U2.2.2 Gr (+) Cocci : Laboratory Diagnosis

Question 1

Samples preferred

Answer 1

Aspirates are preferred

Question 2

Swabs submitted

Answer 2

Swabs are submitted, it must be at least 2

Question 3

Gram Stained Smears are used for ____

Answer 3

Direct Detection

Question 4

Culture Media for Isolation and Identification

Answer 4

BAP, CAP, Broth, Selective Media, Selective & Differential Media

Question 5

Broth used in Culture Media

Answer 5

Thioglycollate, BHI, Blood-Broth

Question 6

Selective Media used in Culture Media

Answer 6

Columbia Colistin Nalidixic Agar, PEA

Question 7

Selective and Differential Media used in Culture Media

Answer 7

MSA, CHROMagar Staph aureus

Question 8

Colonial Characteristics

BAP

Answer 8

Round, Smooth, White or Yellow pigmented, creamy colonies

Question 9

Hemolysis seen in S. aureus colonies

Answer 9

Beta-hemolvsis

Question 10

Staph spp.
Colonies are small-medium sized, gray colonies; non-hemolytic

Answer 10

S. epidermidis

Question 11

Staph spp.
medium sized colonies, yellow pigmented colonies

Answer 11

S. saprophyticus

Question 12

Staph spp.
medium sized colonies; Beta-hemolytic

Answer 12

S. lugdunensis

Question 13

Staph spp.
pinhead colonies (greenish discoloration) on CAP

Answer 13

S. aureus

Question 14

detection of enzyme catalase

Answer 14

Catalase Test

Question 15

Catalase Test
converts H2O2 to water and O2

Answer 15

Catalase

Question 16

Catalase Test
Reagent

Answer 16

3% H2O2

Question 17

Catalase Test
(+) Result Test

Answer 17

Bubbling/Effervescence

Question 18

Important Test to differentiate
Staphylococcus and Micrococcus from Streptococcus

Answer 18

Catalase Test

Question 19

Oxidase reagent reacts with cytochrome C in the cytochrome oxidase

Answer 19

Modified Oxidase Test

Question 20

Uses Rgt: 6% tetramethyl phenylenediamine HCI
in dimethyl sulfoxide (DMSO)

Answer 20

Modified Oxidase Test

Question 21

Modified Oxidase Test
(+) Result

Answer 21

Dark Blue

Question 22

Differentiates Staphylococcus from
Micrococcus

Answer 22

Modified Oxidase Test

Question 23

detection of staphylocoagulase (coagulase)

Answer 23

Coagulase Test

Question 24

uses Rabbit Plasma

Answer 24

Coagulase Test

Question 25

Two Types of Coagulase Test

Answer 25

1. Slide Coagulase (Screening) 2. Tube Coagulase (Confirmatory)

Question 26

to differentiate organisms based on the ability to oxidize or ferment sugars

Answer 26

Oxidation Fermentation Test

Question 27

Oxidation Fermentation Test (+) Color of Fermenters

Answer 27

Yellow

Question 28

Oxidation Fermentation Test (+) Color of Oxidizers

Answer 28

Red + Yellow

Question 29

Oxidation Fermentation Test (+) Color of Non-utilizer

Answer 29

Red

Question 30

detection of DNAse activity

Answer 30

DNAse Test

Question 31

Reagent: Use of Toluidine Blue or methyl Green

Answer 31

DNAse Test

Question 32

DNAse Test (+) Result

Answer 32

Hydrolysis of surrounding medium (clear zone)

Question 33

formation of acetoin from glucose (Butylene Glycol Pathway)

Answer 33

Voges Proskauer Test

Question 34

Differentiates Coagulase (+) Staphylococcus

Answer 34

Voges Proskauer Test

Question 35

Voges Proskauer Test Positive Result

Answer 35

Red coloration in MRVP Broth

Question 36

Differentiates Coagulase (+) Staphylococcus

Answer 36

PYR Test (Pyrrolidonyl Arilamadase) Test

Question 37

PYR Test (Pyrrolidonyl Arilamadase) Test (+) Result

Answer 37

Pink or Cherry-Red coloration

Question 38

Useful Test to differentiate CONS

Answer 38

Novobiocin (5ug) Susceptibility

Question 39

T/F Staphylococcus saprophyticus is resistant to novobiocin, indicated by the lack of a zone of inhibition around the disk.

Answer 39

T

Question 40

Helpful for CONS

Answer 40

Susceptibility to Polymyxin B (300 units)

Question 41

Most useful test for confirming S. lugdunensis

Answer 41

Ornithine Decarboxylase Test

Question 42

Ornithine Decarboxylase Test (+) Result

Answer 42

Violet Coloration on ODC tube

Question 43

used to differentiate S. aureus from CONS

Answer 43

Commercially Available Rapid Agglutination Kits

Question 44

useful for ID MRSA

Answer 44

Commercially Available Rapid Agglutination Kits

Question 45

- more specific and sensitive from traditional methods - use of plasma coated latex beads

Answer 45

Commercially Available Rapid Agglutination Kits

Question 46

Detection of Resistance Detection of resistance to macrolides such as clindamycin

Answer 46

Macrolide Resistance

Question 47

Detection of Resistance Method used in Macrolide Resistance

Answer 47

D-Zone Test

Question 48

Detection of Resistance Place Erythromycin and Clindamycin Disk close together

Answer 48

D-zone Test

Question 49

Detection of Resistance Detection of mecA gene - gold standard

Answer 49

MRSA

Question 50

Detection of Resistance Recommended Screening for MRSA

Answer 50

Cefoxitin Test

Question 51

Detection of Resistance MIC of VRSA

Answer 51

>16 ug/mL

Question 51

Detection of Resistance Use of Vancomycin Agar Plate (spot inoculation)

Answer 51

VRSA

Question 52

Detection of Resistance T/F Healthcare Associated MRSA include sepsis, infection of surgical wound sites, pneumonia

Answer 52

T

Question 52

Detection of Resistance MIC of MRSA

Answer 52

≥ 4ug/mL

Question 53

Detection of Resistance Treatment of VRSA

Answer 53

Linezolid