Lecture 38: Lawsonia Intracellularis Flashcards
Lawsonia is a gram ___, obligate ___
Negative, intracellular
What is the endotoxin for Lawsonia intracellularis
Lipid A
What is the function of O antigen
Hinders complement killing
What assists Lawsonia intracellular to move through SI mucous and attach to enterocytes
Unipolar flagellum
Lawsonia intracellular has a ___system that aids in escape from phagolysosome once in enterocyte
Type III secretory system
What is the purpose of Lawsonia surface antigen A (LsaA protein)
Involved in enterocyte adhesion/ invasion
Lawsonia intracellularis has no anexic growth on culture meaning….
Unable to grow in cell free media
Lawsonia requires interactions with other ___to cause disease which is called ___
Microbiota, dysbiosis
T or F: gnotobiotic pigs do not develop disease when experimentally fed Lawsonia
True
What does Lawsonia intracellularis cause
Proliferation enteropathy
What are the primary reservoirs for L. Intracellularis
Intestinal tract and environment of infected animals, viable infeces
What are some other potential reservoirs for L. Intracellularis
Mice, rats, and rabbits
What is the pathogensis of L. Intracellularis
- Ingested via fecal-contaminated material
- Survive stomach pH
- Attach to apical membrane of enterocytes in crypts of SI
- Increase mitotic events and decrease differentiation into enterocytes (rapidly dividing)
- Replace goblet cells and villus enterocytes
- Rugose or corrugated mucosa
What is responsible for the increase in mitotic events in L. Intracellularis
B-catenin/wnt upregulated
What is responsible for the decrease in differentiation of enterocytes in L. Intracellularis
Notch1 downregulated
What is the result of infection with L. Intracellularis
- Thickening of mucosa
- Malabsorptive diarrhea
- Possible fever and inflamed SI and colon
How is L. Intracellularis transmitted by infected animals
Fecal shedding
What are the reservoirs for Porcine Proliferative enteropathy
Rats and mice
How long does porcine proliferative enteropathy infection last
Months
Where does L. Intracellularis initiate in PPE
Distal jejunum and ileum
___is associated with clinical disease of PPE in piglets
Stressors
What is the subclinical form of L. Intracellularis in pigs
Poor performance, no diarrhea, necropsy shows signs of proliferative enteropathy- iletlitis/ corrugated mucosa
What occurs in the intestinal adematosis form of L. Intracellularis in pigs
Diarrhea, thickening of intestinal mucosa due to hyperplasia of crypt epithelium
What occurs in the necrotic enteritis/ileitis form of L. Intracellularis in pigs
Diarrhea, extensive necrosis and replacement of mucosa by necrotic membrane
What occurs in the regional iletis form of L. Intracellularis in pigs
Thickening if smooth muscle wall, contracted segment of distal SI- garden hose gut
What occurs in the acute form of proliferative hemorrhagic enteropathy
Dysentery, thickening of intestinal mucosa and acute hemorrhage into intestinal lumen, tarry feces present in lumen
Who is affected by PPE and porcine intestinal adenomatosis
<4 months old (weanlings/growers)
Who is affected by porcine hemorrhagic enteropathy
> 4 months (finishers/breeders) primarily gilts
T or F: pigs with PPE recover spontaneously with immunity
True
PPE can cause formation of ___casts
Yellow fibronectroic casts
When is L. Intracellularis most common in horses
August-January, spikes November-December
What are the reservoirs for L. Intracellularis in horses
Rabbits, rodents, birds, infected foals
What horses are affected by L. Intracellularis
Foals, weanlings, yearlings (3-13 months)
What are the main stressors that contribute to L. Intracellularis in horses
Weaning 4-7 months, combined with immunity gap at 4-8 months
What are the clinical signs of L. Intracellularis in horses
Corrugated ileum, edema of head, throat latch, ventral abdomen, prepuce, vulva, osmotic diarrhea, weight loss, failure to thrive
When is L. Intracellular detectable by PCR
12 days
When do horses who are infected with L. Intracellularis get loose feces
Day 15
When do horses infected with L. Intracellular get edema
Day 17
What stain can be used to dx Lawsonia
Warthin starry silver stain
How do you dx Lawsonia intracellularis
- Feces PCR/qpcr
- Blood immunoperoxidase monolayer assay
What dx can you use in horses only to dx L. Intracellularis
Ultrasound-thickening of SI mucosa, bloodwork- hypoproteinemia
Why do yuo need to be careful when using the immunoperoxidase monolayer assay to dx L. Intracellularis in pigs
Lifelong carriers with immunity so can be positive- need to do PCR
What is the tx for L. Intracellularis in pigs and horses
Oxytetracycline and doxycycline
What is the tx for L. Intracellularis in foals
Erythromycin, rifampin, IV plasma to increase oncotic pressure
What vaccine is available for pigs and horses for L. Intracellularis
Enterisol ileitis
How do you give vaccine to pigs
Orally in drinking water or IM
How do you give vaccine to horses
Intra-rectally can’t give orally stomach pH will destroy
What vaccine for L. Intracellularis is only available for pigs
Porcilis ileitis
One way to control and prevent L. Intracellularis is to reduce ___in gut microbiome
Dysbiosis
How can u decrease dysbiosis in gut micro biome to prevent L. Intracellularis
- Prebiotics
- Probiotics
- Course non-pelleted feed
What caused diarrhea or “wet tail” in the Syrian hamster
L. Intracellularis
What Syrian hamsters are significantly affected by L. Intracellularis
3-10 week old, high mortality
What is tx for L. Intracellularis in Syrian hamster
- Correct life threatening electrolyte balance and dehydration
- Enrofloxacin, doxycycline, trimpethorpins
What are some sequela of L. Intracellularis in Syrian hamsters
Obstruction, intussuception, rectal prolapse
