Streptococcus Flashcards

1
Q

Appears as lancet – shape or diplococci)

A

Streptococcus pneumoniae

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2
Q

Streptococcus O2 and CO2 requirement

A

Facultative anaerobe

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3
Q

NOTE‼️: Genus streptococcus are commonly found as part of normal flora; encountered in clinical specimens as contaminants or as components of mixed cultures with minimal or unknown clinical significance.

A

pasar bacte qt ehehe

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4
Q

BROWN and SMITH: ALPHA hemolytic (partial hemolysis)

A

*Viridans streptococci

*Streptococcus pneumoniae

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5
Q

BROWN and SMITH: BETA hemolytic (complete hemolysis)

A

Streptococcus pyogenes (Group A)

Streptococcus agalactiae
(Group B)

Streptococcus equisimilis, zoopedemicus, equi
(Group C)

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6
Q

BROWN and SMITH: GAMMA hemolytic (Non-hemolytic)

A

Enterococcus faecalis

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7
Q

LANCEFIELD CLASSIFICATION is based on what carbohydrate?

A

Based on the C – carbohydrate antigen found in the cell wall

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8
Q

DO NOT have carbohydrate cell wall antigen

A

Streptococcus pneumoniae

Viridans streptococci

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9
Q

Group C strep

A

S. equisimilis,
S. zooepidemicus
S. equi

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10
Q

Group G strep

A

S. arginosus

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11
Q

STREPTOCOCCUS OF MEDICAL IMPORTANCE

A
  1. pyogenes (A)
  2. agalactiae (B)
  3. pneumoniae
  4. viridans
  5. faecalis (D)
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12
Q

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

A

Streptococcus pyogenes

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13
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

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14
Q

Its habitat skin and Upper Respiratory tract of humans, carried on nasal,
pharyngeal, sometimes anal mucosa

A

Streptococcus pyogenes

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15
Q

Characteristic that has earned the designation ‘’flesh – eating bacteria”

A

Streptococcus pyogenes (Group A strep)

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16
Q

Most strains of S. pyogenes produces capsules composed of____

A

hyaluronic acid

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17
Q

S. pyogenes Fastidious, requires enriched media for primary isolation incubated with ______.

A

5% – 10% CO2

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18
Q

Catalase negative (- )
PYR - positive (+)
Bacitracin: Sensitive

A

Streptococcus pyogenes

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19
Q

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

A

S. pyogenes

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20
Q

test for Group A Streptococcus
demonstrate presence of pyrrolidonyl arylamidase

(+): development of a deep cherry red color
within a minute addition of reagent

A

PYR Hydrolysis Test (POSITIVE)

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21
Q

Presumptive test for S. pyogenes

Used to differentiate Streptococcus pyogenes and Streptococcus agalactiae

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

A

Bacitracin Susceptibility Test

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22
Q

use as basis for serological classification using Lancefield method

A

C - carbohydrate

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23
Q

major virulence factor of group A S pyogenes. (most important virulence factor)

A

M – Protein

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24
Q

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

permits differentiation of certain types of streptococci by agglutination with specific antisera,

A

T – Protein

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25
Q

allows organism to cling to epithelial surfaces

Cytotoxic; destroys rbc and wbc

A

Lipoteichoic Acid (LTA)

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26
Q

depolymerizes DNA; facilitate removal of purulent exudate/ discharges

A

Streptodornase (Streptococcal Deoxyribonuclease)

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27
Q

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

A

Streptokinase (Fibrinolysin)

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28
Q

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

A

Diphosphopyridine nucleotidase

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29
Q

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

A

Streptolysin S

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30
Q

oxygen labile; antigenic) Immunogenic;

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

A

Streptolysin O

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31
Q

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

A

160–200 units

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32
Q

associated with streptococcal toxic shock syndrome and scarlet fever.

