Microbiology - Differential Tests

Front 1

What is the principle of the catalase test? 

Back 1

 See if org has catalase enzyme which converts H2O2 into H2O + O2 (look for the O2 bubbles)

Front 2

What is the principle of the tube coagulase test? 

Back 2

 See if the bug has free coag. if yes

Front 3

What is the principle of the slide coagulase test? 

Back 3

 See if the bug has bound coag. If yes

Front 4

What is the principle of the DNAse Toluidine blue method? 

Back 4

 See if the bug has the enzyme. If yes

Front 5

What is the principle of the HCL flood plate DNAse test? 

Back 5

 intact DNA is cloudy. if bug has DNase

Front 6

What is the principle of the CAMP test? 

Back 6

 see if the bug has CAMP which interacts with staph hemolysin.

Front 7

What is the principle of the latex agglutination acid method? 

Back 7

 add acid

Front 8

What is the principle of the latex agglutination enzyme extraction method? 

Back 8

 use pronase B enzyme + test isolate. incubate

Front 9

What is the principle of the PYR test? 

Back 9

 look to see if bug has PYR enzyme which turns Sutter's reagent (cinnamaldehyde) into B-naphthylamine (pink)

Front 10

What is the principle of the hippurate test? 

Back 10

 see if the bug can use hippurate to form glycine which interacts with ninhydrin to form a purple complex.

Front 11

What constitutes a positive result in the columbia agar deep test? what bug is positive for this test? 

Back 11

 Orange pigment in the stab line (used the excess starch in the media); gr B strep

Front 12

Where do you incubate the Optochin/Taxo P test? What result is considered 'S'? 'R'? 

Back 12

 CO2 incubator; = 14 is susceptible

Front 13

What is the principle of the bile solubility test? 

Back 13

 see if the organism can dissolve in bile

Front 14

What is the principle of the BEA test? how much bile is in this media? 

Back 14

 see if the bug can withstand 40% bile; see if the bug can hydrolyze esculin to esculetin.

Front 15

What is the principle of the NaCl test? 

Back 15

 see if the bug can withstand salt.

Front 16

What is the principle of the VP test? 

Back 16

 see which path bug uses. looking for acetoin (neutral) from butylene glycol path. + = red

Front 17

What are the 2 reagents for VP? 

Back 17

 alpha naphthol & KOH

Front 18

What specific indicator is used in the VP test? 

Back 18

 methyl red

Front 19

What is the principle of the decarboxylase test? which indicator is used? 

Back 19

 see if the bug can remove the COOH group to form an amine (basic). uses bromcresol purple

Front 20

What is the principle of the TSI test? 

Back 20

 see if the bug can ferment glu + sucrose/lactose

Front 21

What is the principle of the citrate test? 

Back 21

 see if the bug can use citrate as its sole carbon source and ammonium as its sole nitrogen source.

Front 22

what is the principle of the SIM test? 

Back 22

 see if the bug produces sulfur

Front 23

What reagent is used to detect indole production? 

Back 23

 Kovac's

Front 24

What is the principle of the oxidase test? 

Back 24

 see if the bug has cytochrome oxidase enzyme. if present

Front 25

What is the principle of the adonitol test? what is considered pos? what indicator is used? 

Back 25

 see if the bug can ferment adonitol. uses phenol red. yellow = pos

Front 26

what is the principle of the PD test? what reagent must be added? 

Back 26

 see if the bug can break down phenylalanine into phenylpyruvic keto acid; ferric chloride

Front 27

what is the principle of the urease test? what is the indicator? 

Back 27

 see if the bug has urease enzyme which hydrolzes urea into ammonia. phenol red indicator

Front 28

what is the principle of the nitrate reduction test? what reagents are added? 

Back 28

 see if the bug can reduce nitrate to nitrite or further. sulfanilic acid

Front 29

What is the principle of using Tinsdale media? 

Back 29

 see if the bug can use turn the potassium tellurite into metallic tellurite.

Front 30

What temps do you set up motility tests for suspected Listeria? 

Back 30

 25 & 37 degrees

Front 31

What is the principle of the porphyrin test? what is it aka? 

Back 31

 see if bug makes porphobilinogen or porphyrin. aka ALA test

Front 32

How do you detect porphobilinogen in ALA test? how do you detect poryphrin? 

Back 32

 porphyrin w/ wood's lamp. porphobilinogen w/ Kovac's

Front 33

when do you use CTA sugars? 

Back 33

 when you are dealing w/ more fastidious bugs and want to see what sugars they use (yellow = pos)

Front 34

what is the principle of the butyrate esterase test? 

Back 34

 see if the bug has the enzyme which hydrolyzes tributyrin to indoxyl

Front 35

what is the principle of the OF media? what is the conc of peptones & carbs 

Back 35

 see if ur bug is a fermenter or non-fermenter or asacchrolytic; peptones to carb in 1:5 ratio

Front 36

What modification is made for NFBs for urease test? 

Back 36

 use Christensens enriches urea media

Front 37

What modification is made for indole test for NFBs? 

Back 37

 use enrichmed media or add a thin layer of chloroform or xylene to the top.

Front 38

What modification is made for the decarboxylation test for NFBs? 

Back 38

 heavier inoculum

Front 39

What modification is made for the esculin test for NFBs? 

Back 39

 don't use BEA b/c bile kills NFBs. plant bug w/ esculin

Front 40

Which bug do you do reverse CAMP test for? 

Back 40

 Clostridium perfringens

Front 41

Which bug shows DZBH on Bru media? 

Back 41

 Clostridium perfringens

Front 42

What does PEA media inhibit? 

Back 42

 swarmers like proteus

Front 43

What is the principle of the lecithinase test? which media is used? 

Back 43

 EYA media. see if bug has enzyme which breaks lecithin down into insoluble diglycerides (ppt out)

Front 44

What is the principle of the lipase test? which media is used? 

Back 44

 EYA media. see if bug has enzyme which breaks fatty acids down into glycerol & insoluble free fatty acids

Front 45

What Abx are used in HPOT? What zone is considered 'R'? 

Back 45

 Kanamycin