Types of Media 2.txt

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Types of Media 2.txt
2011-11-30 22:46:40
study guide media p2

media used for lab final
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  1. Mannitol Salt Agar (MSA)
    • •MSA Is a selective and differential media
    • •Was used in: Staphylococci lab
    • •Was used for: Determining fermentation (yellow – positive & red/pink – negative)
    • •What is the gram reaction of the organism that can grow on MSA? Gram (+)
    • •What is the name of the selective agent? NaCl
    • •What is the name of the differential agent? mannitol
    • •What is the name of the pH indicator in this medium? Phenol red
  2. m-staphylococcus broth (MSB)
    • • Was used in: Staphylococci lab
    • • Was used for: to grow/determine is microbe was staph
    • • What type of organism grow in this medium? Halotolerant organisms (salt tolerant organisms) such as Staphylococcus aureus
    • • How do you classify this medium? MSB is enriched selective medium
    • • What in the medium allows the organisms to grow? 10% NaCl
  3. Blood Agar (BA)
    • • Was used in: Staphylococci and Streptococci lab
    • • Was used for: Staphylococci - used to determine hemolytic reactions (alpha, beta, gamma) and Streptococci lab – used for bacitracin, optochin, and throat culture.
    • • What toxin is responsible for the staphylococcus lab? Alpha toxin
    • • What organism produces this toxin for the staphylococcus lab? S. aureus
    • • What is the enriched in this medium? 5% sheeps blood
    • • What is the differential agent in this medium? .5% NaCl
    • • Which plate shows alpha hemolysis? Incomplete hemolysis, producing cloudy zone of greening around the colony due to production of methemoglobin.
    • • Which plate shows beta hemolysis? Complete hemolysis, giving a clear zone with a clean edge around the colony.
    • • Which plate shows gamma hemolysis? No hemolysis or no change in the blood agar around the colony.
  4. Bile Esculin Agar Slant (BEsC)
    • • Type of media - (BEA) is a selective differential agar used to isolate and identify members of the genus Enterococcus, also known as "group D streptococci".
    • • Was used in: Streptococci lab
    • • Was used for: Bile Esculin Biochemical test
    • • Principle - Enterococcus hydrolyze esculin to products that react with ferric citrate in the medium to produce insoluble iron salts, resulting in the blackening of the medium. Test results must be interpreted in conjunction with gram stain morphology.
    • • Selective agent - Bile salts are
    • • Differential agent - Esculin
    • • pH indicator -
  5. Brain Heart Infusion Agar (BHIA) slant
    • • Type of meida - (BHI Agar) is an enriched non-selective medium for the isolation and cultivation of most anaerobic bacteria and other fastidious microorganisms.
    • • Was used in: Streptococci lab
    • • Was used for: Catalase test
  6. Rabbit Plasma
    • • Type of reagent: rabbit plasma.
    • • Was used in: Staphylococci lab
    • • Was used for: Coagulase test
    • • Protocol: rabbit plasma is placed in a sterile tube using a sterile loop, a colony of staph. is added to the rabbit plasma. Tube is incubated at 35c for 4 hours.
    • • Results: positive: plasma clots within 4 hours negative: plasma doesn't clot within 4 hours significance: staph. aureus is positive. staph. epidermidis is negative.
  7. Staphylococcus Medium 110 (SM110)
    • • Was used in: Staphylococci and Streptococci lab
    • • Was used for: to grow/determine is microbe was staph and what strain (color pigmentation used yellow or white)
    • • What is the advantage of using this medium in the microbiology lab? SM110 also contains NaCl and mannitol, but it lacks phenol red. Its advantage over MSA is that is favors colony pigmentation by different strains of S. aureus. Since this medium lacks phenol red, no color change takes place as mannitol is fermented.
    • • How is this medium different from MSA? Does not have a pH indicator therefore colony pigmentation occurs.
