23 - Brachyspira and Lawsonia Flashcards
Lawsonia intracellularis microbiological characteristics
- Obligate INTRACELLULAR parasite
- Can’t be grown outside of cell culture
- Biocontainment level 2
- *PCR
Brachyspira spp microbiological characteristics
- Aerotolerant anaerobe
- Do NOT typically form colonies
- Challenging to grow
- Biocontainment level 2
- *varying degrees of hemolysis
- *Treponema spp. closely related to it: similar growing requirements
- *PCR
Natural host or habitat of Lawsonia intracellularis
- Obligate intracellular organism
- Lives IN THE ENTEROCYTES of hosts
Natural host or habitat of Brachyspira spp.
- Found in GIT of many species
o Domestic and wild birds
o Pigs
o People
o Rodents
o Dogs
Lawsonia intracellularis virulence factors
- Type 3 secretion systems
- Very little known
Brachyspira spp. virulence factors
- Speculation, but poorly defined
- Flagella: SEE SWIMMING ON A WET MOUNT
- Chemotaxis: attracted to mucouos
- Hemolysins?
- *bacteriophage attack!
What does Lawsonia intracellularis cause in pigs?
- Proliferative enteritis (ileitis)
o Corrugation of mucosa!
What are the multiple forms of Lawsonia intracellularis disease in pigs?
- Intestinal adenomatosis: hyperplasia of crypt epithelium
- Necrotic enteritis
- Regional ileitis
- Proliferative hemorrhagic enteropathy: *can resemble swine dysentery
What does Lawsonia intracellularis cause in horses and what does it commonly affect?
- Proliferative enteropathy
- *weaning foals (4-6months)
What are the clinical signs seen in horses with Lawsonia intracellularis?
- Weight loss
- Diarrhea
- Colitis
How is Lawsonia intracellularis transmitted?
- Fecal oral route
Lawsonia intracellularis horse and pig strains
- UNKNOWN whether they are the same
What does Lawsonia intracellularis cause in hamsters?
- ‘wet tail’
o Diarrhea, dehydration
o Anorexia
o Death - *devasting outbreaks in large colonies (ex. pet store)
What does Lawsonia intracellularis usually affect in hamsters? (age group)
- Weanlings (3-8 weeks)
What do you treat Lawsonia intracellularis with and how do you control it?
- Antimicrobials and aggressive rehydration
- *isolate affected animals
What do B. hyodysenteriae and (B. hampsoni) cause in pigs?
- Swine dysentery
- Incubation period: 3-7days (experimentally)
- *see spirochetes in fecal smear
What are the clinical signs with Swine dysentery?
- *diarrhea: mild and watery to muco-hemorrhagic
- Inappetence
- Pyrexia
- Mortality in peracutely affected animals
- *most commonly see in older pigs (grower finisher)