selective differential enriched

Question 1

Selective media

Answer 1

Used to isolate specific bacteria

Incorporate chem substances to prevent growth for one bacteria type and aid another.

Question 2

Phenylehtyl alcohol agar (PEA)

Answer 2

Selects gram+ by inhibiting gram-
Isolation of most gram+
Selective media

Question 3

Crystal violet agar

Answer 3

Selective medium
Exerts an inhibitory effect on most gram+
Isolates G-

Question 4

7.5%sodium chloride agar (methanol salt agar)

Answer 4

Selective media
Inhibitory to most organism other than halophilic (salt loving)
Most useful in detection of staphylococcus members.

Question 5

Differential/ selective media

Answer 5

Can distinguish among morphologically and biochemically related groups

Question 6

Mannitol salt agar

Answer 6

diif/sel

Contains a high salt concentration. 7.5% NaCl which inhibits the growth of most bacterial other than staphylococci.

Question 7

MacConkey agar

Answer 7

diff/sel
The inhibitory action of crystal violet on the growth of g+ organisms allows isolation of G-
2 main groups
Coliform bacilli
Dysentery, typhoid, and paratyphoid bacilli

Question 8

Coliform bacilli

Answer 8

macConkey
Produce acid as a result of lactose fermentation. Bacteria exhibit red coloration on surface.
E.Coli produce greater quantities of acid from lactose than other coliform species= medium surrounding growth also turn pink.

Question 9

Dysentery, typhoid, and paratyphoid bacilli

Answer 9

MacConkey
Not lactose fermenters and therefore don’t produce acid.
Colonies appear tan and frequently transparent.
Salmonella.

Question 10

Eosin-methylene blue agar (Levine)- (EMB)

Answer 10

dii/sel
Lactose and the dyes eosin and methylene blue permit differentiation between enteric lactose fermenters and nonfermenters.
Identification of the colon bacillus
E.Coli- blue and black colonies with Metallic green sheen caused by the large amount of acid

Question 11

Enrich media

Answer 11

Media that has been supplemented with highly nutritious materials, such as 
Blood 
Serum
Yeast extract
Cultivation of fastidious organisms.

Question 12

Blood agar

Answer 12

Enriched media
enriched ingredients that cultivate fastidious organisms (streptococcus spp)
Hemolytic properties

Question 13

Streptococci- gamma hemolysis

Answer 13

No lysis of red blood cells.

No significant change in medium found

Question 14

Alpha hemolysis

Answer 14

Streptococci hemolytic
Incomplete lysis of red blood cells.
Reduction of hemoglobin to methemoglobin
Greenish halo around bacterial growth.

Question 15

Beta hemolysis

Answer 15

Streptococci hemolytic

Lysis of RB cells with complete destruction and use of hemoglobin by organism.

Question 16

MSA agar plate

Answer 16

halophilic (salt loving) staphilococci grow 
pH indicator (pink) turns yellow when fermentation produces acid.
Isolates salt loving (selective) and manitol fermenters (differential)

Question 17

Muller-Hinton-Tellurite agar plate

Answer 17

Corynebacteria spp (diphteriods) appear as black pinpoint colonies.
growth with out black pinpoints does not indicate diphteroids

Question 18

Sabourand Agar plate

Answer 18

isolates fungi (molds and yeast)
has a 5.6 pH= molds and yeast growth and inhibits bacterial growth

Question 19

Yeast

Answer 19

Sabourand Agar plate

individual colonie growth may or may not be pigment. appear moist and shiny

Question 20

mold

Answer 20

Sabourand Agar plate
appear fuzzy and dry
form mass of mycelium ( mass of hyphae)

Question 21

Chocolate agar palate

Answer 21

is a non-selective, enriched growth medium.

used for growing fastidious respiratory bacteria, such as Haemophilus influenzae and Neiserria