlantic and Gulf Coast States
2013Co-Authors: Jo Ann M. Burkholder, Harold G. Marshall, Howard B. Glasgow, David W Seaborn, Nora J. Deamer-meliaAbstract:In the absence of purified standards of toxins from Pfiesteria species, appropriately conducted fish bioassays are the “gold standard ” that must be used to detect toxic strains of Pfiesteria spp. from natural estuarine water or sediment samples and to culture actively toxic Pfiesteria. In this article, we describe the standardized steps of our fish bioassay as an abbreviated term for a procedure that includes two sets of trials with fish, following the Henle-Koch postulates modified for toxic rather than infectious agents. This procedure was developed in 1991, and has been refined over more than 12 years of experience in research with toxic Pfiesteria. The steps involve isolating toxic strains of Pfiesteria (or other potentially, as-yet-undetected, toxic Pfiesteria or Pfiesteria-like species) from fish-killing bioassays with natural samples; growing the clones with axenic algal prey; and retesting the isolates in a second set of fish bioassays. The specific environmental conditions used (e.g., temperature, salinity, light, other factors) must remain flexible, given the wide range of conditions from which natural estuarine samples are derived. We present a comparison of information provided for fish culture conditions, reported in international science journals in which such research is routinely published, and we provide information from more than 2,000 fish bioassays with toxic Pfiesteria, along with recommendations for suitable ranges and frequency of monitoring o
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toxigenic Pfiesteria species updates on biology ecology toxins and impacts
Harmful Algae, 2012Co-Authors: Jo Ann M. Burkholder, Harold G. MarshallAbstract:Abstract The genus Pfiesteria includes two toxigenic species, Pfiesteria piscicida and Pfiesteria shumwayae , that are thinly thecate dinoflagellates with apparently cosmopolitan distribution, especially in shallow, poorly flushed, eutrophic estuaries. They are heterotrophic prey generalists that typically feed via phagotrophy and prefer live fish or their fresh tissues as food. They can also engage in limited mixotrophy through temporary retention of kleptochloroplasts from algal prey. Toxicity is highly variable among strains, ranging from apparently nontoxic to highly toxic. Some strains produce a group of hydrophilic toxins with metal-mediated free radical production. Various metals can be involved in the toxin congeners, and the purified toxins are highly labile. These toxins can adversely affect mammalian cells as well as fish. Toxic strains are capable of killing fish by both toxins and physical attack from feeding upon epidermis and other tissues. Non-inducible strains do not produce sufficient toxin to kill fish, but some are capable of causing larval fish death by physical attack. From 1991 to 1998, Pfiesteria spp. were linked to major kills of juvenile Atlantic menhaden ( Brevoortia tyrannus ), mostly at densities of ≥4(3) × 10 2 to 10 3 (rarely, 10 4 ) flagellate cells mL −1 . These kills mainly occurred in the second largest and largest estuaries on the U.S. mainland, especially two main tributaries of the Albemarle-Pamlico Estuarine System, following decades of hurricane-free conditions. Between kills, Pfiesteria abundance was low in surface waters ( −1 ), and the available evidence suggests that the populations were mostly in the lower water column and within surficial sediments. Apparently highly sensitive to scouring effects from major storms, Pfiesteria populations have been sparse in the affected estuaries since several hurricanes struck the Albemarle-Pamlico in the late 1990s. Recent research highlights include characterization of a novel group of Pfiesteria toxins, culture of a toxigenic strain on a sterile fish cell line, axenic culture on a semi-defined medium, the discovery of a new mode of heterotrophic feeding in dinoflagellates as manifested by Pfiesteria , and other advances in understanding the nutritional ecology and prey acquisition of these harmful dinoflagellates.
