Nematodes Review Exam 2

Question 1

Direct Smear

Answer 1

mix with saline
40x
trophozoites and motile bacteria

Question 2

Passive/Standard Flotation

Answer 2

sodium nitrate=fecasol
10 minutes
ova
10x

Question 3

Centrifugal flotation

Answer 3

1g feces with sodium nitrate
centrifuge 3-6 minutes, 1-2000 rpm
reverse meniscus
wait 10 minutes

Question 4

fecal sedimentation

Answer 4

ova too large for standard flotation

fluke eggs do not float

Question 5

cellophane tape test

Answer 5

pinworms (oxyuroidea) and tapeworm proglottids
water/mineral oil
10x
ova

Question 6

Baerman

Answer 6

warm water/saline
10 hours
larvae

Question 7

misc. fecal test

Answer 7

fecal occult blood-minor bleeding from parasites

vomitus can also aid in diagnosis of parasites

Question 8

fecal culture

Answer 8

parasites mature into adult/larvae

Question 9

modified mcmasters

Answer 9

estimate number of oocysts per gram of feces

used in large animals and adapted from human hookworms

Question 10

staining fecal slides

Answer 10

direct smear=new methylene blue and Lugoi iodine
trophozoites=diff quick or Wright or Geimsa
Acid-fasting=ID Cryptosporidium sp. with Diff Quick

Question 11

Blood samples

Answer 11

Hemoprotozoa
Heartworm
Subcutaneous worm
ELISA, IFA, PCR Testing – if sending out, make sure you use the correct tube

Question 12

Thick or thin smears prepared as is for WBC differential counts

Answer 12

Thin – protozoan and rickettsial parasites

Thick – if low parasitemia

Question 13

Buffy coat smear

Answer 13

concentration technique for protozoal and rickettsiae in WBCs

Question 14

direct drop

Answer 14

drop of blood from LTT

microfilariae

Question 15

Filter test

Answer 15

concentrate microfilaria in blood

Question 16

Modified Knott’s Test

Answer 16

dilute formalin 2%
ID microfilariae
Dirofilaria immitis vs. Acantheocheilonema reconditum

Question 17

Antigen test

Answer 17

look for present infection
current infections only
monoclonal antibodies

Question 18

Antibody test

Answer 18

host immune response
current and prior infections
test contains antigen

Question 19

symbiosis

Answer 19

Predator-prey (short-lived)
· Phoresis (to carry)
· Mutualism (both benefit)
· Commensalism (one benefits, the other is not harmed and does not benefit- “hitchhiker”)
· Parasitism – one is metabolically dependent and may harm the host

Question 20

Hosts:

Answer 20

Definitive 
Intermediate host
Paratenic host (transport host)
Reservoir host
Dead-end host

Question 21

transmission routes

Answer 21

ingestion: fecal-oral or intermediate/paratenic host
vector
transdermal, transplacental, transmammary

Question 22

location in host

Answer 22

predilection site

abberant or erratic parasite (heartworm)

Question 23

female parasites

Answer 23

Oviparous – eggs with single-cell or morula
Ovoviviparous – eggs with 1st stage larva
Larviparous – eggs are retained, birth live larvae

Question 24

parasite life cycle

Answer 24

Egg (eventually molts – emerges from the egg)
· Four larval stages (wormlike) Infective 3rd stage larva
· Sexually mature adult (predilection site within the definitive host)
· Egg containing a larva, free-living larva, or larva within an intermediate host

Question 25

Roundworms/Ascaroidea

Answer 25

small inestine
fecal float
eggs round with thick shell

Question 26

Trichostrongyloidea

Answer 26

trichostrongyle type ova in ruminants
abomasum, small and large inestine
diarrhea, anemia, hypoalbuminemia, “bottle jaw”, reduced growth, death

Question 27

Rhabiditoidea/threadworms

Answer 27

only a partheogenic female is parasitic
small intestine
diarrhea
Baerman or fecal culture

Question 28

Trichuroidea/whipworms and capillarids

Answer 28

lemon shaped bi polar plugs

may be misdiagnosed

Question 29

Oxyuroidea/pinworms

Answer 29

cecum/colon/rectum
cellophane tape test
ova are oval

Question 30

Spiruoidea

Answer 30

varies

Question 31

Filaroidea

Answer 31

Dirofilaria immitis-adult female give birth to live microfillarae