STREPTOCOCCUS | IDENTIFICATION OF STAPHYLOCOCCUS & STREPTOCOCCUS Flashcards by Vince Patangan

susceptible to bacitracin

S. pyogenes

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[bacitracin susceptibility test (taxo “A” disk)]

identify the bacteria based on the result:

result:
- bacitracin susceptibility test POSITIVE

Streptococcus pyogenes

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[determine whether the result is SUSCEPTIBLE or RESISTANT to novobiocin test]

result:
<17 mm zone of inhibition

resistant

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[bacitracin susceptibility test (taxo “A” disk)]

determine whether the result is SUSCEPTIBLE or RESISTANT:

uniform growth right up to the rim of the disk

resistant

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[determine the bacteria]

catalase-negative, gram-positive cocci&raquo_space; bacitracin (resistant)&raquo_space; CAMP (positive) = ???

streptococcus agalactiae

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no hemolysis or α-hemolysis (greening) on sheep blood agar and smell like butterscotch, especially on chocolate agar

Viridans streptococci

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group B streptococci

Streptococcus agalactiae

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catalase negative

streptococcus

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β-hemolytic and produce zones of hemolysis that are only slightly larger than the colonies (1-2 mm in diameter)

Streptococcus agalactiae

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a wider zone of β hemolysis

viridans group

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part of the normal vaginal flora in 5-25% of women

Streptococcus agalactiae

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[determine the test]

procedure:
1. To 0.5 mL of undiluted rabbit plasma, add one loopful of growth from18-to 24-hour agar culture, 0.1 mL of broth culture, or a single colony from a blood agar plate

Incubate in a water bath at 35 C and examine for clotting at 30-minute intervals for 4 hours
If no clot is observed at the end of 4 hours, let stand at room temperature for 18 to 24 hours. Observe for clotting

tube coagulase test

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[determine the test]

detects the presence of free coagulase enzyme produced by S. aureus

tube coagulase test

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hydrolyze sodium hippurate and give a positive response in the so-called CAMP test
bacitracin resistant

(Christie, Atkins, Munch-Peterson/CAMP)

Streptococcus agalactiae

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The Streptococcaceae consist of a large family of medically important species, including ______________ and ________________

Streptococcus spp., Enterococcus spp.

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[determine the test]

Positive hydrolysis: purple color

rapid hippurate hydrolysis test

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Many selective media, such as phenylethyl alcohol agar (PEA), Mannitol Salt agar (MSA), and colistin-nalidixic acid agar (CNA), are used for the isolation of ______________ from mixed cultures

staphylococci

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clinically isolated streptococci is separated into ______________ and __________________

β-hemolytic streptococci / pyogenic (pus-forming) streptococci,

non-β-hemolytic (nonpyogenic)

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S. pneumoniae is a member of the ___________

S. mitis group

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[determine the test]

procedure:
1. Inoculate one to two colonies on a bile esculin agar plate, slant, or broth

Incubate at 35 C for 18 to 24 hours

bile esculin test

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[CAMP test]

a positive test is recognized by the appearance of an ___________ shape at the juncture of the ___________ and _________ streaks

arrowhead, S. agalactiae and S. aureus

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[Enterococcus spp.]

_________ and _________ are the pathogenic species most commonly encountered

E. faecalis, E. faecium

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[detection of GBS in pregnant women]

the most useful tests are _____________ and __________

positive hippurate hydrolysis, CAMP tests

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[choose the correct answer]

CAMP test positive

a. S. pyogenes
b. S. agalactiae

b. S. agalactiae

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[infections | viridans streptococci] has a high correlation with gastrointestinal carcinoma

S. gallolyticus subsp. gallolyticus

[infections | viridans streptococci] - pharyngitis - normally found in the oral cavity, gastrointestinal tract, and female genital tract - transient normal microbiota of the skin - most common isolates associated with bacterial endocarditis in native valves and, less frequently in prosthetic valve infections

S. constellatus subsp. pharyngis

[determine the test] procedure: 1. Emulsify a well-isolated colony in a drop of water on a glass slide to produce a dense, uniform suspension. 2. Add one drop of plasma to the suspension and mix; then rotate for 5 seconds

slide coagulase test

Beta-Hemolytic streptococci:

- S. pyogenes - S. agalactiae

group C streptococci

rhamnose-N-acetylgalactosamine

[virulence factors] S. pyogenes can cause red red-spreading rash called

scarlet fever

they are rarely found in human disease states but produce normal coagulation ("souring") of milk

group N streptococci

group F streptococci

glucopyranosyl-N-acetylgalactosamine

[choose the correct answer] PYR positive a. S. pyogenes b. S. agalactiae

a. S. pyogenes

[determine the test] procedure: 1. Inoculate one to two colonies into 2 mL of 6.5% NaCl broth 2. Incubate tube at 35 C for 18 to 24 hours

salt tolerance test

it is recommended that all pregnant women be screened for GBS at ________________ gestation

35 to 37 weeks

[virulence factors] capable of producing an erythematous sandpaper-like rash

- streptolysin O - streptolysin S - deoxyribonuclease (DNase) - streptokinase - hyaluronidase - erythrogenic exotoxins

[virulence factors] adhesion molecules that mediate attachment to host epithelial cells

lipoteichoic acid & protein F

[determine the bacteria] no hemolysis on blood agar >> bile esculin >> 6.5% NaCl (positive) = ???