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Toxigenic Pfiesteria species—Updates on biology, ecology, toxins, and impacts
Harmful Algae, 2012Co-Authors: Jo Ann M. Burkholder, Harold G. MarshallAbstract:Abstract The genus Pfiesteria includes two toxigenic species, Pfiesteria piscicida and Pfiesteria shumwayae , that are thinly thecate dinoflagellates with apparently cosmopolitan distribution, especially in shallow, poorly flushed, eutrophic estuaries. They are heterotrophic prey generalists that typically feed via phagotrophy and prefer live fish or their fresh tissues as food. They can also engage in limited mixotrophy through temporary retention of kleptochloroplasts from algal prey. Toxicity is highly variable among strains, ranging from apparently nontoxic to highly toxic. Some strains produce a group of hydrophilic toxins with metal-mediated free radical production. Various metals can be involved in the toxin congeners, and the purified toxins are highly labile. These toxins can adversely affect mammalian cells as well as fish. Toxic strains are capable of killing fish by both toxins and physical attack from feeding upon epidermis and other tissues. Non-inducible strains do not produce sufficient toxin to kill fish, but some are capable of causing larval fish death by physical attack. From 1991 to 1998, Pfiesteria spp. were linked to major kills of juvenile Atlantic menhaden ( Brevoortia tyrannus ), mostly at densities of ≥4(3) × 10 2 to 10 3 (rarely, 10 4 ) flagellate cells mL −1 . These kills mainly occurred in the second largest and largest estuaries on the U.S. mainland, especially two main tributaries of the Albemarle-Pamlico Estuarine System, following decades of hurricane-free conditions. Between kills, Pfiesteria abundance was low in surface waters ( −1 ), and the available evidence suggests that the populations were mostly in the lower water column and within surficial sediments. Apparently highly sensitive to scouring effects from major storms, Pfiesteria populations have been sparse in the affected estuaries since several hurricanes struck the Albemarle-Pamlico in the late 1990s. Recent research highlights include characterization of a novel group of Pfiesteria toxins, culture of a toxigenic strain on a sterile fish cell line, axenic culture on a semi-defined medium, the discovery of a new mode of heterotrophic feeding in dinoflagellates as manifested by Pfiesteria , and other advances in understanding the nutritional ecology and prey acquisition of these harmful dinoflagellates.
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Taxonomy of Pfiesteria (Dinophyceae)
Harmful Algae, 2006Co-Authors: Harold G. Marshall, Matthew W. Parrow, Elle H. Allen, Valerie M. Knowlton, Parke A. Rublee, Malte Elbrachter, Paul E. Hargraves, Jo Ann M. Burkholder, Wayne L. Hynes, Todd A. EgertonAbstract:The dinoflagellate species originally described as Pfiesteria shumwayae Glasgow et Burkholder, recently transferred to a new genus, PseudoPfiesteria Litaker et al., is reclassified into the redefined genus Pfiesteria Steidinger et Burkholder, as Pfiesteria shumwayae within the order Peridiniales. This change is based upon consideration of a compilation of previous and new morphological analyses and molecular phylogenetic analyses. Morphological analysis with scanning and transmission electron microscopy supports previous findings except in the sulcal area. In the cells examined, the sulcus is partly concealed by the peduncle cover plate (p.c.), which originates at the right side of the sulcus along the left side of the 6c and 5? plates. The fine structure of the p.c. appears similar to that of other thecal plates. The 1? plate can also extend slightly over the sulcus. Transmission electron microscopy revealed that Pfiesteria shumwayae can have at least six sulcal plates; the number remains uncertain and may vary. The sulcal plates of this small, delicately thecate species have not been clearly discerned by scanning electron microscopy of membrane-stripped and/or suture-swollen cells. The Kofoidian thecal plate formula for the genus Pfiesteria is Po, cp, X, 4', la, 5–6?, 6c, p.c., ?s, 5?, 0p, 2?'. The monophyletic grouping of ?Pfiesteria-like? taxa within the order Peridiniales, as well as the grouping of Pfiesteria piscicida and Pfiesteria shumwayae within the same genus, is also supported by the preponderance of previous molecular evidence, and by the phylogenetic trees contributed in the present analysis. Pfiesteria appears to be closely related to as-yet informally described cryptoperidiniopsoids and calcareous dinoflagellates such as Thoracosphaera; thus, the family classification requires revision that is beyond the scope of this study.
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Characterization of Pfiesteria ichthyocidal activity.
