diagnostic chart

Question 1

gram-positive, rod-shaped, strict anaerobic, spore

Answer 1

Clostridium spp. (e.g C. difficile)

Question 2

beta-hemolytic species

Answer 2

Pyogenic group; Streptococci (Group A, B, C, G) (e.g S. pyogenes, S. agalactiae)

Question 3

gamma-hemolytic species

Answer 3

Enterococcus faecalis, Enterococcus faecium

Question 4

alpha-hemolytic species: optochin-resistant

Answer 4

Viridans type; Streptococci (e.g S. anginosus, S. salivarius)

Question 5

alpha-hemolytic: optochin-sensitive

Answer 5

Streptococcus pneumoniae (aka Pneumococcus)

Question 6

are alpha/beta/gamma-hemolytic species in pairs/chain or clusters? catalase (+) or (-)?

Answer 6

Pairs/chain; Catalase (-)

Question 7

Gram positive; cocci; aerobic/facultative; Catalase (+); Coagulase (+) species

Answer 7

Staphylococcus aureus

Question 8

Gram positive; cocci; aerobic/facultative; Catalase (+); Coagulase (-) species

Answer 8

Staphylococcus epidermis

Question 9

Is haemophilus influenzae gram positive or negative?

Answer 9

Negative

Question 10

Gram-negative; rods; strict aerobic; oxidase (+)

Answer 10

Pseudomonas aeruginosa

Question 11

gram-negative; rods; strict anaerobic

Answer 11

Bacteroides spp. (e.g B. fragilis)

Question 12

Features of haemophilus influenzae?

Answer 12

Gram-negative; rods; aerobic/facultative; fastidious growth

Question 13

lactose-fermenting enteric gram-negative bacilli (Enterobacterales)

Answer 13

Escherichia coli (E. coli), Enterobacter spp., Klebsiella spp. (e.g K. pneumoniae)

Question 14

non-lactose-fermenting enteric gram-negative bacilli (Enterobacterales)

Answer 14

Salmonella spp., Shigella spp., Proteus spp. (e.g P. mirabilis)

Question 15

How to differentiate between lactose-fermenting species?

Answer 15

Using MacConkey’s agar

Question 16

How to culture Neisseria spp. and H. influenzae?

Answer 16

Use chocolate agar

Question 17

What is optochin (antibiotics) used to differentiate?

Answer 17

Differentiate between Pneumococcus (Streptococcus pneumoniae) vs Viridans type

Question 18

Gram-negative; cocci/coccobacilli; aerobic/facultative; oxidase (-)

Answer 18

Acinetobacter spp. (e.g A, baumannii)

Question 19

acid-fast bacteria

Answer 19

Mycobacterium spp. (e.g M. tuberculosis)

Question 20

Atypical bacteria

Answer 20

Legionella spp. (e.g L. pneumophilla); Chlamydia spp. (e.g C. pneumoniae); Mycoplasma spp. (e.g M. pneumoniae)

Question 21

gram-negative atypical bacteria

Answer 21

Legionella spp. (e.g L. pneumophilla); Chlamydia spp. (e.g C. pneumoniae)

Question 22

Use blood agar for?

Answer 22

Differentiate between alpha/beta/gamma hemolytic bacteria (hemolysin producers)

Question 23

Is E.coli gram positive or gram negative? Lactose or Non lactose fermenting?

Answer 23

Gram negative; Lactose fermenting

Question 24

What kind of hemolysin producer is Enterococcus faecalis?

Answer 24

Gamma hemolytic

Question 25

Is Staphylococcus epidermis gram positive or gram negative? Catalase (+) or (-)? Coagulase (+) or (-)?

Answer 25

Gram positive; Catalase (+); Coagulase (-)