Streptococcus Flashcards

1
Q

Streptococcus

They belong to the family

A

STREPTOCOCCACEAE

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2
Q

Streptococcus

● Some species are part of the indigenous human microbiota
○ Some species are______

A

CAPNOPHILIC

Place in candle jar

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3
Q

Streptococcus

● Their growth is enhanced by____, _____ or _____ that is incorporated in culture media

A

blood, serum or glucose

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4
Q

● All streptococci except (2) the are included in the Lancefield
classification

A

VIRIDANS GROUP and S. pneumoniae

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5
Q

Streptococcus

MICROSCOPY:

A

Gram (+) spherical cells that are arranged in chains or pairs.

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6
Q

Streptococcus

CULTURE:

A

Appear grayish, pinpoint, and translucent to slightly opaque while some species have mucoid colonies

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7
Q

Streptococcus

BIOCHEMICAL TESTS:

A

Catalase (-)
Oxidase and Gas production (-)
non motile
ferments carbohydrates

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8
Q

Streptococcus

NOTORIOUS PATHOGENS:

A

Streptococcus pyogenes
Streptococcus pneumoniae

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9
Q

CLASSIFICATION OF STREPTOCOCCI

A

ACADEMIC/ BERGEY’S CLASSIFICATION

SMITH AND BROWN CLASSIFICATION

LANCEFIELD CLASSIFICATION

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10
Q

Classification

● Based on TEMPERATURE REQUIREMENT

A

ACADEMIC/ BERGEY’S CLASSIFICATION

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11
Q

Classification

● Based on HEMOL YTIC PATTERNS

A

SMITH AND BROWN CLASSIFICATION

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12
Q

Classification

● Based on the extraction of C CARBOHYDRATE from
streptococcal cell wall.

A

LANCEFIELD CLASSIFICATION

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13
Q

Staph vs strep

Colonies

A

Staph: Larger, mucoid

Strep: Small-medium, pinpoint (very evident zone of hemolysis)

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14
Q

Flesh eating bacteria

A

S. pyogenes

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15
Q

Meningitis

A

S. agalactiae

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16
Q

Only grows @ 37°C

A

Pyogenic group

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17
Q

Pyogenic group ate

● Mostly __-hemolytic

A

β

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18
Q

Pyogenic group includes

A

● S. pyogenes
● Groups C and G streptococci

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19
Q

● Can grow at 45°C & 37°C

A

Viridans group

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20
Q

Viridans group

● NOT PART of the lancefield
Group but some are___-hemolytic

A

α

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21
Q

● Can grow at 10°C & 37°C

A

Lactic group

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22
Q

Lactic group

●___-hemolytic and has
Lancefield N antigen

A

Non hemolytic

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23
Q

● Often found in dairy products

●_____, causes normal
coagulation and souring of milk

A

Lactic group

S. lactis

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24
Q

● Can grow at 10°C, 45°C & 37°C

A

Enterococcus group

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25
Q

Enterococcus

● Part of normal microbiota of the
human____
● ______

A

intestine

E. faecalis

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26
Q

ALPHA HEMOLYTIC STREPTOCOCCI

Describe and give 2 examples

A

● They have partial/ incomplete
hemolysis of red blood cells
around the colonies

● For the culture, greenish or incomplete hemolysis

● S. pneumoniae and Viridans group

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27
Q

BETA HEMOLYTIC STREPTOCOCCI

Description and examples

A

● Exhibit a complete lysis of red
blood cells

● Clear zone of hemolysis around
the colony

● S. pyogenes, S. agalactiae

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28
Q

GAMMA HEMOLYTIC STREPTOCOCCI

Description and examples

A

● Do not exhibit the lysis of red
blood cells

● The RBC surround the colony
are unaffected

● S. bovis or E. faecalis

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29
Q

Lancefield classification

________, the microbiologist who
developed the classification method

○ found out that the ______can be
extracted from he streptococcal cell wall by placing the organism in _____
and heating the suspension for____

A

Rebecca Lancefield

C carbohydrates

dilute acetic acid

10 minutes

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30
Q

● It is most significant in classifying and identifying beta-hemolytic streptococci

