Bacte Final Quiz Flashcards
needs are relatively complex, and exceptional media components must be used for growth
Fastidious
basic and straightforward needs
Nonfastidious
Artificial environment where needs of bacterial organisms are met to proliferate and grow
Media
Phases of growth media
Broth, Agar, Semi-solid
nutrients are dissolved in water
Broth media
bacterial growth is indicated by turbidity
Broth Media
Most common solidifying agent
Agarose
Agarose melts at what temp?
95 C
Agarose solidify after temp. falls below?
50 C
Agarose cool around?
55-60 C
used to observe and detect the motility of bacteria
Semi-solid
provides an indication of the type of organism present based on oxygen requirement
Semi-solid
used to enhance growth of a particular bacteria by
providing specific nutrients required
Ex. BYCE (Buffered charcoal-yeast extract agar )- contains L-cysteine for Legionella pneumophila
Enrichment media
supports growth if most non-fastidious organism Ex. Tryptic soy agar, nutrient agar
Nutritive media
contain inhibitory agents against a specific bacteria, while allowing only a “selected” bacteria to grow
Selective media
allows bacteria to exhibit metabolic/culture characteristics that can be distinguished
Differential media
Broth/agar
Brain heart infusion
● Purpose: Cultivation of fastidious organisms
● Components: Dextrose, pork brain, and heart
dehydrated infusions
Brain Heart Infusion
Purpose: Cultivation of fastidious microorganisms such as Haemophilus spp., Brucella spp. and pathogenic Neisseria spp.
Chocolate Agar
Components: Peptone base, enriched solution of hemoglobin ( hemin “X” factor and Nicotinamide adenine
dinucleotide NAD “V” factor)
Chocolate Agar
Purpose: Selective isolation of gram-positive cocci
Columbia CNA with Blood
Components: Peptones sources , 5% defibrinated sheep blood
- Colistin ( C ) - disrupts GN cell membrane
- Nalidixic acid (NA) - blocks DNA replication
Columbia CNA with Blood
Purpose: Selective (enrichment) liquid medium for enteric pathogens
GN Broth
Components:
- Mannitol - primary carbon source
- Sodium citrate and Sodium deoxycholate
- bile salts that inhibit GP organisms
- Peptone base broth with Glucose
GN Broth
Purpose: Differential, selective medium for the isolation and differentiation of Salmonella and Shigella spp. from other gram-negative enteric bacilli
● Components: Peptone-base agar with bile salts, lactose, sucrose, agar salicin, and ferric ammonium citrate; indicators include bromthymol blue and acid fuchsin
Hektoen Enteric Agar
Purpose: Isolation and differentiation of lactose fermenting and non–lactose- fermenting enteric bacilli
Macconkey Agar
Components: Peptone base with lactose; gram-positive organisms inhibited by crystal violet and bile salts; neutral red as indicator
* * Lactose Fermenters, Non-lactose fermenters, Slow Fermenters
Macconkey Agar
Purpose: Selective isolation of aerobic gram-positive cocci and bacilli
PhenylEthyl Alcohol Agar
Components:
- Nutrient Agar Base
- Phenylethyl Alcohol (inhibits GN)
- 5% Sheep Blood
PhenylEthyl Alcohol Agar
Purpose: Cultivation of non-fastidious microorganism, determination of hemolytic reactions
Sheep Blood Agar
Components:
- Trypticase soy agar
- Brucella agar or Beef Heart Infusion
- 5% Sheep Blood
Sheep Blood Agar
Purpose: Selective for N.gonorrohoeae and N.meningitidis. Supports the growth of Francisella and Brucella spp.
MODIFIED THAYER-THAYER MARTIN AGAR
Components: Blood agar based enriched with hemoglobin and supplement B
- Colistin = inhibit GN
- Vancomycin = inhibit GP
- Nystatin = inhibit yeast
- Trimethoprim = inhibit Proteus spp.
MODIFIED THAYER-THAYER MARTIN AGAR
Purpose: Enrichment broth or semi-solid, supports growth of anaerobes, aerobes, microaerophilic, and fastidious microorganism
THIOGLYCOLLATE BROTH
Components:
- Pancreatic digest of casein
- Soy broth
- Glucose
THIOGLYCOLLATE BROTH
Purpose: Isolation and differentiation of Salmonella and Shigella spp. from other gram negative enteric bacilli
● Components: Yeast extract agar w/ lysine, xylose, lactose & sucrose
- Sodium deoxycholate = inhibits GN
- Phenol Red = pH indicator
- Ferric ammonium citrate = H2s indicator
XYLOSE-LYSINE-DEOXYCHOLATE (XLD) AGA
Nutrient agar base with ferric citrate. Hydrolysis of esculin by group D streptococci imparts a brown color to medium; sodium deoxycholate inhibits many bacteria.
Bile esculin agar (BEA)
