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117 Cards in this Set
- Front
- Back
Things on a microscope I should know:
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Arm
Base Ocular lens Objective lens Stage Condenser Body tube Iris diaphragm Coarse and fine adjustment |
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Function of coarse adjusement.
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Raises and lowers stage only on scanning.
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Iris diaphragm -
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Controls the amount of light to the slide and through the condenser.
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Condenser -
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concentrates light on specimen.
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Three morphologies -
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cocci
bacillus spirilum |
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Total magnification of
Scanning - Low - High - Oil - |
40x 100x 400x 1000x |
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Parfocal -
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microscopes under focus in scanning will focus again with little adjustment.
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True motility -
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purposful and directional movement.
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Brownian motion -
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static vibration movement.
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Streaming -
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moving with the flow of water
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Simple stains - 2 ex.
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direct stain
negative stain |
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direct stain -
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stains the bacteria itself
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negative stain -
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stains the background.
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what does a heat-fix do?
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stops the bacteria from washing away during staining.
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Differential stain ex. (1)
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Gram stain
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Steps of making a Gram stain -
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1. Bacteria on slide
2. Air dry 3. Heat-fix 4. Crystal violet 5. Water 6. Gram's Iodine 7. Water 8. 95% ethanol alcohol 9. Water 10. Safranin 11. Water 12. bibulous paper. |
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Mordant for Gram stain -
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Gram's Iodine
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Primary stain for Gram stain -
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Crystal violet
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Decolorizing agent for Gram stain -
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Ethanol.
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Gram positive chracterisics of cell wall - 2.
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1. thick peptidoglycan
2. teichoic acid. |
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Gram negative chacteristics- 2
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1. thin peptidoglycan
2. lipopolysaccharides |
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Color of:
Gram negative - Gram positive - |
Pink
purple |
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Following the ethanol alchohol, before safranin, how would :
Gram positive look? Gram negative - |
- purple
- Colorless. |
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Most important step of Gram stain?
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Decolorizing, if crystal violet left on too long, it will cause both Gram negative and Gram positive to lose their color.
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Acid fast stain:
Primary stain - Decolorzing agent - Counterstain - |
carbolfuchsin dye
acid alcohol Methylane blue |
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Acid fast cells color -
non acid fast cells color - |
- red
- blue |
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acid fast cell wall contain -
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mycolic acid
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Capsules - what these bacteria have to cause them
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outside layer of polysaccharide
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Endospore stain procedure:
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1. Smear bacteria and one drop of water on slide.
2. airdry 3. Heat-fix. 4. bibulous paper on slide 5. malachite green 6. water 7. safranin 8. water |
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Why do endospores require harsh treatment to be killed?
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They live for survival. They don't allow particals to flow into it so harsh conditions need to open pours to allow stain in it.
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Endospore appears what color?
The rest will appear ? |
Green
pink or red |
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Disease caused by Acid Fast bacteria -
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Tuberculosis
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2reasons why capsules are helpful
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1. increase virulence
2. attach to surfaces easily. |
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Why are capsule forming bacteria harmful for humans?
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Immune system doesn't respond to it quickly and immune against antibiotics.
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Mordant in acid fast stain -
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heat
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Inoculate -
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add bacteria to sterile medium
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Incubate
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put in favorable temps to allow growth
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streak plate method -
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allows million of bacteria to be so spread out that it forms distinguishable colonies
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spread plate -
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dilutes bacteria with 10 mL ofwater to count colonies
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Pour plate -
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diluted cells are mixed with agar then into petridish.
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aseptic technique -
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1. flame loop, cool
2. take off cap with pinky 3. flame top 4. get bacteria 5. flame top 6. put cap on 7. spread bacteria on slide 8. flame loop |
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How many bacteria per ml were there in the original culture tube?
30 colonies in the 10^-7 |
30/10^-7 x (10^7/10^7) = 3.0x10^8 bacteria/mL
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Nutreint broth tuves are sterile when...
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the media is clear
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Nutrient agar plates are sterile when...
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the plate is clear even after incubation.
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colony -
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one cell grows and divides to make million of bacteria.
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Plaque formation -
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Fromed by bacteriophages because bacteriophage is a virus, so the virus kills part of the lawn to make the clear spots.
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Metabolism -
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all chemical reactions that occur within living organims.
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oxygen requirements - 5
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1. Obligate aerobes
2. Obligate anaerobes 3. Faculative anaerobes 4. Microaerophiles 5. aerotolerant |
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Obligate aerobes -
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require oxygen to grow
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Obligate anaerobes -
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Can only survive with no oxygen.
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Faculative anaerobes -
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grow with or without oxygen, but bette with oxygen
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Microaerophiles -
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small amount of oxygen
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Aerotolerant -
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grow with or without oxygen.