A

Lancefield classification

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31
Q

HEMOLYTIC PATTERN - B

LANCEFIELD GROUP

SPECIES

A

A - S. pyogenes
B - S. agalactiae
C - S. agalactiae subsp. equisimilis

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32
Q

HEMOLYTIC PATTERN
Alpha or Gamma
Alpha, Beta or Gamma

LANCEFIELD GROUP

SPECIES

A

D - S. bovis
D - Enterococci

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33
Q

HEMOLYTIC PATTERN
Alpha, Beta or Gamma

LANCEFIELD GROUP

SPECIES

A

None but some of the strains may have A, C, F, G or N

Viridans

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34
Q

pneumonia and viridans don’t have ___

A

C carbohydrates

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35
Q

LANCEFIELD GROUP SUGARS
GROUP A
GROUP B
GROUP C

A

N - acetylglucosamine

Rhamnose - glucosamine

Rhamnose - n - acetylglucosamine

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36
Q

LANCEFIELD GROUP SUGAR

GROUP D

A

Glycerol teichoic

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37
Q

LANCEFIELD GROUP SUGAR

GROUP F

A

Glucopyranosyl –N– acetylglucosamine

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38
Q

T or F

GAS

● It is not considered as part of the indigenous microbiota
● It is pathogenic to humanity

A

True

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39
Q

GAS

● It is acquired through_______ that are released through coughing or sneezing
● Highly resistant to____ and can be recovered from swabs several hours after the collection

A

CONTAMINATED DROPLETS

DRYING

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40
Q

GAS

The species for this group is Streptococcus pyogenes which is
________ and _______
(involves deeper tissues and organs)

A

FEVER-PRODUCING AND FLESH EATING BACTERIA

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41
Q

S. pyogenes

● The principal virulence factor is______

A

PROTEIN M

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42
Q

○ Attached to the peptidoglycan
○ Antiphagocytic
○ Adherence to the mucosal cells

A

Protein M of S. pyogenes

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43
Q

GAS

● Culture on BAP:

A

colonies are small, translucent,
smooth and exhibit well-defined beta hemolysis

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44
Q

GROUP A (ENZYMES AND TOXINS)

HEMOLYSINS

ENZYMES

TOXINS

A

STREPTOLYSIN O
STREPTOLYSIN S

DEOXYRIBONUCLEASE (DNase)
HYALURONIDASE

PYOGENIC TOXINS - Serotypes
A, B, C and F

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45
Q

○ Responsible for the subsurface
hemolysis on BAP that is
incubated anaerobically

A

STREPTOL YSIN O

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46
Q

○ High antigenic and induces
antibody response

○ Serological test to be used to
detect recent infections with S.
pyogenes is the_______

A

STREPTOLYSIN O

ANTI-STREPTOLYSIN O (ASO)

47
Q

= POSITIVE ASO

A

<200 Todd Units/ mL (IU/mL)

48
Q

○ It is an oxygen - stable hemolysin and non-antigenic

○ Responsible for the surface
hemolysis on BAP that is
incubated

A

STREPTOLYSIN S

49
Q

It lowers the viscosity of exudates giving the pathogens more mobility

A

DEOXYRIBONUCLEASE (DNase)

50
Q

DEOXYRIBONUCLEASE (DNase)

Four types:

A

Antigenic Enzymes A, B, C, D

51
Q

It causes fibrin clot lysis

A

STREPTOKINASE

52
Q

A protein that binds to plasminogen and activates the production of plasmin.

A

Streptokinase

53
Q

It activates a host blood factor that dissolves fibrin clots.

A

Streptokinase

54
Q

Solubilizes the ground substance of mammalian tissues.

A

HYALURONIDASE

55
Q

PYROGENIC TOXINS -

A

SEROTYPES A, B, C and F

56
Q

Refers as super antigens

A

PYROGENIC TOXINS -

57
Q

Pyrogenic toxins

Formerly known as______

A

ERYTHROGENIC TOXINS

58
Q

degrades proteins and mediates
- rashes that are caused by Scarlet Fever.

A

EXOTOXIN B (Cysteine Protease)

59
Q

OTHER VIRULENCE FACTOR

A

Protein F
Lipoteichoic Acid
Hyaluronic Acid Capsule
Hemolysins, Toxins & Enzymes

60
Q

GROUP A (RELATED INFECTIONS/ DISEASE)

A

PHARYNGITIS OR TONSILLITIS (Strep
Throat)

SCARLET FEVER (SCARLATINA)

CELLULITIS

ERYSIPELAS

IMPETIGO

RHEUMATIC HEART FEVER

ACUTE GLOMERULONEPHRITIS

STREPTOCOCCAL TOXIC SHOCK SYNDROME

61
Q

● It is spread by air droplets and
close contact
● Its diagnosis relies on the culture of specimen (throat swab) or direct antigen detection

