Exam 2 Protozoans Flashcards
(149 cards)
1
Q
Direct life cycle
A
Involves definitive hosts only (no intermediate host required to complete life cycle)
2
Q
Indirect life cycle
A
Involves a definitive host and either an intermediate or paratenic host
3
Q
Intermediate host
A
Host that harbors pre-adult stages of the parasite.
Required for completion of the indirect life cycle
4
Q
Paratenic host
A
- Transport host
- Host harbors pre-adult stages of the parasite
- little/no development occurs
- host is not required for completion of the life cycle
5
Q
Definitive host
A
Host that harbors the adult/mature stage of the parasite
6
Q
Reservoir host
A
- Source of infection for humans and domesticated animals
- all parasites have a reservoir host
7
Q
Prepatent period
A
Time interval between host acquiring the parasite and the earliest ability to detect parasite on the host (detects the diagnostic stage)
8
Q
Patent period
A
Time period during which the parasite produces it’s diagnostic stage
9
Q
Trophozoite
A
feeding/active stage of a protozoan
10
Q
Cyst
A
life cycle stage with a protective membrane
11
Q
Pseudocyst
A
Flagellate trophozoite form that’s rounded with internalized flagella
12
Q
Oocyst
A
Apicomplexan life stage in which the infective entities (sporozoites) develop
13
Q
Sporocyst
A
- develops within the Apicomplexan oocyst
- when present, contains sporozoites
14
Q
Sporozoite
A
- Apicomplexan cell form that infects new hosts. (infectious agent)
- Develops within sporocysts (or oocysts when sporocysts are absent)
15
Q
Merozoite
A
- Apicomplexan motile stage
- formed from asexual reproduction within host cell
- can enter into another asexual or a sexual repro phase of life
16
Q
Meront
A
Structure merozoites develop in
17
Q
Bradyzoite
A
- type of merozoite
- typified by slow growth and rapid replication
18
Q
Tachyzoite
A
- type of merozoite
- typified by rapid growth and replication
- eventually becomes a bradyzoite
19
Q
Phylum Sarcomastigophora
A
- trophozoites with flagellum
- reproduce by binary fission
- direct life cycles (+/- cysts)
- Giardia & Tritrichomonas
20
Q
Phylum Apicomplexa
A
- obligate intracellular parasites at some point in life
- asexual repro followed by sexual repro
- direct or indirect life cycles
21
Q
Giardia genetic assemblage A & B
A
humans (randomly cats, dogs)
22
Q
Giardia genetic assemblage C & D
A
dogs (rare in humans)
23
Q
Giardia genetic assemblage E
A
sheep, goats, cattle, pigs, hoofed livestock, wild rum, (rare in humans)
24
Q
Giardia genetic assemblage F
A
cats (rare in humans)
25
Giardia genetic assemblage G
rodents
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Giardia genetic assemblage H
marine mammals
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Transmission of giardia
fecal-oral (usually water, sometimes feed)
If humans - human:human more likely, not animal:human
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Giardia prepatent and patent periods
Prepatent: 3-16 days
Patent: variable
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What's in a Giardia cyst
2 trophozoites
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Where do trophozoites like to go?
brush border of duodenum & jejunum
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Key things about Giardia clinical signs
- infection more common in young
- young are the greatest environmental contaminators
- can have clinical signs before patency
- Clinical signs USUALLY absent in EQ, rum, SA camelids, dogs, cats
32
Giardia pathogenesis
- villous atrophy, crypt hyperplasia
- decrease disaccharidase activity
- break down tight junctions
- all cause malabsorptive diarrhea (bacteria, sodium, glucose in gut draw water)
- diarrhea can be acute, chronic, or intermittent
33
Clin signs:
- decreased feed efficiency in kids, lambs, calves
- diarrhea, weight loss, impaired growth rate
G. duodenalis
34
Clin signs:
| - diarrhea, ill-thrift, impaired growth rate in faols
G. duodenalis
35
Detect Giardia
- wet mount (common)
- centrifugal fecal float (repeated)
- ELISA, immunochromatographic tests
- Immunofluoresence (probably best)
- PCR
- post mortem saline smear of SI mucosa scrapings
36
Wet mount protocol
- must be fresh feces (within 20 mins)
- mount with saline, look for motility
- then stain with iodine - look for concave disks
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Treat Giardia
- only if have diarrhea (Giardia is not cause of diarrhea)
- Metronidazole or fenbendazole sometimes effective, but reinfection still possible
- treat with other drugs if have cryptosproidium co-infection (common)
38
Control for Giardia
- control environement: decontaminate, treat affected animals (+bath), try to decrease re-introduction from outside sources
- hard to control if cattle or an uncontrolled environment (e.g. outdoor animal)
39
Tritrichomonas foetus species infected
- cattle (regulated)
- cats
- swine (nasal sinuses, GI)
- seen in dogs but rare
40
Transmission of Trich
cattle - venereally
cats - fecal oral or direct contact
Does not survive well in environment (no cyst form)
41
