Culture Media and its Preparation page 2 Flashcards
(20 cards)
an enriched medium meaning that it provides extra rich nutrient environment for the microbes; is also differential as microbiologist can differentiate clinically significant bacteria in throat and sputum on blood agar as a result of hemolysis patterns
blood agar
blood agar contains how many percent of sheep blood?
5%
extra-cellular bacteria that act on red blood cells
hemolysins
hemolysins act on red cells to lyse them completely
beta hemolysis
produce a greenish discoloration around the colony indicating incomplete hemolysis
alpha hemolysis
what color is the discoloration indicating incomplete hemolysis?
greenish discoloration
hemolysins have no effect on red cells
gamma hemolysis
Blood agar is usually inoculated on a patients _________
throat swab
In hemolysis, what are microbiologists trying to detect?
presence of Group A beta hemolytic streptococci
a gram positive cocci that causes beta hemolysis on blood agar
Group A beta hemolytic streptococci
major human pathogen in Group A beta hemolytic streptococci which is the causative agent of strep throat
streptococcus pyogenes
What does normal throat flora exhibit?
alpha or gamma hemolysis
selective medium because it has high concentration of NaCl
Mannitol Salt Agar
What genus grows well in Mannitol Salt agar?
Staphylococcus
is also differential as it contains a dye that identifies Staphylococcus as it produces an organic acid from mannitol fermentation and changes the pH indicator from red to yellow
Mannitol Salt Agar
nutrient blend used to support microbial growth
medium
three physical forms of media
broth
solid
semi solid
What type of media is more versatile in usage?
solid
microorganisms are grown and sub-cultured on different types of chemical media
chemically defined or synthetic
complex or nonsynthetic
what are the different sterilization methods?
autoclaving
dry-heat
filtration
UV exposure
ethylene oxide
