Quiz 2 (Protozoa & Arthropods) Flashcards
4 Main Phylums of Protozoa
- Sarcomastigophora
- Apicomplexans
- Ciliophora
- Microspora
Protozoan Nutrition
Autotrophic
Heterotrophic (Holozoic (ingests via mouth) or Saprozoic (absorbs through cell membrane))
Sarcomastigophora species
Giardia spp.
Trichomonads (Tritrichomonas foetus (cattle), Tritrichomonas blagburni (felids), Tetratrichomonas spp./Pentatrichomonas hominis (non-pathogenic bovine trichomonads))
Trypanosomes (Trypanosoma cruzi)
Apicomplexan species
Order Eucoccidia: E. bovis and E. zuernii
Cystoisospora suis
Cryptosporidium (Toxoplasma gondii and Sarcocystis cruzi)
Oder Piroplasmidia: Cytauxzoon felis
Giardia spp.
Direct life cycle
Most mammals (ingestion of cyst, longitudinal binary fission)
Cysts: 4 nuclei, Trophozoites: 2 nuclei
Clinical signs: diarrhea, or asymptomatic
Dx: Fecal float, direct smear, ELISA
Trichomonads
Flagella, undulating membrane, axostyle
Psuedocysts
Longitudinal binary fission
Includes Bovine Genital Trichomonosis (T. foetus) and Feline Trichomoniasis (T. blagburni)
Tritrichomonas foetus
Bovine Genital Trichomonosis
Can cause early embryonic death and abortion
Bulls are asymptomatic
Cows: vaginitis, etc.
Dx: recover organisms -> PCR, direct smear, culture
Prevention: replace old bulls, don’t borrow/lease animals, TEST, cull open cows, etc.
Non-pathogenic Bovine Trichomonads
Pentatrichomonas hominis
Tetratrichomonas spp.
Tritrichomonas blagburni
Feline Trichomoniasis
Large bowel disease
Transmission unknown
Chronic diarrhea
Dx: direct smear, culture, PCR, colonic biopsy
Control: keep infected cats away from others, clean litterbox daily
Trypanosoma cruzi
Parasite of all vertebrates, transmitted by blood-feeding invertebrates
Have kinetoplast and nucleus
Pleomorphic: elongated body with single flagellum (trypomastigote, promastigote, epimastgote) or round body with short (if any) flagellum (amastigote)
Cytoskeleton with microtubules
Chagas Disease (Reduviid Bug)
INFECTIVE STAGE = metacyclic trypomastigote
“Classical Coccidia”
Eimeria and Cystoisospora
Eimeria and Cystoisospora differences
Eimeria: mammals + BIRDS, 4 sporocytes w/ 2 sporozoites
Cystoisospora: only mammals, 2 sporocytes w/ 4 sporozoites
Eimeria bovis
Affects ileum and colon of cattle Reproduce by gametogony Easier to diagnose Oocysts present when disease begins Mucosal damage
Eimeria zuernii
Affects ileum and colon of cattle
Reproduce by schizogony
Bloody diarrhea, anemia, emaciation
Acute and chronic phases
Cystoisospora suis
Pigs
Primary disease of suckling piglets, contaminated feces
Sporozoites penetrate villous epithelium
Pasty/liquid diarrhea, NO BLOOD
Cryptosporidium
Affects intestine (profuse yellow, watery diarrhea)
Fecal-oral transmission
Waterborne outbreaks: Milwaukee 403,000 affected,104 deaths
Oocyte resistance: Heat (64-72 degrees C), UV, chlorine, bleach, water treatments
Toxoplasma gondii
Obligate, intracelluar parasite
IH: most mammals (tachyzoites, bradyzoites), DH: felids (oocysts)
Transmission: ingesting oocyts, raw/undercooked meat, or congenital (transplacental)
Clinical signs: fever, anorexia, jaundice
Dx: fecal float, IFA, ELISA, Bx, PCR
Sarcocystis spp.
DH: carnivore, IH: herbivore
Transmission: DH consuming IH with sarcocyst, IH ingesting sporocyst
Gametogony
Schizonts form in endothelial cells of blood vessels
Sarcocysts cruzi
Dalmeny Disease in cattle (fever, weightloss, diarrhea, etc.)
