microbiology lab 2

Question 1

how can you describe a colony?

Answer 1

punctiform, circular, rhizoid, irregular, filamentous

Question 2

how can you describe the edge?

Answer 2

entire, undulate, lobate, filamentous, curled

Question 3

how can you describe the surface?

Answer 3

smooth and glistening, rough, wrinkled, dry or powdery

Question 4

how can you describe the elevation?

Answer 4

flat, raised, covex, pulvinate, umbonate

Question 5

what is enteric?

Answer 5

bacteria that exist in the intestines of animals/humans

Question 6

what is aerobic?

Answer 6

bacteria that can grow/live when oxygen is present

Question 7

what is anaerobic?

Answer 7

bacteria that do not require oxygen for growth and cannot have present

Question 8

what is pathogenic?

Answer 8

a microbe able to cause damage in susceptible host

Question 9

what does it mean when colonies on BAP present with red surrounding colonies?

Answer 9

non-hemolytic bacteria present (gamma hemolysis)

Question 10

what does it mean if colonies are present and surrounded by a green zone?

Answer 10

partially hemolytic bacteria present (alpha hemolysis)

Question 11

what does it mean if colonies are present and surrounded by a transparent clear zone?

Answer 11

completely hemolytic bacteria present (beta hemolysis)

Question 12

what does it mean if no colonies are present?

Answer 12

no bacteria present in sampel or accidentally killed in incubation of plate by overheating

Question 13

what will the make plate grow?

Answer 13

designed to grow gram negative bacteria

Question 14

what does it mean if no bacteria are present on MAC plate?

Answer 14

cannot grow in prescene of bile salts/ crystal violet
gm+ and non-enteric

Question 15

what does it mean if colonies are visable and are white?

Answer 15

gm- enteric bacteria are lac- therefore, cannot use lactose and instead metabolize the peptide in the media,

Question 16

what does it mean if colonies are visible and pink?

Answer 16

gm- enteric bacteria are lac+ and use lactose, produce acid, and activate neutral red dye

Question 17

what is purpose of flaming loop?

Answer 17

ensures bacteria are not transferred to bench

Question 18

what is purpose of heat fixing?

Answer 18

kills the bacteria and causes bacteria cells to adhere to slide

Question 19

what is prupose of crystal violot?

Answer 19

stains peptidoglycan in bacteria cell wall, especially in thick layer (gm+)

Question 20

what is purpose of grams iodine?

Answer 20

application of mordant, forms insoluable complex with crystal violet fixing the stain in cell wall

Question 21

what is purpose of acetone- alcohol?

Answer 21

gm+ dehydrates cell, trapping crystal violet and iodine, (gm-) dissolves lipopolysaccride in outer membrane and washes stain excess

Question 22

what is safranin?

Answer 22

stains thinner peptidoglycan coat of gram- cells pink, so can see these cells lost their stain

Question 23

what causes nasocomial infections?

Answer 23

poor hand hygeine
contaminated fomites
surgeries (poor aspesis)

Question 24

what are impacts of nasocomial infections?

Answer 24

loss of rom or mobility
250,000 deaths
longer stay in hosptial

Question 25

prevention of nasocomial infections? a

Answer 25

aspesis, hand hygiene, disinfecting surfaces

Question 26

what is MRSA?

Answer 26

antiobiotic resistant staph infection

Question 27

what is VRE?

Answer 27

cause of antibiotic resistant gastrointestinal infection