Flash cards over lab procedures Blake

Question 1

Mycobacterium are what

Once stained, they are resistant to what

Answer 1

Lipophilic

They are resistant to destaining due to the presence of cell wall-bound mycolic acids.

Question 2

Carbol fuchsin penetrates the mycobacterial lipid with the aid of

Whereupon the organism resists destaining with

Answer 2

Phenol

Acid alcohol and consequently cannot stain with methylene blue stain.

Question 3

Acid-fast stain procedure

Answer 3

1.) Prepare smear and heat fix
when using M.goronae only a brief heat fix is required compared with other mycobacterium that require a 2 hour heat fix in 60C.
2.) Flood slide with Kinyoun carbol fuchsin and let stain for 5mins.
3.) Wash with tap water
4.) Add acid alcohol and allow alcohol to flow over slide until slide appears colorless.
5.) Wash with tap water
6.) Add new methylene blue for 1 minute.
7.) Wash, blot, and examine under oil immersion.

Question 4

+ number seen

Answer 4

1-2/300 fields

Question 5

Minus number seen

Answer 5

0

Question 6

1+

Answer 6

1-9 organism/ 100 fields

Question 7

2+

Answer 7

9 or more/100 fields

Question 8

3+

Answer 8

1-9/ field

Question 9

4+

Answer 9

Greater than 9/Field

Question 10

Auramine- Rhodamine Fluorochrome stain procedure

Answer 10

1.) Prepare slide and heat fix
2.) Flood fixed slide with Auramine Rhodamine T solution and let stain for 15 minutes
3.) Wash with tap water and flood with decolorizer for 2-3 minutes
4.) Wash with tap water and counterstain for 4-5 minutes
5.) Wash with tap water, blot gently and air dry
6.) Examine by fluorescence microscopy using a 40X objective for the detection of fluorescence organisms.

Question 11

Auramine and rhodamine Penetration is aided by

Answer 11

Phenal

Question 12

In the Auramine and Rhodamine method, the cellular components of the mycobacterium cell will have a

Answer 12

Golden yellow or orangish fluorescence.

Question 13

What is the secondary stain used in the Auramine Rhodamine method?

Answer 13

Potassium permanganate is used to quench nonspecific background fluorescence

Question 14

Decolorizer in Auramine Rhodamine method

Answer 14

HCL

Question 15

Inoculate group B strep at what angle

Answer 15

90 degrees in CAMP tests

Arrow head hemolysis is positive result

Question 16

MIC procedure using Macrobroth procedure

Answer 16

Note- the antibiotics that can be used on S. Aureus are Erythromycin or ampicillin, or other agents. The antibiotics used for Ecoil are levofloxacin or ampicillin.
1.) Label 10 disposable tubes 1-9 and growth control. Place 1 mL of sterile water in each tube. A 3 antibiotic disks to tubes 1 or 2. Allow to set at RT for 15 minutes.
2.) Add 1mL of water to tubes 2 and serially dilute tubes 3-9. Discard the last mL from tube 9.
4.) Prepare the inoculum of an organism to be tested by preparing a suspension of Tryptic soy broth equivalent to a 0.5 Mcfarland suspension.
5.) Make a 1:2 dilution of the Mcfarland suspension
6.) Add 1mL of diluted T-soy broth to each of tubes 1-9, and the growth control tube number 10 and incubate overnight at 35C
7.) On the following day, read tubes for turbidity. Read from tubes 1-9#, the MIC of the organism is the last tube showing no visible turbidity
8.) Calculate the MIC by determining the concentration of the drug in that tube and state it in the same units as the drug.

Question 17

Micro broth Lab procedure

Answer 17

1.) Prepare a .5 Mcfarland standard with test organism in broth or saline
2.) Dilute
3.) Using a sterile pipet, add 0.1mL to each well of a microtiter plate
4.) cover and incubate for 18-24 hours
5.) read MIC

Question 18

E-test susceptibility testing

Answer 18

1.)Prepare a 0.5 Mcfarland standard with test organism in broth
2.) Using a sterile swab, inoculate the entire surface of a Mueller Hinton agar plate
3.) Lay E test strip onto agar surface
4.) Incubate for 18-24 hours
5.) record MIC and interpretations

Question 19

Preparation of Inoculum

Answer 19

1.)Select four to five colonies
2.) Transfer these colonies to a test tube containing about 5 milliliters of a suitable liquid medium, such as soybean casein digest broth, Trypticase soy broth.
3.) The inoculum density should be obtained by diluting it with sterile saline to obtain a turbidity equivalent to that of a freshly prepared turbidity standard 0.5 Macfarland.

Question 20

MIC=MBC when

Answer 20

The plate shows no growth after incubation

Question 21

The mordant is

Answer 21

Phenol

Question 22

Platinum catalyst binds

Answer 22

Oxygen with hydrogen to produce H2O