Part I: Gram Positive Cocci (Staphylococci aureus) Flashcards
Gram Positive Cocci are categorized by (5)
- Staphylococci
- Micrococci
- Group D - Non Enterococci & Enterococci
- Streptococci
Gram Positive Cocci : Staphylococci
Coagulase (+) :
Coagulase (-) :
Coagulase (+) : S.aureus
Coagulase (-) : S.saprophyticus & S. epidermidis
Gram Positive Cocci : Group D - Non Enterococci (2)
S. bovis
S. gallolyticus
Gram Positive Cocci : Enterococci (4)
E. faecium
E. faecalysis
E. avium
E. durans
Gram Positive Cocci : Streptococci
Beta Hemolytic : (2)
- S. pyogenes (Group A)
- S. agalactiae (Group B)
Gram Positive Cocci : Streptococci
Alpha Hemolytic: (2)
- S. pnuemoniae
- Viridans Streptocci
Streptocci
Alpha Hemolysis: Viridans Strep spp. (4)
S. mutans
S. sanguis
S. mitis
S. salivarium
Staphylococci appearance under microscope
Grape-like clusters
Staphylococci grows under ___________% NaCI
7.5-10% NaCI
Staphylococci are resistant in TAXO A or also known as
Bacitracin (0.02-0.04)
Test used differentiate Staphylococci and Micrococci from Streptococci
Catalate Test
Catalase Test reagent
Hydrogen peroxide
Catalase Test positive result shows
Bubbling / Effervescence
inoculate from BAP under Catalase Test shows
FALSE NEGATIVE REACTION
- Most significant species
- Normal flora of anterior nares and nasopharynx
S.aureus
S.aureus can cause
Non-toxin Mediated disease
Toxin Mediated disease
S. aureus : Toxin Mediated Disease (3)
- Food poisoning
- Scalded skin syndrome /Ritter’s syndrome
- Toxic Shock Syndrome
S. aureus : Non-Toxin Mediated Disease (7)
- wound infection
- boils
- carbuncles
- furuncles
- cellulitis
- bullous impetigo
- Stye
S. aureus : VIRULENCE FACTOR
- Major Virulence Factor
- Converts fibrinogen to fibrin
- agglutinate bacterial cells in plasma
Coagulase
S. aureus : VIRULENCE FACTOR
- reasons as to why S.aureus is resistant to Penicillin
Beta-lactamase / Penicillinase
S. aureus : VIRULENCE FACTOR
- Spreading factor
- allows bacteria to invade tissues
Hyaluronidase / Duran Raynal Factor
S. aureus : VIRULENCE FACTOR
- destruction of DNA-
- decreases viscosity of S.aureus
Dnase / Thermonuclease
S. aureus : VIRULENCE FACTOR
causes Toxic Shock Syndrome
TSST-1
S. aureus : VIRULENCE FACTOR
causes FOOD POISONING
Enterotoxin A and B