A

PHARYNGITIS OR TONSILLITIS (Strep Throat)

62
Q

● Caused by the release of pyrogenic toxins

● Associated with STRAWBERRY COLORED TONGUE

A

SCARLET FEVER ( SCARLATINA)

63
Q

● Susceptibility test: (Erythrogenic Toxin Test) positive result shows erythema or redness of the skin

Scarlet fever

A

DICK’S TEST

64
Q

Diagnostic Test:
(Anti-Erythrogenic Toxin Test)
positive result exhibits a BLANCHING PHENOMENON

Scarlet fever

A

SCHULTZ -
CHARLTON TEST

65
Q

It is a contagious infection of
subcutaneous skin tissue that
is characterized by redness and
edema

A

Cellulitis

66
Q

Acute infection of the dermal
layer of the skin with painful
swollen, reddish spot

A

Erysipelas

67
Q

A skin infection that is caused
by a group A streptococcus
that may lead to necrotizing
fasciitis, which is also known as…

A

Impetigo

GALLOPING GANGRENE or FLESH EATING BACTERIA SYNDROME

68
Q

● Characterized by fever, inflammation of the heart, joints and blood vessels
● Complication of PHARYNGITIS

A

RHEUMATIC HEART FEVER

69
Q

A.K.A BRIGHT’S DISEASE

A

ACUTE GLOMERULONEPHRITIS

70
Q

A.K.A BRIGHT’S DISEASE

A

ACUTE GLOMERULONEPHRITIS

71
Q

Inflammatory disease of the renal glomeruli

Deposition of antigen-antibody
complex to the kidneys

A

ACUTE GLOMERULONEPHRITIS

72
Q

Whole organ shuts down and
leads to death

A

STREPTOCOCCAL TOXIC SHOCK SYNDROME

73
Q

GROUP A (LABORATORY TESTS)

A

BACITRACIN DISK TEST/ TAXO A
(0.04 units)

SULFAMETHOXAZOLE AND TRIMETHOPRIM TEST (SXT)

Pyrrolidonyl Arylamidase (PYR) test

74
Q

● Differentiates S. pyogenes from other beta-hemolytic groups

● helpful in identifying group A
in throat cultures

A

BACITRACIN DISK TEST/ TAXO A
(0.04 units)

75
Q

are also susceptible to Bacitracin

A

Groups C and G

76
Q

● Group ____ are also resistant SXT
● Group___ are sensitive (Not so
important)

● (+) RESULT: Exhibits Resistance

A

SULFAMETHOXAZOLE AND TRIMETHOPRIM TEST (SXT)

B

C

77
Q

● More specific than bacitracin
● Detects the presence of PYR
enzyme
● (+) RESULT:____

A

Pyrrolidonyl Arylamidase (PYR) test

Cherry Red Color

78
Q

● These are part of the indigenous microbiota of the female genital tract and lower gastrointestinal tract

A

GROUP B – STREPTOCOCCI

79
Q

● NOSOCOMIALL Y transmitted by unwashed hands of a mother or health care personally to the newborn or infant

A

GBS

80
Q

● Causes infection on the fetus during the passage through the colonized birth canal and premature rupture of mother’s membranes

A

GBS

81
Q

● Species for GBS group:

A

Streptococcus agalactiae

82
Q

● As for the recommendation of CDC, all pregnant women should be screened for group B streptococci…

A

35 - 37 weeks of gestation

83
Q

GBS RELATED INFECTIONS:

A

➔ Neonatal meningitis and sepsis
➔ Pneumonia
➔ Postpartum infection
➔ Urinary Tract Infection
➔ Endocarditis

84
Q

GROUP B (LABORATORY TESTS)

A

CAMP TEST (Christie-Atkins-Munch-Petersen)

HIPPURATE HYDROLYSIS TEST

85
Q
  • Used to detect B-hemolysis
    ● Used to differentiate S. agalactiae from other beta-hemolytic streptococci
    ● Culture medium is____
    ●___ is for the reinforcement
    of the reaction
A

CAMP TEST (Christie-Atkins-Munch-Petersen)

BAP

SAU

86
Q

CAMP TEST

Reagent:

A

beta-lysin strip or beta-lysin
producing strain of SAU

87
Q

● It is used to differentiate S. agalactiae from other beta-hemolytic streptococci

