Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
23 Cards in this Set
- Front
- Back
|
clinical microbio
|
the study of organisms that cause disease
-bacteriology, virology, mycology, parasitology |
|
|
bacteria and archae
|
-single-celled, no membrane bound nucleus, no other oragnelles
-prokaryotes = prenucleus -common type in human infection -rod-shaped, spherical and spiral -rigid cell walls -binary fission |
|
|
normal bacterial flora
|
- aka microbiota
-bacteria outnumber cells in the body -keep disease-causing organisms from breaching host defenses |
|
|
eucarya
|
-organisms contain membrane bound nucleus, eukaryotes = true nucleus
-contains organelles -fungi: single (yeast) or multicellular (molds) -gain energy from organic materials -protozoa: microscopic, found in water, complex, large, motile |
|
|
nomenclature
|
- first word is genus capitalized, second word is species name, not capitalized
-full name italicized or underlined |
|
|
microscope
|
important factors: magnification, resolution, contrast
|
|
|
acidic and basic dyes
|
-basic dyes carry positive charge and bond to cell structures that carry negative charges-STAIN THE CELL (ex. methylene blue, crystal violet, safranin, malachite green)
-acidic dyes carry positive charge and are repelled by cell structure that carry negative charge-STAIN THE BACKGROUND |
|
|
how to prepare the smear for staining
|
1. sterilize the inoculating loop
2. obtain a loopful of broth culture and place on slide "smear" with a loop to make a thin, uniform film on the slide 3. air dry completely |
|
|
gram stain steps
|
1. flood with crystal violet-stain cells-wait 1 min
2. gently wash with tap water 3. flood with iodine- holds primary dye onto cell- at this point it is purple-wait 1 min 4. decolorize with ethyl alcohol- at this point gram + are purple and gram - have no color (IMPT STEP) 5. wash with tap water 6. flood with safrinin- wait 10 secs-recolorizes cells that lose stain through decolorization- stains both but only see gram - appear red 7. wash with h2o 8. air dry |
|
|
acid fast stain
|
-for genus mycobacterium
-uses heat to facilitate staining 1. primary dye: carbol fuchsin- colors acid fast bacteria red 2. decolorize with acid alcohol- remives stain from non acid-fast bacteria 3. counter stain with methylene blue- non acid fast bacteria-->BLUE, acid fast -->RED |
|
|
capsule stain
|
do this if u suspect a capsule
-negative stain, only stains bacjground -capsule stands out |
|
|
endospore stain
|
-enhances endospore
-uses heat -if u suspect baciliius infection |
|
|
flagella stain
|
-single or several flagella
-staining increases diameter of flagella |
|
|
morphology of prokaryotic cells
|
1. coccus: spherical
2. bacillus: rod or cylinder shaped 3. coccobacillus: short round rod 4. vibrio: curved rod 5. spirillum: spiral shaped 6. spirochete: helical shape 7. pleomorphic: bacteria able to vary shape -Cells adhere together after cell division for characteristic arrangements -division along a single plane may result in pairs or chains of cells- pairs = diploccoci; chains = streptococci -division along 2 or 3 perpendicular planes form cubical -division along several random planes form clusters |
|
|
direct testing
|
-Demonstration of the presence of an infectious agent
- culture, microscopy, molecular methods such as PCR |
|
|
indirect testing
|
-Demonstration of presence of antibodies to a particular infectious agent: Serology
|
|
|
sterile body sites
|
-normally do not contain any bacteria, so any bacteria found there are significant (if they are not sterile that means there is an infection
-blood, CSF, urine |
|
|
non-sterile body sites
|
-open to the external environment and normally contain bacteria
-throat, feces, skin -specimens only look for specific pathogens |
|
|
specimen
|
1. collection
2. aprropriateness 3. transport to lab 4. innoculation of media 5. culture and isolation 6. identification 7. report |
|
|
urine culture- how to minimize contam
|
-: transfer urine to a tube with preservative within 10 min then can be kept for 48hrs at room temp; important to tell patient how to collect sample (clean area, collect mid stream
|
|
|
how to minimize contamination
|
-*look at chart
|
|
|
criteria for rejection of a specimen
|
o Unlabeled or improperly labeled specimen
o Prolonged storage or transport o Improper or damaged container o Specimen received in fixative o Oropharyngeal contaminated sputum o Specimens unsuitable for culture request (anaerobic culture from not acceptable source, urine from Foley catheter) o Dry Swab |
|
|
end of lecture
|
*read over!
|
