Rhabditids Flashcards
What is characteristic of the Rhabditids?
Rhabditiform esophagus
What are the regions of the rhabditiform esophagus?
Corpus
Isthmus
Bulb
Name the 3 groups of Rhabditids:
Rhabditis strongyloides
Halicephalobus gingivalis
Strongyloides spp.
What species does Rhabditis strongyloides infect?
Cattle
Dog
Swine
Horse
Sheep
What type of environment is Rhabditis strongyloides most often associated with?
Wet or damp/dirty straw bedding
Lesions of Rhabiditis strongyloides are localized to which specific areas of the body?
Skin areas in contact with bedding
What are the clinical signs of superficial contact dermatitis associated with rhabditic dermatitis?
Alopecia
Pruritus
Erythema
Pustules
Serum exudate
How is Rhabditis strongyloides diagnosed?
History and lesions surggestive
Skin scraping or biopsy
Find larvae in hair follicles
Rabditiform esophagus
What is the treatment protocol for Rhabditis strongyloides?
Ivermectin
+
Antibiotics
What is the main host of Halicephalobus gingivalis?
Equine
How is Halicephalobus gingivalis transmitted?
- Ingestion + Lactogenic transmission
- Inhalation
- Hematogenous spread
In which locations of the body with Halicephalobus gingivalis be found?
CNS
Kindeys
Heart
Maxilla
Nasal cavity
Prepuce
Mammary gland
Bone
Which parasites have parthenogenetic females?
Strongyloides spp.
Halicephalobus gingivalis
How might Halicephalobus gingivalis be diagnosed?
ID parasites in lesions, urine, semen
Ultrasound kidneys
Explain the unique life cycle of strongyloides:
Both free-living and parasitic generations
Parasitic females ONLY
Females reproduce by parthenogenesis
Eggs contain L1
- Which species of strongyloides shed eggs with an L1?
- Which species of strongyloides shed a hatched L1?
- All species except S. stercoralis
- S. stercoralis
What is characteristic about the adult female strongyloides?
Filariform esophagus
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:
- Infective filariform L3 (parasitic adult female)
- Free-living rhabditiform adult (male OR female)
Which stage is shed in feces for Strongyloides stercoralis?
L1
Egg containing the L1 hatches in the small intestine for this species
How might Strongyloides be transmitted?
Skin penetration by L3 -> Blood
Ingestion of L3 -> Contaminated food/water, colostrum/milk, transmammary infection -> Penetrate oral mucosal -> Blood
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
Which of the rhabditids exhibits somatic migration?
Strongyloides
Adults stay in the blood -> become hypobiotic in adipose tissue -> activated during gestation -> mammary glands
Strongyloides infections are most prevalent in which populations?
Young hosts
Immunocompromised hosts
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
What are some of the clinical signs associated with larval migration of strongyloides?
Which species does Strongyloides stercoralis infect?
Dog
Primates
What are the unique features of Strongyloides stercoralis?
L1 hatches from egg in the host gut
L1 develops rapidly into an infective L3 -> Autoinfection
How can strongyloides be diagnosed?
Find L1 in egg in fresh feces
EXCEPT FOR STRONGYLOIDES STERCORALIS
What clinical signs might be associated with Strongyloides stercoralis?
Cutaneous - skin penetration (LARVAE)
Respiratory - bronchopneumonia (LARVAE)
Intestinal - mucoid to watery diarrhea (ADULT)
How might you diagnosis Strongyloides stercoralis?
Examine fresh feces for rhabditiform L1 (BAERMANN)
Detect filariform L3 at 24-36 hours
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.
Which of the strongyloides species is only known to have parthenogenetic females?
Strongyloides tumefaciens
Where do eggs hatch for Strongyloides tumefaciens?
Nodules in the large intestine
Shed L1 in feces
