23 - Brachyspira and Lawsonia Flashcards

1
Q

Lawsonia intracellularis microbiological characteristics

A
  • Obligate INTRACELLULAR parasite
  • Can’t be grown outside of cell culture
  • Biocontainment level 2
  • *PCR
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2
Q

Brachyspira spp microbiological characteristics

A
  • 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
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3
Q

Natural host or habitat of Lawsonia intracellularis

A
  • Obligate intracellular organism
  • Lives IN THE ENTEROCYTES of hosts
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4
Q

Natural host or habitat of Brachyspira spp.

A
  • Found in GIT of many species
    o Domestic and wild birds
    o Pigs
    o People
    o Rodents
    o Dogs
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5
Q

Lawsonia intracellularis virulence factors

A
  • Type 3 secretion systems
  • Very little known
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6
Q

Brachyspira spp. virulence factors

A
  • Speculation, but poorly defined
  • Flagella: SEE SWIMMING ON A WET MOUNT
  • Chemotaxis: attracted to mucouos
  • Hemolysins?
  • *bacteriophage attack!
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7
Q

What does Lawsonia intracellularis cause in pigs?

A
  • Proliferative enteritis (ileitis)
    o Corrugation of mucosa!
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8
Q

What are the multiple forms of Lawsonia intracellularis disease in pigs?

A
  • Intestinal adenomatosis: hyperplasia of crypt epithelium
  • Necrotic enteritis
  • Regional ileitis
  • Proliferative hemorrhagic enteropathy: *can resemble swine dysentery
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9
Q

What does Lawsonia intracellularis cause in horses and what does it commonly affect?

A
  • Proliferative enteropathy
  • *weaning foals (4-6months)
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10
Q

What are the clinical signs seen in horses with Lawsonia intracellularis?

A
  • Weight loss
  • Diarrhea
  • Colitis
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11
Q

How is Lawsonia intracellularis transmitted?

A
  • Fecal oral route
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12
Q

Lawsonia intracellularis horse and pig strains

A
  • UNKNOWN whether they are the same
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13
Q

What does Lawsonia intracellularis cause in hamsters?

A
  • ‘wet tail’
    o Diarrhea, dehydration
    o Anorexia
    o Death
  • *devasting outbreaks in large colonies (ex. pet store)
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14
Q

What does Lawsonia intracellularis usually affect in hamsters? (age group)

A
  • Weanlings (3-8 weeks)
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15
Q

What do you treat Lawsonia intracellularis with and how do you control it?

A
  • Antimicrobials and aggressive rehydration
  • *isolate affected animals
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16
Q

What do B. hyodysenteriae and (B. hampsoni) cause in pigs?

A
  • Swine dysentery
  • Incubation period: 3-7days (experimentally)
  • *see spirochetes in fecal smear
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17
Q

What are the clinical signs with Swine dysentery?

A
  • *diarrhea: mild and watery to muco-hemorrhagic
  • Inappetence
  • Pyrexia
  • Mortality in peracutely affected animals
  • *most commonly see in older pigs (grower finisher)
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18
Q

What is the difference in disease associated with B. hampsonni vs. B. hyodysenteriae?

A
  • SAME
    o B. hampsonii is less SEVERE
19
Q

How can you control Swine dysentery?

A
  • Unclear where it comes from (carriers, wildlife?)
  • Antimicrobials in affected herds
  • NO effective vaccines
20
Q

What does B. pilosicoli cause in pigs?

A
  • Spirochetal colitis
    o Less severe than swine dysentery
  • *typically self-limiting
21
Q

What does Spirochetal colitis (B. pilosicoli) look like in finishing pigs?

A
  • ‘wet cement’ feces WITHOUT blood
22
Q

What does Spirochetal colitis (B. pilosicoli) look like in younger pigs?

A
  • Severe diarrhea (watery or mucoid)
23
Q

What is a major concern with Spirochetal colitis (B. pilosicoli) in pigs?

