Lab Medicine

Question 1

Consideration when culturing?

Answer 1

You might need to grow the culture on different media & in different environments (hot/cold/aerobic/anaerobic, etc)

Question 2

Name two body fluids that should be sterile:

Answer 2

Blood and urine in the bladder

Question 3

How long do blood cultures take / when do you perform them

Answer 3

24-48 hours / when you are seeking out a systemic infection

Question 4

Gold standard for diagnosing Strep Throat / what else can it be used to test for?

Answer 4

Throat culture / Candida, diphtheria, gonococcal pharyngitis

Question 5

When do you do a sputum cx / what finding would lead you to believe it is contaminated? / what is it neither sensitive nor specific for?

Answer 5

Suspected TP or pneumonia / lots of different stuff growing / Strep pneumonia

Question 6

Why order a wound culture? / Sensitivity? / If a wound culture is negative?

Answer 6

Determine if wound is infected & with what / What can you tx the organism with? / you still cannot rule out infection

Question 7

Anaerobic bacteria that grows in brain, lungs, and abdomen

Answer 7

B. fragilis

Question 8

Why do a CSF culture?

Answer 8

Suspected meningitis

Question 9

3 most common causes of bacterial meningitis:

Answer 9

N. meningitidis, S. pneumonia, H. flu

Question 10

Reason to collect a urine culture?

Answer 10

Suspected pyelonephritis or cycstitis

Question 11

What is different about viral culturing than bacterial culturing?

Answer 11

Bacteria can grow on media, viruses require cell cultures b/c they only replicate in living cells not on cell-free media

Question 12

What is the main problem you have to deal with when culturing fungi?

Answer 12

They grow REAL slowly (6-8 weeks)

Question 13

Stain for detecting Mycobacteria TB / Leprae?

Answer 13

Acid-fast

Question 14

Mycoplasma Serology?

Answer 14

Cold Agglutinin

Question 15

O&P?

Answer 15

Stool for ova and parasites - detects cysts & distinguishes parasitic infection (i.e. amebic dysentery) from bacterial infection

Question 16

Dx for Malaria

Answer 16

Thick/thin blood smear & Giemsa staining

Question 17

NAAT - what does it stand for / what is the main example of this? / What is it?

Answer 17

Nucleic Acid Amplification Test / PCR / Genome sequencing

Question 18

If you catch someone with a primary syphilis infection & a chancre, what can you use to test it?

Answer 18

Dark-field microscopy

Question 19

2 Tests that SCREEN for syphilis:

Answer 19

RPR or VRDL

Question 20

Confirm positive results of syphilis screening tests with:

Answer 20

FTA-ABS or MHA-TP

Question 21

Screening test for HIV? / Confirmatory?

Answer 21

ELISA / Western Blot