Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CLINICAL CHEMISTRY 1 - LECTURE > BACTERIOLOGY LEC - MIDTERMS: L2 - STREPTOCOCCI > Flashcards

BACTERIOLOGY LEC - MIDTERMS: L2 - STREPTOCOCCI Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

3 genera of family Streptococcaceae Bergey’s Manual of Determinative Bacteriology)

A
  1. Streptococcus
  2. Enterococcus (Note: previously from genus streptococcus)
  3. Lactococcus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

T OR F

Streptococcaceae are gram positive cocci, and catalase positive, making them differ from Staph

A

False
Staph - catalase positive
Strep - catalase negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T or F

Streptococcaceae are fastidious, facultative aerobes and needs 5-10% CO2 for growth

A

False

- Strep areFacultative anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

MOTF
Patterns of Hemolysis
1. Beta hemolytic - complete hemolysis of RBC, clear or colorless zone
EX: S. pyogenes, S. agalactiae

  1. Gamma hemolytic - non-hemolytic, Enterococcus spp.
  2. Alpha hemolytic - incomplete or partial hemolysis of RBC, green discoloration
    Ex: S. pneumoniae, S. viridans
A

ALL TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

MOTF
Physiological Division

  1. Viridans division - salt tolerant, grow at high pH, and Temp range of 10°C to 45°C.
  2. Pyogenic division - includes beta hemolytic strains (A,B,C,D,E,F,&G)
    - Streptococcal organisms that are able to create diseases or infections associated with pus formation
  3. Enterococcus division - not beta hemolytic, not salt tolerant, and grow at high pH.
  4. Lactic division - not clinically significant & associated with dairy industry
A

2,4 - TRUE
1,3 - FALSE

  1. Viridans division - not beta hemolytic, not salt tolerant, and grow at high pH.
  2. Enterococcus division - salt tolerant, grow at high pH, and Temp range of 10°C to 45°C.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

MOTF
Lancefield Grouping
By Rebecca Lancefield 1993

  1. Divides the Streptococci into serologic groups - Based on antigenic properties of carbohydrate group antigens in their cell wall
  2. ABCDFG - clinically significant
  3. Mostly associated with human infection.
  4. ABCDE were the first five and cuurrently at almost 20 groups (A-H)(K-T)
A

All true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Beta Hemolytic Streptococcus

Enumerate all

A

Lancefield group A - S. pyogenes

Lancefield group B
- S. agalactiae

Lancefield group C & G - S. dysgalactiae &S. Equi

Lancefield group A, C, F & G - S. anginosus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

MOTF
Group A: Streptococcus pyogenes (GAS)

  1. Normal flora
  2. Most virulent for humans
  3. Acquired only thru direct contact - person to person contact
A

1,3 - false
2 - true

1 - not normal flora
3 - also by inhalation of aerosol droplets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cell surface antigens of GAS

  • This structure is antiphagocytic; it prevents organisms from being phagocytized.
  • Reason for mucoid colonies
A

Hyaluronic acid Capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cell surface antigens of GAS

  • Interferes with complement activity, Precipitates fibrinogen, Clumps platelet and wbc, Inhibits migration of WBC
  • Can differentiate S pyogenes
A

M protein (about 80 types)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Group-specific cell wall antigen of GAS

A

Grp.A sugar: rhamnose-N-acetylglucosamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Allow them to act like immune cells and attach to fc portion of IgG and IgA

A

IgG & IgA-binding proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  • Cleaves C5a component of complement

- Inhibits neutrophil chemotaxis in vitro

A

C5a protease

(C5a - important anaphylatoxin, will attach to mast cells and basophils - initiating release of histamine and start inflammatory reaction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

MOTF

  1. F protein - allows binding to fibronectin in pharyngeal epithelium
  2. Lipoteichoic acid: - attached to M protein
    - may allow binding to fibronectin
A

BOTH T

Fibronectin - binding sites for organism on membranes on host cells or structures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

MOTF
1. Streptokinase - fibrinolysin that lyses blood clots (just like staphylokinase)

  1. Hyaluronidase - hydrolyze or breakdown hyaluronic acid which is part of the connective tissue, important in spreading the infection
  2. Diphosphopyridine nucleotidase - degrades host DNA & RNA
  3. Streptodornase - Associated with the organism’s ability to
    destroy WBCs
A

1,2 - true
3,4 - false

  1. Streptodornase - degrades host DNA & RNA
  2. Diphosphopyridine nucleotidase - Associated with the organism’s ability to
    destroy WBCs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  • Responsible for the increase in temperature and rashes (specially in Scarlet fever)
  • Cause of Streptococcal TSS
A

Pyrogenic exotoxins/ erythrogenic toxins (A, B, C)

Most potent: Exotoxin A

NOTE: Staph TSS is more fatal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

