WEEK 5: STREPTOCOCCI Flashcards by ZACHARIE JAEDIEL GONZAGA

Complete lysis of RBC’s around colony
**Clear area **around colony

BETA

How well did you know this?

Not at all

Perfectly

Partial lysis of RBC’s around colony
Greenish discoloration of area around colony

ALPHA

How well did you know this?

Not at all

Perfectly

No lysis of RBC’s around colony
No change in agar

GAMMA

How well did you know this?

Not at all

Perfectly

Small area of intact RBC around colony surrounded by a wider zone of complete hemolysis

ALPHA PRIME

How well did you know this?

Not at all

Perfectly

i. Gram (+) cocci arranged in pairs or chains
ii. Facultative anaerobe but some are aerotolerant anaerobes
iii. Some are capnophilic
iv. Non-motile; (-) catalase, oxidase and gas production

Streptococci

How well did you know this?

Not at all

Perfectly

Negative in Catalase test

Streptococci

How well did you know this?

Not at all

Perfectly

test the ability of the organism to
breakdown of H2O2 into oxygen and water

Catalase Test

How well did you know this?

Not at all

Perfectly

organisms that are positive in catalase test

Staphylococcus & Micrococcus

How well did you know this?

Not at all

Perfectly

in catalase test, copious bubble form if the organism is?

Positive

How well did you know this?

Not at all

Perfectly

No or few bubbles

Negative in Catalase test

How well did you know this?

Not at all

Perfectly

What is being extracted in Lancefield Classification?

C Carbohydrate

How well did you know this?

Not at all

Perfectly

Group A strep

S. pyogenes

How well did you know this?

Not at all

Perfectly

Group B strep

S. agalactiae

How well did you know this?

Not at all

Perfectly

Group C strep

S. dysgalactiae, S. equisimilis

How well did you know this?

Not at all

Perfectly

Group D Non enterococcus

S. bovis group / S. gallolyticus

How well did you know this?

Not at all

Perfectly

Group D Enterococcus

E. faecalis, E. faecium

How well did you know this?

Not at all

Perfectly

Pneumococcus

S. pneumoniae

How well did you know this?

Not at all

Perfectly

Which of the species under Streptococci group does not have a Lancefield Classification?

S. pneumoniae

How well did you know this?

Not at all

Perfectly

Viridans strep (A, C, F, G, N)

S. anginosus, mutans, mitis

How well did you know this?

Not at all

Perfectly

What is the hemolytic pattern of Group A strep? (S. pyogenes)

β (beta)

How well did you know this?

Not at all

Perfectly

What is the hemolytic pattern of Group B strep? (S. agalactiae)

β (beta)

How well did you know this?

Not at all

Perfectly

What is the hemolytic pattern of Group C strep? (S. dysaglactiae, S. equisimilis)

β (beta)

How well did you know this?

Not at all

Perfectly

What is the hemolytic pattern of Group D Non enterococcus? (S. bovis group)

α,γ (alpha, gamma)

How well did you know this?

Not at all

Perfectly

What is the hemolytic pattern of Group D Enterococcus? (E. faecalis, E. faecium)

α,β,γ (alpha, beta, gamma)

How well did you know this?

Not at all

Perfectly

What is the hemolytic pattern of Pneumococcus? (S. pneumoniae)

α (alpha)

What is the hemolytic pattern of Viridans strep? (Anginosus, mutans, mitis)

β, α, γ (beta, alpha, gamma)

- Grows at 37C - Mostly has β-hemolytic reactions - S. pyogenes, group C and G streptococci

Pyogenic group

- Grows at 37C and 45C - indigenous microbiota in the URT - S. mutans, S. mitis and S. salivarius

Viridans group

- Grows at 10C and 37C - found on dairy products - S. lactis

Lactic group

- Grows at 10C, 37C and 45C - part of the indigenous microbiota of the human intestine - E. faecalis

Enterococcus group

 Attached to the peptidoglycan  Antiphagocytic  For adherence to mucosal cells  Primary

M Protein

Mediates adherence to host epithelial cells

Protein F (Fibronectin-binding protein)

Mediates attachment to mucosal cells

Lipoteichoic acid

 Prevents opsonized phagocytosis  Mask bacterial antigens

Hyaluronic acid Capsule

 Group of four enzymes with nuclease activity  Degrade host DNA (DNase) and RNA

Streptodornase (DNases)

 Subsurface hemolysin (Oxygen labile)  Toxic to RBC’s, WBC’s and platelets  Induces antibody response - anti-streptolysin O

Streptolysin O

 Surface hemolysin (Oxygen stable)  Lysis WBC’s and is non immunogenic

Streptolysin S

Causes lysis of fibrin clots

Streptokinase (Fibrinolysin)

Solubilizes hyaluronic acid in connective tissues

Hyaluronidase

Exotoxins are associated with Scarlet Fever and Streptococcal Toxic shock-like syndrome

