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Medium that allows growth of certain types of bacteria while permitting growth of another, bacterial isolation
Medium that allows one to distinguish between different microorganisms based on a difference in colony appearance (color, shape, or growth pattern) on a colony
Highly nutritious material (blood, serum, yeast)
Spherical in shape
packets of 4
Packets of 8
rigid or flexible
helical and rigid
helical and flexiable
Phenylethyl alcohol, Crystal violet, 7.5% sodium chloride agar.
Phenylethyl alcohol agar
PEA gram positive used for isolation of most gram positive organisms.
Crystal violet agar
Gram negative, inhibitory effect on most gram positive organisms.
7.5% sodium chloride agar
Nonhalophilic, inhibitory, staphylococcus
MacConkeys agar is a good example of this because it contains bile salts and crystal violet which inhibit gram positive organisms and allow gram negatives to grow.
Mannitol salt agar
yellow means mannitol positive, pink means/ carbohydrate mannitol. Staphylococci exhibit yellow zone surrounding their growth. Change in coloration
gram negative, Either lactose negative or lactose positive, Salmonella
Eosin-methylene blue agar
Only e.coli turns metallic green
Produce thick mucoid, pink colonies
media that have been supplemented with highly nutritious material, blood serum, yeast.
TSI Triple sugar-iron test
designed to differentiate among the different groups of genera of the enterobacteriaceae, which are all gram negative bacilli caple of fermenting glucose with production of acid.
No carbohydrate fermentation, Red/Red or orange, Alkaline/Alkaline or Alkaline/No change
groups of bacteria that are found in the intertinal tract of humans and lower mammals are classified as these members.
Salmonella and Shigella
Proteus and Klebsiella
Normal intestinal flora
Escherichia and Enterobacter
Sulfur indole motility agar
1/2 stab SIM (deep), cherry red, 24-48 hours
Methyl Red test
E. coli and E aerogenes. pH range of 4 positive and is red
Methyl Red test
pH range of 6 means negative and is yellow
green to deep prussian blue
Citrate positive culture
Identified by the presence of growth on the surface of the slant and is accompanied by blue color.
Citrate negative culture
Will show no growth and the medium and remain green
Forming an insoluble black ferrous sulfide precipitate that is seen along the line of the stab inoculation and in indicative of H2S production.
urease, alkaline, deep pink
Hydrogen peroxide will bubble if positive, No bubble if negative.
Phenylalanine deaminase test
ammonia, green means positive, No color means negative.
Chemical substance that destroy or inhibit the growth of microorganisms in living tissue.
Chemical substance used on living tissue
used on nonliving materials
Lysol solution 2% to 5%, poisonous and must be used externally. Similar to phenol.
70% to kill stuff
Tincture of iodine, iodine suspended in alcohol
Influences its effects on microorganisms with higher concentrations producing a more rapid death.
length of exposure
All microbes are not destroyed within the same exposure time. Sensitive forms are destroyed more rapidly that resistant ones.
Conditions under which a disinfectant or antiseptic affects the chemical agent, Temperature, pH. type of material on which microorganisms exist.
Normal skin flora
Skin has staphylococci, streptococci, enterococci, diptheroid, bacilli, yeast and fungus.
Golden color, Strep and staph
Black and diphtheria
Staph and yellow, pigmented or non pigmented
Is determined by dividing the highest dilution of the chemical being tested that destroyed the microorganism in 10 minutes.