Introduction

Question 1

sterilization

Answer 1

the removal of all life ( including spores) via chemical or physical means

Question 2

disinfection

Answer 2

removal of pathogenic organisms but may not include spores.

- most are chemical agents applied to inanimate objects ei. 70% isopropyl alcohol

Question 3

antiseptics

Answer 3

disinfectants used on living tissue

- ie. skin cleansed with isopropyl alcohol/iodine prior to phlebotomy draw.

Question 4

Autoclave

Answer 4

moist heat under pressure

• 15psi (or 1 ATM) at 121C for 15 minutes.
• all bacteria and spores are killed.
• reliable cheap and easy

Question 5

Gram stain purpose/ principal

Answer 5

principally used in micro to distinguish gram pos from gram neg bacteria.

• purpose is to asses spec. quality
• early indicator of infections process
• culture work up may be guided by gram stain

Question 6

Steps of a gram stain

Answer 6

1. heat fix or methanol fix slide
2. apply the primary stain and rinse ( crystal violet)
3. apply fixative and rinse ( Gram’s Iodine)
4. QUICKLY decolorize and rinse ( acetone)
5. apply counter stain and rinse(safranin)
6. Blot dry

Question 7

Specimen collection

Answer 7

• in appropriate containers
• transported in the alloted time
• transported under the correct temperatures

Question 8

Specimen planting

Answer 8

properly labeled/minimum requirements

• need the pt name/ specimen source/ date and time of collection, also the DOB or MRN#
• then planted on the appropriate media ( most to least inhibitory)

Question 9

Specimens are unacceptable if…

Answer 9

• wrong name/ labels
• transported in wrong temp
• wrong container
• wrong time
• dry swabs
• qns
• duplicate
• • poor sample = poor quality of results

Question 10

4 classifications of media

Answer 10

• Supportive: supports growth of most organisms (BAP)
• Selective: contains nutrients that select for a certain bacteria to the disadvantage of others. Inhibitory agents are dyes, antibiotics, bile salts, alcohols, acids. (PEA)
• Differential: allows colonies of one species to exhibit certain characteristics to distinguish from others ( MAC)
• Enrichment: used to enhance a particular bacteria’s growth from mixed culture bu nutrient specificity(BYCE)

Question 11

Acridine Orange

Answer 11

Florochrome stain- binds to nucleic acid

• need a flourescent microscope needed
• nonspecific stain- used to confirm the presence of bacteria on gram stains that are hard to interpert or no bacteria seen but expected
• fix smear with acridine orange by flooding slide for 2 mins then rinse, air dry and examine