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Catalase:
Media used? Reagent added? Positive test - if positive, what present? |
slide
hydrogen peroxide Bubbles catalase |
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Gelatin Hydrolysis:
Media used: Reagent added? Positive test? If positve, what present? Negative test - |
test tube
ice Liquid Produces proteases Solid |
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Hydrogen sulfide production:
Media used: Reagent added- Positive test - What present if positive? Negative - |
SIM tube
iron sulfate 75% black iron sulfide small amount or no black. |
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Oxidase:
Media used- Positive test - What is present? Negative test - |
oxidase dryslide
color change to blue Cytochrome C No color change. |
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Glucose/Dextrose Fermentation/ Lactose/ Sucrose:
Media used Reagent added Positive? Whats in it? Negative? |
- Durham tubes
- Phenol Red - Yellow/Orange and bubbles - Acid - red/pink, so it's base and no bubbles |
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Starch hydrolysis:
Media used: Reagent added Positive - what's in it? Negative? |
- Starch plate
- Iodine - clear zone/ yellow halo Amylase present - no clear zone. |
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Urea production:
- Media used Reagent added - positive - what's in it? Negative - |
- Small tube
- phenol red - pink - Urease present - orange. |
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Oxygen requirement:
- media used? Positive: What requirement is it? Negative? What requirement is it? |
- Thioglycollate tube (FTM)
- Green present - Faculative anaerobe - No green present - Obligate aerobe. |
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Why use biochemical test to determine unknown?
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Because Gram stain only determines characterstics in cell wall, while the biochemical tests test multiple things to distinguish between them.
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Why can't we test oblifate anerobe?
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We live in an oxygen rich environement.
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What two compounds are produced by action of urease on urea?
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Ammonia and carbon dioxide
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Breaking down the previous to results in what to ph?
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Increases it.
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Disinfectants -
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chemicals used on inanimate objects
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Antiseptics -
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chemicals that are used on the skin
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Bactericidal agents -
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killing bacteria.
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Bacteriostatic agents -
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temporary inhibiting growth/divide
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Phenol coefficeint -
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compare an antibiotic to phenol to determine if it's strong or weak.
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Chemotherapeutic agents/ antibiotics -
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antimicrobial compounds that can be taken internally.
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MIC -
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minimum inhibitory concentration
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MIC - definition -
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the smallest value of antibiotics that still do the job.
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Kirby-Bauer agar method:
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1. Microorganisms spread over plate to form lawn
2. Paper discs impregnated with various antibiotics are spread on surface. 3. incubation |
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Zone of inhibition -
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the area of no growth
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Big zone -
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bacteria is inhibited
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Narrow spectrum -
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antibiotics that can work against one type
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Broad spectrum -
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antibiotics that can work against multiple.
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Why would it be important to know the pathogen before treating with antibiotics?
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Certain antibiotics can work faster and better than others. Also some bacteria can resist certain antibiotics.
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Sterile -
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totally free from organisms.
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Physical methods -
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Radiation and Heat and UV
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Chemical methods -
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disinfectents
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How does heat work?
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denatures the enzymes to inhibit growth.
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Thermal death time -
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length of time required to kill all bacteria at a given temp
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The higher the temp....
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shorter the TDT
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Autoclave requirements -
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15 minutes
121 celcius 15 pounds of pressure |
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UV kills by...
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creating thymine dimers in the DNA to cause inhibition of growth.
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Epidemiology -
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study of how, when where, what and who are involved with the spread and distribution of diseases in a population
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infectious disease -
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a disease caused by microorganisms that enter the body and multiply in tissues.
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Communcable -
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able to be transferred.
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Epidemic -
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If the number of newly reported cases in a given period of time in a specific area is excessive.
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Ex of epidemics -
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Ebola, black plague, infuenza.
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Staphylococci -
Streptococci |
clumps of circles
links of circles. |
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Streptobacilli - |
Links of rods
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- Gram positve
- Cocci - staphylococci |
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- Gram negative
- bacillus - diplobacilli/streptobacilli |
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- Gram positive
- bacillus - staphylobacilli |
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Acid Fast cells
bacillus |
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non acid fast cells
bacillus |
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Capsules
bacilli |
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Endospores
bacilli vegetative cells - ones just pink. |
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Negative sucrose/lactose/glucose test.
Basic/ no bubbles. |
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Postive sucrose/lactose/glucose test
Acidic/ bubbles. |
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Positive for sucrose/lactose/glucose
acidic , but no bubbles. |
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Positive starch hydrolysis.
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Negative starch hydrolysis.
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negative gelatin hydrolysis.
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Positve geletin hydrolysis.
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Minimum inhibitory concentration for antibiotics. The first clear one is the minumum anount needed.
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positive urea production
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Negative urea production
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Positve catalase test.
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Negative catalse test.
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Positve hydrogen sulfide production
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Negative hydrogen sulfide production
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Growth in a plate?
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Measuring zone of inhibitionDiameter
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