Streptococcal pyrogenic exotoxins A, B, C (SPE)

Spreading-factor enzyme

Hyaluronidase

 Suppurative fasciitis, hospital gangrene, necrotizing erysipelas  Invasive infection characterized by inflammation and necrosis of skin, subcutaneous fat and fascia

Necrotizing Fasciitis

superficial and localized

Impetigo

involves deeper tissue invasion

Cellulitis

acute spreading erythematous lesion

Erysipelas

Two types of Post-Streptococcal Sequelae

Rheumatic Heart Fever and Acute glomerulonephrits (AGN)

diffuse red rashes (chest to extremities)

Scarlet Fever

Condition wherein organ system shuts down leading to death

Streptococcal Toxic Shock Syndrome

what organism causes these clinical Infections? 1. Bacterial Pharyngitis and Tonsilitis 2. Pyodermal Infections 3. Necrotizing Fascitis 4. Streptococcal Toxic Shock Syndrome 5. Post-Streptococcal Sequelae

Streptococcus pyogenes

i. Virulence Factor  Capsular material interferes with phagocytic activity and complement cascade activation  normal flora usually found in vagina or GIT

Streptococcus agalactiae

Deposition of ab-ag complexes in glomeruli

Acute glomerulonephrits (AGN)

 Cross reactive antibodies against streptococcal antigens and human heart tissue  Fever and inflammation of heart and blood vessels

Rheumatic Heart Fever

 Transmission occurs vertically or during delivery (associated with obstetric complications)  In newborn it causes pneumonia, sepsis and meningitis  In adult, causes endometritis and wound infections

Streptococcus agalactiae

 Small-colony forming β-hemolytic isolates  Resembles S. pyogenes infections

S. anginosus group

 Large-colony forming β-hemolytic isolates  Resembles S. pyogenes infections

S. dysgalactiae subsp. equisimilis

i. Virulence Factor  Capsular polysaccharide  Antigenic polysaccharide resulting to 80-100 serogroup  Antiphagocytic

Streptococcus pneumoniae

ii. Associated Disease 1. Pneumonia (lobar and community acquired) – leads to edema of lungs and drowning in own fluids 2. Sinusitis, Otitis Media, Bacteremia, Meningitis

Streptococcus pneumoniae

* Gram-positive diplococci (lancet or bullet shape) * Capnophilic

Streptococcus pneumoniae

Products produced by S. agalactiae

- Hemolysin - DNases - Hyaluronidase - Protease - CAMP factor (Christie-Atkins-Munch-Peterson)

leads to edema of lungs and drowning in own fluids

Pneumonia

 Polysaccharide capsule, extracellular dextran and cell surface-associated proteins (adhesins)  Enhance attachment to host cell surfaces

Viridans Streptococci

1. Subacute bacterial endocarditis from patients with damaged heart valves. 2. Bacteremia, septicemia and cavities

Viridans Streptococci

In Neufeld- Quellung reaction, it's positive if the capsule ______.

Swell

What are the five groups under Viridans Streptococci

- S. mitis - S. mutans - S. salivarius - S. bovis - S. anginosus

i. Virulence Factor  Extracellular surface protein, serine protease and gelatinase for adhesion  Cytolysins and resistance to antimicrobial agents

Enterococcus

ii. Associated Disease 1. Nosocomial infection 2. UTI (catheterization), bacteremia (hemodialysis, surgery), endocarditis (prosthetic heart valves)

Enterococcus

Disease Associations: Pyogenic infections, endocarditis, dental caries

S. anginosus, S. mutans, S. mitis

Disease Associations: Pharyngitis, Pyodermal infections, NF, STSS, PSS (Rheumatic fever, AGN)

S. pyogenes

Disease Associations: Neonatal sepsis (pneumonia, meningitis) puerperal fever, pyogenic infections

S. agalactiae

Disease Associations: Pharyngitis, impetigo, pyogenic infections

S. dysgalactiae, S. equi

Disease Associations: UTI, endocarditis, pyogenic infections, bacteremia

E. faecalis, E. faecium

Selective medium for Beta-hemolytic Streptococci

Blood Agar with trimethoprim and sulfamethoxazole

Nonhemolytic organism with lancefield group N, often found in dairy products

Lactococci

Disease Associations: Pneumonia, meningitis, pyogenic infections

S. pneumoniae

Disease Associations: UTI, endocarditis, pyogenic infections,

S. bovis group

Small, round, glistening, dome-shaped, mucoid colonies. Colonies tend umbilicated as they age; α hemolytic

Pneumococci

Minute to small, gray, domed, smooth; α, β,γ hemolytic

Viridans

Grayish white (pinpoint), transparent to translucent, matte or glossy; large zone of β hemolysis

Group A (S. pyogenes)

Small, cream or white, smooth; α, β,γ hemolytic

Group D

Larger that Group A streptococci; translucent to opaque; flat glossy; narrow zone of β hemolysis

Group B (S. agalactiae)

Test for susceptibility to 0.04U Bacitracin

Bacitracin Susceptibility test (Taxo A)

Produce pus, mostly β-hemolytic

Pyogenic

Normal biota of the human intestine

Enterococci

Found as normal biota in the upper respiratory tract of humans

Viridans

Enriched isolation of Streptococci

Blood Agar

In Taxo A test, what is the indication that the organism tested positive?

any zone of inhibition

Causes pseudo catalase

E. faecalis and E. faecium

What group tests positive in Taxo A test?

