Cyanobacteria

Question 1

What conditions favour algal blooms?

Answer 1

Increased temp, light, high nutrient concentrations, still waters

Question 2

What are cyanobacteria?

Answer 2

photosynthetic prokaryotes, inhabit diverse habitats

Question 3

What are the routes of exposure for cyanotoxins?

Answer 3

skin contact, inhalation, ingestion, haemodialysis,

Question 4

What are the four types of cyanotoxins talked about in class?

Answer 4

Anatoxin-a, anatoxin-a(s), Microcystin, cylindrospermopsin

Question 5

What are the examples of hepatotoxins talked about in class?

Answer 5

Microcystins, and cylindrospermopsin

Question 6

What are the producing genera of microcytsins?

Answer 6

anabaena, microcystis, plankothrix and pseudoanabaena

Question 7

What is the structure of the microcystins?

Answer 7

cyclic peptides with several amino acids

Question 8

What is the MOA of microcystins?

Answer 8

inhibition of protein phosphatase 1 and 2, disrupts cell signalling and potentially leads to cell death

Question 9

What is one property of microcystins that make it concerning?

Answer 9

Can bioaccumulate in marine organisms

Question 10

How do we diagnose microcystin poisoning?

Answer 10

Protein phosphatase inhibition assay

Question 11

What are the early and late symptoms of animals of microcystin poisoning?

Answer 11

Early: shallow breathing, diarrhea, vomiting, increased bilirubin and coagulation times, alanine transaminase, alkaline phosphatase and creatine kinase activity, hypoglycemia, hyperphosphatemia and hyperkalemia

Late: icterus, hemorrage, hepatic necrosis, renal tubular necrosis, increased total bilirubin concentration

Question 12

What are the symptoms in humans after having microcystin poisoning?

Answer 12

nausea, vomiting, headache, muscle weakness, increased bilirubin, and aspartate aminotransferase

Question 13

What are the species that produce cylindrospermopsin?

Answer 13

cylindrospermopsis raciborskii, aphanizomenon ovalisporum and umezakia natans

Question 14

What is the structure of cylindrospermopsin?

Answer 14

Alkaloid with tricyclic ring structure

Question 15

What is the LD 50 of cylindrospermopsin?

Answer 15

5mg/kg

Question 16

Whats the MOA of cylindospermopsin?

Answer 16

inhibiting protein synthesis through DNA fragmentation-possible p450 actication- damages hepatocytes, impaired liver and kidney functions

Question 17

What are the effects of cylindrospermopsin poisoning in humans?

Answer 17

vomiting, headache, fever, bloody diarrhea, hepatomegaly and renal damage

Question 18

What are the acute symptoms for animals of cylindrospermopsin poisoning?

Answer 18

liver damage, lung damage (if inhaled), renal tubular necrosis, ulceration in GI tract, atrophy of lymphoid tissues in spleen and thymus, hemorrhages in the heart

Question 19

What are some chronic symptoms in animals for cylindrospermopsin poisoning>

Answer 19

genotoxicity, mild liver and kidney damage, potentially reproductive damage

Question 20

Where is cylindrospermopsin most prevalent in the world?

Answer 20

Asia

Question 21

What are the neurotoxins described in class?

Answer 21

Anatoxin-a, homoanatoxin and anatoxin-a(s)

Question 22

What are the genera that produce anatoxin-a

Answer 22

Anabaena, aphanizomenon, microcystis, oscillatoria

Question 23

What are the genera that produce anatoxin-a(s)

Answer 23

anabaena, oscillatoria

Question 24

What is the structure of anatoxins?

Answer 24

structurally similar alkaloids

Question 25

What is the MOA of anatoxin-a and homoanatoxin?

Answer 25

nicotinic agonists-mimic acetylcholine, constant flow of sodium ions, and repetitive action potentials

Question 26

What is the MOA of anatoxin-a(s)

Answer 26

irreversibly binds acetylcholinesterase

Question 27

What are the early effects of anatoxin poisoning in animals?

Answer 27

muscle fasciculations, tremors, rigidity, and eventual paralysis/resp. failure (death)

Question 28

What is the LD50 for anatoxin in humans?

Answer 28

250ug/kg

Question 29

What are the two dermatotoxins discussed in class?

Answer 29

lyngbyatoxins and aplysiatoxins

Question 30

What species produce lyngbyatoxins and where is it found?

Answer 30

Lyngbya majuscule and found in tropical and subtropical regions

Question 31

What is the structure of lyngbyatoxins?

Answer 31

polycyclic diterpenes

Question 32

What is the MOA of lyngbyatoxins?

Answer 32

contains functional groups that allow it to interact with biological membranes and other cellular structures

Question 33

What are the species that produce aplysiatoxins?

Answer 33

L. majuscula, schizothrix calcicola and phormdium species

Question 34

What is the structure of aplysiatoxins and what is special about this toxin?

Answer 34

polycyclic diterpenes, ability to undergo structural modifications

Question 35

What is the MOA of aplysiatoxins?

Answer 35

activation of protein kinase C which leads to abnormal cell signalling, and cell proliferation

Question 36

What are the acceptable levels of microcystins in drinking water and recreational water?

Answer 36

1ug/L in drinking water, 10ug/L in recreational

Question 37

What is the most common and most toxic microcystin congener?

Answer 37

MC-LR-leucine arginine amino acid present

Question 38

Why are lakes prone to algal blooms?

Answer 38

Urea fertilizer and increasing warmth

Question 39

What was special about the dugouts in Saskatchewan?

Answer 39

MC levels were not detectable often

Question 40

Where is one of the habitats with the most concentrated MC levels and what is a theory behind that?

Answer 40

Wetlands, high levels of TN and TP but low ratio of the two

Question 41

What are natural MC degradation strategies?

Answer 41

sunlight, bacteria, fungi, and plants