Blue-Green Algae

Question 1

When is blue green-algae seen? where?

Answer 1

hot summer months
year to year variation

often blown to shore on surface

Question 2

Why is it important to sample the water immediately?

Answer 2

species can change within 24h

other toxins can be present in stagnant water: bacteria, protozoa, (clostridium botulinum)

Question 3

What factors affect toxicity?

Answer 3

species of algae
bacteria in bloom
growth conditions (ph, N/P ratio (low ratio favors), sunlight and temp, accumulation, decomposition (lyse and release toxin)

Question 4

what sample can you use for ID?

Answer 4

formalin, fresh or frozen (<24h) can be eval lethality using mouse assay

Question 5

what species are there?

Answer 5

microcystis (irregular) - Mike - 1hr
anabena (separate filaments) - anna most common (3mins dead)
aphanizomenon (packets of filaments) - fannie - very rare

Question 6

What toxin is in anabena and what are the properties?

Answer 6

anatoxin-a (alkaloid)

• very fast death factor
• heat labile
• post synaptic depolarizing NM blocker
• presynaptic effects as well
• nicotinic agonist
• anticholinesterase activity (nicotinic and muscarinic effects)

Question 7

What are the clinical signs of anatoxin?

Answer 7

paralysis
tremors
 convulsions
salivation, vomiting, diarrhea
dyspnea (abdominal breathing)
death in 4min

Question 8

what is the pathology of anatoxin?

Answer 8

agonal hemorrhage and congestion
autolysis
death by resp arres

Question 9

what is the Dx of anatoxin?

Answer 9

mouth bioassay

swollen liver

Question 10

what is the treatment for anatoxin?

Answer 10

calves need to be kept alive with artifical resp fro 30h
AC
atropine = some relief
but doesnt prevent death irreversibly bound to cholinesterase enzyme

Question 11

What toxin is in microcystis and what are the components?

Answer 11

microcystin

• peptide hepatoxin (liver necrosis, apoptosis)
• peptide neurotoxin (post synaptic NM blocker)

Question 12

What is the MOa of microcystin?

Answer 12

hyperphosphorylation of proteins and keratin
tumor promotor
hepatotoxin

Question 13

what are the clinical signs of microcystin?

Answer 13

death within 1h

GIT (vomiting, hemorrhagic diarrhea)

hepatic (icterus, photosensitization in survivors)

CNS (convulsions

Question 14

What pathology is seen with microcystin?

Answer 14

liver - swollen, mottled, congestion, hemorrhage, necrosis, apoptosis
kidney - tubular nephritis
lung - hemorrhage
heart - degeneration

Question 15

What is the Dx for microcystin?

Answer 15

mouse bioassay - water sample
path - hepatic syndrome
liver enzymes elevated within 45min

Question 16

What is the treatment for microcystin?

Answer 16

AC

supportive (dehydration and shock)

Question 17

What is the toxin in aphanizomenon and what components does it have? MOA?

Answer 17

aphantoxin
a - saxitoxin (inhibits sodium channel, exonal transmission)
b - mixture (neuromuscular action, inhibition of nerve conduction)

no parasympathomimetic

Question 18

What are the clinical signs of aphantoxin?

Answer 18

paralysis
death by resp depression
depression of resp centre

Question 19

What is the path of aphantoxin?

Answer 19

no lesions

Question 20

What is the treatment of aphantoxin?

Answer 20

symptomatic
SC
mix of sodium nitrate and sodium thiosulfate

Question 21

What can be done for prevention for blue-green?

Answer 21

treat water with Cu-sulfate (1-2 ppm)
diquat herbicide
shade
lime (removes phosphate, increasing NP ratio)
duckweed (shades water on surface)
chlorine -shocks pond
increase NP ratio - concern nitrate poisoning