Lecture 29 - Lawsonia Flashcards
What species are present in the genus Lawsonia?
Intracellularis
What are that basic characteristics of L. Intracellularis?
Non-spore forming
Microaerophilic
Curved-shaped bacillus
Obligate intracellular
What is the structure of the membrane of L. Intracellularis?
Trilaminar
What other bacteria has a trilaminar membrane?
Mycoplasma
What is needed to grow L. Intracellularis?
Cell-free media doesnt work
Dividing cell culture needed with microaerophilic atomosphere
What is the method by which L. Intracellularis gets into its host?
Adheres to enterocytes then invades them
Leaves the phagosome and hangs out in the cytoplasm of the enterocyte
What does L. Intracellularis do to enterocytes?
Induces hyperplasia
What immune response occurs with L. Intracellularis infections?
None really
See no real inflammation at site of infection and T/B cell response is reduced
how is L. Intracellularis transmitted?
Fecal-Oral
What are the three major results see in the host due to the hyperproliferation caused by L. Intracellularis?
Thickening of the mucosa = hypertrophy
Increased non-functioning crypt cells = malabsorption
Fecal shedding
What animals is proliferative enteropathy an emerging disease?
Horses
Where was proliferative enteropathy first seen?
Pigs
What is the model for horse?
Rabbit
What is the model for pigs?
Hamster
What lesions are seen with L. Intracellularis infections?
Intestinal hyperplastic lesions
What is thought to be the carrier host of L. Intracellularis?
Dogs
Why are dogs though to be the carrier host of L. Intracellularis?
Have serum antibodies present for L. Intracellularis even without disease
What form of L. Intracellularis infection is most common in pigs?
Chronic
What are the reserviors for L. Intracellularis in pig populations?
Rats + Mice
When do you see clinical L. Intracellularis disease in pigs?
With stress
What are the two presentations of the chronic form of L. Intracellularis seen in pigs
PIA
– and –
PHE
Term: PIA
Porcine Instestinal adenomatosis
What age does PIA occur?
6 to 20 weeks
What symptoms are seen with PIA?
Water to pasty, brownish blood stained poop
Poor growth
Can recover spontaneously
What is seen with severe PIA?
Coagulative necrosis of adenomatous mucosa
Can recover spontaneously
Term: PHE
Proliferative hemorrhagic enteropathy
When is PHE seen?
4 to 12 months
What symptoms are seen with PHE?
Cutaneous pallor + Weakness
Black tarry feces
Die quick
What are the differential diagnosis for PHE?
Swine dysentery
Gastric ulcers
Salmonella
What are the resiviors in horse populations?
Rabbits
What is the window of risk seen in weanling horses?
Decreased colostrum Ab’s
– and –
Mounting own cell-mediated response
plus have a lot of stress
What symptoms area seen in horses with L. Intracellularis infections?
Lethargy + Anorexia + Fever
Hypoproteinemia + Hypoalbunemia
Peripheral edema!!
What are the differiential diagnosis for horses with L. Intracellularis infections?
Parasitism
Bacterial infection
Viral infection
Plant toxicity
What bacterial infections can look like L. Intracellularis?
Clostridium
Salmonella
Rhodococcus
What is the preferred method of confirmation of a L. Intracellularis infection in both horses and pigs?
IPMA - immunoperoxidase monolayer assay
What is done diagnostically in horses only when a L. Intracellularis infection is suspected?
Blood work + Ultrasound
What special stain is used for L. Intracellularis?
Warthin-Starry sliver stain
What is the treatment for L. Intracellularis?
Oxytetracycline + Doxycyline
What characteristics of an AB must be present to treat L. Intracellularis?
Lipophilic or aamphoteric to concerntrate in host cytoplasm
What vaccine is avalible for L. Intracellularis? Why is this different?
Pigs - take orally in drinking water
Horses - rectally
ITS THE SAME VACCINE
