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Questions and Answers
Match the Lancefield group to the correct species:
Match the Lancefield group to the correct species:
S.equismimilis = C S.bovis group = D, non-Enterococcus S.agalactiae = B E.faecalis = D, Enterococcus S.mutans = None S.pyogenes = A E.faecium = Enterococcus, D S.anginosus = F
Lancefield's classification of Streptococcus is based on?
Lancefield's classification of Streptococcus is based on?
Cell wall polysaccharide
Streptolysin O is?
Streptolysin O is?
Antigenic
What would be an incorrect reaction for Enterococcus?
What would be an incorrect reaction for Enterococcus?
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Sequelae of group ___________________________ infection may lead to acute rheumatic fever or acute glomerulonephritis.
Sequelae of group ___________________________ infection may lead to acute rheumatic fever or acute glomerulonephritis.
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Colonies of Streptococcus pneumoniae at 24 hours are typically?
Colonies of Streptococcus pneumoniae at 24 hours are typically?
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What are the best tests to identify B-hemolytic streptococci isolated from a throat culture of a 15-year-old male?
What are the best tests to identify B-hemolytic streptococci isolated from a throat culture of a 15-year-old male?
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What is the expected reaction of the B-hemolytic streptococci for Species: Streptococcus pyogenes?
What is the expected reaction of the B-hemolytic streptococci for Species: Streptococcus pyogenes?
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What is the expected reaction of the B-hemolytic streptococci for Species: Streptococcus agalactiae?
What is the expected reaction of the B-hemolytic streptococci for Species: Streptococcus agalactiae?
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What is the expected reaction of the B-hemolytic streptococci for Species: Groups C, F, and G?
What is the expected reaction of the B-hemolytic streptococci for Species: Groups C, F, and G?
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What is the expected reaction for the a-hemolytic and non-hemolytic streptococci for Species: Group D Enterococcus?
What is the expected reaction for the a-hemolytic and non-hemolytic streptococci for Species: Group D Enterococcus?
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What is the expected reaction for the a-hemolytic and non-hemolytic streptococci for Species: Group D-S.bovis group?
What is the expected reaction for the a-hemolytic and non-hemolytic streptococci for Species: Group D-S.bovis group?
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What is the expected reaction for the a-hemolytic and non-hemolytic streptococci for Species: Streptococcus pneumoniae?
What is the expected reaction for the a-hemolytic and non-hemolytic streptococci for Species: Streptococcus pneumoniae?
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What is the expected reaction for the a-hemolytic and non-hemolytic streptococci for Species: Viridans streptococci?
What is the expected reaction for the a-hemolytic and non-hemolytic streptococci for Species: Viridans streptococci?
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Identify B-hemolytic streptococci that are PYR negative, CAMP negative, resistant to bacitracin, and susceptible to sulfamethoxazole.
Identify B-hemolytic streptococci that are PYR negative, CAMP negative, resistant to bacitracin, and susceptible to sulfamethoxazole.
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The nutritionally variant streptococci require?
The nutritionally variant streptococci require?
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What has intrinsic resistance to penicillin and the aminoglycosides, shows acquired resistance to many antibiotics including vancomycin, and are nosocomial pathogens?
What has intrinsic resistance to penicillin and the aminoglycosides, shows acquired resistance to many antibiotics including vancomycin, and are nosocomial pathogens?
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Study Notes
Lancefield Classification
- Lancefield groups categorize Streptococcus species based on specific polysaccharide antigens found in cell walls.
- Group A Streptococcus matches with S.pyogenes, which is associated with harmful infections.
- Group B Streptococcus corresponds to S.agalactiae, significant in neonatal infections.
- S.equismimilis falls under Group C.
- Non-Enterococcus categories include S.bovis group (D) and additional groups such as C, F, or G.
- Enterococcus species like E.faecalis and E.faecium correspond to Group D.
Streptococcus Characteristics
- Streptolysin O is an antigenic component important for serological testing.
- Streptococcus pneumoniae colonies at 24 hours present as mucoid and alpha-hemolytic.
- Group-specific reactions are essential for identifying beta-hemolytic streptococci:
- S.pyogenes typically shows PYR positive and bacitracin susceptible.
- S.agalactiae is usually CAMP positive and PYR negative.
Clinical Implications
- Infections caused by Group A Streptococcus can lead to complications such as acute rheumatic fever or acute glomerulonephritis.
- Enterococci have intrinsic resistance to penicillin and aminoglycosides, posing a challenge in treating infections and may show acquired resistance to other antibiotics like vancomycin.
- Nutritionally variant streptococci require Vitamin B6 for growth, highlighting their specific nutritional needs.
Test Identification
- For identifying beta-hemolytic streptococci, tests like bacitracin sensitivity and PYRase are crucial.
- Distinctions between groups can guide appropriate antibiotic therapy and clinical management decisions.
- PYR negative tests are uncommon for Enterococcus, serving as an identification marker for bacterial differentiation.
Additional Information
- Viridans group streptococci, known for their alpha-hemolytic properties, play a role in endocarditis and are generally opportunistic pathogens.
- The expected reactions of non-hemolytic streptococci, like the S.bovis group and Streptococcus pneumoniae, highlight their biochemical profiles for laboratory diagnosis.
Studying That Suits You
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Description
This quiz focuses on Chapter 8 of Clinical Microbiology, specifically matching Lancefield groups to their corresponding species. Each card presents a different species, allowing for interactive learning and memorization of key classifications.
