Midterm 1 T/F

Question 1

Limulus test is suitable for detection of Gram-bacteria

Answer 1

T

Question 2

Impedance measurement works with special media only

Answer 2

T

Question 3

The microbial count can be determined by detecting the amount of ATP

Answer 3

F

Question 4

Listeria monocytogenes’ b-haemolysis strengthens the haemolysis of Staphylococcus aureus

Answer 4

T

Question 5

Salmonella colonies are reddish purple on XLD agar

Answer 5

T

Question 6

Salmonella decomposes lactose

Answer 6

F

Question 7

MRSV agar can be used instead of RVS broth in the enrichment procedure of Salmonella

Answer 7

T

Question 8

Selective media of moulds have low pH

Answer 8

T

Question 9

Enterococcus faecalis is one of the most resistant among the non-spore forming
microbes

Answer 9

T

Question 10

Enterococcus faecalis is catalase positive

Answer 10

F

Question 11

E.coli can ferment lactose

Answer 11

T

Question 12

Enterobacteriaceae are oxidase positive

Answer 12

F

Question 13

Staphylococcus aureus is cultured in Fraser broth

Answer 13

F Giolitti-Cantoni broth and

Baird-Parker agar

Question 14

Positive colonies of E.coli are bluish green on TBX agar

Answer 14

T

Question 15

Enterobacteriaceae cannot ferment glucose

Answer 15

F

Question 16

Which statement is true for Clostridium perfringens?

1. Cultured on Sulphite cycloserine agar
2. B and C strains pathogenic for humans
3. In LS broth incubated at 25°C
4. No haemolysis on blood agar

Answer 16

1. T
2. F A and C strains pathogenic
3. F Incubation at 46°C
4. F Haemolysis

Question 17

Which statement is true for Staphylococcus aureus?

1. Produces toxin between 8-45°C
2. Reduces the nitrate to nitrite
3. No haemolysis on blood agar
4. Gram negative

Answer 17

1. F Between 20-45°C
2. T
3. F b-Haemolysis
4. F Gram-positive

Question 18

Which statement is true for Salmonella?

1. Indol production is negative
2. Voges-Proskauer test is positive
3. Lactose-fermentation is positive
4. H2S production is positive

Answer 18

1. T
2. F
3. F
4. T

Question 19

Which statement is false for Listeria monocytogenes?

1. Catalase test is positive
2. Rhamnose negative
3. Its typical colonies on ALOA agar are blue
4. Shows summersaulting motility at 25°C

Answer 19

1. T
2. F
3. T
4. T

Question 20

Which statement is false for E.coli?

1. Citrate utilization test is positive
2. Indole test is positive
3. Voges-Proskauer test is negative
4. Methyl red test is positive

Answer 20

1. F
2. T
3. T
4. T

Question 21

Enterococcus faecalis can grow:

1. Between 10-60°C
2. At pH 2.6
3. At 6.5% salt concentration
4. Grow on blood agar with 70% bile content

Answer 21

1. F Grows between 10-45°C
2. F At pH 9.6
3. T
4. F 40% bile content.

Question 22

Which statement is false for the water removal?

1. The microbes can multiply at certain water activity (aw) circumstances
2. The reducing of water activity inhibit the multiplication of microorganisms
3. The bacteria can grow below 0.7 aw
4. The aw requirement of bacteria is higher than the moulds

Answer 22

1. T
2. T
3. F Bacteria: 0.91
4. T Moulds: 0.80