Bacteriology - Laboratory Evaluation of Gram-Positive Bacteria Flashcards
How are S. pneumoniae and viridans streptococci differentiated in the laboratory?
Streptococcus pneumoniae is bile soluble and optochin sensitive.
How can capsulated S. pneumoniae bugs be detected in the laboratory?
Quellung positive (capsule swells when antisera is added)
What determines the Lancef ield grouping of streptococci?
C-carbohydrate in the bacterial cell wall
How are groups A and B differentiated in the laboratory?
Group A is bacitracin sensitive.
How are spores from gram-positive rods killed?
Autoclave (spores are resistant to heat and most chemicals)
Name the gram-negative organisms associated with each of the following statements:
Three pathogenic gram-negative cocci
- Neisseria meningitides
- Neisseria gonorrhea
- Moraxella catarrhalis
Name the gram-negative organisms associated with each of the following statements:
Six gram-negative coccobacilli
- Haemophilus influenzae
- Pasteurella
- Brucella
- Bordetella pertussis
- Francisella
- Legionella
Name the gram-negative organisms associated with each of the following statements:
Three clinically important gram-negative rods that are typically lactose fermenting
- Enterobacter
- Escherichia coli
- Klebsiella (all implicated in urinary tract infections [UTIs])
Name the gram-negative organisms associated with each of the following statements:
Two obligate intracellular organisms
- Chlamydia (steals adenosine triphosphate [ATP] from host)
- Rickettsia (lacks coenzyme A [CoA] and nicotinamide adenine [NAD] → cannot produce own ATP)
Name the gram-negative organisms associated with each of the following statements:
Four obligate aerobes
- Nocardia
- Pseudomonas
- Mycobacterium tuberculosis
- Bacillus
Name the gram-negative organisms associated with each of the following statements:
Three obligate anaerobes
- Clostridium
- Bacteroides
- Actinomyces (no catalase and/or superoxide dismutase → susceptible to oxidative damage)
How are the pathogenic Neisseria species differentiated in the laboratory?
Neisseria meningitidis ferments maltose.
How can Pseudomonas be rapidly differentiated from many lactose nonfermenters in the laboratory?
Pseudomonas is oxidase positive.
Provide culture requirements or conditions for each of the following bacteria:
Corynebacterium diphtheriae
Tellurite agar or Loeffler media
Provide culture requirements or conditions for each of the following bacteria:
Bordetella pertussis
Bordet-Gengou potato blood agar
