Introduction to Microbiology Techniques Flashcards
What is a defined media?
Media where all ingredients AND their amounts are known.
What is another name for a Primary media, what does it do and what are examples?
Non selective media, supports large number of organisms. Sheep Blood agar, Trypticase soy
What is selective media and what is an example?
Inhibits some organisms, CNA
What is differential media and what is an example?
Indicators of biochemical reactions, MAC
What are some examples of combination medias?
MAC, XLD, HEK
What are enrichment medias? Examples?
Allows for more growth than primary media, Chocolate. Often incubated in CO2 for fastidious organisms.
What are maintenance medias? What can be grown on them?
Allows for extended growth time (limits sugars or adds extra buffer) Salmonella and E. Coli.
What do Dyes inhibit?
Gram pos
What are some selective agents and what do they inhibit?
Heavy Metals (ex: Bismuth sulfite for Salmonella*) Antimicrobials Sodium desoxycholate (bile salts) inhibits GP Phenylethyl alcohol= inhibits GN Azide= Inhibits GN NaCl = Only allows Staphylococcus
What type of media is SBA?
Primary
What type of media is Trypticase Soy?
Primary
What type of media is CNA?
Selective
What type of media is MAC? Selective for? Colors?
Selective and differential; selective for Gram (-), dark pink = pos= uses lactose Clear = (bright pink)= neg= does not use lactose
What are specimens from normally sterile areas place on?
Enrichment (chocolate)
What things are taken into account when selecting a media?
Type of specimen
What condition is suspected
Results of preliminary exam of specimen
What type of Media is XLD? selective for? Colors?
Selective Isolation and Selective differential media; Selects Gram (-) via bile salts; CHO (+)= Yellow, CHO (-) = Clear/red H2S = Black
What type of media is HEK?
Hektoen; Selective Isolation and Selective differential media Selects Gram (-) via bile saltsCHO (+)= orange, CHO (-) = Clear/gree H2S = Black
What type of media is EMB?
Selective Isolation and Selective differential media Selects Gram (-) Ecoli = metallic green
What type of media is bismuth sulfide?
Heavy metals; Selective FOR Gram (-)
What type of media is thoglycollate?
liquid; anaerobes grow lower
What media type is Brain Heart infusion?
Primary
What media type is Martian lewis or Thayer Martian? What grows on it?
Selective enrichment agar for fastidious, inhibits usually flora for Neisseria gonorrhoea
What are the three levels of hemolysis?
Alpha = Partial and Green Beta = Complete Gamma = no hemolysis
What is the most commonly used disinfectant used on non metallic surfaces?
10% Bleach
What is the standard temperature, PSI, and time for autoclave?
121 Degrees C, 15PSI, 15-20min
What is Obligate anaerobe
Requires O2
What is it called when an organism requires little O2?
Microareophilie
What is a facultative anaerobe?
Grows best with O2 but can grow without O2
What is Ambient Air and its Element amounts?
Room air, non-CO2, O2=21% CO2= .03%
What are CO2 incubator element amounts? What kind of incubator is it?
O2= 15% CO2= 5-10%; aerobic
What are Microareophilic incubator elements?
O2= 5% CO2= 10%
What are anaerobic incubator elements?
O2=0% CO2= 5-10% (rest is N)
What goes in ambient air incubation?
Biochemicals, differential media, Antimicrobial susceptibility
What goes in CO2 incubation?
Primary plates and fastidious organisms
What is a direct smear?
Specimen is plated directly on slide and then gram stained provides initial clue to cause of infection
What are two stains that require fluorescent microscope readings?
Acid fast, Acridine orange, and Calcofluor white
What is the most important characters for making the diagnosis of “gangrene” based on a direct smear?
Necrotic Background and absence of intact cells
What method is MALDI-TOF?
Rapid method