Where does Trich live in cattle
Cows - multiply (asex repro) in vagina ~2 wks, then uterus
Bulls - penis/prepuce/urethra epithelium, bulls are reservoir
42
Trich clinical signs in cattle
Herd problem of decreased pregnancy rates
Bulls - usually no signs, chronic carrier
Cows - vaginitis, endometritis, infertility, pyometra - but self limiting, rare to be a carrier
43
Detect Trich in cattle
- wet mount/smear of genital secretions
- single positive culture or PCR+ (vs. 3 negative cultures to be negative)
- sampling protocols change by state
- if detected, quarantine, test everyone, cull any positives
44
Control Trich in cattle
Bulls - replace older with younger, test any new bulls, test all bulls 2 wks post breeding
Cows - maintain a breeding season to ID repro probs, fence maintenance
45
Where does Trich live in cats
- epithelium of cecum, colon, maybe ileum (non invasive)
| - asexual repro, no cyst stage, don't know pathogenesis
46
Trich risk factors in cats
- purebred
- catteries/shelters (crowded)
- presence of other enteric protozoans
- history of diarrhea last 6 mo in cat or it's playmate
47
Trich clinical signs in cats
- malodorous, wax/waning large bowel diarrhea
| - fecal incontinence, straining, irritated anus
48
Detect Trich in cats
- Colon flush preferred sample
- fecal loop, freshly voided diarrhea
- wet mount to visualize
- fecal culture, PCR, histo biopsy (but trich rarely seen)
49
Key things about colon flush
- examine within 20 mins
- don't refrigerate
- otherwise Trich dies
50
Treat Trich in cats
- spontaneous resolution of diarrhea 4 mo - 2 yrs
- Remain infected, can relapse, intermittent shedding
- No treatment approved, but Ronidizole is used
51
Hemoprotozoans
- infect circulatory system
- vector-borne (usually ticks)
- indirect life cycles
- Cytauxzoon felis, Hepatozoon americanum, Hepatozoon canis, Babesia
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Cytauxzoon felis definitive host
Amblyomma americanum
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C. felis distribution
south central US in felids
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C. felis intermediate host
wild and domestic felids
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C. felis reservoir host
bobcat
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C. felis transmission
Tick acquires as nymph
transstadial transmission
blood meal --> intermediate host
host --> gametes to tick by blood meal
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What does C. felis like to invade
- first macrophages (mononuclear WBC's) especially in lungs, spleen, liver
- then merozoites infect RBC's
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C. felis prepatent period
11-19 days
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C. felis clinical signs
5-14 days post infection
non-specific general signs
Leukopenia, thrombocytopenia, anemia, etc
Death 1-4 days after clinical signs start - highly fatal to cats
60
C. felis seasonality
dependent on tick activity
| spring-summer (peak mid May to mid June)
61
Detect C. felis ante-mortem
Blood smear (RBC's or WBC's with meronts)
If not helpful, FNA
If not helpful, PCR whole blood
62
Detect C. felis post-mortem
Impression smear: lung & spleen first choice,
-2nd choice: liver, lymph node, bone marrow
or PCR
63
Hepatozoon americanum distribution
SE US, central & south america
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Hepatozoon americanum definitive host
Amblyomma maculatum
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H. americanum intermediate host
wild and domestic canids
66
H. americanum paratenic host
rabbits, rodents
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Hepatozoon americanum reservoir host
coyotes, maybe foxes
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H. americanum transmission
Tick ingests gamonts in leukocytes during blood meal
sexual repro in hemocoel of tick
Tick must be eaten by intermediate/paratenic host
69
Paratenic host ingests tick, sporozoite comes out of tick, invades host, grows a bit and then stops developing is called a ______
cystozoite
70
What's unique about H. americanum pathogenesis?
sporozite pairs with macrophage, goes to skeletal muscle, makes macrophage form onion skin cyst by mucopolysaccharide material
Late merozoites enter macrophages for asex or sex repro
71
H. americanum prepatent period
35 days
72
mild to moderate nonregenerative anemia + profound neutrophilic leukocytosis (+/- periosteal proliferation)
key clinical signs for H. aermicanum
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Detect H. americanum
AM - clinical signs + muscle biopsy
not blood smear - rare to see parasite on smear
whole blood PCR
backdoor diagnosis
PM- histo of muscle
74
Hepatozoon canis definitve host
Rhipicephalus sanguineus & Amblomma spp
75
H. canis intermediate host
red fox, dogs
76
H. canis reservoir host
red fox
77
Detect H. canis
- blood smear (up to 100% neutrophils infected) but leukocyte count WNL
- positive blood smear = positive ID
78
What Babesia spp are eradicated from US?