Enterococcus spp.

[virulence factors] responsible for hemolysis on SBA plates incubated anaerobically

Streptolysin O

[determine the bacteria] α-hemolysis on sheep blood agar >> optochin disk >> resistant >> bile esculin (negative) = ???

Viridans streptococci

[determine the bacteria] α-hemolysis on sheep blood agar >> optochin disk >> susceptible = ???

S. pneumoniae

[virulence factors] most common DNase

clinical manifestations include: - UTI - bacteremia - endocarditis - intraabdominal, pelvic, wound, and soft tissue infections

Enterococcus spp.

_____________ contains the C polysaccharide unrelated to the Lancefield grouping

S. pneumoniae

[virulence factors] _______ is acid-labile and heat-labile

T substance

Pyogenic streptococci isolated frequently from humans

S. pyogenes S. agalactiae S. dysgalactiae subsp. equisimilis S. anginosus group

[virulence factors] four (4) enzymes

- streptokinase - streptodornase - hyaluronidase - diphosphopyridine nucleotidase

is immunogenic, capable of lysing the same cells and cultured cells, broken down by oxygen, and will produce hemolysis only in the absence of room air

Streptolysin O

[determine the test] - reacts with hydrogen peroxide to liberate oxygen - when a colony is emulsified in 3% hydrogen peroxide, the resultant bubbles on the slide may be visualized, which constitutes a positive test result

catalase test

[CAMP tests] The _______________ intensifies the lysis of sheep red blood cells when placed in the appropriate inoculation points with S. aureus

CAMP factor

[determine the test] Positive: Indicator changes from green to yellow

pyruvate broth

"flesh-eating bacteria"

S. pyogenes

the PYR and hippurate or CAMP tests can be used to identify __________ and ____________, respectively

groups A and B streptococci

[choose the correct answer] CAMP test negative a. S. pyogenes b. S. agalactiae

a. S. pyogenes

normal microbiota: skin, nasopharynx, gastrointestinal tract, genital tract

group C, F, and G beta-hemolytic streptococci

[hemolysis] sometimes called gamma hemolysis

non-hemolytic

S. saprophyticus is resistant to __________

novobiocin disk

S, agalactiae is able to hydrolyze _________ and is positive in the ___________

hippurate, CAMP test

[determine the test] based on the differential susceptibility to ethyl hydroxycupreine hydrochloride

optochin susceptibility test (taxo "P" disk)

___________ infections usually are associated with neonates and are acquired before or during the birthing process

Group B S. agalactiae (GBS)

for isolating group A streptococci from throat swabs, the most common medium is ____________ supplemented with trimethoprim-sulfamethoxazole

5% sheep blood agar

_________ resistance is seen more frequently with E. faecium with E. faecalis

vancomycin

[Hemolysis] complete disruption of erythrocytes with clearing of the blood around the bacterial growth

β hemolysis

[choose the correct answer] bacitracin sensitive a. S. pyogenes b. S. agalactiae

a. S. pyogenes

growth of Streptococcus is enriched on _________________

media containing blood or serum

[determine the test] positive result: causes clumping when mixed with plasma

slide coagulase test

[determine the test] Positive test result—blackening of the agar or broth

bile esculin test

[optochin susceptibility test (taxo "P" disk)] identify the bacteria based on expected results: - Zone diameter of inhibition >15 mm

S. pneumoniae

[determine the test] This test is used to determine the ability of an organism to utilize pyruvate. This aids in the differentiation

pyruvate broth

other name for pneumoniae

pneumococcus

colonies: dome-shaped appearance

S. pneumoniae

normal microbiota: oral cavity

Abiotrophia spp.