– act as superantigens

A

Erythrogenic Toxin

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33
Q

Most common cause of bacterial sore throat

A

PHARYNGITIS (Streptococcal sore throat)

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34
Q

Characterized by massive brawny edema and a rapidly advancing marin of infection

A

Erysipelas

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35
Q

surface is covered with pus and later is encrusted.

honey colored crust

A

Impetigo (Sreptococcal pyoderma)

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36
Q

Follows infection associated with mild trauma, burns, wounds, or surgical incisions; pain, tenderness, swelling, and erythema occur.

lesion is NOT raised, and the line between the involved and uninvolved tissue is indistinct.

caused by Hyaluridinase

A

Cellulitis

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37
Q

characterized by shock, bacteremia, respiratory failure, and multiorgan failure; tends to follow minor trauma

A

Streptococcal Toxic Shock Syndrome

38
Q

Occurs in association with S pyogenes pharyngitis or with skin or soft tissue infection

A

Scarlet Fever

39
Q

develops 1–4 weeks after S pyogenes skin infection (pyoderma, impetigo); after random streptococcal skin infections, the incidence of nephritis is less than 0.5%.

A

Acute glomerulonephritis

40
Q

Patients with more severe streptococcal sore throats have a greater chance of developing _________

A

Rheumatic fever

41
Q

most serious sequela of S pyogenes because it results in damage to heart muscle and valves

A

Rheumatic fever

42
Q

Streptococcus pyogenes : TREATMENT

A

Doses of Penicillin and Erthromycin

Allergic Patient: Clindamycin, Erthromycin, Cephalexin

43
Q

What bacteria.
Habitat: Female genital tract and lower gastrointestinal tract

Important cause of infection in OB/GYNE patient

A

Streptococcus agalactiae

44
Q

major virulence factor of S. agalactiae

A

Sialic acid (sialic acid capsule)

45
Q

HINT: B- BRAS

CAMP test positive;

hydrolyse sodium hippurate;

Bacitracin Resistant;

bile soluble;

PYR Negative (–)

A

Streptococcus agalactiae

46
Q

Test used to differentiate Group B strep (agalactiae) to S. aureus

A

CAMP test
(+) arrow head beta hemolysis

47
Q

Neonatal sepsis
Neonatal meningitis

Infections are associated with neonates acquired before or during the birthing process.

A

S. agalactiae

48
Q

Direct Contact: person to person from mother in utero or during delivery; nosocomial transmission by unwashed hands of mother or health care personnel

A

S. agalactiae

49
Q

Used to differentiate grp B streptococci from other beta hemolytic streptococci

– S. agalactiae possesses the enzyme hippuricase or hipurate hydrolase

  • (+) = purple color after addition of ninhydrin
A

Hippurate Hydrolysis test

50
Q

contains the C polysaccharide unrelated to the Lancefield grouping

A

Streptococcus pneumoniae

51
Q

AKA Frankel’s pneumococcus

A

Streptococcus pneumoniae

52
Q

Colonizer of upper respiratory tract; Capable of spreading to the lungs,
paranasal sinuses, and middle ear

A

Streptococcus pneumoniae

53
Q

Gram +
Lancet-shaped diplococci

A

Streptococcus pneumoniae

54
Q
  1. Test to swell the capsule
  2. Stain used to stain the capsule
A
  1. Quellung reaction
  2. India ink stain
55
Q

On blood agar resemble a doughnut

A

Streptococcus pneumoniae

56
Q

Polysaccharide capsule – major virulent of _____

A

Streptococcus pneumoniae

57
Q

BACTERIAL MENINGITIS S. pneumoniae SIGNS and SYMPTOMS appear within ________?

A

1 to 2 days after being exposed.

58
Q

MOST COMMON bacterial pneumonia among elderly patient especially with COPD

A

LOBAR PNEUMONIAE

59
Q

Clinical Manifestations: rusty colored sputum

A

Streptococcus pneumoniae

60
Q

Most common cause of otitis media in children

A

S. pneumoniae

61
Q

Test used to differentiate S. pneumoniae and viridans. Since both are alpha hemolytic

A

Optochin Test (letter P and disk)

62
Q

S. pneumoniae optochin test result

A

(+) sensitive, susceptible, with ZOI

63
Q

The most accurate and reliable specific method for IDENTIFICATION of S. pneumoniae

A

Newfiled Quellung test (capsular precipiation)

64
Q

CONFIRMATORY test for
S. pneumoniae

A

Bile Solubility

Positive (+): absence of turbidity. After 3 hours of incubation

reagent: Sodium desoxycholate (bile salts)

65
Q

Inoculation of sputum with pneumonococci to susceptible animal.

