Gram Positive Cocci Flashcards
Test to separate Staphylococcus & Micrococcus from Streptococcus
Catalase Test
* Catalase Positive: Staphylococcus, Micrococcus;
* Catase Negative: Streptococcus
In tetrads
Micrococcus
Grapelike in clusters
Staphylococci
Identification of Staphlococci
- Arrangement:
- O2 Requirement:
- Hemolysis:
- Glucose utilization:
- Bacitracin:
- Furazolidone:
- Lysostaphin
- Microdase:
- Catase:
- Coagulase:
- DNAse:
- Arrangement: Grape-like clusters
- O2 Requirement: Facultative anaerobe
- Hemolysis: Beta-hemolytic
- Glucose utilization: Fermentation
- Bacitracin: Resistant
- Furazolidone: Susceptible
- Lysostaphin Susceptible
- Microdase: Negative
- Catalase: Positive
- Coagulase: Positive
- DNAse: Positive
Test to differentiate S. aureus from other Staphylococci spp.
Coagulase Test
* Coagulase Positive: S. aureus
* Coagulase Negative: S. epidermidis, S. saprophyticus
Used in Coagglutination test which it binds to the Fc portion of IgG
Protein A (Cowan 1 strain)
Clumping factor
Bound coagulase - detected in Slide Coagulase test
Coagulase Reacting Factor
Free coagulase - detected in Tube coagulase test
Spreading Factor/Duran Reynal Factor
Hyaluronidase factor
causes Osteomyelitis (#1 common cause - S. aureus)
Fibrinolysin
Staphylokinase
dissolves fibrin clot
Leukocidin
Panton Valentine Leukocidin
lysis of neutrophils and macrophages
Infection caused by Exfoliatins/Epidermolytic toxin
Scalded Skin Syndrome
Generalized form of Scalded Skin Syndrome
Ritter’s disease
<90% of the Body is affected
Localized form of Scalded skin syndrome
Pemphygus neonatorum
Milder with few blisters
Toxin causing Food Poisoning
Enterotoxin A & B
Toxin causing Toxic shock syndrome (TSST-1)
Enterotoxin F
Commonly associated case of TSS
Menstruating women using TAMPONS
Infection caused by S. epidermidis
Endocarditis after prosthetic-heart valve insertion
IV catheters by BIOFILM production
Infection caused by S. saprophyticus
UTI in sexually active young females
Honeymoon cystitis
Differential test of Coagulase Negative Staphylococci (CONS)
Novobiocin
* Novobiocin Susceptible: S. epidermidis
* Novobiocin Resistant: S. saprophyticus
Coagulase Positive in Tube Test
S. aureus
S. intermedius
Test to differentiate S. aureus from S. intermedius
Acetoin (VP) Test
Rapidly differentiate micrococci from staphylococci
Microdase Test
Streptococcus Classification based on Antigenic determinant
Lancefield Classification
Streptococcus Classification based on Hemolysis
Brown and Smith Classification
Streptococcus Classification based on Temperature
Academic or Bergey’s Classification
Streptococcus Colonies on BAP
Pinpoint colonies
Staphylococcus colonies on BAP
Pinhead colonies
Differentiate Streptococcus
Hemolysis Pattern
Group A Streptococci
S. pyogenes
Group B Streptococci
S. agalactiae
Group C streptococci
S. eqeuisimilis
S. aqeusimus
S. dysagalactiae
Group D
Enterococcus
Strep causing Beta-hemolysis
S. pyogenes (GAS)
S. agalactiae (GBS)
Strep causing Alpha-hemolysis
S. pneumoniae
Viridans group
Strep causing Gamma hemolysis
Enterococci
Anti-phagocytic cell wall of S. pyogenes
M protein
Streptolysin O
Oxygen labile - will produce hemolysis only in the absence of O2
Antigenic
Responsible for subsurface hemolysis and increase in anaerobic
Streptolysin S
Oxygen stable
Non-antigenic
Responsible for surface hemolysisi and increased aerobically
Responsible for
the beta-hemolytic pattern
Streptolysin
Toxin causing Scarlet fever
Exotoxin A - Erythrogenic toxin/Pyrogenic toxin
Toxin causing Necrotizing Fascitis