  8. MacConkey Agar (MAC)
    • • Type of media - Classified as biochemical media
    • • Was used in: Enterics lab
    • • Was used for: Lactose (lactose positive – red/pink & lactose negative – yellow)
    • • Selective agents – Biosalts and crystal violet (to inhibit most gram positive organisms)
    • • Differential agents – is used to distinguish organisms from each other based on a reaction that occurs as they grow. Lactose positive and lactose negative
    • • pH indicators – neutral red
    • • What is the Gram reaction of organisms that grow on MAC? Gram (-)
    • • Which plate(s) show an organism that ferments lactose? Lactose positive organisms (E. coli) produce acid when they grow. This acid causes the pH to drop. Neutral red is absorbed and the colony turns red as in the second plate.
    • • Which plate(s) show an organism that does not ferment lactose? Lactose negative organisms (salmonella & shigells) do not produce acid when they grow on MAC. Lactose negative organisms remain colorless and translucent as in the first plate.
  9. Triple Sugar Iron Agar (TSI)
    • • Type of media – Differential biochemical media
    • • Was used in: Enterics Lab
    • • Was used for: Hydrogen Sulfide Production Test
    • • Selective agents & Differential agents - this is a key medium for use in beginning the identification of a Gram-negative bacilli of the enteric group. It contains glucose (0.1%), lactose (1%), sucrose (1%) and peptone (2%)as nutritional sources. Sodium thiosulfate serves as the electron receptor for reduction of sulfur and production of H2S. Detects fermentation of sucrose, lacotse, glucose, as well as production of hydrogen sulfide and/or gas.
    • • pH indicators – Phenol red
    • • Reading TSI:
    • • 1. Slant (A – yellow: this means fermented (+) sucrose and or glucose) or (K – red/pink: this means fermented (-) in the slant)
    • • 2. Butt (A-yellow: this means glucose fermented) or (K-pink/red: this means fermented (-) in the butt)
    • • 3. Gas (G – for presence of gas which is bubbling or lifting at the butt) or (no G for no bubble or lifting at the butt)
    • • 4. H2S (S when there is black at the butt – ferrous sulphide is produced) or (no S if there is not black in the butt)
    • • What color indicates that fermentation has occurred? Yellow
  10. Motility Medium Triphenyl Tetrazolium Chloride (MTM)
    • • Type of media – General purpose media
    • • Was used in: Enterics Lab
    • • Was used for: Motility Test
    • • Which tube(s) shows a negative result for motility? Last two
    • • Which tube(s) shows a positive result for motility? First two
    • • What is percentage of agar in this medium? .4% agar
    • • What is the name of the indicator dye for this medium? Triphenyl-Tetrazolium chloride
    • • What is the name of the red precipitate in a motile positive test tube? Formazan
  11. Urea Broth (UB)
    • • Type of media – Biochemical media
    • • Was used in: Enterics Lab
    • • Was used for: Urease biochemical test
    • • pH indicators – phenol red
    • • Which tube(s) show the production of urease? Second tube (intense pink color)
    • • What is the name of the substrate in this medium? Urea
    • • What is the name of the product(s) produced in a positive urease result? 2 ammonia & CO2
  12. Simmons Citrate Agar (CIT)
    • • Type of media – Enriched biochemical medium
    • • Was used in: Enterics Lab
    • • Was used for: Citrate utilization biochemical test
    • • pH indicators - Bronthynol blue
    • • Which test tube shows the utilization of citrate? Second tube (blue) - Positive- alkaline pH causes media to change from green to prussian blue Negative- no color change
    • • What is the name of the carbon source in this medium? Sodium citrate
    • • What is the name of the Nitrogen source in this medium? Ammonium salts
    • • What is the name of the pH indicator in this medium? Bronthynol blue
    • • What is the name of the end product that creates an alkaline pH in a positive test result? In organisms capable of utilizing citrate as a carbon source, the enzyme citrase hydrolyzes citrate into oxaoloacetic acid and acetic acid. The oxaloacetic acid is then hydrolyzed into pyruvic acid and CO2. If CO2 is produced, it reacts with components of the medium to produce an alkaline compound (e.g. Na2CO3). The alkaline pH turns the pH indicator (bromthymol blue) from green to blue. This is a positive result (the tube on the right is citrate positive). Klebsiella pneumoniae and Proteus mirabilis are examples of citrate positive organisms. Escherichia coli and Shigella dysenteriae are citrate negative.
