Question

Identify the bacteria involved in respiratory infections using the following laboratory test results:
Gram-positive cocci
Catalase-positive: a.
Catalase-negative
Beta-hemolytic, bacitracin inhibition: b.
Alpha-hemolytic, optochin inhibition: c.
Gram-positive rods
Non-acid-fast: d.
Acid-fast: e.
Gram-negative cocci: f.
Gram-negative rods
Aerobes
Coccobacilli: g.
Rods
Grow on nutrient agar: h.
Require special media: i.
Facultative anaerobes
Coccobacilli: j.
Intracellular parasites
Form elementary bodies: k.
Do not form elementary bodies: l.
Wall-less: m.

Accepted Answer

Step 1: For Gram-positive cocci, first differentiate based on the catalase test. Catalase-positive Gram-positive cocci are typically Staphylococcus species, so for 'Catalase-positive', identify the genus Staphylococcus. Step 2: For catalase-negative Gram-positive cocci, further classify based on hemolysis and antibiotic sensitivity. Beta-hemolytic and bacitracin-sensitive bacteria are usually Streptococcus pyogenes (Group A Streptococcus). Step 3: For alpha-hemolytic and optochin-sensitive Gram-positive cocci, the typical identification is Streptococcus pneumoniae. Step 4: For Gram-positive rods, distinguish between acid-fast and non-acid-fast. Non-acid-fast rods that are respiratory pathogens often include genera like Listeria or Bacillus, while acid-fast rods are characteristic of Mycobacterium species. Step 5: For Gram-negative cocci, common respiratory pathogens include Neisseria species. For Gram-negative rods, differentiate aerobes by growth characteristics: coccobacilli that grow on nutrient agar might be Haemophilus influenzae, while those requiring special media could be Bordetella pertussis. Facultative anaerobic coccobacilli include Brucella. Intracellular parasites forming elementary bodies are Chlamydia species, while those not forming elementary bodies could be Rickettsia. Wall-less bacteria are Mycoplasma species.

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Gram Staining and Morphology

Biochemical and Hemolytic Tests

Special Growth Requirements and Intracellular Characteristics