Applied and environmental microbiology, 2005Co-Authors: Andrew S. Gordon, Harold G. Marshall, Michael A Mallin, Kathryn J. Coyne, Alan J. Lewitus, Sandra E. Shumway, Parke A. RubleeAbstract:Drgon et al. (4) concluded that the “aquarium bioassay format is unsuitable to accurately assess the ichthyocidal activity of Pfiesteria spp.” and “ichthyocidal activity of Pfiesteria spp. is mostly due to direct interactions of the zoospores with fish skin and gill epithelia rather than to soluble factors.” These conclusions are not justified, because microbial community analyses of control aquariums were not included and previous studies (5, 8) that utilized similar experimental approaches and found significant (100%) fish death attributable to soluble factors were overlooked. It is known a priori that aquariums containing fish or inoculated with whole sediment will develop a complex microbial community. This has been previously noted for the aquarium bioassay for Pfiesteria ichthyotoxicity (2). Given this complexity, a key factor in attributing fish death to Pfiesteria spp. is the difference between Pfiesteria- or sediment-inoculated aquariums and corresponding controls.
Patricia A. Tester - One of the best experts on this subject based on the ideXlab platform.
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description of a new genus of Pfiesteria like dinoflagellate luciella gen nov dinophyceae including two new species luciella masanensis sp nov and luciella atlantis sp nov
Journal of Phycology, 2007Co-Authors: Patrice L. Mason, Karen A. Steidinger, Mark W. Vandersea, Kimberly S Reece, Nancy A. Stokes, Wayne R Litaker, Hae Jin Jeong, Jae Yeon Park, Steve Kibler, Patricia A. TesterAbstract:A new genus of Pfiesteria-like heterotrophic dinoflagellate, Luciella gen. nov., and two new species, Luciella masanensis sp. nov. and Luciella atlantis sp. nov., are described. These species commonly occur with other small (<20 μm) heterotrophic and mixotrophic dinoflagellates in estuaries from Florida to Maryland and the southern coast of Korea, suggesting a possible global distribution. An SEM analysis indicates that members of the genus Luciella have the enhanced Kofoidian plate formula of Po, cp, X, 4′, 2a, 6″, 6c, PC, 5+s, 5‴, 0p, and 2″″. The two four-sided anterior intercalary plates are diamond shaped. The genus Luciella differs from the other genera in the Pfiesteriaceae by a least one plate in the plate tabulation and in the configuration of the two anterior intercalary plates. An SSU rDNA phylogenetic analysis confirmed the genus as monophyletic and distinct from the other genera in the Pfiesteriaceae. The morphology of Luciella masanensis closely resembles Pfiesteria piscicida Steid. et J. M. Burkh. and other Pfiesteria-like dinoflagellates in size and shape, making it easily misidentified using LM. Luciella atlantis, in contrast, has a more distinctive morphology. It can be distinguished from L. masanensis and other Pfiesteria-like organisms by a larger cell size, a more conical-shaped epitheca and hypotheca, larger rhombic-shaped intercalary plates, and an asymmetrical hypotheca. The genus Luciella is assigned to the order Peridiniales and the family Pfiesteriaceae based on plate tabulation, plate pattern, general morphology, and phylogenetic analysis.
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identification of Pfiesteria piscicida dinophyceae and Pfiesteria like organisms using internal transcribed spacer specific pcr assays1
Journal of Phycology, 2003Co-Authors: Wayne R Litaker, Karen A. Steidinger, Mark W. Vandersea, Steven R. Kibler, Kimberly S Reece, Nancy A. Stokes, David F. Millie, Brian J. Bendis, Ryan J. Pigg, Patricia A. TesterAbstract:The putative harmful algal bloom dinoflagellate, Pfiesteria piscicida (Steidinger et Burkholder), frequently co-occurs with other morphologically similar species collectively known as Pfiesteria -like organisms (PLOs). This study specifically evaluated whether unique sequences in the internal transcribed spacer (ITS) regions, ITS1 and ITS2, could be used to develop PCR assays capable of detecting PLOs in natural assemblages. ITS regions were selected because they are more variable than the flanking small subunit or large subunit rRNA genes and more likely to contain species-specific sequences. Sequencing of the ITS regions revealed unique oligonucleotide primer binding sites for Pfiesteria piscicida , Pfiesteria shumwayae (Glasgow et Burkholder), Florida “Lucy” species, two cryptoperidiniopsoid species, “H/V14” and “PLO21,” and the estuarine mixotroph, Karlodinium micrum (Leadbetter et Dodge). These PCR assays had a minimum sensitivity of 100 cells in a 100-mL sample (1 cell·mL � 1 ) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA. DNA purification and aspects of PCR assay development, PCR optimization, PCR assay controls, and collection of field samples are discussed.
