Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Medical Microbiology lectures > L.2 Streptococcus (beta-haem) + Enterococci > Flashcards

L.2 Streptococcus (beta-haem) + Enterococci Flashcards

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

What is Group A Beta-Haemolytic Streptococcus?

A

Streptococcus pyogenes

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

What is Group B Beta-Haemolytic Streptococcus?

A

Streptococcus agalactiae

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

What infections can Group C Beta-Haemolytic Streptococci cause?

A

Pharyngitis, sinusitis, impetigo, endocarditis

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

What does Group D Beta-Haemolytic Streptococcus include?

A

The enterococci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What infections can Group D Beta-Haemolytic Streptococci cause?

A

Wound lesions, urinary tract infections, some cases of SBE

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

What is the characteristic of Group F Beta-Haemolytic Streptococcus?

A

Streptococcus anginosus; grows better anaerobically

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

Which group of Beta-Haemolytic Streptococci resembles group A strains?

A

Group G

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

What is a common non-invasive infection caused by Group A Streptococcus?

A

Pharyngitis

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

What are the symptoms of pharyngitis caused by Streptococcus pyogenes?

A

Abrupt onset, fever, headache, red/pus-filled throat

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

What percentage of childhood pharyngitis is caused by Group A Streptococcus?

A

5–30%

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

What is scarlet fever and its main characteristics?

A

Rash (sunburn-like, sandpaper texture), mainly affects <10 years, due to erythrogenic toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the characteristics of impetigo caused by Group A Streptococcus?

A

Honey crust lesions, pus-filled blisters

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

What is erysipelas?

A

Acute skin infection cellulitis, potential spread to bloodstream

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

What is necrotising fasciitis?

A

Rare infection of deep tissue causing pain, redness, swelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What predispositions increase the risk for necrotising fasciitis?

A

Cancer, diabetes, dialysis, steroids

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

What is Streptococcal Toxic Shock Syndrome?

A

Cytokine storm triggered by superantigens, rapidly progressing infection

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

What are the symptoms of Streptococcal Toxic Shock Syndrome?

A

High fever, rash, hypotension, multiorgan failure, desquamation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When do non-suppurative sequelae occur after infection?

A

1-5 weeks after infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What autoimmune disease can develop post pharyngitis?

A

Rheumatic fever

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

What systems can rheumatic fever affect?

A

Multiple systems, joints, heart, brain, skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is glomerular nephritis?

A

Post skin infection inflammatory disease affecting the kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What type of infections are notifiable in iGAS?

A

Only Invasive infections are notifiable iGAS.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How many cases of iGAS were notified in 2023?