MOTF

  1. Streptolysin O - antigenic, oxygen labile
  2. Streptolysin S - oxygen stable, non-antigenic but toxic (surface hemolysin)
A

Both true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

MOTF
Erysipelas
1. St. Anthony’s fire
2. Has pus production, but exotoxin A production
(increase temperature in the area) & rashes
3. Itchiness and hotness

A

1,3 - true

2 - false, has no pus production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
  • Inflammation of deep tissues including the skin

- Common in middle aged individuals

A

Cellulitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
  • Begins as fluid-filled blisters that usually erupts creating weeping lesions
  • Common in children
A

Impetigo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Red, swollen tonsils

A

Strep throat

- Streptococcal pharyngitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
  • Made streptococcus pyogenes earn the name of “flesh-eating bacteria”
  • Active component: Exotoxin A
  • Destruction of tissue a rate of 2 inches per hour
A

Necrotizing fasciitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  • Cause Hypotension, multi-organ failure, fever,
    erythema, swelling, tachycardia, acute respiratory distress, renal impairment and shock
  • Toxin mediated
A

Streptococcal toxic shock syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  • May occur after streptococcal pharyngitis or other infection
  • Strawberry tongue, rashes, fever
A

Scarlet fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  • Cardiac inflammation and scarring
  • Acute stage consist of pancarditis (infected entire layer of heart)
  • Autoimmune response
A

Rheumatic heart disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Systemic disease that affects the connective tissue around the arterioles

A

Acute rheumatic fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Triggers inflammation and proliferation of
glomerular tissue that can result in damage to
the basement membrane

A

Acute glomerulonephritis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

MOTF
GAS
1. BAP: white to gray pinpoint colonies, translucent, opalescent.
2. Wide zone of B-hemolysis
3. Contaminated (throat): BAP with SXT
(trimethoprim/sulfamethoxazole)
4. Mucoid colonies may be produced especially strains that are positive for M protein

A

All are true

NOTE: M protein 49 - most virulent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Differentiate staphylococcus from streptococcus

A

Catalase test

Staph = positive
Strep = negative
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

BAP WITH SXT = GAS are resistant or susceptible?

A

Resistant (R)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Taxo A/Bacitracin Disk test of GAS:

A
  • 0.02 to 0.04 unit used (0.04 more common)
  • Only Gas is susceptible for taxo A
  • Zone of inhibition = Positive for GAS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

PYR Test: Pyrrolidonyl arylamidase test for GAS

- Reagent used

A

Reagent: L-pyrrolidonyl-2-naphthylamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

L-pyrrolidonyl-2-naphthylamide is hydrolyzed by the enzyme

A

Pyrrolidonyl arylamidase (produced specifically by GAS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Hydrolization of L-pyrrolidonyl-2-naphthylamide will release _______

A

B-naphthylamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Color developer acted to B-naphthylamide

A

p-dimethylaminocinnamaldehyde (pink color)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Serological tests for GAS:

A
  1. ASO (anti-streptolysin O)

2. Sero typing of specific M CHON

37
Q

MOTF
DICK TEST - for scarlet fever
1. 0.1ml toxin (test arm) & 0.1ml toxoid (control arm)
2. Positive: (+) redness in test arm (1 cm)

A

Both true

38
Q

MOTF
SCHULTZ-CHARLTON TEST
1. Checks out the rashes whether it is caused by scarlet fever or not
2. Inject 0.1 mL of anti-toxin subcutaneously and fading of rashes after 6 to 8 hours means positive (there is scarlet fever)

A

Both true

NOTE: There is neutralization of erythrogenic toxin via the anti-toxin

39
Q

MOTF
Group B: Streptococcus agalactiae (GBS)
1. Normal flora of the GIT & Vaginal tract
2. Bigger beta-hemolytic compared to GAS
3. Able to mimic host molecules via its Polysaccharide capsule

A

1,3 true
2 - false

2 - GAS has wider beta hemolysis

40
Q

MOTF
GBS Pathogenesis
1. Mostly the infections are nosocomial and manifest in immunocompromised individuals
2. Can be through neonatal infection and Adult streptococcal infection
3. Neonatal infection: infection of amniotic fluid through placental membranes and passing through birth canal

A

All true

NOTE:
Nosocomial infection types:

  1. Early-onset - first week of life
  2. Late-onset - first week to about 3 months after birth
41
Q

CAMP test meaning of acronym:

A

Christie, Atkins and Munch-Peterson

42
Q

MOTF
CAMP TEST
1. In BAP, in the middle are the unknown and perpendicular to it are the SAU
2. Do not incubate anaerobically or with increase CO2 to prevent false reaction
3. Contains synergistic hemolysis of SAU and GAS
4. Positive result: arrowhead zone of hemolysis

