11 – Erysipelothrix

Question 1

Microbiological characteristics

Answer 1

• Biocontainment level 2
• Non-spore forming Gram-positive rods
  o Slender, non-branching rods
  o Irregular cells, curved
• Facultatively anaerobic
• Grows better with 5-10% CO2
• Gamma-hemolytic or weakly alpha-hemolytic on blood agar
• Catalase negative

Question 2

Morphology

Answer 2

• ‘kinky’ or ‘cheese doodle’
• Rougher the colony=smoother the individual bacteria

Question 3

Natural host or habitat

Answer 3

• Widely disseminated
  o Can be found in environment (resistant to salt, drying and pickling)
  o Associated with many species (found in slime of fish)
• Agricultural context=healthy carriers are primary SOURCE

Question 4

Agricultural context: healthy carriers are primary source

Answer 4

• Shed in feces and secretions
  o Directly infect others
  o Contaminates environment (up to 6months in pig feces)

Question 5

E. ruhsiopathiae and tonsillarum biochemical difference

Answer 5

• Ability to ferment sucrose

Question 6

Virulence factors

Answer 6

• Capsule
• Neuraminidase
• Hyaluronidase

Question 7

Capsule

Answer 7

• Resistance to phagocytosis
• Experimentally, capsule deficient strains UNABLE to cause disease in mice

Question 8

Neuraminidase

Answer 8

• Promotes attachment, aids in invasion
• Virulence related to level of expression

Question 9

Hyaluronidase

Answer 9

• Role in invasion

Question 10

E. ruhsiopathiae (pigs)

Answer 10

• Older than 3 months (due to waning of maternal immunity)
• Exposure through mouth (food or water)
• Maintained in herd healthy cariiers
• Enters body through palatine tonsils followed by systemic spread (bacteremia)
• Divided into acute, subacute and chronic syndromes

Question 11

E. ruhsiopathiae (pigs); acute

Answer 11

• Depression, inappetence, pyrexia and sometimes death
• Development of characteristic DIAMOND skin lesions (2-3 days after exposure)
• If severe, diamond lesions may not have time to develop before death

Question 12

E. ruhsiopathiae (pigs): subacute

Answer 12

• disease less severe than acute

Question 13

E. ruhsiopathiae (pigs): chronic

Answer 13

• long term sequelae following acute disease
• arthritis, stiffness
• possibly cardiac insufficiency if serious damage to heart valves during acute phase

Question 14

E. ruhsiopathiae (pigs) : clinical signs

Answer 14

• diamond lesions
• vegetative of mitral valves
• necrosis of ear tip
• chronic proliferative synovitis

Question 15

E. ruhsiopathiae (turkeys)

Answer 15

• route of exposure not determined: oral
• incubation period in natural infections unknow
• experimentally 2-5 days
• onset is peracute to acute
• mortality from 2-25%

Question 16

Peracute-acute E. ruhsiopathiae (turkeys)

Answer 16

• begins with death of several birds and others which are ‘droopy’
• toms may have congested, purple snoods
• often death is per-acute, and pathologically lesions may be absent
• in birds that die=endocarditis is frequently the cause

Question 17

E. rhusiopathiae (wild ungulates)

Answer 17

• associated with large die-offs
  o may represent a first encounter of naïve population
  o may be secondary to stress of warmer than normal temperatures
• *recently recovered from dead caribou in BC

Question 18

E. rhusiopathiae (humans)

Answer 18

• Occupational exposure (vets, butchers, fish handlers)
• Erysipeloid: mild form
• Systemic infection: severe form

Question 19

E. rhusiopathiae (humans): erysipeloid

Answer 19

• Skin lesions
  o Mild, localized infections
  o Typically on fingers of hand
  o Lesion 2-7 days after exposure

Question 20

E. rhusiopathiae (humans): systemic infection

Answer 20

• L sided endocarditis
• High mortality rate
• Typically, debilitated patients

Question 21

E. rhusiopathiae (dogs)

Answer 21

• Not believed to be pathogenic from pigs
• Recently described as a cause of endocarditis
  o Fever
  o Recent onset murmur
• Treat with high doses of antimicrobial
  o Penicillins
  o Extended treatment length required

Question 22

E. piscisicarius (fish)

Answer 22

• Mortality of ornamental fish species in US
• Clinical signs
  o Lethargy
  o Hovering in water
  o Hemorrhage of fins and skins

Question 23

Specimens to collect

Answer 23

• Necropsy (liver, spleen, kidney, heart, synovial tissues, LONG BONES)
• *measure at least 3 sites!
• Difficult to get from skin lesions
• Blood cultures: dogs with suspect endocarditis

Question 24

Sample handling

Answer 24

• Do NOT freeze samples

Question 25

Lab ID

Answer 25

• Standard lab culture methods
• Selective media helpful
  o Pre-enrichment useful
  o Sodium azide
  o Agar with antibiotics
• Easily by biochemical methods
• MALDI-TOF
• Pathogenicity testing using mouse infection model (historical)

Question 26

E. rhusiopathiae zoonotic/interspecies transmission

Answer 26

• Ability to cause disease in wide variety of hosts
• Risk in people is occupational

Question 27

E. tonsillarum zoonotic/interspecies transmission

Answer 27

• Not know to be associated with disease in people

Question 28

Treatment options

Answer 28

• Penicillin
• Pathological changes associated with infection may complicate therapy

Question 29

Drugs to avoid/intrinsic resistance

Answer 29

• Sulfonamides
• Aminoglycosides
• Glycopeptides (vancomycin): not a problem as a VET