B. bigemina, B. bovis, B. caballi, B. equii
79
Babesia definitive & intermediate hosts
DH: ixodidae ticks
IH: mammals
80
What babesia species doesn't do transstadial transmission?
B. bovis
81
What babesia spp do transovarial transmission
B. canis, B. bigemina, B. bovis, B. equii
82
Babesia transmission
gamonts in RBC's --> tick
sporozoites become infective AT attachment/bite of tick
anything contaminated with blood can transmit
83
Babesia prepatent period
7-14 days
84
Icterus, anemia, fever
| hemoglobinemia, hemoglobinuria, splenomegaly
Babesiosis clinical signs
85
B. canis definitive host
Rhipicephalus sanguineus
86
anorexia, anemia, thrombocytopenia, splenomegaly
B. canis clinical signs
87
B. gibsoni definitive host
Don't know
| suspect H. longicornis
88
B. gibsoni
most commonly diagnosed cause for canine babesiosis
| Fighting dog breeds common - pit bull, staffordshire terrier
89
Lab finding of Thrbombocytopenia, (hemolytic) anemia, hyperglobulinemia
+ access to blood = Babesia indication
90
Detect Babesia
Blood smear (primary)
PCR - top choice
Serology if available
91
Treatment outcomes of Babesia
```
complete cure
subclinical carrier (anemia resolved)
partial recovery (thrombocytopenia, hyperglobulinemia, anemia stay)
```
92
Bovine Babesiosis
B. bigemina, B. bocis
Hosts: R. annulatus, R. microplus
Federally regulated!!
93
Equine piroplasmosis
= EQ babesiosis
B. caballi, B. equii
Host: Amblyomma cajennense - TX
(outside of texas = itarogenic transmission)
State regulated!
94
Cryptosporidium infection in humans
- usually transmitted from another human (vs. animal to human)
- C. hominis most common
- C. parvum 2nd
95
Class Conoidasida (internal Apicomplexans)
- Cystoisospera, Toxo, S. neurona can have direct or indirect versions
- Cryptosporidium (D), Eimeria (D), Cystoisospora (DI), Sarcocystidae family (mostl I, toxo DI)
96
What internal apicomplexan has sporulated oocysts passed in feces?
Cryptosporidium species (also makes thick and thin-walled forms)
97
Where does Crytpo like to live in host?
lower GI, bile duct, respiratory tracts
Intracellular but extracytoplasmic
98
Major hosts of concern for Crypto
cattle, immunosuppressed humans
99
Crypto prepatent period
3 days+
100
Crypto transmission
fecal contamination in young or immunosuppressed animals
101
severe, watery diarrhea, GI lesions with villous atrophy
Cryptosporidium spp.
102
Detect Crypto
Fecal float (common)
Immunofluoresence (best but costly)
Direct smear
ELISA being developed, PCR, histo
103
Cryptosporidium parvum
very young calves
usually self-limiting
key reservoir for C. hominis
104
C. canis
dogs less than 6 months
common co-infection with Giardia
older dogs can be asymptomatic shedders
105
C. felis
```
immunosuppressed cats (more common in younger)
common co-infection with Giardia
```
106
Eimeria spp
Causes coccidiosis - rum, chicken, camelid, pig, EQ
| high degree of host specificity
107
Eimeria prepatent period
species dependent
| 4-35 days
108
Eimeria disease severity
- Low numbers ingested - inapparent disease, partial immunity
- Moderate numbers ingested - mild disease, partial immunity
- large numbers ingested - severe disease, could be death
109
Premunition
body able to protect itself against pathogen, but doesn't eliminate infection (this is GOOD - keeps immunity stimulated)
relatively immune to severe infection but has chronic low-grade infection
110
Where in the rum body is coccidiosis more severe?
