mini quiz 4 - ch 7 Flashcards
‘myco’ = what?
fungus
features of a fungal pathogen
- multicellular, no true organs
- heterotroph
- EXTRACELLULAR DIGESTION
- septate or aseptate
- spores
- sexual and asexual reproduction
saprobe
an organism who derives its nourishment from non living or decaying organic matter
fungi as infectious disease agent:
- obligate or non obligate?
- facultative?
obligate
facultative
2 modes of fungal pathogenecity
1- invasive ( surface - skin, gills, shell) (deeper - viscera, muscles, vessels)
2- toxic (mycotoxins) spoil feed. Liver and kidney necrosis, gill necrois, blood vessel damage
what is an important technique when diagnosing fungus?
Sterile techniques essential
main diagnosis methods for fungus
microscopy (saprolignia) (Ich) (trichmaris)
culture (antibiotic and baiting techniques)
2 types of baits for culture media
nutrient rich - hemp seed, salmon eggs, paste
nutrient poor - hair, insect wing, pollen
2 types of culture media, and why use them
solid: get thalli/hyphae only
fluid: get zoospore production
prevention and treatment of fungus
- good husbandry
- prophylactic or treatment bath (malachite green, formalin, hydrogen peroxide, salt or sea water dip, wescodyne, ova dine, pyceze)
- no vaccines, dont need em
what is an oomycete
egg fungus
saprolegnia spp:
- where do you find it
- what does it look like
- what does it affect
- promoting factors
- what sort of transmission
- fish defences?
- treatment/prevention
- opportunistic fw worldwide
- cotton like tufts, hyphae aseptate
- primarily eggs, also gills, skin
- sexual maturation, wounds, environmental stress, infection
- horizontal
- mucus
- good husbandry, good flow rates
is saprolignia a fungus or a mold?
mold. protist.
what is special about Apanomyces astaci?
- where is it found?
- what is it known as?
- what diagnosis technique is available?
OIE listed. CFIA ‘immediately notifiable’.
- europe,japan
- crayfish plague
- PCR - (ONLY FUNGAL THING W PCR!)
what is the only fungal pathogen that has a PCR test?
Aphanomyces astaci - crayfish plague
phylum deuteromycetes = what?
secondary fungi, fungi imperfecti. PROTIST
what phylum does ich belong to?
deuteromycetes
what is ich’s full name?
Ichthyophanus baferi
ICH:
- where found
- how is it acquired?
- mostly marine, but also fw. cultured + wild
- ingestion of thick walled spores
2 types of virility for ich
acute (lethal in 30 days)
chronic (lethal in ~ 6 months)
how to prevent ich
avoid using dead fish as feed
symptoms of ich
nodules in fillets, white spots on liver, heart
Fusarium:
- what animal does it affect?
- what would you observe?
- endemic?
- found in what media?
- lobsters, crab, some shrimp
- ‘burn spot disease’ black gills, darkening skin
- black gill disease local in shrimp
- soil and water borne spores
phylum Ascomycetes = what?
sac-fungi
Trichomaris invadens:
- what phylum
- what animal does it affect
- what type of pathogen
- symptoms
- asteromycetes
- snow crab/tanner crabs
- obligate fungal pathogen, septate hyphae
- black spots on carapace or limbs.
what is a main cause of fungal pathogens?
too wet, make it more dry. hatcheries work better with dry conditions.
fungal pathogens more problematic for what type of animal?
- shellfish over fish
- wild over farmed
fungal presence implies what?
poor husbandry. often overlooked.
Which aquatic fungal pathogen is OIE listed?
why is it listed?
is it a problem in BC?
Aphanomyces astaci - crayfish plague
- rapid spread, asymptomatic
- no, N.American spp more resistant.
2 common treatments and 2 common prevention techniques for fungal pathogens
Treatments: - baths (formalin, malachite green, saltwater ) -Pyceze Prevention: -good husbandry -elevated flow rates
`what stage in the farming of salmon is most challenged by Saprolegnia infections and why? What other two pathogens are commonly found with saprolegnia infections?
- eggs, non-motile, spores can easily attach (why you should elevate flow rates), no mucus glands yet
- ?
2 trends with aquatic fungal diseases
- obligate (need a host)
- facultative (easy to culture)
similarities among the diagnosis of fungal, bacterial,and viral pathology?
-culture media and micorscopy the best
what are the differences among the diagnosis of fungal, baterial and viral pathogens?
viruses extremely difficult to use microscopy. pcr and flouro tests the best
