Streptococcus Flashcards by Gay Amor Tipolo Gacang

Q

Characterized by greenish hemolysis around the colony

A

ALPHA (α)

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Due to incomplete/ partial destruction of red blood cells

A

ALPHA (α)

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Example of bacteria that has alpha hemolysis

A

Viridans streptococci and Streptococcus pneumoniae

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Characterized by clear, colorless zone of hemolysis

A

BETA (β)

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Due to complete destruction of red blood cells

A

BETA (β)

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Example of bacteria that has beta hemolysis

A

Streptococcus pyogenes and
Streptococcus agalactiae

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Non – hemolytic on blood agar

A

GAMMA (γ)

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Example of bacteria that has gamma hemolysis

A

Enterococcus faecalis

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

LANCEFIELD CLASSIFICATION is Based on the ________ antigen found in the cell wall

A

C – carbohydrate

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Bacteria’s that do not have carbohydrate cell wall antigen

A

Streptococcus pneumoniae & Viridans streptococci

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

LANCEFIELD CLASSIFICATION

A

A

Streptococcus pyogenes

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

LANCEFIELD CLASSIFICATION

B

A

Streptococcus agalactiae

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

LANCEFIELD CLASSIFICATION

C

A

Streptococcus equisimilis,
Streptococcus zooepidemicus,
Streptococcus equi

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

LANCEFIELD CLASSIFICATION

D (enterococci)

A

Enterococcus faecalis,
Enterococcus facium

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

LANCEFIELD CLASSIFICATION

D (non-enterococci)

A

Streptococcus bovis,
Streptococcus durans

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

LANCEFIELD CLASSIFICATION

G

A

Streptococcus arginosus

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Lancefield Classification & Hemolytic Pattern (Smith & Brown)

Streptococcus pyogenes

A

A & beta

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Lancefield Classification & Hemolytic Pattern (Smith & Brown)

Streptococcus agalactiae

A

B & beta

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Lancefield Classification & Hemolytic Pattern (Smith & Brown)

Strep. agalactiae subsp. equisimilus

A

C & beta

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Lancefield Classification & Hemolytic Pattern (Smith & Brown)

Enterococcus – Streptococcal faecalis

A

D
Alpha or Beta or None

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Lancefield Classification & Hemolytic Pattern (Smith & Brown)

Non-enterococcus –Strep. bovis

A

D
Alpha or none

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Lancefield Classification & Hemolytic Pattern (Smith & Brown)

Streptococcus pneumoniae

A

NA
Alpha

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

Lancefield Classification & Hemolytic Pattern (Smith & Brown)

Streptococcus viridans

A

NA
Alpha or none

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

Q

produces large (1cm in diameter) zones of β hemolysis around
colonies greater that 0.5 mm in diameter

A

Group A β Hemolytic Streptococcus

How well did you know this?

1

Not at all

2

3

4

5

Perfectly

main human pathogen associated with local or systemic invasion and post – streptococcal immunologic disorders

Group A β Hemolytic Streptococcus

HABITAT: Skin and Upper Respiratory tract of humans, carried on nasal, pharyngeal, sometimes anal mucosa

Group A β Hemolytic Streptococcus

Prone to progression with involvement of deeper tissues and organs, a characteristic that has earned the designation ‘’flesh – eating bacteria”

Group A β Hemolytic Streptococcus

Fastidious, requires enriched media for primary isolation incubated with 5% – 10% CO2

Streptococcus pyogenes

ferment wide variety of carbohydrate with production of lactic acid with or without gas

Streptococcus pyogenes

Blood agar: Appears as circular, translucent, grayish to opalescent colonies, matte or glossy large zone beta hemolysis

Streptococcus pyogenes

Streptococcus pyogenes Morphological, Cultural and Biochemical Characteristics: Catalase test PYR Bacitracin

Catalase negative PYR positive Bacitracin sensitive

test for Group A Streptococcus

PYR Hydrolysis Test (POSITIVE)

demonstrate presence of pyrrolidonyl arylamidase

PYR Hydrolysis Test (POSITIVE)

PYR Hydrolysis Test (POSITIVE): develops what color within a minute addition of reagent

Cherry red color

Bacitracin Susceptibility Test (+) =

any presence of ZOI

Presumptive test and Used to differentiate Streptococcus pyogenes and Streptococcus agalactiae

Bacitracin Susceptibility Test (+)

Bacitracin Susceptibility Test (+) S. pyogenes S. agalactiae

S. pyogenes (sensitive) S. agalactiae (resistant)

specialized polysaccharide or teichoic acid; found in the surface of the cell wall

C - carbohydrate

Group A specific cell wall antigen

C - carbohydrate

use as basis for serological classification using Lancefield method

C - carbohydrate

Protein antigens:

M - Protein T - Protein

Protein antigens: major virulence factor of group A S pyogenes.

M – Protein

appears as hair-like projections of the streptococcal cell wall

M – Protein

Immunity to infection with group A streptococci is related to the presence of type-specific antibodies to _______

M – Protein

Protein antigens: acid-labile and heat-labile

T – Protein

PROTEIN ANTIGENS obtained from streptococci by proteolytic digestion, which rapidly destroys M proteins.

T – Protein

PROTEIN ANTIGENS permits differentiation of certain types of streptococci by agglutination with specific antisera

T – Protein

allows organism to cling to epithelial surfaces

Lipoteichoic Acid (LTA)

Cytotoxic; destroys rbc and wbc

Lipoteichoic Acid (LTA)

most important virulence factor

M protein antigen

aid in the attachment of the organism to portal of entry

M protein antigen

Antiphagocytic; promotes invasiveness of the organism

Capsule (Hyaluronic acid)

depolymerizes DNA; facilitate removal of purulent exudate/ discharges

Streptodornase (Streptococcal Deoxyribonuclease)

enzymatic activity can be measured by the decrease in viscosity of known DNA solutions.

Streptodornase (Streptococcal Deoxyribonuclease)

antibody to DNAse develops after streptococcal infections (normal limit = 100 units), especially after skin infections.

Streptodornase (Streptococcal Deoxyribonuclease)

produced by many strains of group A -hemolytic streptococci.

Streptokinase (Fibrinolysin)

transforms the plasminogen of human plasma into plasmin, an active proteolytic enzyme that digests fibrin and other proteins.

Streptokinase (Fibrinolysin)

are antigenic and specific for each bacterial or tissue source.

Hyaluronidase

splits hyaluronic acid, an important component of the ground substance of connective tissue.

Hyaluronidase

aids in spreading infecting microorganisms (spreading factor)

Hyaluronidase

An enzyme elaborated into the environment and is related to the organism's ability to kill leukocytes, PMN’s and macrophages

Diphosphopyridine nucleotidase

EXTRACELLULAR ENZYMES

A. Streptodornase (Streptococcal Deoxyribonuclease) B. Streptokinase (Fibrinolysin) C. Hyaluronidase D. Diphosphopyridine nucleotidase

Hemolysins oxygen stable; non antigenic : surface BAP hemolysis during aerobic condition

Streptolysin S

Hemolysins oxygen labile; antigenic

Streptolysin O

Immunogenic; responsible for some of the hemolysis seen when growth is in cuts deep into the medium in blood agar plates.

Streptolysin O

combines quantitatively with antistreptolysin O (ASO)

Streptolysin O

an antibody that appears in humans following infection with any streptococci that produce streptolysin O.

antistreptolysin O (ASO)

ASO serum titer in excess of___________ is considered abnormally high and suggests either recent infection with S. pyogenes

160–200 Todd units/mL