```
large intestine
(SI is longer, faster cell turnover)
```
111
Severe, bloody diarrhea, rapid loss of condition, stress or very young (<6 mo) calf
Coccidiosis by Eimeria
112
3-6 wk chick, poor growth, sudden mucoid diarrhea or death
Coccidiosis by Eimeria
113
Detect Eimeria & Cystoisospera
```
Fecal float (unsporulated oocysts) - but supportive only
PM histo
```
Diagnosing coccidiosis is usually presumptive
114
Prevent Eimeria
- Goal is good husbandry!! (clean environment)
- Coccidiostats for early asexual stages - can use prophylactically so animal can get premunition
- Attenuated live vacc for chickens
115
Cystoisospora spp
- Coccidiosis in dogs, cats, pigs
- highly host specific
- can have direct or indirect life cycle depending on spp
116
Where does Cystoisospera like to live in host?
GI, lymph nodes
117
Cystoisospera prepatent period
4-12 days
118
Dog (<4 mo or debilitated) with diarrhea, abdominal pain, weight loss... OR no clinical signs
Coccidiosis by Cysoisospera
119
What Cysto species are in cats?
C. rivolta (newborns)
| C. felis
120
Piglet with watery, white to yellow diarrhea (no blood), decreased growth
neonatal porcine coccidiosis
| high morbidity, low mortality
121
Most common cause of Equine Protozoal Myloencephalitis (EPM)
Sarcocystis neurona
122
EPM
- inflam of brain and spinal cord (S. neurona rides up via leukocyte)
- common but clinical signs rare
- western hemisphere
123
S. neurona hosts
definitive: N & S american opossum
Intermediate: cats, coons, armadillo
dead end host: horse
124
Detect S. neurona
Serology
Immunoblot, ELISA, indirect FA
Diagnosis of exclusion (backdoor)
125
Neospora caninum hosts
DH: wild and dom canids
IH: rum, domestic dog
126
Neospora pathogenesis differences
Brady and Tachy's can revert back to eachother for transplacental transmission (only Tachy can cross placenta)
127
Neospora prepatent period
5 days
128
Neospora transmission
fecal oral
| transplacental
129
Neosporosis in dogs
- Mom may be asymptomatic
- multiple litters can be affected, but only some show clinical signs
- puppies get neuro signs (LMN disease in pelvic limbs), can become generalized
- also fatal infections in dogs 8-15 (+/- pyogranulomatous dermatitis)
- clinical signs ONLY when dog is intermediate host
130
Detect Neospora
IFAT(indirect fluroescent ab test) - igG titer >800
| PCR with tissue, IHC
131
Treat neospora in dogs
Clindamycin
| prevent scavenging, predation
132
Neosporosis in cattle
placental and fetus disease
abortions (3 mo to term), stillbirths
live calf: alive, fine, alive but chronically infected, alive with clinical signs
133
Detect neospora in cattle
```
competitive ELISA (cELISA)
Tissue: histo, IHC, PCR - placenta, fetal brain primary choice
```
134
Toxoplasma gondii hosts
DH: domestic, wild felids
IH: any warm-blooded vertebrate
135
Where does Toxo like to live in host?
GI cells, lymph nodes
136
Toxo Prepatent period
3-10 days if bradyzoites in tissue cysts are source of infection
19-21 days of sporulated oocysts are source
137
Can cats re-shed Toxo oocysts after first time?
Only if co-infected with Cystoisospora felis, then shed T. gondii oocyts
138
T. gondii clinical signs in cats
infections usually unapparent
| pneumonia, ocular lesions - uveitis
139
Top parasitc rule-out for abortion in sheep, goats
T. gondii
140
T. gondii clinical signs in pigs
no signs, maybe repro issues
| piglets - pneumonia, myocarditis, encephalitis
141
T. gondii clinical signs in dogs
usually no signs
| co-infection with canine distemper virus = lung, liver, CNS signs
142
Humans and T. gondii transmission
1. undercooked meat
| 2. sporulated oocyts (gardening)
143
Detect T. gondii
DH: fecal float, serology
IH: biopsy smear, IHC, EFLA, PM histo
144
Prevent toxo
Cats: indoors, no hunting, no raw food, no rodents
Humans: cook meat to 75C/167F, wash things, sterilize litter box, wear gloves
145
Rhipicephalus sanguineus transmits what 2 apicomplexans?
```
Babesia canis (RBC's)
Hapatozoon canis (WBC's - neutrophils)
```
146
Lice types
sucking
| chewing
147
Lice life stages
egg (nit)
nymph (x3)
adult
all on 1 host (transmit by direct contact)
148
When do you see lice
- crowded conditions
| - young, old, immunocompromised animals with something else going on
149
3 species with paratenic hosts
Hepatozoon americanum
Neospora
Cystoisospera
