E2 Genus Staph & Strep Flashcards
What do Staphylococcus look like?
Buch of grapes
How is Staph differentiated from Strep?
Catalase +
otherwise they look similar
What is are some clinical hallmarks of Staph infection?
Pimple or boil = abscess
Mastitis in cows
What special syndrome can be cause by a Staph infection?
Toxic Shock
What are the coagulase & B-hemolysis of S. aureus?
Coag = + B-Hemo = +
Are Staph commensals and only opportunistic pathogens?
Yes
What is special about some colonies of Staph?
Live in biofilms
What factors of Staph are most important for pathogenesis?
- Protein A = avoids phagocytosis
2. Survives intracellularly in phagocytes
What are some soluble virulence factors?
Leukocidin
Catalase
Coagulase
DNase
What is Toxic Shock Syndrome?
Superantigen activation
Is antibiotic resistance a major problem in Staph?
Yes!
Methicillin Resistance
Use Vancomycin!
What is positive about food animals harboring drug resistant Staph?
Isolates are host-adapted!
What is Staphylococcus hyicus?
Greasy Pig Disease
Esp. piglets
What is Staphylococcus pseudintermedius?
Canine skin infection
Normally commensal
Are Strep bacteria commensals?
Yes!
What is different about the arrangement of Strep cocci?
Chains!
What are the three types of Strep hemolysis?
- Beta = complete
- Alpha = partial
- Gamma = NONE
Are Lancefield groupings related to virulence?
No. Just random groups!
What are M-proteins?
Strep proteins
Related to hemolysis
What is Strep’s most important virulence factor?
Capsule!
Is M-protein a virulence factor?
No!
Where do Strep like to live?
Mucus membranes and intestines
How does Strep spread through tissues?
Digest fibrin clots
What does M-protein do?
Help Strep avoid phagocytosis
Do Strep survive inside phagocytes like Staph?
No cannot survive inside
What is Strep agalactiae?
Mastitis in cows
Detect B-hemolysis in bulk tanks
40% of mastitis infections
What is Strep zooepidemicus?
Common cause of wound infections in horses
Can cause arthritis
What is Strep equi?
Strangles in horses
Streptolysins kill phagocytes
How is Strep equi diagnosed?
PCR detects M-protein
Need 3 neg tests in a row to be declared nagative
Is there a vaccine for Strep Equi?
Yes, but NOT a DIVA vaccine
What is Strep equisimilis?
Suppurative arthritis
Young pigs
Transmitted from gential tract of sow
ZOONOTIC!
What is Strep suis?
Colonizes tonsils 1. Arthritis 2. Meningitis 3. Septicemia & sudden death ZOONOTIC
What are the two types of Strep suis?
Type I
= baby pigs
= more invasive
=meningitis
Type II
= older pigs
= septicemia
What is scary about resistance in Staph & Strep?
Vancomycin resistance
= last choice antibiotic
What is a good antibiotic choice for non-resistant Strep or Staph?
Penicillin