CATALASE-NEGATIVE COCCI

Streptococcus

Enterococcus

Viridans

Genus of catalase-negative, gram positive cocci

Spherical to ovoid

Shape of Streptococci

Group a,b,c and Streptococci pneumoniae

Streptococci that have a capsule

Group a

Streptococci that have pili

Facultative anaerobic

Classification of Streptococci according to oxygen needs

Capnophilic 5-10% CO2

Classification of Streptococci according to carbon dioxide needs

Lipoteichoic acid and proteins

Streptococci cell wall contains what?

Pyogenic

Streptococci that grows neither at 10 C nor 45 C

Streptococci pyogenes

Example of pyogenic streptococci

Viridands

Streptococci that grows at 45 C but not at 10 C

Streptococci mutans

Example of viridands streptococci

Enterococcus

Streptococci that grows at 10 C and 45 C ; can withstand temperature above 60 C

Lactic group

Streptococci that grows at 10 C but not 45 C

Streptococci lactis

Example of lactic streptococci group

Pus former

Pyogenic streptococci characteristic

Microaerophiles

Viridans streptococci characteristic

45 C

Viridands grows at what temp?

10 C

Lactic group grows at what temp?

Alpha hemolytic

Incomplete lysis of RBC

Greenish discoloration

Color of alpha hemolytic

Beta hemolytic

Complete lysis of RBC; clear colorless zone

Gamma hemolytic

Non-hemolytic colonies

Alpha prime (wide zone alpha hemolysis)

Small zone of intact erythrocytes immediately adjacent to bacterial colony

Beta hemolytic

Inner ring of alpha prime

Alpha hemolytic

Outer ring of alpha prime

Double zone hemolysis

Hemolytic pattern performed by Clostridium perfrigens

Clostridium perfrigens

Double zone hemolysis is seen in what bacteria?

Target hemolysis

Double zone hemolysis is also known as what?

Stabbing agar

Demonstrates subsurface hemolysis

Precipitin test

Lancefield's classification is based on what test?

Lancefield's classification

System that groups beta-hemolytic streptococci based on scecific cell wall carbohydrate antigens using serological test

Precipitin test (lancefield classification)

Based on the antigenic characteristic of group specific C substance, which is a cell wall polysaccharide

Todd-hewitt broth

Lancefield’s classification uses what culture?

Rebecca lancefield 1930

Lancefield's classification was developed when and by who?

Group a

Pinpoint colonies, wider beta zone;

Skin flora;

M protein

Streptococcus pyogenes

Example of group A classification

M protein

Principal virulence factor of Group A classification

Group B

Pinpoint colonies narrower beta zone;

Normal flora of URT, GIT,GUT;

Major pathogen newborn;

Cause endocarditis, neonatal sepsis and meningitis

Wider beta zone

Beta zone of Group A classification

Narrower beta zone

Beta zone of Group B classification

Streptococcus agalactiae

Example of Group B classification

Group C

S.equinus, S.equisimus and S.zooepidemicus

Group D

classification of the only streptococcus that hydrolyze esculin;

Grows on bile esculine agar (BEA)

Esculin

Group D is the only streptococcus that hydrolyze what?

Streptococcus faecalis

Only streptococcus that hydrolyze esculin

Bile esculine agar (BEA)

Group D classification/S.faecalis grows on what agar?

Group F

Small colony variants of Groups A,C,F,G,E,L,M,P,U;

Streptococcus anginosus

Group F is collectively known as what?

Alpha hemolytic

Hemolytic pattern of S.pneumoniae

6.5% NaCl

Enterococcus grows on how much NaCl?

Positive

Coagulase test of Enterococcus

Methylene blue and crystal violet (McConkey)

Enterococcus grows on what selective media?

4% bile blood agar

Enterococcus grows in how much bile blood agar?