Supparative Fascitis, Hospital gangrene, Necrotizing Erysipelas
Streptococcal Pyrogenic Exotoxin (SPE)
Flesh eating bacteria
S. pyogenes
Causes ERYSIPELAS
S. pyogenes
Finding - Strawbery Tongue
Scarlet Fever
S. pyogenes important sequelae
PSGN
Rheumatoid fever
Type III Hypersensitivity reaction
Susceptibility test for Scarlet fever
Screening test
Dick’s Test
Diagnostic Test for current scarlet fever
Schultz charlton
Major cause of Neonatal meningitis
S. agalactiae
CAMP Factor
Enhances hemolysis of S. aureus
Differentiate Group A from Group B Streptococci
Bacitracin Test
* Suscpetible - Group A
* Resistant - Group B
mnemonics: BR AS
Hemolytic pattern of S. agalactiae in CAMP test
Arrowhead zone of Hemolysis
Identification of Group A - S. pyogenes
- Bacitracin:
- SXT:
- PYR Test:
- CAMP Test:
- Hippurate Test:
- Bacitracin: Susceptible
- SXT: Resistant
- PYR Test: Positive
- CAMP Test: No enhanced hemolysis
- Hippurate Test: Negative
Identification of Group B - S. agalactiae
- Bacitracin:
- SXT:
- PYR Test:
- CAMP Test:
- Hippurate Test:
- Bile Esculin:
- Growth in 6.5%:
- Bacitracin: Resistant
- SXT: Resistant
- PYR Test: Negative
- CAMP Test: Arrowhead hemolysis
- Hippurate Test: Positive
- Bile Esculin: Negative
- Growth in 6.5%: Positive
Identifies Group B Streptococci
CAMP test
Hippurate hydrolysis
Bacitracin Disk
Taxo A with 0.04 units
ZOI: 10 mm
Negative CAMP Test
Negative: No enhancement of hemolysis
End products of hydrolysis of hippuric acid
Glycine
Benzoic acid
Positive test of Hippurate hydrolysis
Deep Purple
Color developer in PYR test
p-dimethylcinnamaldehyde
Medium for isolation of S. agalactiae
Todd Hewitt Broth
S. pneumoniae in Gram stain
Lancet shaped/Bullet shaped, Encapsulated
Young colonies of S. pneumoniae
Dome shaped
Old colonies of S. pneumoniae
Coin with a raised rim
Pneumonia associated to S. pneumoniae
Lobar Pneumonia
with Rusty colored Sputum/Anchovy sause
Major cause of Otitis Media
S. pneumoniae
Identification of S. pneumoniae
- Optochin:
- Bile Solubility:
- Inulin Fermentation:
- Animal inoculation:
- Neufeld quellung’s test:
- Optochin: Susceptible
- Bile Solubility: Soluble
- Inulin Fermentation: Positive
- Animal inoculation: Positive
- Neufeld quellung’s test: Capsulaw swelling
Skin Test of S. pneumoniae
Frances Test
Viridans group causing Sub-acute bacterial endocarditis
S. sanguinis
Viridans causing Bacterial Endocarditis
S. mitis
Viridans causing Dental caries
S. mutans
Oral streptococci
Identification of Viridans Streptococci
- Optochin:
- Bile Solubility:
- Growth in 6.5% NaCl:
- Bile esculin:
- Inulin Fermentation:
- Animal inoculation:
- Neufeld quellung’s test:
- Optochin: Resistant
- Bile Solubility: Insoluble
- Growth in 6.5% NaCl: Positive
- Bile esculin: Negative
- Inulin Fermentation: Negative
- Animal inoculation: Negative
- Neufeld quellung’s test: Negative
Differentiates S. pneumoniae from Viridans
Optochin Test
Presumptive test
Optochin Disk
Taxo P
Reagent in Optochin test
Ethylhydrocupreine HCl
Identification (confirm) of S. pneumoniae
Bile solubility
Presumptively identify Group D Streptococci and Differentiate Group D from Non-Group D Viridans Streptococci
Bile Esculin Test
Vancomycin Resistant
Group D Enterococci
Bacteria causing COLON cancer
S. bovis
Growth Factor of E. faecalis
Vitamin B12
Nutritionally Variant Streptococci
Abiothrophia
Growth factors of Abiothrophia
Vitamin B6
Pyridoxal
Thiol
Exhibit sattelitism in S. aureus
Abiothrophia
Differentiates S. bovis from S. salivarius
Starch hydrolysis
Mannitol fermentation