microbial growth and control Flashcards

Question

Describe columbia CNA ager

Answer 1

red in color enriched, selective and differential media contains antimicrobial agents colistin and nalidixic acid: suppress growth of gram - used to isolate gram(+) microbe similar to BAP, enriched allow for differential based on hemolytic activity

Answer 2

enriched, non-selective, non-differential derivative of blood agar plate contain RBC lysed by heat cooking of RBC gives media chocolate color Lysed RBC give nutrient to cultivate fastidious pathogenic bacteria example: gram (-) Haemophilus influenzae and Neisseria meningitidis.

Answer 3

``` pale red in color selective and differential media presence of crystal violet and bile salt restrict gram (+) growth only gram (-) grown ```

Answer 4

to differentiate between lactose fermentors and non ferment if ferments lactose turn red if does not ferment lactose is white

Answer 5

changes due to microbe consumption of nutrients

Answer 6

yellow: pH bigger than 8.0- non ferment microbe | pink/dark red: pH less than 6.8 ferments lactose

Answer 7

Gram negative Escherichia coli: ferment lactose: pink colonies Enterobacteriacea: salmonella, shigella- used to isolate intestinal pathogenic microbes such as above

Answer 8

varient of MacConkey formulated to detect presence of pathogenic strain of escherichia coli under standard gut condition Escherichia coli able to ferment lactose and sorbitol E-coli 0157 ferment sorbitol use sorbitol to differentiate strain escherichia coli- red, acidic from pathogenic 0157: white colony

Answer 9

red in color selective and differential contain Eosin and methylene blue restrict growth of gram (+) bacteria microbe different based on ability to ferment lactose in media non ferment lactose grow white lactose ferment grow dark( purpler/black) if escherichia coli grown on EMB agar plate colonies have distinctive metallic green

Answer 10

red in color selective and differential selective for gram (+) bacteria differentiate members of staphylococci contain high concentration of sodium chloride- prevent growth of orther microorganism( selectivity) presence of alternate sugar( mannitol) hype phenol red differential for pathogenic and non-pathogenic strain of staph

Answer 11

ability to ferment mannitol so in mannitol salt ager, lowers pH of medium and change dye from red to yellow

Answer 12

process of spread bacteria culture onto petri dish filled with agar done using sterile loop motion: back and forth sweeping

Answer 13

bacterial sample onto agar cells held in place bacteria that's plated are fixed to support fermentation and visualization colonies are visible to naked eye only after cells multiplied often over 1 million

Answer 14

culture free of outside contaminate

Answer 15

isolate microbe on agar plate: either quadrant streak or 4-phase dilution once isolated and expanded, pure culture further examined for size, shape, motility, gram status and biochemical properties

Answer 16

sample spread across plate to establish dilution gradiant sample spread onto 4 regions spread sample then with clean loop dip into end of previous phase and create new streaks when all finished should be diluted results should be individual colonies in 4 phase

Answer 17

invert plate and incubate 12-14 hours at 37 degrees celsius

Answer 18

best to encourage growth of bacteria

Answer 19

each region is examined in the 4 phase or 4 quadrant | for changes in color, colonies or signs that selective or differentiation between bacteria

Answer 20

for yeast growth

Answer 21

restrict growth of pathogenic bacteria

microbial growth and control Flashcards

(45 cards)