Lesson 6 Flashcards
Are growth of microorganism on a culture medium
Cultures
Is a liquid, semi-solid or solid medium utilized to observe growth patterns of microorganism as well as for transport and storage.
Culture Medium
Culture composed of only one specie
Pure Culture
Culture composed of more than one specie
Mixed Culture
– Is composed of several species
contained in a separate culture
medium (one species/culture
medium).
– It is used for academic and
industrial purposes.
Stock Culture
Colonies may be described as being
large, medium, small, or pinpoint.
Size
Refers to the edge of colonies
Form or Margin
■ Determined by tilting culture plate and looking at the
side of the colony
■ Raised, convex, flat, umbilicate, or umbonate
Elevation
May be described as transparent, translucent, opaque.
Density
Used to describe a particular colony genus in genera
Color
Determined by touching a colony with a sterile loop
Consistency
Inherent characteristic of specific organisms
Pigment
What is the distinctive odor of staphylococcus aureus?
Old Sock
Vinelike growth in media
Streamers
Overall cloudiness of liquid
Turbidity
It contains 0% agar
Liquid Medium
It contains 0.5 to 1% agar
Semi-Solid Medium
It contains 2-3% agar
Solid Medium
Agar will melt at what temperature?
80 to 90°C
Agar will solidify at what temperature?
40 to 50°C
Cooling temp for distribution of agar into plates
55-60°C
• It is a medium where all the
components are known to the
user.
• It is use for research purposes.
Synthetic or Defined Medium
• It is composed of some unknown
substances (peptones, meat and
yeast extracts).
• It is very useful for isolation of
bacteria.
• examples: nutrient broth, TSB
and MacConkey agar
Non-Synthetic or Complex Medium
• It used for obligate intracellular
bacteria (Rickettsia, Chlamydia).
• Examples: W138, HELA 229 cells
and Mc Coy cells
Tissue Culture Medium
Are routinely used in the laboratory and without added supplement
- Simple Media/General Purpose Media/Supportive Media
■ It is used to propagate the growth of certain group of organisms.
■ They contain specific nutrients; liquid-type media.
■ It can also be used as supplement to agar plates.
■ Examples: Alkaline Peptone Water, Selenite F, Thioglycolate, tetrathionate, Gram- negative (GN)
broth, Lim broth (group B streptococci)
Enrichment Broth
■ These are media with added supplements such as blood, vitamins and yeast extract, necessary
for the growth of fastidious organisms.
■ These are solid-type media
Enriched Media/Nonselective Media
Standard nonselective culture medium
BAP
Has horse blood is used for the isolation of Hemophilus
CAP
These are media that allow visualization of
metabolic differences between groups of
bacteria.
■ Examples: MacConkey, BAP, EMB, and HEA
Differential Media
“Greenish” zone of hemolysis
ALPHA
“Clear” zone of hemolysis
Beta
Means No Hemolysis
Gamma
These are media incorporated with antibiotics, dyes or chemicals to
inhibit the growth of other organisms while promoting the growth of
the desired organism.
Selective Media
contains bile salt and dyes (acid fuchsin)
for non-enteric pathogens; it inhibits the normal
flora of the lower GIT.
HE Agar
It contains 0.25% Sodium Deoxycholate salt and sodium thiosulfate to differentiate Salmonella (red with black centers) from Shigella (red or clear colonies).
XLD Agar
Inhibitory to Gram-positive Bacteria
- Crystal/Gentian Violet
- Basic Fuchsin
- Bile Salt
Inhibitory to Gram-negative Bacteria
- Potassium Tellurite
- Sodium Azide
Inhibitory to Swarming Bacteria
- Alcohol
- Chloral Hydrate
Is used to isolate bacteria with specific growth requirements.
Special Media