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104 identification of Pfiesteria piscicida dinophyceae and Pfiesteria like organisms using its specific pcr assays
Journal of Phycology, 2003Co-Authors: R. Wayne Litaker, Karen A. Steidinger, Mark W. Vandersea, Steven R. Kibler, Patricia A. Tester, Kimberly S Reece, Nancy A. Stokes, David F. Millie, Brian J. Bendis, Ryan J. PiggAbstract:The putative harmful algal bloom dinoflagellate, Pfiesteria piscicida, frequently co-occurs with other morphologically similar species collectively known as Pfiesteria-like organisms (PLOs). This study specifically evaluated whether unique sequences in the ribosomal internal transcribed spacer regions (ITS1 and ITS2) could be used to develop PCR assays capable of detecting PLOs in natural assemblages. ITS regions were selected because they are more variable than the flanking small subunit (SSU) or large subunit (LSU) ribosomal RNA genes and more likely to contain species-specific sequences. Sequencing of the ITS regions revealed unique oligonucleotide primer binding sites for Pfiesteria piscicida, Pfiesteria shumwayae, Florida “Lucy” species, two cryptoperidiniopsoid species, “H/V14” and “PLO21,” and the estuarine mixotroph, Karlodinium micrum. These PCR assays had a minimum sensitivity of 100 cells in a 100 mL sample (1 cell mL-1) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA.
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104 Identification of Pfiesteria Piscicida (Dinophyceae) and Pfiesteria‐Like Organisms Using its‐Specific PCR Assays
Journal of Phycology, 2003Co-Authors: R. Wayne Litaker, Karen A. Steidinger, Mark W. Vandersea, Steven R. Kibler, Patricia A. Tester, Kimberly S Reece, Nancy A. Stokes, David F. Millie, Brian J. Bendis, Ryan J. PiggAbstract:The putative harmful algal bloom dinoflagellate, Pfiesteria piscicida, frequently co-occurs with other morphologically similar species collectively known as Pfiesteria-like organisms (PLOs). This study specifically evaluated whether unique sequences in the ribosomal internal transcribed spacer regions (ITS1 and ITS2) could be used to develop PCR assays capable of detecting PLOs in natural assemblages. ITS regions were selected because they are more variable than the flanking small subunit (SSU) or large subunit (LSU) ribosomal RNA genes and more likely to contain species-specific sequences. Sequencing of the ITS regions revealed unique oligonucleotide primer binding sites for Pfiesteria piscicida, Pfiesteria shumwayae, Florida “Lucy” species, two cryptoperidiniopsoid species, “H/V14” and “PLO21,” and the estuarine mixotroph, Karlodinium micrum. These PCR assays had a minimum sensitivity of 100 cells in a 100 mL sample (1 cell mL-1) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA.
