Rhabditids Flashcards Preview

Parasitology 376 > Rhabditids > Flashcards

Flashcards in Rhabditids Deck (34):
1

What is characteristic of the Rhabditids?

Rhabditiform esophagus

2

What are the regions of the rhabditiform esophagus?

Corpus

Isthmus

Bulb

3

Name the 3 groups of Rhabditids:

Rhabditis strongyloides

Halicephalobus gingivalis

Strongyloides spp.

4

What species does Rhabditis strongyloides infect?

Cattle

Dog 

Swine

Horse

Sheep

5

What type of environment is Rhabditis strongyloides most often associated with?

Wet or damp/dirty straw bedding

 

6

Lesions of Rhabiditis strongyloides are localized to which specific areas of the body?

Skin areas in contact with bedding

7

What are the clinical signs of superficial contact dermatitis associated with rhabditic dermatitis?

Alopecia

Pruritus

Erythema

Pustules

Serum exudate

8

How is Rhabditis strongyloides diagnosed?

History and lesions surggestive

Skin scraping or biopsy

Find larvae in hair follicles

Rabditiform esophagus 

9

What is the treatment protocol for Rhabditis strongyloides?

Ivermectin 

Antibiotics

10

What is the main host of Halicephalobus gingivalis?

Equine

11

How is Halicephalobus gingivalis transmitted?

  1. Ingestion + Lactogenic transmission
  2. Inhalation
  3. Hematogenous spread

12

In which locations of the body with Halicephalobus gingivalis be found?

CNS

Kindeys

Heart

Maxilla

Nasal cavity

Prepuce

Mammary gland

Bone

13

Which parasites have parthenogenetic females?

Strongyloides spp.

Halicephalobus gingivalis

14

How might Halicephalobus gingivalis be diagnosed?

ID parasites in lesions, urine, semen

Ultrasound kidneys

15

Explain the unique life cycle of strongyloides:

Both free-living and parasitic generations

Parasitic females ONLY

Females reproduce by parthenogenesis 

Eggs contain L1

 

16

  1. Which species of strongyloides shed eggs with an L1?
  2. Which species of strongyloides shed a hatched L1?

  1. All species except S. stercoralis
  2. S. stercoralis

17

What is characteristic about the adult female strongyloides?

Filariform esophagus

 

A image thumb
18

What is the life cycle of strongyloides species?

Adults in the small intestinal mucosa

Parthenogenetic adult females produce eggs

Egg with rhabditiform L1 she in feces

 

Homogonic rhabditiform L1 develops into:

1.  Infective filariform L3 (parasitic adult female)

2.  Free-living rhabditiform adult (male OR female)

19

Which stage is shed in feces for Strongyloides stercoralis?

L1

Egg containing the L1 hatches in the small intestine for this species

20

How might Strongyloides be transmitted?

Skin penetration by L3 -> Blood

Ingestion of L3 -> Contaminated food/water, colostrum/milk, transmammary infection -> Penetrate oral mucosal -> Blood

21

Strongyloides species can cause infection through skin penetration by an L3 or ingetion of an L3.  These routes both cause infection of the blood.  From the blood, how does the organism get to the small intestine?

Carried in blood to lungs

Into airways

Couged up

Swallowed 

Adult females into the SMALL INTESTINE

22

Which of the rhabditids exhibits somatic migration?

Strongyloides

Adults stay in the blood -> become hypobiotic in adipose tissue -> activated during gestation -> mammary glands

23

Strongyloides infections are most prevalent in which populations?

Young hosts

Immunocompromised hosts

24

What is the epidemiology of strongyloides in foals, ruminants, pigs, dogs, and primates?

Foals : nursing age

Ruminants : nursing age

Pigs : most common at nursing age

Dogs & primates : prevalence dependent on warm, moist, unsanitary conditions

25

What are some of the clinical signs associated with larval migration of strongyloides?

26

Which species does Strongyloides stercoralis infect?

Dog

Primates

27

What are the unique features of Strongyloides stercoralis?

L1 hatches from egg in the host gut

L1 develops rapidly into an infective L3 -> Autoinfection

28

How can strongyloides be diagnosed?

Find L1 in egg in fresh feces

EXCEPT FOR STRONGYLOIDES STERCORALIS

29

What clinical signs might be associated with Strongyloides stercoralis?

Cutaneous - skin penetration (LARVAE)

Respiratory - bronchopneumonia (LARVAE)

Intestinal - mucoid to watery diarrhea (ADULT)

30

How might you diagnosis Strongyloides stercoralis?

Examine fresh feces for rhabditiform L1 (BAERMANN)

Detect filariform L3 at 24-36 hours

31

Where do the majority of strongyloide species live?

Which species is different?

Where does it live?

Strongyloides species mostly habor the small intestine.

Strongyloides tumefaciens, however, habros the LARGE INTESTINE.

32

Which of the strongyloides species is only known to have parthenogenetic females?

Strongyloides tumefaciens

33

Where do eggs hatch for Strongyloides tumefaciens?

Nodules in the large intestine

Shed L1 in feces

34