A

1,3 - false
2,4 - true

1 - In bap: middle - sau, perpendicular - unknown

3 - Sau and GBS

43
Q

SODIUM HIPPURATE HYDROLYSIS

Reagent used:

A

0.4 ml 1% Na hippurate

44
Q

If GBS is present, it will hydrolyze sodium hippurate into ______

A

Benzoic

acid and glycine

45
Q

MOTF

  1. Ferric chloride - detect benzoic acid producing purple color
  2. Ninhydrin - detect glycine
A

BOTH TRUE

NOTE: Purple color = positive for SHH > meaning GBS is present

46
Q

Characteristics of Group C, F & G: Miscellaneous Beta Hemolytic Streptococcus

A
  • beta-hemolytic streptococci
  • Normal microbiota: skin, nasopharynx, GIT, GUT
  • Contains Endogenous strain: gain access to the sterile site and
    cause infections
  • Direct contact: person to person
47
Q

Differentiate Group C F G (On a 5% SBA)

A

Group C - Grayish white, glistening; (F and G are matte)

Group F - has narrow to wide zone of B-hemolysis ( C and G are wide)

Group G - matte, wide zone

48
Q

Enumerate Group C and G and Group F

A 
Group C&G
- S. equi subsp. zooepidemicus,
-  S. equi subsp. equi
- S. dysgalactiae subsp. equisimilis,
- S. dysgalactiae subsp. dysgalactiae
- S. anginosus
(They cause infection similar to Group A)

Group F
- S. anginosus

49
Q

Group C, F & G: Identification

Test differentiate them from group B

A

CAMP and Hippurate

50
Q

Group C, F & G: Identification

Test differentiate them from group A

A

PYR - Pyrrolidonyl arylamidase test

51
Q

Group C, F & G: Identification

Test differentiate them from group D

A

Bile esculin

52
Q

Group C, F & G: Identification

SXT: resistant or susceptible?

A

Susceptible (unlike A and B)

53
Q

Group C, F & G: Identification

Vogues-Proskaur

A

S. dysgalactiae subsp. equisimilis = Vp (-)

S. anginosus (C,G,F) = Vp(+)

54
Q 
MOTF
Streptococcus pneumoniae 
1.  Formerly Diplococcus pneumoniae
2. Beta-hemolytic
3. Capnophilic - 5-10% CO2
4. Encapsulated, facultative anaerobe, fastidious
A

1,3,4 - true
2 - false

2 - alpha-hemolytic

55
Q

Major virulence factors of Streptococcus pneumoniae (Enumerate)

A
  1. CAPSULAR ANTIGENS: Resist phagocytosis and antigenic
  2. M-CHON
  3. PNEUMOLYSIN - released in cell lysin
  4. Autolysin - aids in the release of pneumolysin
56
Q

Pathogenesis of Streptococcus pneumoniae

A

Respiratory Tract ➞ sinuses and middle ear ➞ sinusitis and otitis media

57
Q

Streptococcus pneumoniae can cause what diseases:

A
  • pneumonia, bacteremia, & meningitis
  • community-acquired bacterial pneumonia; common in US

NOTE: Rusty sputum - sputum characteristic

58
Q

MOTF
Streptococcus pneumoniae
1. Gram(+) lancet-shaped diplococci
2. Mucoid, dome shape, transparent colonies

A

Both true

59
Q

Streptococcus pneumoniae colonies later develop a _____

appearance after 48 hours of incubation

A

crater-like

60
Q

Streptococcus pneumoniae test - Optochin Test/ Taxo P

- Optochin (antibiotic) also known as

A

ethylhydrocupreine hydrochloride

61
Q

Streptococcus pneumoniae test - Optochin Test/ Taxo P

  1. Sensitivity testing, inoculating the specimen using lawn technique
  2. Use of 5ug - Ethylhydrocupreine HCl
  3. POSITIVE: (+) ≥14 mm (susceptible for S. pneumoniae)
A

All true

S. pneumoniae are susceptible to Optochin test

62
Q

T or F

Pneumococcus are bile soluble

A

True

63
Q

Differentiates the Pneumococcus (bile soluble) from other alpha-hemolytic Streptococci (non bile soluble)

A

Bile Solubility Test:

64
Q

Examples of bile salts used:

A

(Na deoxycholate; Na taurocholate)

65
Q

Positive result of bile solubility test

A

POSITIVE: has autolysis (clear solution because it dissolves the bile)
- CLEAR SOLUTION = Presence of S. Pneumococcus

NEGATIVE: TURBID

66
Q

Test of S. pneumococcus which makes use of an antisera and causes a change on the refractive index of the capsule, making it more swollen and visible

A

Quellung Test:

67
Q

Quellung Test positive result:

A

Counterstain - methylene blue (usually)