Observe after 16-24 hours, death occurs (+)

A

Mouse virulence test

66
Q

used to detect the presence of antibodies against streptococci

A

Francis skin test

67
Q

ENTEROCOCCI resistant to PCN

A

E. faecalis

68
Q

ENTEROCOCCI grow 6.5% NaCl

A

E. faecium

69
Q

ENTEROCOCCI grow in 40% bile

A

E. durans

70
Q

have the group D group-specific substance

A

ENTEROCOCCI

71
Q

Enterococci normal flora of the human GIT and female genitourinary tract

A

E. faecalis and Enterococcus faecium

72
Q

Bile esculin positive (hydrolyze esculin)

(deep blue —> black pigmented colonies

A

ENTEROCOCCI

73
Q

Culture media for isolation and cultivation of Enterococci

A

CAP

74
Q

is the principal cause of dental caries (tooth decay).

A

S. mutans

75
Q

Group-specific antigen extraction of Streptococcus pyogenes by treating with hydrochloric acid method is known as

A

Lancefield’s method

76
Q

selective medium for
Streptococcus pyogenes?

A

Crystal violet blood agar

77
Q

Susceptibility to bacitracin can be used to identify

A

Streptococcus pyogenes

78
Q

Test to differentiate Group B strep and Group A strep

A

Bacitracin test

GroupB (-) resistant
Group A (+) sensitive (ZOI) suso

79
Q

Test to differentiate S. pneumoniae from viridans

A

Bile solubility test

  • (POSITIVE +) bile soluble / absence of turbidity

Reagent: Sodium desoxycholate (bile salts)

80
Q

ONLY GROUP _____ STREP WILL GROWN ON _____ TEST

A

Group B strep (+) on CAMP TEST

81
Q

ASO, anti-DNase, antistreptokinase, and anti- hyaluronidase titers to detect past infection with

A

S. pyogenes

82
Q

dental caries (tooth decay) and infective endocarditis are associated with WHAT streptococci

A

Viridans streptococci

83
Q

Streptococci of this group are predominantly animal pathogens and comprise four species

A

group C streptococci.

S. equi, S. equisimilis, S. dysgalactiae and S. zooep­ idemicus.

84
Q

What strep group are commensals in the throats of human beings, monkeys or dogs.

A

group G streptococci

85
Q

ASO titers higher than _____ Todd units/ mL are indicative of prior streptococcal infection.

A

200 Todd

NOTE: High levels are usually found in acute rheumatic fever but in glomerulonephritis, titers are often low.

86
Q

The _________ grow in the presence of 6.5% NaCl, 40% bile, at ph 9.6, at 45°C and in 0.1% methelyne blue

A

Enterococci

87
Q

Pike’s medium contains what?

A

(blood agar containing 1 in 1,000,000 crystal violet and in 1 in 16,000 sodium azide)

88
Q

Selective medium for Streptococcus pyogenes

A

PNF medium

NOTE:
The PNF medium which is the Selective medium for Streptococcus pyogenes can be prepared by incorporating Polymixin B Sulfate, Neomycin sulfate and Fusidic Acid in the Horse Blood Agar medium for the growth of Streptococcus pyogenes.

89
Q

NOTE: For isolating group A streptococci from throat swabs the most common medium is blood agar supplemented with antibiotics trimethoprim/ sulfamethoxazole to suppress the groth of normal flora.

A

❤️

90
Q

what test is used to classify organisms in lancefield system

A

Lancefield precipitation test, also known as the Lancefield grouping test or the precipitin reaction.