Equine Protozoal Myeloencephalitis in horses (head tilt, eye drooping, facial paralysis)- schizonts destroy neural cells, no sarcocysts
Cytauxzoon felis
Piroplasmida Reservoir: bobcat DH: domestic cats IH/vector: salivary glands of ticks Schizogony occurs in macrophages of cats, merozoites released when macrophage ruptures and enter RBC and develop to piroplasms Fatal and non-fatal forms **Schizogenous stage is most destructive
Lifecycle of Trypanosomes
- Metacyclic trypomastigote = infective stage in feces
- Trypomastigotes: circulate in blood, go to organs/muscle
- Amastigote: in cells, reproduce via binary fission, clusters produce psuedocysts, rupture
- Epimastogotes: reproduce via binary fission
Coccidias (Order Eucoccidia)
Eimeria Cystoisospora Toxoplasma Neospora Cryptosporidium Sarcocystis
Characteristics of Protozoa
~60,000 species
Eukaryotic, single-celled
Have organelles of locomotion
Characteristics of Insecta
Segmented body (head, thorax, abdomen)
Simple or complete metamorphosis
Includes: Anoplura (sucking lice), Mallophaga (chewing lice), Diptera (2 winged flies), and Siphonaptera (fleas)
Characteristics of Arachnida
2 body regions: head (gnathosoma/capitulum) and body (idiosoma)
Simple metamorphosis
Includes: Acarina
Diptera
Myiasis: facultative or obligatory
Includes: Culicidae (mosquitos), Tabanidae (horse and deer flies), and Muscidae (stable flies)
Culicidae
Mosquitos
Most prominent blood-sucking parasite
Larvae: always aquatic, complex metamorphosis, spiracles
Antennae: female- pilose, male- plumose
Includes subfamilies Anopheles, Aedes, and Culex
Anopheles
Plasmodium vector Eggs: single with floats Larva: No air tube Pupa: short air tube Adult: resting position is ANGLED
Aedes
Eggs: single on dry surface
Larva: short air tube at angle to water surface
Pupa: air tube variable
Adult: resting position parallel to host
Culex
Vector for Yellow Fever, Dengue Fever, West Nile Virus
Eggs: rafts parallel to water surface
Larva: short air tube at angle to water surface
Pupa: air tube long and slender
Adult: resting position parallel to host
Tabanidae
Horse and deer flies
Found where water is abundant
Eggs laid on vegetation near water ->larvae hatch and enter water (tabanus = predators, chrysops = vegetarians) ->larvae pupate on dry ground along bank -> Adults emerge
IH: trypanosoma, elaeophora
Vectors: anaplasma, anthrax, Equine Infections Anemia
Muscidae
Stable flies (Stomoxys calcitrans)
Males AND females are blood feeders
Mechanical vector for bacteria, Equine Infectious Anemia, Habronema muscae, Trypanosoma evansi
Eggs deposited, hatch, larva pupate in dead plant matter
Control: insecticides, remove rotting straw/plant matter
Anoplura
Sucking lice
Mammals only
Thorax is wider than head
Mallophaga
Chewing/biting lice
Found on mammals and birds
Head is wider than thorax
Siphonaptera
Fleas Ctenocephalides felis (cat flea) 40% of veterinary effort Host-specific 95% of lifecycle spent off host *sperm stored in spermatheca during mating
Acarina
Ticks and mites
2 families: Ixodidae and Argasidae
Eggs-> larva (“seed tick”)-> nymph -> adult
Disease transmission (transstadial and transovarial)
Tick paralysis
Ixodidae
Inclues:
Rhipicephalus sanguineus ("Brown Dog Tick")
Ixodes scapularis ("Black-legged Tick")
Amblyomma americanum ("Lone Star Tick")
Dermacentor variabilis ("American Dog Tick"/"Wood Tick")Flea control methods
Host-targeted insecticides
Environmental insecticides
Mechanical methods
Brown Dog Tick
Rhipicephalus sanguineus
3 host tick
Disease vector for babesia, erlichia canis
All over US
Black-legged Tick
Ixodes scapularis
3 host tick
SE to central US and along E coast
Lone Star Tick
Amblyomma americanum
3 host tick
Tick paralysis
Southern US
American Dog Tick/ Wood Tick
Dermacentor variabilis
3 host
Most of US
Vector for RMSF and anaplasma
Ear mites
Otodectes cynotis External ear canal Females: suckers on legs 1,2,4 Males: suckers on all leg pairs Permanent parasite Transmission through direct contact NOT ZOONOTIC Ear swab
Follicle mites of dogs
Demodex canis Alligator/cigar shaped Adults- 8 legs, larva- 6 legs permanent parasite Localized and generalized parasitism Dx: skin scrape, pustule/abscess contents NOT ZOONOTIC
Scabies
Sarcoptes scabiei
Host: most mammals
Tunnel through dermis causing scaling, excoriations, pruritis
Eggs/feces are allergens, can cause hypersensitivity
Female- suckers on legs 1,2
Males- suckers on legs 1,2,4
Water treatments effective against crypto
Reverse osmosis Distilled Steaming hot Pastuerized Canned/bottled Filtered less than 1 micron
