BAP or SBA: An abbreviation for blood agar plate
or sheep blood agar. Blood agar contains mammalian blood (usually sheep,
rabbit or horse), typically at a concentration of 5-10%. Blood agar is
an enriched media used to isolate bacteria and to detect hemolytic
activity.
Indoletest: The indole test is a
biochemical test performed on bacterial species to determine the ability
of the organism to split indole form the amino acid tryptophan. The
results of an indole test are indicated by a change in color following a
reaction after the addition of Kovacs reagent. A positive result is
shown by the presence of a red color. A negative result appears yellow.
The Indoletest is a key test for separating Proteus mirabilis
(indole-negative) and Proteus vulgaris (indole-positive) and
Klebsiella pneumoniae (indole negative) and K. pneumoniae oxytoca
(indole-positive).
No
MacConkey: MacConkey agar is a selective medium
that inhibits the growth of Gram-positive bacteria due to the presence
of crystal violet and bile salts. Most Gram-negative bacteria grow well
on MacConkey. MacConkey agar also contains neutral red (a pH indicator)
and lactose (a disaccharide). Lactose fermenting bacteria or Lactose +
bacteria on MacConkey will appear as bright pink colonies. Non-lactose
fermenting bacteria will be colorless (or, if they have any color, will
be their natural color rather than pink).
Gram stain: The Gram stain, is a
laboratory staining technique that distinguishes between two groups of
bacteria that have differences in the structure of their cell walls.
Standard bacterial taxonomy makes a distinction between Gram-negative
bacteria, which stain red/pink and the Gram-positive bacteria, which
stain blue/purple. Different antimicrobial agents are directed
specifically at gram-positive bacteria and gram-negative bacteria.
Oxidase: The oxidase test is used to determine
if a bacterium produces certain cytochrome c oxidases. The reagent,
tetramethyl-p-phenylenediamine is used as a redox indicator. The
reagent turns dark blue when oxidized (oxidase positive). The reagent is
colorless when reduced (oxidase-negative). Pseudomonas species
and Aeromonas species are gram-negative bacilli that are oxidase-positive.
Neisseria species are gram-negative cocci that are oxidase
positive.
MacConkey: MacConkey agar is a selective medium
that inhibits the growth of Gram-positive bacteria due to the presence
of crystal violet and bile salts. Most Gram-negative bacteria grow well
on MacConkey. MacConkey agar also contains neutral red (a pH indicator)
and lactose (a disaccharide). Lactose fermenting bacteria or Lactose +
bacteria on MacConkey will appear as bright pink colonies. Non-lactose
fermenting bacteria will be colorless (or, if they have any color, will
be their natural color rather than pink).
Indoletest: The indole test is a
biochemical test performed on bacterial species to determine the ability
of the organism to split indole form the amino acid tryptophan. The
results of an indole test are indicated by a change in color following a
reaction after the addition of Kovacs reagent. A positive result is
shown by the presence of a red color. A negative result appears yellow.
The Indoletest is a key test for separating Proteus mirabilis
(indole-negative) and Proteus vulgaris (indole-positive) and
Klebsiella pneumoniae (indole negative) and K. pneumoniae oxytoca
(indole-positive).
MacConkey: MacConkey agar is a selective medium
that inhibits the growth of Gram-positive bacteria due to the presence
of crystal violet and bile salts. Most Gram-negative bacteria grow well
on MacConkey. MacConkey agar also contains neutral red (a pH indicator)
and lactose (a disaccharide). Lactose fermenting bacteria or Lactose +
bacteria on MacConkey will appear as bright pink colonies. Non-lactose
fermenting bacteria will be colorless (or, if they have any color, will
be their natural color rather than pink).
