Antiseptic
Chemicals used on living tissues to decrease the number of microorganisms
Disinfectant
Chemical agents used on inanimate objects to reduce the number of microorganisms on the surface
Antibiotic
A substance produced by a microorganism that is inhibitory for other microorganisms
Plaque
After several rounds of infection and release, all the bacteria in the area of the original virus are lysed and clear areas (plaque) form
Viruses that infect bacteria are known as
Bacteriophage
What agar medium is used for antibiotic sensitivity testing?
Mueller-Hinton agar plate
What does the starch agar plate test for?
Presence of enzymes to break down starch into glucose molecules
What does the casein (skim milk) agar plate test for?
Presence of enzyme to break down casein protein into individual amino acids
What does the lipid (spirit blue) agar plate test for?
Presence of lipase enzymes to break down lipids into fatty acids
What does the phenol red glucose broth test for?
Acid and gas production from glucose fermentation
What does the phenol red lactose/and phenol red Mannitol broth test for?
Acid production from lactose or mannitol fermentation
What does the methyl red VP broth test for?
Mixed acids from glucose fermentation that lower the pH below 4.5
What does the Voges-Proskauer MR-VP broth test for?
tests for butanediol production from glucose fermentation
What does the oxidase TSA slant test for?
Presence of cytochrome c oxidase in some aerobic bacteria
What does the catalase TSA slant test for?
Presence of catalase enzyme used to break down H2O2
What does the citrate slant test for?
Use of citrate as the only carbon source for ATP generation
What does the nitrate broth test for?
Presence of enzyme nitrate reductase for use of nitrate as an alternative electron acceptor in the ETC
What does the indole tryptone broth test for?
Presence of enzyme tryptophanase which breaks down tryptophan in medium to pyruvate, ammonium, and indole
What does the urea broth test for?
Presence of enzyme urease which breaks down urea in medium to ammonia
What does the TSI agar slant test for?
Enzymes to convert sodium thiosulfate to H2S and fermentation of glucose and lactose and sucrose
What are the positive and negative results of the phenol red glucose broth?
Positive = yellow Negative = red/pink
What are the positive and negative results of the phenol red lactose/mannitol broth?
Positive = yellow and cloudy Negative = red/pink and cloudy
What are the positive and negative results of the MR-VP methyl red test?
Positive = red Negative = yellow or orange
What are the positive and negative results of the MR-VP Voges-Proskauer test?
Positive = red Negative = yellow
What are the positive and negative results of the TSA slant oxidase test?
Positive = purple Negative = clear or yellow
What are the positive and negative results of the TSA slant catalase test?
Positive = bubbling Negative = no bubbles
What are the positive and negative results of the citrate slant?
Positive = deep blue Negative = dark green
What are the positive and negative results of the nitrate broth?
Positive = bright orange Negative = cloudy or no change
What are the positive and negative results of the tryptone broth indole test?
Positive = bright pink top layer Negative = yellow or greenish layer
What are the positive and negative results of the urea broth?
Positive = bright pink Negative = light orange
What are the positive and negative results of the triple sugar iron (TSI) agar slant?
Positive = blackening for H2S production Negative = no blackening for H2S
What are the positive and negative results of the starch hydrolysis agar plate?
Positive = clear zone around area of growth Negative = no zone around area of growth
What are the positive and negative results of the casein hydrolysis agar plate?
Positive = clear zone around area of growth Negative = no zone around area of growth
What are the positive and negative results of the lipid hydrolysis spirit blue agar plate?
Positive = deep blue zone around area of growth Negative = clear or light blue zone around area of growth
What are the positive and negative results of the lipid hydrolysis (spirit blue) agar plate test?
positive = deep blue zone around area of growth negative = clear or light blue zone around area of growth
What are the positive and negative results of the starch hydrolysis agar plate?
positive = clear zone around area of growth negative = no zone around area of growth
What are the positive and negative results of the casein hydrolysis agar plate?
positive = clear zone around area of growth negative = no zone around area of growth
A greater or bigger diameter of zone of inhibition corresponds to what?
increasing sensitivity of bacteria to antibiotics
Bacteria that are resistant to antibiotics correspond to what?
a lower or smaller diameter of zone of inhibition; which compared to intermediate or sensitive bacteria that have large diameters
Viruses are what? Incapable of what?
Obligate intracellular parasites,
Incapable of independent replication