Pfiesteria (Algal Blooms) Flashcards
Eutrophication
excess nitrogen and phosphorus in lakes due to run-off
Toxic algal blooms bacteria
cyanobacteria (blue-green algae)
toxic, photosynthetic bacteria (mostly fresh water)
toxic protozoa
diatoms: amnesic shellfish poisoning
dinoflagellates: red tide
cyanobacteria
blue-green algae
photosynthetic bacteria
endosymbionts
cyanotoxins
What toxin is produced by cyanobacteria?
BMAA neurotoxin
BMAA neurotoxin mechanism
Can be misincorporated into nascent proteins in place of L-serine, possibly causing protein misfolding and aggregation.
Binding activity of BMAA inhibited in the presence of excess L-serine
What is pseudo-nitzschia associated with?
Amnesic Shellfish Poisoning
What does pseudo nitzschia produce?
domoic acid = amnestic toxin
How does domoic acid damage neurons
neurotoxin analogue of glutamate, damages neurons through influx of Ca2+; causing short-term memory loss
What makes red tide?
Karenia brevis
What toxin does Karenia brevis make?
Brevetoxins
what do brevetoxins cause?
gastroenteritis and respiratory symptoms
What disease is associated with brevetoxins?
Neurotoxic Shellfish Poisoning (NSP)
The genera Gambierdiscus and Prorocentrum cause what disease?
Ciguatera Fish Poisoning (CFP)
Ciguatoxin exposure symptoms
causes gastro, neuro and cardio problems
The genera Diophysis causes what disease?
Diarrhetic shellfish poisoning (DSP)
What toxin does Diophysis make?
okadaic acid
The generas Alexandrium and Gymnodinium cause what disease?
Paralytic Shellfish Poisoning (PSP)
what toxin class does alexandrium and gymnodinium make?
saxitoxins
What are the major algal toxin associated diseases on the east coast? (3)
Neurotoxic shellfish poisoning, ciguatera fish poisoning, and pfiesteria complex
Where is Pfiesteria piscicida found?
mid-atlantic and SE USA
What does Pfiesteria cause? (primarily)
massive fish kills with lesions
How is Pfiesteria transmitted to humans?
through water exposure
Where/When was Pfiesteria first discovered?
During the middle of an outbreak (1991-1997) in 1992 on the Pamlico and Neuse Rivers in North Carolina. Primarily on the Neuse River
Where else has Pfiesteria been found?
Maryland – Potomac River
Pfiesteria lab exposure symptoms:(6)
respiratory and eye irritation skin rashes gastroenteritis cognition deficits personality changes
Pfiesteria acute env. exposure symptoms:
respiratory and eye irritation, headaches, and/or sore throat within 4 hours of exposure
What induces the growth of non-toxic Pfiesteria?
agricultural waste
what is needed in the environment to induce toxicity in zoospores?
presence of fish induce toxicity in zoospores
Fish-induced amoeboid and cyst stages to become zoospores that then become toxic
What is the effect of Pfiesteria toxin(s) on fish?
paralyze fish, disrupt osmotic balance, cause tissue damage, death
What are some of the current Pfiesteria research outcomes?
controversial life cycle (Axenic)
Toxicity disputed
rapid PCR diagnostic developed
Environmental reforms - improved disposal of ag waste
What species is most prevalent in Florida?
Karenia brevis
