Pfiesteria piscicida

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Pfiesteria piscicida
Pfiesteria piscicida

Pfiesteria piscicida

Systematics
without rank: Dinoflagellates
Order : Phytodiniales
Family : Pfiesteriaceae
Genre : Pfiesteria
Type : Pfiesteria piscicida
Scientific name
Pfiesteria piscicida
Steidinger & JM Burkholder

Pfiesteria piscicida is a unicellular plankton organism belonging to the dinoflagellate group , which was responsible for many harmful algal blooms in the 1980s and 1990s off the coasts of North Carolina and Maryland . The species name piscicida is made up of pisces (Latin for "fish") and caedere (Latin for "to kill") and means to kill fish.

Life cycle

The complex life cycle of Pfiesteria piscicida according to Burkholder: red = poisonous stages, yellow = possibly poisonous stages, blue = inactive stages

Early research revealed a very complex life cycle for Pfiesteria piscicida with up to 24 different stages from cysts , multiple amoeboid forms, and poisonous zoospores . The transitions between the stages depend on the environmental conditions, for example the availability of feed. This complicated life cycle is now controversial, as further research has shown a simple haplontic life cycle with no toxic amoeba stages. The amoeba observed on the affected fish could be another, uninvolved species.

Toxicity

It was initially suspected that Pfiesteria killed fish with a poison released into the water in order to paralyze the prey. This hypothesis has been challenged because in some experiments no poison isolated and no poisonous effect could be observed. Ultimately, the toxicity seems to depend on the strain observed and the analytical method used. PCR analyzes indicate that the organism has no genes for the synthesis of polyketides , the typical poisons of toxic dinoflagellates. The poison has now been isolated and characterized as a metal complex that releases short-lived free radicals . It was also possible to explain how non-toxic stages change into toxic ones.

On microplastic , Pfiesteria piscicida achieved a density about fifty times as high as in the surrounding water and about two to three times as high as on comparable driftwood floating in the water .

Effects on humans

The effects of P. piscicida poison on humans have so far been little researched. At a conference at the American Centers for Disease Control (CDC) in Atlanta in September 1997 , the participants unanimously characterized the clinical symptoms of poisoning with Pfiesteria poisons. The symptoms include:

  • Memory loss
  • confusion
  • burning pain on direct skin contact with the water
  • other symptoms such as headache, rash, blurred vision, breathing disorders, muscle cramps, diarrhea, vomiting and others.

Pfiesteria poison was held responsible for damage to the health of people who had close contact with water in which P. piscicida was present. A study by the Maryland Department of Health and Hygiene described 146 cases of P. piscicida- related illness , most of whom were fishermen or similar professions. Experiments on rats showed a slowdown in learning, but no impairment of memory.

Discovery story

Pfiesteria piscicida was first discovered in the fish cultures at the NCSU around 1988 and clearly identified. It was discovered in aquariums where experiments were carried out on fish. The fish there came from many regions of the world, but all fell ill with the same, hitherto unknown disease. JoAnn M. Burkholder, her colleague Howard B. Glasgow, as well as Cecil Hobbs and other members of the NCSU water botany laboratory were called to learn more about this activity of the small dinoflagellate and its life cycle. Researchers worked with fish pathologists Edward J. Noga and Stephen A. Smith to understand the effects of the microorganism on fish health. Dr. Karen Steidinger and colleagues at the Florida Marine Research Institute (now the Fish and Wildlife Research Institute ) helped these researchers classify the dinoflagellates taxonomically . They came to the conclusion that Pfiesteria piscicida represented a kind of a new family of its own , for which they also postulated a new order (Dinamoebales).

Individual evidence

  1. ↑ Burkholder JM & Glasgow HB (1997): Trophic controls on stage transformations of a toxic ambush-predator dinoflagellate . J. Eukaryote. Microbiol. Vol. 44, Issue 3, pp. 200-2005. doi : 10.1111 / j.1550-7408.1997.tb05700.x
  2. ↑ Litaker RW, Vandersea MW, Kibler SR, Madden VJ, EJ Noga, testers PA (2002). Life cycle of the heterotrophic dinoflagellate Pfiesteria piscicida (Dinophyceae) . Journal of Phycology, Vol 38, Iss. 3, pp. 442-463. doi : 10.1046 / j.1529-8817.2002.01242.x
  3. ↑ Peglar MT, Nerad TA, Anderson OR, Gillevet PM (2004). Identification of amoebae implicated in the life cycle of Pfiesteria and Pfiesteria-like dinoflagellates . J. Eukaryote. Microbiol., Vol. 51, Issue 5, pp. 542-552. doi : 10.1111 / j.1550-7408.2004.tb00290.x
  4. ↑ https://www.scientificamerican.com/article/study-casts-doubt-on-cell
  5. ↑ Burkholder JM, Gordon AS, Moeller PD et al. (2005). Demonstration of toxicity to fish and to mammalian cells by Pfiesteria species: comparison of assay methods and strains . Proc. Natl. Acad. Sci. USA, Vol. 102, Issue 9, pp.3471-3476. doi : 10.1073 / pnas.0500168102
  6. ↑ Berry JP, Reece KS, Rein KS et al. (2002). Are Pfiesteria species toxicogenic? Evidence against production of ichthyotoxins by Pfiesteria shumwayae. Proc. Natl. Acad. Sci. USA, Vol.99, Iss.17, pp.10970-10975. doi : 10.1073 / pnas.172221699
  7. ^ Moeller PD, Beauchesne KR, Huncik KM, Davis WC, Christopher SJ, Riggs-Gelasco P, Gelasco AK (2007). Metal complexes and free radical toxins produced by Pfiesteria piscicida . Environ. Sci. Technol., Vol. 41, Issue 4, pp. 1166-1172. doi : 10.1021 / es0617993
  8. ^ Marie Therese Kettner, Sonja Oberbeckmann, Matthias Labrenz, Hans-Peter Grossart: The Eukaryotic Life on Microplastics in Brackish Ecosystems. In: Frontiers in Microbiology. 10, 2019, doi : 10.3389 / fmicb.2019.00538 .
  9. ^ Symptoms of Pfiesteria piscicida infection . rightdiagnosis.com, April 17, 2015
  10. ↑ Archived copy ( Memento of the original dated December 21, 2006 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Report on Pfiesteria and Related Harmful Blooms: Natural Resource and Human Health Concerns, Congressional Research Service @1@ 2Template: Webachiv / IABot / www.ncseonline.org

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