[virulence factors] scarlet fever is caused by

streptococcal pyrogenic exotoxins

[determine the test] - releases free β-naphthylamide, which is detected and shown by the color change after adding the color reagent - uses filter paper disk

PYR test

[determine the test] A modified broth containing 6.5% NaCl is used

salt tolerance test

[hemolysis] incomplete lysis of erythrocytes with reduction of hemoglobin and the formation of green pigment

α hemolysis

group B streptococci

rhamnose-glucosamine polysaccharide

[determine the test] uses 10% sodium desoxycholate e to the side of a young (13- to 24-hour), well-isolated colony growing on 5% sheep blood agar

bile solubility test

the cell wall of S. pneumoniae contains an antigen, referred to as _____________

C substance

[Lancefield classification] group A streptococci

rhamnose-N-acetylglucosamine

[Lancefield classification] this carbohydrate is contained in the cell wall of many streptococci and forms the basis of serologic grouping into Lancefield groups ______ and ______

A-H, K-U

[StrepB Carrot Broth (SCB)] vaginal or rectal swabs are placed into SCB and incubated ____ to ____ hours at ______

18 to 24, 35°C

[infections | viridans streptococci] - normal oral and gastrointestinal microbiota - associated with abscess formation in the oropharynx, brain, and peritoneal cavity

S. anginosus group

[virulence factors] infections: "strep throat"

pharyngitis

the CAMP test detects production of a diffusible, extracellular protein that __________ the hemolysis of sheep erythrocytes by ______________

enhances, Staphylococcus aureus

[virulence factors] obtained from streptococci by proteolytic digestion, which rapidly destroys M proteins

T substance

[Lancefield classification] the serologic specificity of the group-specific carbohydrate is determined by ___________

amino sugar

most laboratories identify Enterococcus spp. presumptively by demonstrating that the isolate is ______ and ______ positive and that it grows at ______ and in _______

PYR and LAP, 45°C, 6.5% NaCl

two (2) important tests for the laboratory diagnosis of S. pneumoniae

- optochin susceptibility test - bile solubility test

[StrepB Carrot Broth (SCB)] β-hemolytic GBS produce an ________ or ____ pigment in SCB after incubation for _____ hours

orange or red, six (6)

PYR-positive

S. pyogenes

[dtermine the test] produces an extracellular enzyme, "CAMP" factor

CAMP test (group B streptococcus)

_____________ determines the lysis of S. pneumoniae in the presence of bile salts

bile solubility test

[virulence factors] four (4) DNases

A, B, C, D

normal microbiota: oral cavity, gastrointestinal tract, female genital tract

Viridans streptococci

[bacitracin susceptibility test (taxo "A" disk)] identify the bacteria based on the result: result: - bacitracin susceptibility test NEGATIVE

Streptococcus agalactiae

[virulence factors] infections: - multisystem involvement that includes renal and respiratory failure, rash, and diarrhea - another disease mediated by production of potent streptococcal pyrogenic exotoxins (SpeA)

streptococcal toxic shock syndrome

[determine the test] Subsequent addition of triketohydrindene hydrate (ninhydrin) results in the oxidative deamination of the αamino group in glycine

rapid hippurate hydrolysis test

- normal microbiota: humans, animals, and birds - colonizers

Enterococcus spp.

[bile esculin test] ____________, which is the byproduct of esculin hydrolysis, combined with ______________ in the medium to give a black complex

esculetin, ferric citrate

[dtermine the test] positive result: forms a clot when incubated with plasma

tube coagulase test

a brown halo around colonies on bile esculin agar and a positive PYR reaction is indicative of _____________

Enterococcus spp.

[virulence factors] enzymes: - related to the organism's ability to kill leukocytes

diphosphopyridine nucleotidase

[virulence factors] infections: - occurs in association with streptococcal pharyngitis - manifested by a rash of the face and upper trunk

scarlet fever

[infections | viridans streptococci] - bacteremia - septicemia - endocarditis

S. bovis group

streptococcus is arranged in _______ or ________

pairs, chains

facultative anaerobes

Streptococcus

[virulence factors] enzymes: - depolymerizes DNA - decrease viscosity of DNA solutions - liquefy exudates and facilitate removal of pus and necrotic tissue

streptodornase

[detection of GBS in pregnant women] ___________, which can be substituted for Lim or TransVag broth

StrepB Carrot Broth (SCB)

________ and ________ are normal biota of the human gastrointestinal tract and female genitourinary tract

E. faecalis, E. faecium

[determine whether the result is SUSCEPTIBLE or RESISTANT to novobiocin test] result: >17 mm zone of inhibition

susceptible

[determine the test] Positive: Colony disintegrates; an imprint of the lysed colony may remain within the zone

bile solubility test

S. pneumoniae is susceptible to ___________

optochin

group D streptococci

glycerol teichoic acid containing D-alanine and glucose

[capsular polysaccharide] the capsule is antigenic and can be identified with appropriate antisera in the ____________

Neufield test

[virulence factors] ________ to determine whether an individual has had a recent infection with S. pyogenes

antistreptolysin (ASO)

these streptococci occur primarily in animals

group E, F, G, H, & K-U streptococci

[determine the test] produces an "arrow-head" hemolysis

CAMP test (group B streptococcus)

