vtpb 426 gram negative unknowns

da unknowns aka gram negative tests; the word bu++ got me flagged so i used but

what kind of hemolysis

gamma

what kind of hemolysis

complete/beta hemolysis

what kind of hemolysis (green)

incomplete/alpha hemolysis

what kind of hemolysis

double zone

phenol red carb broth

positive test= yellow
A acidic (or if there is gas A+G)

phenol red carb broth

negative test= darker red
K (alKaline)

TSIA (triple sugar iron agar)

K/N
but unchanged (N) , slant either alkaline or unchanged (K)
no fermentation

TSIA (triple sugar iron agar)

K/A
slant alkaline (K), but acidic (A)
peptone use on slant

TSIA (triple sugar iron agar)

A/A
slant and but acidic (A)
yellow/yellow

TSIA (triple sugar iron agar) (gas cracks)

A/A+G
acidic but and slant +gas

TSIA (triple sugar iron agar)

hydrogen sulfide gas produced = black precipitate
means some fermentation happened tho
can block results but needs to be acidic so but is acidic
hard to determine just from this but fermentaiton happens and h2s produced

nitrate test steps

1. add reagents A and B according to bottle

2. wait 2-3 mins

3. if NO color change add small amt of Zn dust with long stick

Nitrate test after reagents added

nitrATE reductase positive

Nitrate test after reagents and Zn added

nitrATE reductase negative

Nitrate test after reagents and Zn added

nitrATE and nitrite reductase positive

urease test

A (acidic)
urease negative
brighter yellow

urease test

K (alKaline)
urease positive
hot pink

tetrazolium salt (MTM)

negative (no motility)

tetrazolium salt (MTM)

positive (motility)

oxidase test positive control

pseud aeruginosa

oxidase test negative control

e coli

oxidase test

positive turns blue

indole test steps

1. add 6 drops Kovac’s reagent

2. dont mix

indole test

indole positive
can sometimes change color again after 20/30 mins; if u want to check add 5-6 more drops

indole test

indole negative

mr/vp (methyl red) test steps

1. pipet 1 mL into tube

2. add 1-2 drops of methyl red and give gentle shake

methyl red test

positive methyl red

methyl red test

negative methyl red

mr/vp (voges-proskauer) test steps

1. add 6 drops of reagent a

2. add 2 drops of reagent b

3. gentle shake

4. wait 20-30 mins

VP test

positive VP
surface color changes

VP test

negative VP
yellow or brown top

citrate test

positive citrate
turns more blue

citrate test

negative citrate
not much color change

macconkey agar

lactose fermenter (A)
hot pink

macconkeys agar

non-lactose fermenter
colorless or translucent

EMB agar

lactose fermenter
blue/black or pink colonies with dark center
fast= metallic green

EMB agar

non-lactose
colorless/translucent

SS agar

non lactose fermenter
colorless/yellowish

SS agar

lactose fermenter
pink/red colonies

SS agar

h2S producing bacteria
black centered colonies

LIA (lysine iron agar)

LDA negative, LDC negative
K/A
we hate LSU (negative negative) purple/yellow

LIA (lysine iron agar)

LDA negative, LDC positive
K/K
purple/purple

LIA (lysine iron agar)

LDA positive, LDC negative
R/A
red on top (aggies on top)

ODC test

positive ODC
purple

ODC test

negative ODC

yellow