STREPTOCOCCUS Flashcards
How do you diagnose S. agalactiae?
- Direct smears
- Colony characteristics and biochemical tests
Give the species of streptococcus:
- No pathogenic properties but omnipresent in milk
- Common milk-souring in short chains
S. lactis
Give the pathogenesis of S. agalactiae. (target organs, spread, symptoms/clinical signs)
- In mammary glands of cows, sheep and goats
- Spread: milker’s hands, contaminated milking machines. mouth of calves
- Enters thru teats and colonize mammary glands resulting to inflammation and fibrosis of adjoining area; milk becomes alkaline and WBC count exceed 500,000/ml; milk reduced, thin and watery
Give the 2 antigens emitted by S. equi.
R and M antigens (M protein is antiphagocytic)
Which specie of Streptococcus is the most common cause of suppurative arthritis in pigs causing lameness, swelling of points, and necrosis of joint surfaces?
S. equisimilis
How do you prevent S. equisimilis infection?
Vaccination
Give the species of streptococcus:
- Meningitis and septicemia in young pigs
- Group D
- Zoonotic
S. suis
What are the classifications of Streptococcus under Sherman system? Give their corresponding associations.
- Pyogenic - pathogenic species
- Viridans - alpha/green hemolysis
- Lactic - associated with milk
- Enterococcus - intestine
Give the species of streptococcus:
- Abundant in feces of horses
- Not known to be pathogenic
S. equinus
Give the species of streptococcus:
- Always present in mouth and intestinal tract of cattle
S. bovis
What is the virulence factor of Streptococcus that interferes with phagocytosis?
Hyaluronic acid capsule
Specie of Streptococcus that is found in secretions from infected udder; long chains
Streptococcus agalactiae
What virulence factors of S. equi makes it acquire high rate of survival?
M protein and hyaluronic acid
What is the incubation period of S. equi?
3 to 6 days to 3 weeks or longer
What diseases does S. zooepidemicus induces?
- Mastitis (cows)
- Fibrinous pleuritis (lambs)
- Pericarditis (lambs)
- Pneumonia (lambs)
S. equisimilus can reside in tonsillar tissues and draining lymph nodes. True or False?
True
Specie of Streptococcus that is most common cause of wound infection in horse
S. zooepidemicus
To what specie is S. zooepidemicus closely related?
S. equi and S. equisimilis
Extracellular products/toxins of Streptococcus that are low molecular weight proteins.
Erythrogenic toxin (A, B, C)
Give the symptoms of S. equi infection.
- High fever
- Small abscesses in submandibular and retropharyngeal lymph nodes; serous nasal discharge
- Rupturing of abscesses (1-2 weeks after infection)
- Bastard strangles
Virulence factors - Extracellular products - Hemolysins: What are the hemolysins responsible for beta hemolysis?
Streptolysins O and Streptolysins S
What is the virulence factor of Streptococcus that inhibits phagocytosis and induce immunotoxic effect on polymorphs and platelets?
Protein M
Extracellular enzyme that promotes spread of infection in tissues
Hyaluronidase
When Streptococcus grows in milk, what does it produce?
Lactic acid