Other CoNS that are resistant to 5-μg novobiocin are ________, __________, and _________

Staphylococcus xylosus, Staphylococcus cohnii, Staphylococcus sciuri

[determine the test] Positive result: dark pink to red color

PYR test

an oxygen-stable, nonimmunogenic hemolysin capable of lysing erythrocytes, leukocytes, and platelets in the presence of room air

Streptolysin S

- normal microbiota: female genital tract and lower gastrointestinal tract - occasional colonizer of the upper respiratory tract

Streptococcus agalactiae (group B)

- not highly invasive - they enter tissue during dental or surgical procedures, which could lead to tooth abscesses, abdominal infections, bacteremia, or valve endocarditis and late-onset prosthetic valve endocarditis

Viridans streptococci

any negative slide coagulase test result must be confirmed with the _______________

tube coagulase test

[virulence factors] is weakly immunogenic

hyaluronic acid capsule

[virulence factors] infections: - "flesh-eating bacteria" - infection tends to disseminate into deeper tissues - categorized as type 1, 2, or 3

necrotizing fasciitis

[bacitracin susceptibility test (taxo "A" disk)] determine whether the result is SUSCEPTIBLE or RESISTANT: - any zone of inhibition around the bacitracin disk

susceptible

causes septicemia, pneumonia, and meningitis in newborns (first 5 days of life)

Group B S. agalactiae (GBS)

[optochin susceptibility test (taxo "P" disk)] identify the bacteria based on expected results: - Zone diameter of inhibition <15 mm

viridans streptococci group

[choose the correct answer] PYR negative a. S. pyogenes b. S. agalactiae

b. S. agalactiae

[virulence factors] infections: three (3) pyodermal infections

- impetigo - erysipelas - cellulitis

[virulence factors] enzymes: - splits hyaluronic acid - aids in spreading infecting microorganisms - spreading factor

hyaluronidase

_________ is the only species of beta-hemolytic streptococci that will give a positive PYR reaction

S. pyogenes

___________ plays a key role in the development of dental caries

S. mutans

[virulence factors] infections: - post-streptococcal sequelae - edema, hypertension, hematuria, and proteinuria, can follow respiratory tract or cutaneous infections and is mediated by antigen-antibody complexes that deposit in glomeruli

acute glomerulonephritis

primary cause of bacterial pneumonia, meningitis, and otitis media

Streptococcus pneumoniae

[identify the bacteria spp.] The colonies are round; are at least 1 to 2 mm in diameter; are convex, opaque, and glistening with a complete edge; and are soft or butter-like in consistency. Some varieties are surrounded by zones of beta-hemolysis. The color of the colony varies from an off-white to cream color to golden yellow

Staphylococcus spp.

[virulence factors] resist phagocytosis and adheres bacterial cell to mucosal cells

M protein

_________ can cause skin infections of dogs but uncommonly infects humans

S. canis

[virulence factors] permits differentiation of certain types of streptococci by agglutination with specific antisera

T substance

[StrepB Carrot Broth (SCB)] broths that turn orange or red are reported as ________ for GBS

positive

[hemolysis] colonies are surrounded by a very small zone of no hemolysis

Alpha-prime (α') or wide zone hemolysis

some species of Streptococcus are ___________

capnophilic

[virulence factors] infections: - post-streptococcal sequelae - manifested by fever, carditis, subcutaneous nodules, and polyarthritis, usually follow respiratory tract infections - after strep throat

rheumatic fever

[infections | viridans streptococci] - the most commonly isolated among the viridans streptococci - primary contributor to dental caries - bacteremia

S. mutans

[determine the bacteria] α-hemolysis on sheep blood agar >> optochin disk >> resistant >> bile esculin >> 6.5% NaCl (PYR) positive = ???

Enterococcus spp.

colonizer of nasopharynx

Streptococcus pneumoniae

[virulence factors] attachment of streptococci to the oral mucosal cells

fibronectin binding

- not considered normal microbiota - inhabits skin and upper respiratory tract of humans - carried on nasal, pharyngeal, and sometimes anal mucosa

Streptococcus pyogenes (group A)

[determine the test] Positive test result: visible turbidity in broth

salt tolerance test

[virulence factors] enzymes: - transforms the plasminogen of human plasma into plasmin - treatment of pulmonary emboli, coronary artery, and venous thromboses - used to lyse clots

streptokinase

- commonly colonize the gastrointestinal tract - they can be isolated from the oropharynx, female genital tract, and skin - causes UTI

Enterococcus spp.

[choose the correct answer] bacitracin resistant a. S. pyogenes b. S. agalactiae

b. S. agalactiae

[determine the bacteria] catalase-negative, gram-positive cocci >> bacitracin (susceptible) = ???

streptococcus pyogenes