Erysipelothrix Flashcards
What are the 2 species of Erysipelothrix of veterinary importance?
- E. rhusiopathiae***
- E. tonsillarum
What are the 2 major morphological features of Erysipelothrix rhusiopathiae?
- Gram positive
- long, filamentous rod
What do the filaments of Erysipelothrix rhusiopathiae cause in the host?
emobli
What respiration does Erysipelothrix rhusiopathiae undergo?
facultative anaerobe
How does Erysipelothrix rhusiopathiae respond to the catalase and oxidase tests?
catalase negative
oxidase negative
Is Erysipelothrix rhusiopathiae motile? Spore-forming?
no
no
What are the 28 serotypes of Erysipelothrix based on? Pigs are susceptible to 15 of these serotypes, what 3 serotypes of E. rhusiopathiae cause swine erysipelas?
- peptidoglycan antigen on the cell wall
- 1a
- 1b
- 2
What are 4 common culture media used for Erysipelothrix isolation?
- blood agar
- heart infusion + sodium azide and crystal violet
- nutrient broth + 1% glucose
- triple sugar iron
How does Erysipelothrix grow on blood agar?
α-hemolytic
How does Erysipelothrix grow on heart infusion agar with sodium azide and crystal violet?
able to ferment glucose and lactose, producine acid, but is not able to ferment maltose and mannitol
What is the result of Erysipelothrix growing in triple sugar iron agar?
H2S is produced by 95% of Erysipelothrix species strains in this media (the only Gram positive able to do so), causing a foul smell
What is the main environment for Erysipelothrix? What is its predilection site in the host?
slurry of cattle herds or sewage from abattoirs (frank pathogen!)
tonsils
lymphoid tissue of intestinal tracts in carrier animals
What are the 3 most common hosts of Erysipelothrix?
- pigs*** (including wild boar)
- horses with vegetative endocarditis
- turkey with swollen snood
When do humans tend to become infected with Erysipelothrix? What 4 conditions does it cause?
occupational zoonosis (contact!) - vets, abattoir workers, butchers, farmers
- purple-colored hardened swelling of fingers
- endocarditis
- pneumonia
- meningitis
In what 2 ways does Erysipelothrix enter their host?
- enter orally to colonize tonsils
- fly vectors
What are the 4 ways that Erysipelothrix exit their host?
- fecal*** (to spread in environment)
- urine
- saliva
- nasal secretion
Why is Erysipelothrix considered less virulent?
less virulence factors compared to other bacteria
What 2 surface structures contribute to Erysipelothrix virulence?
- capsule (lipopolysaccharide, slime, glycocalyx) - resistance to phagocytosis
- surface protective proteins (spA, B, and C antigens) - biofilm formation, adhesion, elicits an immune response
How have we used Erysipelothrix surface protective proteins?
incorporated into a vaccine (subunit)
What 3 enzymes contribute to Erysipelothrix virulence?
- neuraminidase (sialidase) - bacterial attachment, invasion, blood vessel destruction leading to hemorrhage and thrombosis
- hyaluronidase - spreading via hyaluronic acid and polysaccharide destruction between adjacent cells
- superoxide dismutase - protection from intracellular killing by macrophages
What does the neuraminidase (sialidase) cause in the host?
bacterial emboli and infarction in heart valves (endocardiitis), spleen, liver, kidney, and joints (polyarthritis)
(destroys blood vessels)
What skin problem does Erysipelothrix cause in pigs?
Diamond Skin disease - rhomboid urticarial skin lesions
What skin problem does Erysipelothrix cause in turkeys?
acute turkey erysipelas, causing swollen and purple/dark snoods
What skin problem does Erysipelothrix cause in humans?
erysipeloid - purplish, swollen, painful, hardened rash on fingers
(unlike wet and exudative skin of Strep infection)
What 6 conditions are caused by Erysipelothrix dissemination from the skin?
- endocarditis
- pneumonia
- meningitis
- osteomyelitis
- arthritis
6 abortion
What are the 5 forms of Erysipelas based on body part tropism?
- SKIN - rhomboid, urticaria,l purple/black, and hard skin lesions arond the belly, inside of thighs, throat, neck, and ears
- RESPIRATORY - pneumonia
- CARDIOVASCULAR - purple/black discoloration of the skin of the belly with cyanotic extremities due to septicemia, emboli, infarcts, and endocarditis that blocks heart valves
- JOINTS - polyarthritis mainly at the elbow, hip, hock, stifle, and knee joints
- UTERINE - abortion due to fever, but bacteria is isolated from fetus
What are the top 2 causes of endocarditis in the pig industry?
- Step. suis
- Erysipelothrix rhusiopathiae
How does Erysipelothrix infection compare to Staph. hyicus and Strep. suis?
Strep. suis manifests similar systemic clinical signs
- Erysipelothrix = lacy-skin disease, no pus formation
- Staph. hyicus = greasy skin
- Strep. suis = contagious pyoderma
What are the main 3 ways of diagnosing Erysipelothrix vs Staph. hyicus and Strep. suis?
- clinical signs - lace-like/diamond-shape skin lesion with no pus formation
- bacteriology - Gram positive and long/filamentous rods, catalase negative, α-hemolytic, H2S in agar
- serology - 28 serotypes
What are 3 common treatments for erysipelas?
- penicillin
- ampicillin
- ceftiofur
(not a member os ESKAPE)
In what 2 ways is erysipelas controlled? Why isn’t the vaccine dependable?
- remove clinically sick or positive animals from herd immediately
- good hygiene - all-in all-out policy followed by disinfection before restocking
- tends to fail due to 28 serotypes
- short duration of immunity (lasts less than 6 mos)