Positive

Bile esculine agar growth of enterococcus

Positive

PYR test of Enterococcus

9.6

pH of Enterococcus

Penincillin resistant

Enterococcus is resistant to what?

Viridans group

Causes tooth abscess leading to a bacterial endocarditis

Viridans

Means green due to a-hemolysis

Tooth abscess

Viridans causes what?

Bacterial endocarditis

Viridans causes tooth abscess leading to what?

Streptococcus anginosus

Small colony variant of Group A,C,F,G

Streptococcus

Catalase negative, beta hemolytic bacterias

Streptococcus pneumoniae

Enterococcus

Viridans

Streptococcus anginosus

Catalase negative, alpha hemolytic bacterias

Non-enterococcus

Streptocccus lactis

Streptococcus intermidius

Catalase negative, non-hemolytic bacterias

Non-enterococcus

Grows in bile;

Does not hydrolyze esculin;

Penincillin sensitive

6.5% NaCl

40% bile

Non-enterococcus is inhibited by what?

Streptococcus intermidius

Used to screen patients with PAP;

Does not cause PAP

Skin and upper respiratory tract

S.pyogenes inhabits what?

Streptococcus pyogenes

Inhabits skin and upper respiratory tract of humans;

Not considered as normal flora but may be carried on nasal, pharyngeal and sometimes anal mucosa

Direct contact with mucosa or secretions

Mode of transmission of S.pyogenes

Transparent to translucent colonies;

Convex or domed;

Circular;

Shiny;

Wide beta zone

Characteristics of S.pyogenes

Lipoteichoic acid

Responsible for adherence of the bacteria to respiratory epithelial cells

M protein

Major virulence factor of S.pyogenes;

Renders the organisms resistant to phagocytosis

Hyaluronic acid capsule

Avoids phagocytosis

Streptolysin O (SLO)

Oxygen labile;

Antigenic toxic;

Responsible for subsurface hemolysis

Oxygen

The O of SLO means what?

Anti-streptolysin O

Streptolysin O stimulates the production of what?

Streptolysin S (SLS)

Oxygen stable;

Non-antigenic;

Responsible for surface hemolysis

Serum

The S of SLS stands for what?

Erythrogenic toxin

Responsible for the characteristic rash seen in scarlet fever

Rash

Erythrogenic toxin causes what seen in scarlet fever?

Bacitracin disk test (Taxo A)

Presumptive test which differentiates group A beta hemolytic Streptococci from other beta hemolytic streptococci

0.024-0.04 units

Paper test of Taxo A contains how much of bacitracin?

PYR test

Detects the presence of the L-pyrrolidonyl-B-naphthylamide using N,N-dimethylaminocinnamaldehyde reagent

L-pyrroglutamyl amino peptidase

Hydrolyzes the L-pyrrolidonyl-B-naphthylamide substrate

Bright red

Positive reaction of PYR test

Enterococcus

Aside from S.pyogenes, what bacteria species also possess the aminopeptidase enzyme?

Aminopeptidase enzyme

S.pyogenes and enterococcus species possess what enzyme?

Spherical to ovoid;

Gram +;

Short or long chains, pairs

Gram stain of S.pyogenes

Dick test

Skin test for scarlet fever

0.1 mL of SF toxin

How much SF toxin is injected in Dick test

1.5-3.0 cm

Redness, swelling and tenderness with a diameter of what will develop in susceptible children? (Dick test)

20-24 hrs

Redness,swelling and tenderness develop within how many hours in susceptible children? (Dick tesT)

Schultz-charlton test

Diagnostic test for scarlet fever

0.2 ml of SF toxin

How much SF toxin is injected in Schultz-charlton test?

Bleaching of rash within 6hrs

Positive reaction of Schultz-Charlton test

TSST-2

What toxin of S.pyogenes causes sepsis?

Acute glomerulonephritis

What post-streptococcal infection follows after skin infection?

Rheumatic fever

What post-streptococcal infection follows after sore throat?