    • Tryptone Broth (TRP)
    • • Type of Media – Differential biochemical medium
    • • Was used in: Enterics Lab
    • • Was used for: Used for Tryptophan Hydrolysis/ “Indole Test”
    • • Which tube(s) shows indole production? The last tube (red on top)
    • • What enzyme is secreted in this positive test result? Tryptophanase
    • • What reagent is used for this medium? Kovacs reagent
  13. Trypitic Soy Agar Slant
    • • Type of Media – Enriched non-selective media
    • • Was used in: Streptococci lab
    • • Was used for: Catalase test
  14. Barin Heart Infusion/NaCl Borth (BHI/NaCl)
    • • Type of Media – is an enriched non-selective medium
    • • Was used in: Streptococci lab
    • • Was used for: Salt tolerance test
    • is rich in a wide variety of nutrients (including many growth factors)
    • and will, therefore, support the growth of a wide range of bacteria.
    • All-purpose media include Nutrient Agar, APT Agar, Plate Count Agar,
    • Heart Infusion Agar, Brain Heart Infusion Agar and Penassay Agar
    • supports the growth of desired organisms while inhibiting the growth of
    • many or most of the unwanted ones – either by purposely adding one or
    • more selective agents which "poison" certain types of organisms or by
    • including or deleting certain nutrients such that the desired organisms
    • and few others are able to grow. Examples on how these things may be
    • accomplished are as follows:
    • is one which allows two or more different types of organisms to grow,
    • but it contains dyes and/or other components upon which different
    • organisms act in various ways to produce a variety of end products or
    • effects, often detected by variations in color. These differences are
    • often very apparent among colonies of a mixed culture growing in a petri
    • dish. Pure cultures, growing in separate tubes of the same differential
    • medium, may also be characterized and differentiated from one another
    • according to a particular biochemical characteristic. Examples of
    • differential media include the following:
  18. Differential Enriched Test(s)
    •Hemolysis Test
  19. Sensitivity Test(s)
    • •Bacitracin Test
    • •Optochin Test
  20. Selective & Differential Test(s)
    •Bile Esculin Test
  21. Selective Test(s)
    • •Salt Tolerence Test
    • •Motility (Motility Medium w/ TTC)
    • Biochemical Test(s)
    • •Oxygen Requirements (Fluid Thioglycollate Medium)
    • •Gelatin Liquefaction Test (Nutrient Gelatin)
    • •Carbohydrate Fermentation (Glucose, Lactose, Mannitol, Maltose and Sucrose broths)
    • •Methyl Red Test & Voges-Proskauer Test (MR-VP Broth)
    • •Citrate Utilzation (Simmons Citrate Agar)
    • •Catalase Test (Trypic Soy Agar)
    • •Nitrate Reduction Test (Nitrate Borth)
    • •Starch Hydrolysis (Starch Agar Plate)
    • •Casein Hydrolysis (Skim Milk Agar)
    • •Tryptophan Hydrolysis/ “Indole Test (Tryptone Broth)
    • •Urease Test (Urea Broth)
    • •Phenylanine Deamination (Phenylalanine Agar)
    • •Hydrogen Sulfide Production (Triple Sugar Iron Agar)
    • •Lysine Decaroxylase Test (Lysine Decarboxylase Broth)
    • •Orinithine Decarboxylase Test (Ornithine Decarbocylase)