specimen processing in the lab

Question 1

the specimen must be clearly identified w

Answer 1

patient source and site of sampling

Question 2

input of data into the computer needs

Answer 2

clinicial info and specimen number for tracking

Question 3

types of testing

Answer 3

rapid testing
- microscopy
culture
molecular testing
special handling/processing needs

Question 4

rapid testing is used when

Answer 4

they usually detect antigens from the pathogen
- done pretty much anywhere
- contamination common

Question 5

microscopy

Answer 5

• gram stain is most common
  wet prep or acid fast stain less common
• used for diagnosis
  presence of organisms/cells in specimen
• gram stain is less sensitive than culture
• used to assess the quality of the specimen “q scoring”

Question 6

media may be

Answer 6

liquid (broth) or solid (plates/agar)
broth is used for
- detecting very low number of organisms
- increasing the number of a type of organism in a specimen
- biochemical testing

Question 7

solid media used for

Answer 7

• isolation of colonies of bacteria
• can be used to detect low numbers

Question 8

differential media

Answer 8

colonies have diff colours based on biochem reaction built into the plate

Question 9

selective media

Answer 9

species are inhibited from growing on the plate by a constituent of the media

Question 10

common media

Answer 10

blood agar, chocolate agar, macconkey medium

Question 11

macconkey medium used for

Answer 11

lactose fermentation detected, enterobacteriaceae and pseudomonas
- used for urine and stool specimens

Question 12

blood agar allows

Answer 12

detection of hemolysis (streptococci)

Question 13

blood cultures

Answer 13

directly to bottles
2 tests: 1 aerobic and 1 anerobic vial
- keep at room temp and needs to be processed within 18 hrs

Question 14

incubation conditions

Answer 14

• aerobic, microaerobic, or anaerobic
  temp most often at 35 degrees

Question 15

colony

Answer 15

the growth of bacteria on solid medium = a pile of bacteria of a single species
- pigment, size, shape, edge, appearance

Question 16

id: biochemical tests

Answer 16

based on the enzymes that an organism is actively expressing

Question 17

spectrometry

Answer 17

MALDI - colony and matrix is vapourized and analyzed by spectrometry for id

Question 18

susceptibility testing tells us

Answer 18

which antimicrobials are likely to be effective against an individual strain

Question 19

susceptibility testing methods

Answer 19

expose organism to conc of antimicrobial
- lack of growth indicates inhibition
other methods: detection of enzymes that break down antimicrobials or molecular means

Question 20

further testing used: typing

Answer 20

antibiogram and biotype
serotyping
molecular typing

Question 21

types of report

Answer 21

preliminary
further
final
corrected
supplementary