Podcast
Questions and Answers
What constitutes the principal marker for potentially pathogenic streptococci in cultures of throat swabs or other clinical samples?
What constitutes the principal marker for potentially pathogenic streptococci in cultures of throat swabs or other clinical samples?
Which type of hemolysis is the principal marker for potentially pathogenic streptococci in cultures of throat swabs or other clinical samples?
Which type of hemolysis is the principal marker for potentially pathogenic streptococci in cultures of throat swabs or other clinical samples?
Which type of Streptococci can be serologically classified using a common C carbohydrate according to Lancefield classification?
Which type of Streptococci can be serologically classified using a common C carbohydrate according to Lancefield classification?
Which test differentiates Group A Streptococci from other Streptococci?
Which test differentiates Group A Streptococci from other Streptococci?
Signup and view all the answers
What is the function of the E.CAMP Test (Christie Atkins Munch Petersen Test)?
What is the function of the E.CAMP Test (Christie Atkins Munch Petersen Test)?
Signup and view all the answers
Which classification does the Pyogenic 10 C - 37 C + 45 C - Viridance - + + refer to?
Which classification does the Pyogenic 10 C - 37 C + 45 C - Viridance - + + refer to?
Signup and view all the answers
What is the basis of classification for Streptococci and Enterococci?
What is the basis of classification for Streptococci and Enterococci?
Signup and view all the answers
Which type of Streptococci produces a clear, colorless zone of hemolysis around it?
Which type of Streptococci produces a clear, colorless zone of hemolysis around it?
Signup and view all the answers
Which Streptococcus group is associated with incomplete or partial hemolysis?
Which Streptococcus group is associated with incomplete or partial hemolysis?
Signup and view all the answers
What kind of zone of hemolysis is characteristic of Beta-hemolytic Streptococci?
What kind of zone of hemolysis is characteristic of Beta-hemolytic Streptococci?
Signup and view all the answers
Lancefield grouping is used for classification based on what characteristic of Streptococci?
Lancefield grouping is used for classification based on what characteristic of Streptococci?
Signup and view all the answers
Which type of Streptococci is more likely to appear in chains when grown in broth cultures?
Which type of Streptococci is more likely to appear in chains when grown in broth cultures?
Signup and view all the answers
Which hemolysin is oxygen-stable and non-antigenic?
Which hemolysin is oxygen-stable and non-antigenic?
Signup and view all the answers
Which virulence factor of Group B Streptococci is known for its antiphagocytic properties?
Which virulence factor of Group B Streptococci is known for its antiphagocytic properties?
Signup and view all the answers
Which exotoxin causes Scarlet Fever?
Which exotoxin causes Scarlet Fever?
Signup and view all the answers
What is the function of Lipoteichoic acid and Protein F?
What is the function of Lipoteichoic acid and Protein F?
Signup and view all the answers
Which Streptococcus species has small, transparent, and smooth colonies with beta-hemolysis?
Which Streptococcus species has small, transparent, and smooth colonies with beta-hemolysis?
Signup and view all the answers
Which test is used to measure Streptolysin O levels?
Which test is used to measure Streptolysin O levels?
Signup and view all the answers
Study Notes
Streptococcus Characteristics
- Streptococcus spp. belong to the family Streptococcaceae
- Inhabit various sites, notably the upper respiratory tract, and live harmlessly as commensals
- Catalase-negative, gram-positive cocci, usually arranged in pairs or chains
- Cells of Enterococci and some Streptococci appear more elongated than spherical
- Streptococcal cells are more likely to appear in chains when grown in broth cultures
- Most members are aerotolerant anaerobes (but behave like facultative anaerobes)
- Some species are capnophilic
Hemolysis
- Alpha hemolysis: partial hemolysis, greenish discoloration around the colony
- Beta hemolysis: complete hemolysis, sharply defined, clear, colorless zone of hemolysis
- Gamma hemolysis: no hemolysis
Lancefield Classification
- Based on the group-specific C carbohydrate (polysaccharide) antigen
- Used to classify Streptococci serologically
Streptococcus Groups
- Group A: S. pyogenes, β-hemolysis, Lancefield group A
- Group B: S. agalactiae, β-hemolysis, Lancefield group B
- Group C: S. equisimilis, β-hemolysis, Lancefield group C
- Group D: Enterococci, α-hemolysis, Lancefield group D
- Group F: S. bovis, non-hemolytic, Lancefield group F
Laboratory Tests
- Bacitracin Susceptibility Test (Taxo A): differentiates Group A Streptococci from other Streptococci
- CAMP Test (Christie Atkins Munch Petersen Test): test for Group B Streptococci
- Gram Stain: gram-positive cocci in pairs or chains
- Cultural Characteristics: pinpoint colonies, β-hemolysis
- J. Leucine Aminopeptidase Test: detects J. Leucine aminopeptidase enzyme
- SXT Susceptibility Test: detects susceptibility to SXT antibiotic
- Serological Tests: detects antibodies against Streptococci
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the classification and characteristics of Streptococci, including colony appearance, growth preferences, and serological classification based on Lancefield classification. Learn about the significance of ß-hemolysis in identifying potentially pathogenic streptococci.
