Pre-Analytics - 2nd Semester Flashcards
Name the 4 groups microorganisms are grouped into
Bacteria
Virus
Fungi
Parasites
Name 2 things bacteria do for humans that ISN’T harmful
- Provide us with vitamin K
- Assist our digestive system
- Protect our body surface from colonizing
pathogens - Part of vaccines
- Part of certain food processing
- Nitrogen fixation assists soil fertility
- Decompose organisms
What is the basic shape of Cocci (Coccus)?
Spherical
What is the basic shape of Bacilli (Bacillus)?
Rod-Shaped
What is the basic shape of Spirilla (Spirillum/Helical)?
Spiral Shaped
What are the 3 major nutritional needs for bacterial growth?
Carbon
Nitrogen
Energy (ATP)
What temperatures are cultures routinely grown at?
35°-42°c
What are anaerobe bacteria?
Bacteria that are unable to grow in the presence of oxygen
What are aerobe bacteria?
Bacteria that needs oxygen to grow
What are capnophilic bacteria?
Bacteria that grow better with a carbon dioxide enriched atmosphere
An infection is dependant on what outcomes?
Size - of the infecting dose
Site - of infection
Virulence - of organism
Speed & Effectiveness - of immune response
Accurate ID, Timeliness and Treatment
What is an ectoparasite?
Parasite that lives on external surfaces
What is fluid from the joint called?
Synovial Fluid
What is Amniotic Fluid?
Fluid tested for chromosomal abnormalities
What is a Parasitic Intestinal Helminth?
A roundworm
What type of plate differentiates based on HEMOLYSIS?
BAP
Blood Agar Plate
What is Peptidoglycan?
It provides structure to bacterial cell walls
Bacteria are treated with?
Antibiotics
What is the difference between Bactericidal antibiotics and Bacteriostatic antibiotics?
Bactericidal KILLS bacteria out right by directly attacking the cell and injuring it.
Bacteriostatic STARVES the cell of nutrients, stopping it from dividing and attacking while letting the immune system attack the bacteria
What colour is Gram positive?
Purple
What colour is Gram negative?
Pink
What is an indirect specimen?
Sample has passed through an area with flora
What is a direct specimen?
Sample is collected from normally sterile tissue
Should a plate be refrigerated before inoculation?
Yes, to prevent bacteria from growing
What is differential media?
contains specific ingredients/chemicals that allow the observers to distinguish between species
Blood agar is a differential medium that distinguishes bacterial species by their ability to break down red blood cells
What is this streaking pattern for?
Fluid
What is this streaking pattern for?
Urine
What is this streaking pattern called?
1/1/1
What is this streaking pattern called?
5/3/1
What is the order of Gram Staining?
Primary Stain - Crystal Violet
Mordant - Iodine
Decolorizer - Alcohol/Acetone
Counterstain - Safranin/Basic Fuchsin
Cells on Slide!
How does a MAC (MacConkey) agar plate work?
It is selective and differentiates by LACTOSE FERMENTATION
selective for gram negative
selectively isolate bacilli usually found in the intestinal tract
How does a BLOOD AGAR plate work?
It’s non selective and differentiates
by HEMOLYSIS
How does a Chocolate AGAR work?
It’s non selective and the red blood cells have been lysed to aid in precise organism growth
commonly used to grow respiratory bacteria
What is an inoculating loop?
A tool used to transfer microbial growth from one site to a plate to introduce contaminants
What is required for labeling samples in the lab?
Last name, First name
Date of Birth
Accession number
PHN/MRN number
Type of specimen
How long is an incubation period?
24-48 hours
What is the KIRBY BAUER disc method?
To test the effectiveness of antibiotics on a specific microorganism
If the organism is susceptible to a specific antibiotic, there will be no growth around the disc containing the antibiotic
If the organism is resistant, there will be growth up to the disc
What is an E Test?
Consists of a predefined gradient of
antibiotic concentrations on a plastic strip to determine the Minimum Inhibitory Concentration (MIC) of antibiotics, antifungal agents and antimycobacterial agents
What are the 3 different types of sample taking methods?
Swab
Blood
Infected Tissue or Fluid
What is the difference between sputum and saliva?
Sputum is spit up from the lungs and is very thick and sticky
Saliva comes from the mouth and is watery and thin
How can we treat a virus?
treatments can only help with symptoms while the immune system fights off the virus
VACCINES are the best preventative method
How long should you leave the Primary Stain on for?
1 minute
Crystal Violet
How long should the Mordant stay on for?
1 minute
Mordant
How long should the Decolorizer stay on for?
Just a quick second and rinse right away
Alcohol or Acetone
How long does the Counterstain stay on for?
1 minute
Safranin or Basic Fuchsin
Thick smears are to determine the presence/absence of what?
Parasites
Qualities of a good thick smear are…
About the size of a dime
Print can be read through it
A Thin smears purpose is to…
separate and count the % of parasitaemia (parasites in the blood)
A quick stain takes how long?
The whole process is 1 minute
Giemsa or Wright
What are 4 main things you need to remember when documenting using lab math?
Abbreviation of units
Singular. (mL not mLs)
No Period at the end
Always have a 0 before the . (0.03g)
Name 2 advantages to point of care testing
Rapid results
small sample needed
faster diagnosis
portable
“simple” to use
Name 2 disadvantages to point of care testing
quality of results
lack of proficiency
possible errors with integration of data
inappropriate use
maintenance on QC (Quality Control)
costs much higher
Pre-analytical errors with point of care include…
not wiping away first drop
excessive squeezing
not sanitizing
under or over filling the strip
incorrect patient ID
incorrect manual data entry
forgetting QC
Automation ADVANTAGES include…
quicker than manual
cheaper b/c performed in bulk volume
higher precision & accuracy
Lab can handle more
tech can multitask
Automation DISADVANTAGES include…
Equipment can malfunction
technology issues
maintenance
Three reagents in a Wright’s stain are…
a) Alcohol - Methanol - Fixative
b) Methylene Blue - Basic Dye - stains acidic elements
c) Eosin - Acidic Dye - Stains bases elements
How can you tell if a THICK blood smear is too thick?
If you can’t read something through it
What is the fixative/mordant found in Gram’s stain?
Iodine
Removal of all pathogenic organisms without killing the spores is…
Disinfection
Destruction of all organisms is…
sterilization
A blood agar plate differentiates bacteria based on what?
hemolytic properties
