Lecture 27 10/22/24

Question 1

Which bacteria can spread through seafood?

Answer 1

-Aeromonas spp.
-Mycobacteria spp.
-Vibrio spp.
-Clostridium spp.

Question 2

What are the characteristics of Aeromonas spp.?

Answer 2

-gram negative
-motile
-facultative anaerobe
-ubiquitous in environment
-infect stressed fish

Question 3

How is Aeromonas transmitted?

Answer 3

-eating raw/undercooked fish
-cuts and abrasions

Question 4

What are the clinical signs of Aeromonas?

Answer 4

-nausea
-diarrhea
-vomiting
-septicemia
-wound infection
-necrotizing fasciitis

Question 5

What are the characteristics of Mycobacteria spp.?

Answer 5

-gram positive
-non-motile
-acid-fast rods
-slow growing/difficult to culture
-fish can be carriers, acutely infected, or chronically infected

Question 6

What is the main clinical sign of Mycobacteria infection?

Answer 6

ulcerative or raised granulomatous lesions on extremities

Question 7

What are the characteristics of Vibrio spp.?

Answer 7

-gram negative
-facultative anaerobe
-rod shaped
-natural habitat is coastal waters where oysters live
-higher conc. between May and October

Question 8

How does Vibrio bacteria transmit?

Answer 8

-eating raw or undercooked oysters
-puncture wound penetrations

Question 9

What are the clinical signs of Vibrio vulnificus infection?

Answer 9

-diarrhea
-vomiting
-septicemia
-skin blistering
-necrotizing fasciitis

Question 10

What are the clinical signs of Vibrio parahemolyticus?

Answer 10

-non-bloody diarrhea
-vomiting
-abdominal pain

Question 11

What are the characteristics of Vibrio cholerae?

Answer 11

-contaminates water and exposed food sources
-incubation between a few hours and 5 days
-death due to dehydration
-prevent through careful food handling and water testing

Question 12

What are the characteristics of Clostridium perfringens?

Answer 12

-Type A causes gastroenteritis and diarrhea
-Type C causes necrotic enteritis

Question 13

What are the characteristics of Clostridium botulinum?

Answer 13

-toxin causes muscle paralysis
-death results from respiratory failure

Question 14

Which marine toxins are found in finfish?

Answer 14

-Scombroid
-Ciguatera

Question 15

Which marine toxins are found in shellfish?

Answer 15

-paralytic
-neurotoxic
-amnesic
-diarrheic

Question 16

What are the characteristics of scombrotoxic fish poisoning?

Answer 16

-consumption of fish containing higher levels of histamine
-bacterial contamination due to poor storage and refrigeration
-clinical signs begin 2 minutes to 2 hours after ingestion
-often resolves on its own

Question 17

What are the clinical signs of scombrotoxic fish poisoning?

Answer 17

-burning/tingling of lips and mouth
-flushing of face
-itchy rash
-vomiting
-diarrhea
-headaches
-blurred vision
-palpitations
-dizziness

Question 18

What are the characteristics of scombrotoxic fish poisoning prevention?

Answer 18

-consume fresh or properly frozen fish
-cooking, canning, smoking, or freezing will NOT destroy histamine
-fish may have unusual odors
-flesh of contaminated fish may have a honeycomb appearance after cooking

Question 19

What are the characteristics of Ciguatera poisoning?

Answer 19

-caused by eating tropical reef fish
-naturally occurring toxin produced by dinoflagellates
-toxin accumulates through food chain
-clinical signs begin within minutes to 30 hours after ingestion

Question 20

What are the clinical signs of Ciguatera poisoning?

Answer 20

-nausea
-vomiting
-diarrhea
-cramps
-sweating
-headaches
-muscle aches
-burning sensation
-weakness
-itchiness
-dizziness
-abnormal temp and/or taste in mouth
-hallucinations/nightmares

Question 21

What complicates Ciguatera poisoning prevention?

Answer 21

-difficult to identify high-risk fishing grounds
-inadequate industry knowledge
-inadequate compliance with FDA regulations

Question 22

What are the characteristics of paralytic shellfish poisoning?

Answer 22

-caused by dinoflagellates associated with “red tide”
-toxin concentrates in shellfish in colder waters
-clinical signs appear after 15 minutes to 10 hours

Question 23

What are the clinical signs of paralytic shellfish poisoning?

Answer 23

mild:
-numbness/tingling of face and extremities
-incoordination
-GI upset
severe:
-muscle paralysis
-resp. failure
-death

Question 24

What are the characteristics of neurotoxic shellfish poisoning?

Answer 24

-toxin produced by dinoflagellate Karenia brevis
-found in gulf coast and SE atlantic coast of US
-clinical signs begin after 1 to 3 hours

Question 25

What are the clinical signs of neurotoxic shellfish poisoning?

Answer 25

-numbness/tingling of mouth and extremities
-GI upset
-incoordination

Question 26

What are the characteristics of amnesic shellfish poisoning?

Answer 26

-caused by Nitzchia pungens
-domoic acid is toxin
-rare syndrome in people
-clinical signs begin within 24 hours

Question 27

What are the clinical signs of amnesic shellfish poisoning?

Answer 27

-GI distress
-dizziness
-headache
-disorientation
-permanent short term memory loss
-seizures
-focal weakness/paralysis
-death

Question 28

What are the characteristics of diarrheic shellfish poisoning?

Answer 28

-okadaic acid
-nausea and diarrhea occur
-recovery in 1-3 days

Question 29

What are the characteristics of puffer fish poisoning?

Answer 29

-tetrodoxin
-symptoms similar to paralytic shellfish poisoning
-major cause of fatal food toxicity in Japan

Question 30

What is important about mercury and the food chain?

Answer 30

it must be converted to methylmercury to enter the food chain and accumulate

Question 31

What are the characteristics of mercury in fish?

Answer 31

-contamination
-larger fish usually have more accumulation
-carnivorous fish often have higher levels

Question 32

How can adverse affects of mercury consumption be avoided?

Answer 32

-know local “consumption” rules
-pregnant women should limit fish consumption
-other sources of mercury should also be considered