Positive: swollen capsules, meaning it has ag-ab reaction

68
Q

MOTF

  1. S. pneumococcus treatment: Penicillin, ceftriaxone/cefotaxime, Trimethoprim/sulfamethoxazole - tmp/smx (STX)
  2. S. pneumococcus is also susceptible to penicillin, macrolides, & cephalosporins
  3. Prevention: Pneumococcal conjugate vaccine
A

1,3 - true

2 - false, SP acquired resistant to penicillin, macrolides, & cephalosporins

69
Q 
T OR F
Streptococcus bovis group
1. Group D non-enterococcus
2. Bile esculin + and PYR - 
3. Unable to grow in 6.5% Nacl 
4. Alpha, gamma hemolytic
A

True

70
Q

Bacteremia caused by Streptococcus bovis has been associated with the presence of

A

Gastrointestinal tumors

71
Q

Enumerate Streptococcus bovis group

A

S. bovis & S. equinus → single species

Others: S. gallolyticus, S. infantarius, S. alactolyticus

72
Q

Enumerate Enterococcus group

A

E. faecalis - causes about 80-90% cases of human enterococcal infection; widely isolated
E. faecium, E. durans, E. avium, E. casseliflavus, E.
gallinarum, E. dispar, & E. canis

73
Q
  • Both Enterococcus and non-Enterococcus are positive for this test
  • Differentiate Group D from other Streptococcal groups
A

BILE ESCULIN HYDROLYSIS

74
Q

The differentiation is based on the Group D’s ability to ______

A

To grow in 40% bile and hydrolyze esculin producing the product esculetin

75
Q

Esculetin reacts with ferric chloride produce

A

brown-black precipitate

76
Q

Esculin is hydrolyzed to ____

A

Esculetin and dextrose

77
Q

Differentiates Enterococcal and non- Enterococcal groups

A

5% SALT BROTH OR SALT TOLERANCE TEST

78
Q 
MOTF
5% SALT BROTH OR SALT TOLERANCE TEST
1. If growth is present in both broth (w/ salt & w/o salt), the organism is salt tolerant - true for Enterococcal group
2. Turbid = presence of enterococcus
3. Clear = non-enterococcus
A

All true

79
Q

MOTF
1. Enterococcus has intrinsic resistance to beta-lactam antibiotics (penicillin, cephalosporins, and aminoglycosides)
2. Use of combination treatment : beta-lactam (penicillin or
vancomycin) with aminoglycosides
3. Vancomycin-resistant Enterococci (VRE) → first reported
in 1986

A

All true

NOTE: It is important to perform first sensitivity testing

80
Q

Enumerate Viridans Group:

A 
S. mutans
S. salivarus
S. mitis
S. sanguinis
S. constellatus
S. intermedius
81
Q
  • Heterogenous group of Streptococcus. They do not have a Lancefield Antigen Classification
  • Normal flora of the human oropharynx, GIT, and the female genital tract
A

Viridans Group

82
Q

Diseases caused by Viridans group:

A

Subacute bacterial endocarditis - cause infection in people with damaged heart valves or those with prosthetic heart valves implanted in their endocardial surfaces

Bacteremia and Septicemia - Transiently enters the blood following dental or genitourinary procedures

Dental caries - Acids are the ones that destroy the enamel

83
Q

Viridans group produce the enzyme ____ which can breakdown sucrose and binds to glucose to form complex polysaccharides like glucans and dextrans

A

Glucosyltransferase - Facilitates the attachment of Viridans groups such as S. mutans to tooth enamel, ferment sugar and release acid as by-product (destroy enamel)

84
Q

Viridans group laboratory diagnosis:

A
  • Resistant to bile (sodium deoxycholate), & optochin
  • Negative to most presumptive tests for Streptococcus
  • Positive to mannitol and sorbitol
  • Positive to urease and VP (Vouges-Proskouer) reaction
85
Q

NUTRITIONALLY VARIANT STREPTOCOCCI (NVS)
NVS - Appears to mimic the Viridans group

What is its main difference from the Viridans group

A

Requires cysteine or pyridoxal (Vitamin B6) for growth

86
Q

NVS - Also known to grow well beside Staphylococcus aureus because it releases _____

A

pyridoxal

87
Q

NVS - given the new genus

A

Abiotrophia and Granulicatella

88
Q 
Other Catalase (-) Streptococcal Like Organisms
- commonly mistaken as Streptococci
A
  • Aerococcus viridans = Rare cause of endocarditis and meningitis ICH
  • Leuconostoc spp = Rarely isolated in clinical sites

-Pediococcus = NF of LGIT, isolated occasionally from
abscesses

-Lactococcus and Gemella = Very rare human pathogens

CLINICAL CHEMISTRY 1 - LECTURE (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions