LAB QUIZ 7

Which organism had growth mostly at the top and some at the bottom (facultative anaerobe) ? prefer O2, can survive w/o

E. Coli

Which organism was aerotolerant anaerobe ? (growth evenly distributed) no preference for O2

Streptococcus Pyogenes

Which organism displayed FACULTATIVE ANAEROBE growth ? (growth at the top) some at bottom) prefers O2, doesn’t require it

Pseudomonas Aerugionsa

Which organism was an obligate anaerobe ? (growth at the bottom) CANT SURVIVE WITH O2, no O2

Clastridium Sporagenes

what do air bubbles in the tube suggest ?

gas production

Name a genus that is catalase POSITIVE and one that is catalase NEGATIVE. catalase: an enzyme that can break down hydrogen peroxide

staphylococcus aureus : catalase positive ( bubbles released)

streptococcus pyogenes: catalase nervative, no bubbles released

what’s the purpose of the starch hydrolysis test ?

to test and see if an organism can utilize starch as a nutrient

What is the name of the small glass tube inside of the Phenol Red and Nitrate reduction broths?

What is the purpose of this tube?

durham tube

the purpose is too see if gas production has occurred

What microorganism does the coagulase test identify with a positive result?

Staph Aureus, if solid: positive result, liquid: organism other than S. Aureus

What is the purpose of the antibiotic susceptibility test?

looking to see if species are resistant or susceptible to antibiotics

which antibiotics were used during last weeks lab on the antibiotic susceptibility/ resistant test ?

NOVOBIOCIN ( staphylococcus epidermis and Staphylococcus saprophyticus)

OPTOCHIN (streptococcus pneumoniae)

BACITRACIN ( Streptococcus pyogenes)

All Gram (+) bacteria, describe genus STAPH shape and BACILLUS shape

staph (cocci), bacillus (rods)

what’s the purpose of phenol red broth test

shows if organism can ferment a specific carbohydrate

what does it mean if it turns yellow during the phenol red broth test

positive fermentation, and if there’s bubbles= positive for gas

what must you do before adding antibiotics on a plate for the antibiotic susceptibility test

you just perform a lawn streak (solid streak)

what does a HALO indicate on the starch hydrolysis test

starch has been utilized

what’s the purpose of the nitrate reduction test

to see if an organism can reduce nitrate and HOW after incubation