MicroBiology Lab Practical 2 Review

catalse

breaks down peroxide into water and oxygen

Catalase negative

streptococci

catalase positive

staphylocci

What is MSA

mannitol salt agar

selective (7.5%NaCl) and differential (mannitol)

phenol red

Why is phenol red added to MSA

detect acid made by fermentation of mannitol

ferments mannitol-yellow color change

S. aureus

non-mannitol fermenter

S. epi

What is a "positive" reaction for MSA plate?

the phenol red turns yellow

coagulase

extra cellular protein

rabbits plasma

plasma clots in presence of coagulase

Coagulase positive

staph aureus

coagulase negative

S. epi

Coagulase positive that is #1 cause of skin and wound infections

Staph auerus

blood agar

enriched media

differential

fastidious organisms

beta hemoylsis

blood cells are completely destroyed

Which organisms are beta hemolytic

S. pyogenes

S. agalactiae

alpha hemolysis

red blood cells are partially destroyed

olive green to brown color

Alpha hemolytic organisms

S. mitis

S. pneumonia

Viridian's

gamme hemolysis

no blood hemolyze

gamma hemolytic organisms

S. lactic

S. faecalis

mites salivarius medium

oral cavity streptococci

selective medium

contains tellurite

What is mitis salivarius medium selective for

viridian's groups

colonies will turn blue

blue pin point colonies

S. mitis

blue gumdrop colonies

S. salivarius

neisseria throat swab is gram ?

gram negative diplococci

what does neisseria produce

oxidase

colonies of neisseria turn ___ if oxidase is present

bue-black

major pathogens of enteric bacteria

salmonella

shigella

escherichia

Gram (-) non spore forming rods are ___ family

enterobacteriaceae

MaCconkey agar is

selective and differential

Macckoney agar is selective for

inhibits growth of gram (+)

bile salts

crystal violet

MacConkey agar is differential for

lactose fermentors

Lactose fermenters are

pink to brick red colonies

non-lactose fermenters are

colorless

EMB is selective for

dyes inhibit gram (+)

EMB is differential for

lactose

EMB lactose fermenters

pigmented colonies

EMB non lactose fermenters

colorless colonies

E. Coli on EMB agar

black colonies w/ metallic green sheen

TSA constituents

3 sugars

glucose

lactose

sucrose

pH indicator=phenol red

TSA glucose fermenter

red slant

yellow deep/butt

Lactose and or sucrose fermenter TSA

slant and deep yellow

Gas prodution

cracks splits bubbles

H2S production

black precipitate

methyl red

ferment glucose produces mixed acids

Positive methyl red test

turns red color after adding one drop of methyl red reagent

negative methyl red test

orange or yellow at alkaline ph

Vogues-Porskauer

production of acetylmethycarbinol from glucose

Positive VP

add VpA and VpB reagent turns red

Citrate

ph indicator

Bromothymol blue

Green-neutral

blue-alkaline

What does bacteria use citrate as?

sole source of carbon and produces alkaline end products=deep blue

wavelength of UV light

265 nanometers

UV light produces

thymine dimers

What does thymine dimers do?

prevents transcription of DNA into RNA

protein synthesis interuppted=death

Is Standardized Disk Susceptibility/Kirby Bauer method quantitive or qualitative

quantitative

Sabourauds Dextrose Agar

inhibits most bacteria and selects for fungi

pathogenic fungal diseases

thrichophyton

microsporum

epidermopyton

fungal disease caused by Malassexia furfur

tine versicolor (johns skin problem)

Rose Gardners disease (sporotrichosis)

sporothrix schenckii

Histoplasmosis (spelunkers)

histoplasma capsulatum

Piedra causes

trichosporsis

fungal growth on hair- pimps at hair follicles

Red/yellow

Glucose fermenter

Enterobacter aerogenes

yellow/yellow

Lactose or Sucrose

red/red

no sugar fermentatin