Brachyspira (Serpulina) Lawsonia Treponema Flashcards
What family does Brachyspira belong to?
Family Spirochaetaceae
Brachyspira Gram__? Shape?
Gram negative Spiral shaped
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Brachyspira Aerobe/Non-aerobe?
Oxygen-tolerate Obligate anaerobes
Brachyspira Where do they typically colonize?
Large Intestine
Look at this chart on species variations
*Chart*
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Look at map of distribution
*Map* Said in class: North Carolina too
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Brachyspira - Pathogens in the genus
B. hyodysenteriae B. pilosicoli B. aalborgi Controversial ones: B. intermedia (avian spirochetosis) B. murdochii, B. innocens, B. canis
**Brachyspira hyodysenteriae**
Swine dysentary!! -Actively growin pigs (6-12wks) **Only strongly beta-hemolytic strain** **Indole Positive**
Brachyspira pilosicoli
Colonic /Intestinal Spirochetosis -Pigs (post-wean), dogs, birds, immunocompromised humans
Brachyspira aalborgi
Human spirochetosis (rare)
Brachyspira- Virulence factors
Cell Wall Flagella
Brachyspira - Cell Wall 2 virulence factors
LPS Hemolysin/ Cytotoxin
Brachyspira - LPS
More like LOS, short/variable O-antigen repeats Endotoxin/Lipid A
Brachyspira- Hemolysin/Cytotoxin
**B. Hyodysenteriae=strongly beta hemolytic** Pore-forming cytotoxin : goblet & colonial epithelial cell damage
Brachyspira - Flagella
Necessary for virulence! -Move through intestinal mucus to access target cells
Brachyspira- Reservoir
Can persist in environment for months if protected from desiccation
Brachyspira Reservoir B. hyodysenteriae
**Asymptomatic carrier pigs** -Mice, shed for <6 months -Dogs, rats, birds
Brachyspira Reservoir B pilosicoli
Isolated from dogs, birds, many mammals, humans Attach to intestinal mucosa is key to carriage
Brachyspira - Transmission
All species - Fecal-Oral
Brachyspira Pathogenesis
Colon colonized==> Inflammation, cytotoxins, PMNS==> Superficial coagulation necrosis with epithelial erosion in mucosa/submucosa -Edema, hyperemia, hemorrhages Failure of colonic absorption
Brachyspira - Signs
Secretory diarrhea Grey to strawberry-colored feces Dehydration - acidotic & hyperkalemic High morbidity, 40% mortality Lasts several weeks Asymptomatic shedders difficult to ID
Brachyspira Differentials
Salmonellosis Lawsonia intracellularis
What is the likely causative agent of these signs in the pictures?
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Brachyspira infection (Likely B. hyodysenteriae)
What is this picture showing?
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Avian intestinal spirochaetosis B. pilosicoli adhering to cecal surface epithelial cells
Brachyspira - Immunology
Poorly understood -Recovered pigs resistant <4 months
Which antibodies fight against a Brachyspira infection?
IgG and IgA - but not highly protective
Brachyspira - Bacterins
Reduce severity of the disease
Brachyspira Samples
Fecal or colonic
Brachyspira Problems with sample collection
Should be conducted quickly, not be allowed to dry
Brachyspira Stained smears
Loosely coiled spirochetes -Must be differentiated from nonpathogenic species
Brachyspira Isolation Selective medias used
Blood agar with several antibiotics: Spectinomycin Rifampin Spiramycin Vancomycin Polymixin Colistin
Brachyspira Incubation
Anaerobic for several days
Brachyspira - Hemolysis
Beta hemolysis (ring) Strength related to pathogenicity **B. hyodysenteriae**
Brachyspira - Lab Dx
PCR (rule out Salmonella & Lawsonia) B hyodysenteriae are indole positive
Brachyspira Treatment
Resistance! Several antibiotics Tiamulin, Valnemulin, tylosin, lincomycin, carbadox (restricted) MTZ for dogs
Brachyspira Control - Avians
Difficult No approved treatments Long withdrawal times
Lawsonia intracellularis Disease & specied affected
*Proliferative Enteropathy* Porcine Equine Rodents (& other mammals) Avians
Lawsonia intracellularis Site of infection
Obligate intracellular pathogen of enterocytes (Apical cytoplasmic area - closest to lumen)
Lawsonia intracellularis Distribution
Worldwide
Lawsonia Virulence factors
LPS - typical Gram Negative T3SS - unknown role
Lawsonia Reservoir
Intestinal tract and environment Possible rodents on horse & pig farms
Lawsonia Transmission
Fecal-oral
Lawsonia - What is required for disease to show?
Interaction with unknown natural flora -Experimental inoculation of germ-free swine does not lead to disease
Lawsonia Pathogenesis
Microbes escape phagocytic vacuole–> Multiply–> Inhibit host cell maturation (but enterocyte division continues, daughter cells infected)
Lawsonia - Site of infection
Distal jejunum and ileum
Lawsonia - Effect at infection sie
Minimal to moderate inflammation -Neutrophils, macrophages, lymphocytes present
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Lawsonia - Type of immunoglobulin?
IgA - specific response
Lawsonia - Lasting immunity?
Recovered pigs are resistant to infection
Lawsonia - Vaccine?
Swine vaccine available, commonly used Oral. Live-attenuated
Lawsonia Diagnosis
Stained smears of intestinal mucosa Histo: evidence of proliferative changes Immunohistochemical stains Isolation NOT feasible PCR
Lawsonia Treatment
Tetracyclines Tylosin Tiamulin Lincomycin Carbadox (where available)
Treponema Typical disease
Digital dermatitis of cattle Contagious ovine digital dermatitis
Treponema paraluiscuniculi
Vent disease of rabbits, ***rabbit syphilis**** Not zoonotic Sexually transmitted (usually)
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