Aeromonas, Vibrio, Plesiomonas

Question 1

Characteristics

Answer 1

-biocontainment level 2

-gram negative rods (Aeromonas and Plesiomonas are straight; vibro are curved)

-aquatic and marine

-ectotherm associations
-enteric disease in endotherms

Question 2

Vibrio cholerae toxin production

Answer 2

Produced cholera toxin which interferes with ion metabolism

Question 3

Aeromonas sp habitat

Answer 3

-aquatic/marine environment
-part of normal microbiome of fish

Question 4

Plesiomonas shigelloides

Answer 4

-aquatic
-not halophilic (sometimes brackish, NOT salt water)

Question 5

Vibrio sp

Answer 5

-found in aquatic and marine environments
associated with shellfish
-can be intestinal tract of mammals including people

Question 6

Aeromonas hydrophila virulence factors

Answer 6

1. Type III secretion systems
2. Hemolysins
3. Enterotoxin

Question 7

Vibrio cholerae

Answer 7

**can grow in high salt conditions!!

Cholera toxin
-when inside the enterocyte, will bind to G proteins
-activated G proteins turn on adenylate cyclase, increasing cAMP
-effects Na, K, HCO3 metabolism
-increased ions in gut lumen results in increased water in lumen and therefore diarrhea

Question 8

Aeromonas hydrophilia presentations

Answer 8

Frogs: red leg disease

Snakes: necrotis stomatitis

Humans: food poisoning

Question 9

Aeromonas salmonicida presentations

Answer 9

Fish: Furunculosis

Question 10

Vibro cholerae presentations

Answer 10

Cholera in humans

Question 11

Vibro vulnificus presentations

Answer 11

humans: septicemia, necrotizing skin and muscle infections
**caused by animal associations

Question 12

Vibro harveyi presentations

Answer 12

Marine fish and invertebrates: wide variety

Question 13

Plesiomonas shigelloides presentations

Answer 13

Fish: opportunistic infections

Humans: gastroenteritis

Question 14

Red leg disease

Answer 14

-gram negatives including A. hydrophilia

-seen in amphibians which are malnourished or in poor quality water

Clinical signs: ulcertations, lethargy, emaciation, petechia on legs and abdomen

Question 15

Aeromonas salmonicida

Answer 15

-causes disease in lots of fish (salmonids, carp, catfish, cod, eels, lumpfish)
-associated with high density aquaculture and aquarium fish
-microplastics are mechanical vector

Clinical signs: ulcerative lesions, hemorrhage, furunculosis (septicemic disease in salmonids)

Question 16

Plesiomonas shigelloides in humans

Answer 16

-results in food related gastroenteritis (unwashed foods, undercooked shellfish)
-associated with tropical and sub tropical regions of world in summer month (don’t eat oysters in mths with R)
-opportunistic infections in fish

Clinical presentations:
1. mild watery diarrhea; self limiting
2. Immunocompromised people: cholera like illness

Question 17

Vibrio cholerae

Answer 17

-not endemic to Canda
Causes:
1.Severe, acute gastroenteritis= contaminated food or water

2. Profuse diarrhea
   -within hours of ingesting organism= Rice water diarrhea
   -can lead to dehydration death

**Boil it, cook it, peel it or forget it

Question 18

Cholera history of microbiology

Answer 18

Used map with histograms for each case
-linked most cases to one water pump

Question 19

Vibrio cholerae vaccination

Answer 19

-Injectable and Oral vaccine
-low production

Question 20

Vibrio species in marine mammals

Answer 20

-found in marine mammals to be causing infection
>Vibrio fluvialis

ex. manatees

Question 21

Vibrio anguillarum

Answer 21

-causes haemorrhagic septicemic disease= Vibriosis

-seen in aquaculture: fin fish, crustaceans, bivalves

Clinical signs: weight loss, red spots, opthalmic involvement (ulceration, exophthalmia)

Question 22

Vibrio harveyi

Answer 22

-important pathogen for wild and farmed marine fish and crustaceans
**common in shrimp

-Organism can luminesce! Shrimp glowing=infected with V. harveyi

Question 23

Treatment of V. harveyi

Answer 23

-challenging as hard to medicate fish. Need to medicate environment
-antimicrobials have been attempted

Tried bacteriophages, biological control (probiotics), dietary supplements

Question 24

Squid vibrio model

Answer 24

Ability to glow.
-linked with symbiosis with Vibrio fischeri

Question 25

Vibrio vulnificus

Answer 25

-cause of serious infections (wounds, primary septicemia, and gastroenteritis) in people (and eels)
*most people that get septicemia are linked with people with pre-existing conditions (liver disease)

-contracted by ingestion or contact with water

Question 26

Specimens to collect

Answer 26

-scrapings of affected tissue
-tissue sections
-whole animal for necropsy

Question 27

Sample handling

Answer 27

-prevent environmental contaminations
-send samples quickly (small fish and amphibians will autolyze)
-do not freeze!

Question 28

Lab ID

Answer 28

-culture; let lab know what species are expected. Some temp at 35-37 degrees, but may need a different temperature

-microscopy

-fluorescent antibody test fot A. salmonicida

-ID based on colony morphology and biochemical

-PCR and sequencing needed to ID unusual organisms isolated from fish or other ectoderms

Question 29

Zoonotic/interspecies transmission

Answer 29

-foodborne illness associated with many organisms

-humans can also become infected from open wounds in environment, and bites/scratches from marine organisms carrying bacteria

Question 30

Treatment

Answer 30

-Consult specialty reptile/amphibian book

Aeromonas hydrophila= frogs= drugs fro gram negatives (aminoglycosides, fluoroquinolones

Aeromonas salmonicida= fish= commercial operations, so use guidelines and susceptibility testing

Question 31

Intrinsic resistance

Answer 31

-beta lactams
-amoxicillin
-ampicillin-sulbactam