BMS 213 final (work in progress)

aseptic technique

method used to keep surfaces and objects free of unwanted bacteria

inoculation

purposefully transferring bacteria with the intention for it to grow

eye piece/ocular lens of microscope

diopter of microscope

objective lens of microscope

stage of microscope

condenser lens of microscope

fine focus of microscope

make fine, final focus adjustments

course focus of microscope

large movements of stage

light source of microscope

base of microscope

move stage of microscope

brightness of microscope

neck of microscope

powers of microscope

4x, 10x, 40x, 100x

count plate procedure

process of getting 5 tubes and plates and diluting the original bacteria until it is not too numerous to count and calculating results

count plate equation

(# of colonies/mL plated) X (1/dilution factor) - cfu/mL

gram staining procedure

Heat Fix

1. Primary stain- Crystal violet (1 minute)

Wash off stain with di-water

2. Mordant- Gram's Iodine (1 minute)

Wash off the iodine

3. Decolorization- Acetone-alcohol (hold slide at 45 degree angle and apply decolorizer, do this for a few seconds)

Stop decolorization by washing slide with gentle stream of di-water

4.Counterstain- Safranin (1 minute)

Wash off gently for only a few seconds

5. Blot dry with bibulous paper & air dry

6.Examine slide under oil immersion

gram stain: gram positive

purple and no outer membrane

gram stain: gram negative

pink with an outer membrane and thinner

capsule stain procedure

1. Begin w/ drop of serum & add Congo red stain

2. Add organisms & emulsify

3. Use 2nd clean slide to draw drop across to other end

4. Air-dry (do NOT heat-fix)

5. Flood w/ Maneval's stain for 1 min. then rinse

6. Blot dry

capsule stain: gram positive

clear visible halo

capsule stain: gram negative

no visible halo

Spore stain procedure

1. heat fixed smear

2. malachite green (forces into endospore) then wait 10 min

3. rinse with water

4. add safranin (vegetative cells)

5. rinse with water, blow dry

spore stain: positive

green cells

spore stain: negative

red/pink cells

requirements for bacterial growth

temperature, pH, osmotic pressure/salt concentration, oxygen

Psychrophiles

cold-loving microbes (-5 to 15 C)

thermophiles

heat loving microbes (45 to 70 C)

mesophiles

moderate temperature loving microbes (25 to 40 C)

acidophiles

grow in acidic environments

Alkalophiles

grow in basic environments

halophile

salt loving microbe

halotolerant

microbe that can tolerate some salt

halosensitive

microbe that cannot tolerate salt

aerobes

microbes that grow in the presence of oxygen

anaerobes

microbes that grow without oxygen

facultative anaerobes

microbes that can grow in the presence and absence of oxygen

CNA blood agar

used to grow gram positive bacteria, 5% sheeps RBC, nutrients, hemolysis

catalase test procedure

put bacteria on slide and then apply 3% hydrogen peroxide to sample, positive result will show bubbles

coagulase test procedure

transfer bacteria to tube with rabbit plasma and then incubate at 35 C, positive result will show a clot

Novobiocin (NB5) procedure

make a lawn plate with bacteria, place novobiocin disc in middle, incubate for 24 hours, zone of inhibition >16 is sensitive, <16 is resistant

Enterococcus faecalic

microbiota in gut

Streptococcus alagactiae

group B strep, in women, can infect infants during birth

Streptococcus mitus

mouth, major cause of cavities

Streptococcus pneumoniae

kids: ear infections elderly: meningitis

sensitive to A disc

Streptococcus pyogenes

group A strep, cause of strep throat

sensitive to P disc

A disc

includes bacitracin which targets cell wall

P disc

includes optochin which inhibits protein pumps

MAC plate

used to grow gram negative bacteria

selective: crystal violet and bile salts

differential: lactose and neutral red