Group A

Meaning of SXT?

Sulfamethoxazole-Trimethoprim

Taxo A resistant and SXT resistant

Group B

Taxo A susceptible and SXT Resistant

Group A

Test for the synergistic hemolysis between group B Streptococcus and β-hemolytic S. aureus.

CAMP Reaction

What organisms test positive in SXT?

Group C and G

What tests positive in CAMP reaction?

Group B

In this test, it's positive if ther is an enhanced hemolysis in arrowhead pattern and no Zone of enhanced hemolysis in arrowhead pattern if it's negative.

CAMP Reaction

Taxo A resistant and SXT susceptible

Group C, F, G

is a diffusible, protein like compound produced by Group B

CAMP factor

* Test for the ability to hydrolyze hippuric acid (Sodium hippurate ) to benzoic acid and glycine * Glycine can be detected with Ninhydrin reagent

Hippurate Hydrolysis

if positive in this test, after addition of color developer, it will turn into pink to cherry-red color within 5 minutes and no color change or an orange color if negative.

PYR Test

In Hippurate Hydrolysis, what is the indication that it's positive and what is the organism that tested positive?

Deep blue (purple) color, S. agalactiae (group B)

Organisms that are positive in PYR test

Group A, Enterococcus

Negative: No color change or development of slight yellow color (Aerococcus and Leuconostoc)

LAP Test

Detects for the ability of the bacteria to grow in the presence of 40% bile and hydrolyze esculin

Bile Esculin Hydrolysis

Test for the ability of the organism to hydrolyze the substrate L-pyrrolidonyl-β-naphthylamide

PYR Test

Indication that the organism is positive for Salt Tolerance Test

Visible turbidity in broth and color change

Used to differentiate Streptococcus pneumoniae from other α-hemolytic streptococci * Ethylhydrocupreine hydrochloride

Optochin (Taxo P) Susceptibility

What is the indication if the organism is positive for Bile Esculin Hydrolysis test?

Blackening of the agar

In LAP test, the result is positive if after adding cinnamaldehyde, there is a development of what color within 1 minute?

Red

Test for the solubility to bile salt (2% sodium desoxycholate or sodium taurocholate)

Bile Solubility Test

Is it negative or positive if in Bile Solubility test, the colony disintegrated?

Positive

Identification of α Hemolytic Streptococci Optochin: R Bile Esculin: + 6.5% Broth: - PYR: -

Group D Non-Enterococcus

Identification of α Hemolytic Streptococci Optochin: R Bile Esculin: - 6.5% Broth: - PYR: -

S. viridans

Detects for the ability of the bacteria to hydrolyze Leucine-β-naphthylamide by enzyme leucine aminopeptidase to β-naphthylamide

LAP Test

Identification of α Hemolytic Streptococci Optochin: S Bile Esculin: - 6.5% Broth: - PYR: -

S. pneumoniae

Identification of β Hemolytic Streptococci Bacitracin: S SXT: R CAMP: - Bile Esculin: - 6.5% NaCl: - PYR: +

Group A

Test the ability of the organism to grow in 6.5% NaCl

Salt Tolerance Test (6.5% NaCl)

Identification of β Hemolytic Streptococci Bacitracin: R SXT: S CAMP: - Bile Esculin: - 6.5% NaCl: - PYR: -

Group C,F,G, Viridans

Identification of β Hemolytic Streptococci Bacitracin: R SXT: R CAMP: + Bile Esculin: - 6.5% NaCl: - PYR: -

Group B

Identification of α Hemolytic Streptococci Optochin: R Bile Esculin: + 6.5% Broth: + PYR: +

Group D Enterococcus

Identification of β Hemolytic Streptococci Bacitracin: R SXT: R CAMP: - Bile Esculin: + 6.5% NaCl: - PYR: -

Group D Streptococcus

Identification of β Hemolytic Streptococci Bacitracin: R SXT: R CAMP: - Bile Esculin: + 6.5% NaCl: + PYR: +

D Enterococcus

Identification of γ Hemolytic Streptococci Bile Esculin: - 6.5% Salt Broth: - PYR: -

Viridans

Identification of γ Hemolytic Streptococci Bile Esculin: + 6.5% Salt Broth: + PYR: +

Group D Enterococcus

Identification of γ Hemolytic Streptococci Bile Esculin: + 6.5% Salt Broth: - PYR: -

Group D Non-enterococcus