Brachyspira Flashcards
What are the characteristics of Brachyspira?
- Spiral shaped
- Anaerobic, O2 tolerant
- Several species
- 3 are important pathogens
What are the Pathogenic Species of Brachyspira?
- B. hyodysenteriae
- B. hampsonii
- B. pilosicoli
- Strong Hemolysis
What are the nonpathogenic species of Brachyspira?
- B. innocens
- B. intermedia
- B. murdochii
- Weakly hemolytic
How are B.hyodysenteriae infections diagnosed?
- Based on clinical signs, lesions, and isolation of spiral shaped organisms with strong hemolytic activity
- Confirmation by PCR or Fluorescent antibody technique
- Dark-field or phase contrast microscopy of colonic mucosal scapings
- Fluorescent in situ hybridization (FISH) with species-specific monoclonal antibody
Where can B. hyodysenteriae be found?
- Both pathogenic and nonpathogenic species reside in the intestinal tract of swine
- Also wild rats and mice
What is the mode of infection of B. hyodysenteriae?
Ingestion
What are the virulence factors of B. hyodysenteriae?
- Hemolysin
- LPS
- Flagella
What are the antigenic characteristics of B. hyodysenteriae?
- Nine serovars based on LPS antigen
What is the pathogenesis of B. hyodysenteriae?
- enters colon
- invades goblet cells, multiplies in the crypts of Lieberkuhn
- Stimulates mucus production
- “Muchohemorrhagic colitis”
- Primarily affects grower/finisher pigs
What are the clinical signs of B. hyodysenteriae infection?
- Fever (104-105F)
- Watery diarrhea with mucus
- +/- blood
- Abdominal pain
- Dehydration
- Chronic cases:
- Persistent diarrhea with dark feces
- “Black scours”
What lesions are seen with B. hyodysenteriae infections?
- Confined to large intestine
- Mucosa covered by mucofibrinous exudate with blood
- Swollen mesenteric lymph nodes
How are B. hyodysenteriae infections treated?
- Antibiotics in the feed/water
- Lincomycin, Tylosin, Tiamuli*, Carbadox*, Virginiamycin
- AMR is common, AST is beneficial
- Recovered animals may become carriers
What are the control measures for B. hyodysenteriae?
- Antimicrobial feed additives
- Depopulation and sanitation of the facility
- Restock with noninfected pigs
What disease does B. hyodysenteriae and B. Hampsonii cause?
Swine Dysentery
Is there a Vaccine for B. hyodysenteriae?
- Autogenous vaccine
- Not very effective