Lecture 27 10/22/24 Flashcards
Which bacteria can spread through seafood?
-Aeromonas spp.
-Mycobacteria spp.
-Vibrio spp.
-Clostridium spp.
What are the characteristics of Aeromonas spp.?
-gram negative
-motile
-facultative anaerobe
-ubiquitous in environment
-infect stressed fish
How is Aeromonas transmitted?
-eating raw/undercooked fish
-cuts and abrasions
What are the clinical signs of Aeromonas?
-nausea
-diarrhea
-vomiting
-septicemia
-wound infection
-necrotizing fasciitis
What are the characteristics of Mycobacteria spp.?
-gram positive
-non-motile
-acid-fast rods
-slow growing/difficult to culture
-fish can be carriers, acutely infected, or chronically infected
What is the main clinical sign of Mycobacteria infection?
ulcerative or raised granulomatous lesions on extremities
What are the characteristics of Vibrio spp.?
-gram negative
-facultative anaerobe
-rod shaped
-natural habitat is coastal waters where oysters live
-higher conc. between May and October
How does Vibrio bacteria transmit?
-eating raw or undercooked oysters
-puncture wound penetrations
What are the clinical signs of Vibrio vulnificus infection?
-diarrhea
-vomiting
-septicemia
-skin blistering
-necrotizing fasciitis
What are the clinical signs of Vibrio parahemolyticus?
-non-bloody diarrhea
-vomiting
-abdominal pain
What are the characteristics of Vibrio cholerae?
-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
What are the characteristics of Clostridium perfringens?
-Type A causes gastroenteritis and diarrhea
-Type C causes necrotic enteritis
What are the characteristics of Clostridium botulinum?
-toxin causes muscle paralysis
-death results from respiratory failure
Which marine toxins are found in finfish?
-Scombroid
-Ciguatera
Which marine toxins are found in shellfish?
-paralytic
-neurotoxic
-amnesic
-diarrheic
What are the characteristics of scombrotoxic fish poisoning?
-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
What are the clinical signs of scombrotoxic fish poisoning?
-burning/tingling of lips and mouth
-flushing of face
-itchy rash
-vomiting
-diarrhea
-headaches
-blurred vision
-palpitations
-dizziness
What are the characteristics of scombrotoxic fish poisoning prevention?
-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
What are the characteristics of Ciguatera poisoning?
-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
What are the clinical signs of Ciguatera poisoning?
-nausea
-vomiting
-diarrhea
-cramps
-sweating
-headaches
-muscle aches
-burning sensation
-weakness
-itchiness
-dizziness
-abnormal temp and/or taste in mouth
-hallucinations/nightmares
What complicates Ciguatera poisoning prevention?
-difficult to identify high-risk fishing grounds
-inadequate industry knowledge
-inadequate compliance with FDA regulations
What are the characteristics of paralytic shellfish poisoning?
-caused by dinoflagellates associated with “red tide”
-toxin concentrates in shellfish in colder waters
-clinical signs appear after 15 minutes to 10 hours
What are the clinical signs of paralytic shellfish poisoning?
mild:
-numbness/tingling of face and extremities
-incoordination
-GI upset
severe:
-muscle paralysis
-resp. failure
-death
What are the characteristics of neurotoxic shellfish poisoning?
-toxin produced by dinoflagellate Karenia brevis
-found in gulf coast and SE atlantic coast of US
-clinical signs begin after 1 to 3 hours
What are the clinical signs of neurotoxic shellfish poisoning?
-numbness/tingling of mouth and extremities
-GI upset
-incoordination
What are the characteristics of amnesic shellfish poisoning?
-caused by Nitzchia pungens
-domoic acid is toxin
-rare syndrome in people
-clinical signs begin within 24 hours
What are the clinical signs of amnesic shellfish poisoning?
-GI distress
-dizziness
-headache
-disorientation
-permanent short term memory loss
-seizures
-focal weakness/paralysis
-death
What are the characteristics of diarrheic shellfish poisoning?
-okadaic acid
-nausea and diarrhea occur
-recovery in 1-3 days
What are the characteristics of puffer fish poisoning?
-tetrodoxin
-symptoms similar to paralytic shellfish poisoning
-major cause of fatal food toxicity in Japan
What is important about mercury and the food chain?
it must be converted to methylmercury to enter the food chain and accumulate
What are the characteristics of mercury in fish?
-contamination
-larger fish usually have more accumulation
-carnivorous fish often have higher levels
How can adverse affects of mercury consumption be avoided?
-know local “consumption” rules
-pregnant women should limit fish consumption
-other sources of mercury should also be considered
