Micro

Question 1

what is MRSA known to be resistant to

Answer 1

beta lactam antibiotics

Question 2

what antibiotics is susceptable to MRSA

Answer 2

vancomyosin or linezolid

Question 3

Common antibiotic for strep pneumo

Answer 3

penicillin

Question 4

common antibiotic for enterococcus faecalis

Answer 4

ampicillin and vancomycin

Question 5

what is CNA agar selective for

Answer 5

GPO

Question 6

alpha hemolysis principle

Answer 6

partial breakdown of haemoglobin

Question 7

beta hem principle

Answer 7

complete breadown on haemoglobin

Question 8

gamma hem principle

Answer 8

bacteria are non hemolytic

Question 9

principle and purpose of catalase test

Answer 9

enzyme that converts hydrogen peroxide into water and oxygen

differentiates strep (neg) and staph (pos)

Question 10

false pos of catalase

Answer 10

rbc carry over
enterococci

Question 11

false neg of catalase

Answer 11

old colonies

Question 12

principle and purpose of coagulase

Answer 12

converts fibrinogen to fibrin using rabbit plasma on a BAP plate to detect staph aureus (pos)

Question 13

false pos of coagulase test

Answer 13

staph isolated on selective media

Question 14

principle and purpose of DNAse

Answer 14

DNAse enzyme cleaves DNA to leave a colorless media

differentiate of aureus (pos) and micrococcus (neg)

Question 15

what is the gold standard of MRSA ID

Answer 15

PCR - but using Oxacillin disc test works

Question 16

location and cause of strep pyo (GAS)

Answer 16

pharyngitis causing strep throat

Question 17

location and cause of strep agal (GBS)

Answer 17

gential tract causing neonatal sepsis and meningitis

Question 18

location and cause of strep pneumo

Answer 18

URT fllora causing pneumonia, eye and ear infection

Question 19

location and cause of viridian strep

Answer 19

mouth and URT flora causing heart damage

Question 20

location and cause of enterococci

Answer 20

GI flora causing UTI and wound infections

Question 21

what antibiotic can enterococci become resistant to

Answer 21

vancymycin resistancve enterococci (VRE)

Question 22

what does a pos PYR look like

Answer 22

red dot on poked disc= pos

Question 23

what is bacitracin (Taxos A) positive result

Answer 23

any zone of inhibition seen

Question 24

how to set up a CAMP test

Answer 24

S aureus middle line, then perpendicular lines to the middle line

Question 25

what is a pos CAMP test look like and what organism

Answer 25

arrow heads as GBS is pos

Question 26

what does a pos BEA look like

Answer 26

black coloration

Question 27

what does pos NaCl tolerance test look like

Answer 27

purple to green = pos BUT if no color change and BAP grew, then still pos

Question 28

principle of decarboxylase

Answer 28

medium contains glucose and bromcresol purple. tubes will turn yellow (acidic) incubated due to glucose fermentation. tubes revert to purple (basic) if decarboxylation occurs.

Question 29

what color should the control tubes for decardboxylase be

Answer 29

yellow - we want to make sure glucose ferments and its the bacteria that decarboxylases.

Question 30

Common characteristic of enterobateriaceae

Answer 30

GNB - ferment glucose - nitrate to nitrITES - ox neg -non spores

Question 31

principle of cytochrome oxidase test

Answer 31

TMPD interacts with the ETC of cytochrome C making dark purple indophenol. (interacts w bacteria containing cytochrome C)

Question 32

false negative of oxidase test

Answer 32

selected off MAC - use only fresh BAP 12-24 hrs

Question 33

principle of TSI

Answer 33

carb fermentation (glucose, lactose, sucrose) H2S production gas production

Question 34

what are non fermenters TSI

Answer 34

K/K (red)

Question 35

what are non lactose fermenter TSI

Answer 35

K/A red/yellow - glucose fermented but not lactose

Question 36

critrate principle and pos

Answer 36

turns blue = pos due to alkaline products produced

Question 37

indole principle and pos

Answer 37

hydrolyze triptophan to form indole which is detected using kovacs cherry red = pos

Question 38

malonate pos colour

Answer 38

change of blue to green = pos

Question 39

phenylalanine test pos

Answer 39

add ferric chloride - green = pos

Question 40

urease test pos

Answer 40

cherry red = pos

Question 41

OF test principle and pos

Answer 41

aerobic = oxidation to gluconic acid anaerobic = fermentation to triose molecules yellow = pos blue = neg (gluose not used)