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Responses of phytoplankton and Pfiesteria-like dinoflagellate zoospores to nutrient enrichment in the Neuse River Estuary, North Carolina, USA
Marine Ecology Progress Series, 2000Co-Authors: James L. Pinckney, Hans W. Paerl, Elin Haugen, Patricia A. TesterAbstract:The recently described toxic dinoflagellate Pfiesteria piscicida and morphologically similar Pfiesteria-like dinoflagellates have become a major water quality issue with possible fish mortality and reported human health implications. The linkages between accelerated nutrient loading, eutrophication, and the proliferation of this group of dinoflagellates, however, are not well established for natural systems. Phytoplankton primary production may provide a key link between nutrient inputs and potential outbreaks of Pfiesteria-like biflagellated zoospores in the Neuse River Estuary, North Carolina. The impacts of nutrient (NO 3 - -nitrogen and PO 4 3- -phosphorus) supply rates, sediment-water column exchange, water column mixing, and phytoplankton prey on the abundance of Pfiesteria-like non-toxic biflagellated zoospores were examined seasonally over 18 mo in a region of the Neuse River Estuary where fish-kills attributed to P. piscicida have been reported. Phytoplankton community responses to the manipulated variables indicated that biomass and productivity were consistently N limited. Dominant phytoplankton taxa, including chlorophytes, diatoms, and cyanobacteria, exhibited significant biomass increases in response to N (as NO 3 - ) additions. Phosphate (as PO 4 3- ) enrichments did not additionally influence the relative growth and abundance of individual algal groups. Pfiesteria-like zoospores did not exhibit significant increases in abundance in response to mixing, sediment, or nutrient-addition treatments. Seasonally, the number of Pfiesteria-like zoospores was positively correlated with phytoplankton biomass and productivity. The abundance of Pfiesteria-like zoospores followed general trends in phytoplankton biomass and production in the estuary, suggesting that the source of organic nutrition supporting growth is likely phytoplankton based. Lowering of phytoplankton growth and bloom potentials through proposed nutrient-input reduction strategies should translate into broad-based water quality improvement, including declines in the frequency and magnitudes of nuisance algal blooms, O 2 depletion, and associated fish and shellfish mortality in the Neuse River Estuary.
David W. Oldach - One of the best experts on this subject based on the ideXlab platform.
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Research Occupational Exposure to Pfiesteria Species in Estuarine Waters Is Not a Risk Factor for Illness
2013Co-Authors: J. Glenn, Holly A. Bowers, Lynn M. Grattan, Leslie A. Wilson, Walter A. Meyer, Robert Mccarter, Richard J. Hebel, Diane L. Matuszak, David W. OldachAbstract:BACKGROUND: Exposure to the dinoflagellate Pfiesteria has, under certain circumstances, been associated with deficits in human learning and memory. However, uncertainties remain about the health risk of chronic, low-level exposures (as seen among occupationally exposed commercial fishermen), particularly in light of studies suggesting that Pfiesteria strains are widespread in the estuarine environment in the U.S. mid-Atlantic region. METHODS: We selected an initial cohort of 152 persons, including 123 persons with regular, occupational exposure to the Chesapeake Bay; 107 of the cohort members were followed for the full four summer “seasons ” of the study. Cohort members were questioned biweekly about symptoms, and data were collected about the areas of the bay in which they worked. These latter data were matched with data on the presence or absence of Pfiesteria in each area, based on polymerase chain reaction analysis of> 3,500 water samples. Cohort members underwent neuropsychological testing at the beginning and end of each summer season. RESULTS: No correlation was found between work in an area where Pfiesteria was identified and specific symptomatology or changes on neuropsychological tests. CONCLUSIONS: Although high-level or outbreak-associated exposure to Pfiesteria species (or specific strains within a species) may have an effect on health, routine occupational exposure to estuarine environments in which these organisms are present does not appear to pose a significant health risk. KEY WORDS: commercial fishermen, dinoflagellates, environmental toxins, neuropsychological testing, occupational health, Pfiesteria. Environ Health Perspect 114:1038–1043 (2006)
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Use of Molecular Probes to Assess Geographic Distribution of Pfiesteria Species
