Article 2: Major Groups of Disease-Causing Bacteria (Worksheet)

Question 1

Gram Positive Cocci: 3 main species

Answer 1

Staphylococcus, Streptococcus, Enterococcus

See “-coccus” think “Cocci”

Question 2

Positive vs Negative Catalase Test

Answer 2

Positive: Staphylococcus

Negative: Streptococcus or Enterococcus

Question 3

Positive vs Negative Coagulase Test

Answer 3

Positive: Staphylococcus aureus

Negative: (Novobiocin Test needed)

Question 4

Positive vs Negative Novobiocin Test

Answer 4

Positive (i.e. Sensitive): Staphylococcus epidermidis

Negative (i.e. Resistant): Staphylococcus saprophyticus

Question 5

Hemolysis on Blood Agar Test (either Streptococcus or Enterococcus species, at this point)

Answer 5

Alpha: (Optochin sensitivity test needed)

Beta: (Bacitracin sensitivity test needed)

Gamma: Enterococcus Species

Question 6

Sensitive vs Resistant Optochin Sensitivity Test

Answer 6

Sensitive: Streptococcus pneumoniae

Resistant: Enterococcus species

Question 7

Sensitive vs Resistant Bacitracin Sensitivity Test

Answer 7

Sensitive: Streptococcus pyogenes

Resistant: Streptococcus agalactiae

Question 8

Gram Positive Rods: 2 subcategories and 4 species

Answer 8

Anaerobic Spore-Forming:
-Clostridium

Aerobic:

• Bacillus
• Listeria
• Corynebacterium

Question 9

Positive vs Negative Anaerobic Growth Test

Answer 9

Positive: Clostridium species

Negative: (Spore formation test needed)

Question 10

Positive vs Negative Spore Formation Test

Answer 10

Positive or Negative: (Motility Test needed)

Question 11

Positive vs Negative Motility Test with a Positive Spore Formation Test

Answer 11

Positive: Bacillus cereus

Negative: Bacillus anthracis or Bacillus cereus

Question 12

Positive vs Negative Motility Test with a Negative Spore Formation Test

Answer 12

Positive: Listeria monocytogenes

Negative: Corynebacterium diptheriae

Question 13

Gram Negative Rods: Enterobacteriaceae Family

Answer 13

Esterichieae coli
Klebsiella pneumoniae
Salmonella enterica
Salmonella typhi
Proteus species
Shigella species
Yersinia pestis

Question 14

Positive vs Negative Lactose Fermentation Test

Answer 14

Positive: Esterichieae coli or Klebsiella pneumoniae

Negative: (H2S Production Test/Motility Test needed)

Question 15

Positive vs Negative H2S Production Test/Motility Test

Answer 15

Positive: Salmonella enterica, Salmonella thyphi, or Proteus species

Negative: Yersinia pestis or Shigella species

Question 16

Gram Negative Cocci: Neisseria Species

Answer 16

Neisseria meningitidis or Neisseria gonorrheae

Question 17

Positive vs Negative Maltose Test

Answer 17

Positive: Neisseria meningitidis

Negative: Neisseria gonorrheae

Question 18

Which bacteria are not usually gram stained and why? (4 of them from worksheet)

Answer 18

Mycoplasmas (Lack of cell wall)
Mycobacteria (Acid fast staining)
Chlamydia and Chlamydophila (Obligate parasite)
Borrelia (Wright’s staining)