● S. agalactiae possesses the enzyme HIPPURICASE or HIPPURATE HYDROLASE

A

HIPPURATE HYDROLYSIS TEST

88
Q

○ Breaks down sodium hippurate into…

A

benzoic acid and glycine

89
Q

Hippurate Hydrolysis

Reagents:

A

Sodium Hippurate and
Ninhydrin (Purple Color)

90
Q

CAMP TEST RESULT
(+) RESULT:

A

ARROWHEAD or BOW TIE SHAPED BETA HEMOLYSIS NEAR S. aureus growth

91
Q

HIPPURATE HYDROL YSIS TEST
(+) RESULT:
(-) RESULT:

A

Purple color after adding ninhydrin

No Color Change

92
Q

● They are also known as ALPHA PRIME
STREPTOCOCCI that lack the Lancefield antigens
○ Expected colonies are MUCOID

A

VIRIDANS STREPTOCOCCI

93
Q

VIRIDANS STREPTOCOCCI

● They are the most common cause of

A

Subacute
Bacterial Endocarditis

94
Q

Viridans

VIRULENCE FACTORS:

A

Capsule
cytolysin
extracellular dextran and adhesins

95
Q

Viridans

LABORATORY RESULTS:

A

Bile insoluble
optochin-resistant (TAXO P)
does not grow in 6.5% NaCl
(+) LAP
(-) PYR

96
Q

STREPTOCOCCUS VIRIDANS:

A

● S. anginosus
● S. mitis
● S. sanguinis
● S. salivarius
● S. mutans

97
Q

VIRIDANS (LABORATORY TESTS)

● _____ is peptidase that hydrolyzes peptide bonds that are adjacent to a free amino group

A

LEUCINE AMINOPEPTIDASE (LAP) Test

98
Q

LAP Test

○ Substrate:
○ Reagent:
○ End product:

A

Leucine-B-naphthylamide

p-dimethylaminocinnamaldehyde
(DMACA)

B-naphthylamine

99
Q

(-) LAP:

A

Acrococcus and Leuconostoc

100
Q

STREPTOCOCCUS PNEUMONIAE
● Also known as

A

diplococcus or pneumococcus

101
Q

● Asymptomatic member of normal respiratory tract
● Causative agent of LUMBAR PNEUMONIAE

A

S. pneumoniae

102
Q

● Most common cause of bacterial pneumonia in elderly and immunocompromised individuals.

A

S. pneumoniae

103
Q

● Its cell wall contains an antigen that is referred to as______ which is not related to the C carbohydrate of the various lancefield groups

A

C SUBSTANCE

Pneumoniae

104
Q

Pneumoniae

Principal Virulence Factor:
Microscopy:

______ SPUTUM indicates S. pneumoniae infection

A

CAPSULE (Polysaccharide)

Gram (+) cocci in pairs that are oval or lancet shaped

RUSTY-TINGED

105
Q

STREPTOCOCCUS PNEUMONIAE (LABORATORY TESTS)

A

NEUFELD -QUELLUNG TEST (CAPSULAR SWELLING TEST)

FRANCIS SKIN TEST

COAGULATION TEST

106
Q

● Allows the detection of S.
pneumoniae and serotyping
isolates
● The underlying principle is that
the capsule swells in the presence of specific anticapsular serum

A

NEUFELD - QUELLUNG TEST
(CAPSULAR SWELLING TEST)

107
Q

● This test is used to detect the
presence of antibodies against
the pneumococci

A

FRANCIS SKIN TEST

108
Q

● It uses the particle-bound
antibody to enhance the
visibility of the agglutination
reaction between the antigen
and antibody

A

COAGULATION TEST

109
Q

ENTEROCOCCI
● They are formerly known as_____
because all the species produce the group D antigen
● The species are indigenous microbiota of human and animal…

A

group D enterococci

intestinal tracts

110
Q

● NOT HIGHLY PATHOGENIC but are frequent cause of nosocomial infections
● They are RESISTANT to multiple antimicrobial agents

A

ENTEROCOCCI

111
Q

Enterococci

The most common isolate:

A

Enterococcus faecalis

112
Q

Enterococci

RELATED INFECTIONS:

A

➔ UTI
➔ Endocarditis
➔ Bacteremia
➔ Wound infection

113
Q

Enterococci
LABORATORY TESTS:

A

(+) Bile esculin
PYR (+) growth in 6.5% NaC