2013Co-Authors: Parke A. Rublee, Jo Ann M. Burkholder, David W. Oldach, Torstein Tengs, Jason W. Kempton, Eric F. Schaefer, Coy Allen, Janera Harris, Holly Bowers, H. B. GlasgowAbstract:We have developed multiple polymerase chain reaction (PCR)-based methods for the detection of Pfiesteria sp. in cultures and environmental samples. More than 2,100 water and sediment samples from estuarine sites of the U.S. Atlantic and gulf coasts were assayed for the presence of Pfiesteria piscicida Steidinger & Burkholder and Pfiesteria shumwayae Glasgow & Burkholder by PCR probing of extracted DNA. Positive results were found in about 3 % of samples derived from routine monitoring of coastal waters and about 8 % of sediments. The geographic range of both species was the same, ranging from New York to Texas. Pfiesteria spp. are likely common and generally benign inhabitants of coastal areas, but their presence maintains a potential for fish and human health problems. Key words: molecular probes, PCR, Pfiesteria, toxic dinoflagellates. — Enviro
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Associations between fish health and Pfiesteria spp. in Chesapeake Bay and mid-Atlantic estuaries
Harmful Algae, 2006Co-Authors: P.j. Tango, Holly A. Bowers, R. Magnien, D. Goshorn, Bruce Michael, R. Karrh, David W. OldachAbstract:Abstract In response to concerns that there may be an association between harmful algal bloom (HAB) species and fish health, including the widespread use of fish health as one indicator of a possible HAB warranting further investigation, evidence for such an association was evaluated in Chesapeake Bay and other mid-Atlantic estuaries (1999–2001). A statistical approach was used, without invoking causality, to test whether there is an association between the prevalence of externally-visible lesions in fish populations above background levels and the presence of Pfiesteria spp. in co-located water and fish samples. Externally visible anomalies (e.g. ulcers, necrosis, parasites, etc.) were recorded for Atlantic menhaden ( Brevoortia tyrannus ) and all other fish collected. Polymerase chain reaction (PCR) techniques were used to test for the presence of Pfiesteria spp. in water samples collected at routine and rapid response sampling events. No actively toxic Pfiesteria was found during this study. Fine-scale (within a given sample site) and broad-scale (estuary-wide sampling) comparisons showed positive associations between externally-visible fish lesions in menhaden populations and the presence of Pfiesteria spp. in co-located samples. Logistic regression modeling of Pfiesteria detection probabilities as a function of prevalence of menhaden with lesions was significant ( P = 0.0096). Reductions in the false positive (tests indicating Pfiesteria presence when its absent) and false negative (tests indicating Pfiesteria is absent when it is actually present) rates occurred when the minimum sample size threshold increased from 1 to 30 fish ( P = 0.003–0.001). This association served as a useful field indicator of potential HAB activity that could warrant further field investigation and testing.
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Detection of Pfiesteria spp. by PCR in surface sediments collected from Chesapeake Bay tributaries (Maryland)
Harmful Algae, 2006Co-Authors: Holly A. Bowers, Parke A. Rublee, Eric F. Schaefer, Robert E. Magnien, Bruce Michael, T. Mark Trice, David M. Goshorn, David W. OldachAbstract:In 1997 blooms of Pfiesteria piscicida occurred in association with fish kills and human health problems in tributaries of the Chesapeake Bay (Maryland) and the scientific and media response resulted in large economic losses in seafood sales and tourism. These events prompted the Maryland Department of Natural Resources (MDNR) to begin monitoring for Pfiesteria spp. in water column samples. Real-time PCR assays targeted to the 18S rRNA gene were developed by our laboratories and utilized in conjunction with traditional microscopy and fish kill bioassays for detection of these organisms in estuarine water samples. This monitoring strategy aided in determining temporal and spatial distribution of motile forms of Pfiesteria spp. (i.e. zoospores), but did not assess resting stages of the dinoflagellates’ life cycle. To address this area, a 3-year study was designed using real-time PCR assays for analysis of surface sediment samples collected from several Chesapeake Bay tributaries. These samples were tested with the real-time PCR assays previously developed by our laboratories. The data reported herein suggest a strong positive association between presence of Pfiesteria spp. in the sediment and water column, based on long-term water column monitoring data. P. piscicida is detected more commonly in Maryland’s estuarine waters than Pfiesteria shumwayae and sediment ‘cyst beds’ may exist for these organisms.
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Occupational exposure to Pfiesteria species in estuarine waters is not a risk factor for illness.
Environmental health perspectives, 2006Co-Authors: J. Glenn Morris, Holly A. Bowers, Lynn M. Grattan, Leslie A. Wilson, Walter A. Meyer, Diane L. Matuszak, Robert J. Mccarter, J. Richard Hebel, David W. OldachAbstract:BackgroundExposure to the dinoflagellate Pfiesteria has, under certain circumstances, been associated with deficits in human learning and memory. However, uncertainties remain about the health risk...