A
  • Poor feed efficiency
24
Q

What are the ways to control Spirochetal colitis (B. pilosicoli) in pigs?

A
  • Antimicrobials
  • NO vaccine
  • Generally good management practices (AIAI, control other diseases)
25
Q

Brachyspira alvinipulli (domestic poultry)

A
  • Associated with wet feces
  • Diarrhea, green-yellow frothy cecal fluid
26
Q

Brachyspira pilosicoli (domestic poultry)

A
  • Colonization of cecum associated with mucosal thickening
27
Q

Brachyspira hyodysenteriae (domestic poultry)

A
  • Severe, necrotizing typhlitis in juvenile rheas (ostriches)
28
Q

What does Brachyspira spp. (B. pilosicoli and B. aalborgi) cause in people?

A
  • Intestinal spirochetosis
29
Q

Where is Brachyspira spp. affecting people most common?

A
  • 30% of people colonized in DEVELOPING
  • Developed countries
    o Children, HIV, MSM (men who have sex with men)
30
Q

What are the clinical signs you can see INFREQUENTLY with intestinal spirochetosis (from Brachyspira spp.)?

A
  • Associated with GIT (non-specific)
  • Chronic diarrhea
  • +/- blood
  • Cramping
  • Colitis
  • *use histology (NOT culture)
31
Q

What can cause digital dermatitis in cattle?

A
  • Treponema spp.
  • *likely polymicrobial
32
Q

What are the 2 presentations with digital dermatitis in cattle (Treponema app.)?

A
  • Proliferative (hairy heal warts)
  • Erosive lesions
33
Q

What does digital dermatitis in cattle suggest? (Treponema spp.)

A
  • Management problem
    o Standing in wet material=predisposed
    o Maceration of skin FACILITATES infection
34
Q

What can be done to control digital dermatitis in cattle? (Treponema spp.)

A
  • Early lesions: topical (washing)
  • Topical antibiotic if more severe (oxytetracycline or lincomycin/spectinomycin)
35
Q

Sample collection and handling: Lawsonia intracellularis

A
  • Feces, RECTAL SWABS (actually rubbing the epithelium)
  • *Ileal tissue collected at necropsy
  • *do NOT freeze
36
Q

Sample collection and handling: Brachyspira spp

A
  • Rectal swabs
  • Colonic or cecal tissues collected at necropsy
  • *do NOT freeze
    o Key to grow it, but less critical for molecular tests
37
Q

Sample collection and handling: Treponema spp

A
  • Swaps or tissue to microscopy
  • *do NOT freeze
38
Q

Lab ID: Lawsonia spp

A
  • Histological examination (silver stains)
  • PCR or feces or ileal/colonic tissues
39
Q

Lab ID: Brachyspira spp

A
  • Microscopy of fecal smears
  • Culture
  • PCR based assays
  • *Sequencing is gold standard for species level ID
  • Histological examination of cecal/colon
40
Q

Lab ID: Treponema spp

A
  • Microscopy
41
Q

Zoonotic and interspecies transmission

A
  • Poorly understood
    o Study of human infections not studied (Brachyspira spp.)
  • *transmission between animals seems likely
    o ROLES OF WILDLIFE in agricultural settings
  • Ex. Snow geese in Nunavut had Brachyspira similar to the porcine strains
    o Possible contact with pigs (summer in artic, winter in US Midwest)
42
Q

Treatment options: Lawsonia

A
  • Susceptible testing IMPOSSIBLE (obligate intracellular parasite)
  • Therapy relies on MACROLIDES/PLEUROMUTILINS
43
Q

What drugs are INEFFECTIVE to treat Lawsonia?

A
  • Penicillins
  • Bacitracin
  • Aminoglycosides
  • Virginiamycin
  • Ionophores
44
Q

Treatment options: Brachyspira

A
  • Pigs: treatment relies heavily on PLEUROMUTLINS and MACROLIDES
  • Lack standardized methods
    o Have come up with agar dilation susceptibility test method (LABOR INTENSIVE)