A

533 cases in 2023.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the two types of streptolysins?
Streptolysin S and Streptolysin O.
26
What is the action of Streptolysin S?
Leucocidal action.
27
What is the effect of Streptolysin O?
Cytotoxic for RBCs, neutrophils, platelets.
28
What role does M protein play in virulence?
Inhibits phagocytosis by binding to Fc portion of IgG.
29
What is a major consequence of M protein deficiency in strains?
Strains lacking M protein are less virulent.
30
Name the exotoxins associated with Streptococcus.
SPE-A, SPE-B, SPE-C.
31
What are the functions of SPE-A and SPE-C?
Erythrogenic toxins.
32
What is the role of SPE-B?
Cysteine protease associated with tissue destruction.
33
What does anti-C5a peptidase do?
Cleaves C5a (chemoattractant).
34
What is the function of streptokinase?
Converts plasminogen to plasmin – facilitates spread.
35
What does hyaluronidase break down?
Tissue hyaluronic acid.
36
What is the classification of Streptococcus agalactiae?
Opportunistic Pathogen.
37
Where is Streptococcus agalactiae commonly found?
Commensal of GI and vaginal flora (30% & 25%).
38
What percentage of adults possess no protective antibodies to GBS?
90% of adults.
39
Who is most at risk for infections caused by Group B Strep?
Elderly, pregnant women, others with other diseases.
40
What is the most common cause of life-threatening infection in newborn babies?
Group B Strep (Streptococcus agalactiae).
41
How many cases of Group B Strep were reported in 2023?
36 cases in 2023.
42
What is the leading cause of life-threatening neonatal infections?
Group B Strep.
43
What is the time frame for early onset GBS infections in babies?
0-6 days (usually <24 hours).
44
What are the common presentations of early onset GBS infections?
Usually sepsis & pneumonia.
45
What is the mortality rate for early onset GBS infections?
11% mortality.
46
What is the time frame for late onset GBS infections in babies?
7+ days (rare after 3 months).
47
What percentage of late onset GBS infections presents as meningitis?
50%.
48
What is the mortality rate for late onset GBS infections?
5% mortality.
49
What percentage of GBS meningitis survivors have neurological sequelae?
50%.
50
What are the results of the Basic Characterisation test for the lab identification?
KoH Negative, Catalase Negative, Oxidase Negative ## Footnote These results help in the initial identification of the bacterial species.
51
Name three Manual confirmatory tests used in lab identification.
* Lancefield grouping * CAMP factor test * Hydrolysis of Hippurate ## Footnote Hydrolysis of Hippurate differentiates S/agalactiae from other beta-haemolytic streptococci.
52
What is the purpose of the MALDI-TOF test?
Automated confirmatory test ## Footnote MALDI-TOF is used for rapid identification of microorganisms based on their protein mass profiles.
53
What molecular confirmatory tests are mentioned?
* RT-PCR * Send CSF to IMSRL Temple Street ## Footnote RT-PCR is used for detecting specific nucleic acid sequences.
54
What is the significance of Group C and G streptococci?
Commensal flora of the human upper airway ## Footnote They are asymptomatic colonizers of the skin, gastrointestinal tract, and female genital tract.
55
Provide an example of a Group C and G streptococcus.
Streptococcus dysgalactiae subsp. equisimilis (SDSE) ## Footnote This strain resembles S. pyogenes infection.
56
What is the characteristic of Non-Enterococcal Group D streptococcus?
Streptococcus bovis ## Footnote It is part of the gastrointestinal flora.
57
What are the hemolytic characteristics of Streptococcus bovis?
α or non haemolytic ## Footnote This characteristic helps differentiate it from other streptococci.
58
What conditions can Streptococcus bovis cause?
* UTIs * Endocarditis ## Footnote Streptococcus bovis infections can be serious and require medical attention.
59
What is the bile aesculin test result for Streptococcus bovis?
Bile Aesculin Positive ## Footnote This test is used to identify group D streptococci.
60
What is the PYR test result for Streptococcus bovis?
PYR negative ## Footnote This helps further distinguish it from other streptococci.
61
Does Streptococcus bovis grow in 6.5% salt?
Does not grow in 6.5% salt ## Footnote This characteristic aids in the identification of this organism.
62
What is the first-line treatment for beta-haemolytic streptococcus?
Penicillin ## Footnote Penicillin is often the drug of choice for treating these infections.
63
What alternative antibiotic is used for beta-haemolytic streptococcus in case of allergy?
Clarithromycin ## Footnote This is used when patients are allergic to penicillin.
64
What is the treatment approach for necrotizing fasciitis caused by beta-haemolytic streptococcus?
Surgery + clindamycin ## Footnote Surgical intervention is critical in managing this serious condition.
65
What genus contains strains formerly classified under the genus Streptococcus?
Genus Enterococcus ## Footnote This genus currently recognizes 40 species.
66
Which two species of Enterococcus are of clinical importance?
* Enterococcus faecalis * Enterococcus faecium ## Footnote These species are significant in human infections.
67
What is the primary habitat of Enterococcus species?
Commensal flora of the GI tract ## Footnote Most infections are endogenous.
68
What percentage of all Hospital Acquired Infections (HAI) were caused by Vancomycin Resistant Enterococci (VRE) in a 2017 study?
9% ## Footnote This statistic highlights the significance of VRE in healthcare settings.
69
What are the two most clinically significant phenotypes of VRE?
* VanA * VanB ## Footnote These phenotypes have different resistance levels to vancomycin and teicoplanin.
70
What is the mechanism of resistance in VRE?
Alteration of cell wall precursors ## Footnote This mechanism complicates treatment options.
71
Name one type of infection commonly associated with Enterococcus species.
* Urinary tract infection * Intra abdominal abscess * Endocarditis * Blood stream infection ## Footnote These infections can be severe and require prompt treatment.
72
What type of specimens are used for lab investigation of Enterococcus?
* Urine samples * Blood cultures * Pus * Rectal swab (carriage specimens) ## Footnote Different specimens help in diagnosing infections and identifying carriers.
73
On which agar does Enterococcus show non-haemolytic growth?
Blood agar ## Footnote This characteristic helps in the initial identification of Enterococcus.
74
What color does Enterococcus faecalis appear on chromogenic VRE medium?
Blue-green ## Footnote This differentiation aids in identifying specific Enterococcus species.
75
What are the treatment options for Enterococci infections?
* Ampicillin + Gentamicin * Vancomycin * Linezolid ## Footnote These treatments vary based on resistance patterns.
76
What is the result of Enterococcus on KoH test?
Negative ## Footnote This result is part of the laboratory identification process.
77
Fill in the blank: Enterococcus species can be resistant to _______.
antimicrobials ## Footnote This resistance includes notable cases like vancomycin-resistant enterococci.
78
True or False: Enterococcus species are fastidious organisms.
False ## Footnote They are not fastidious and grow easily on various media.
79
What color does Enterococcus appear on MacConkey agar?
Magenta pinpoint ## Footnote This appearance is characteristic of Enterococcus in culture.
80
What test result indicates that Enterococcus can hydrolyze aesculin?
Black growth on bile aesculin agar ## Footnote This is used as a confirmatory test for Enterococcus.

Medical Microbiology lectures (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions