Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/27

Click to flip

27 Cards in this Set

  • Front
  • Back
How are all Listeria species the same? How are they differentiated?
All Listeria Species:
1) Catalase +
2) Lack Oxidase
3) Hydrolyze Esculin

Differentiate:
1) Carbohydrate Fermentation
2) Blood Hemolysis
What color is seen with Listeria mono. on TSAYE agar?
blue green incandescense
What are characteristics of Listeria monocytogenes?
B-Hemolysis, homofermentative: glucose --> lactate, acetate, acetoin, ferments rhamnose
Describe the enrichment phase for Listeria, what is different from usual?
Two phased enrichment with preliminary enrichment in a marginally selective broth, followed by enrichment in a more selective broth
What are the selective ingredients in UVM1 broth. What is it used for?
It is used for preliminary enrichment of Listeria. The selective agents are Nalidixic acid (inhibits gm-) and acriflavin (inhibits gm+). Repairs injured cells.
What are selective ingredients of Fraser broth? Differential Agents? What is it used for?
Listeria monocytogenes selective enrichment (2nd step). Selective ingredients are acriflavin, nalidixic acid, LiCl (inhibits growh of enterococci, promotes salt tolerent org's like Listeria). Differential agents are esculin and ferric ammonium citrate. Broth will darken due to hydrolysis of these.
What is MOX agar used for? What are selective, differential ingredients? What will colonies look like?
Used for Isolation of L.mono. Selective ingredients are LiCl, colistin sulfate, moxalactam. Differential ingredients are esculin and ferric ammonium citrate. Colonies will have black precip.
What is PALCAM agar used for? What are selective and differential ingredients? What will colonies look like?
Use for isolation of Lmono. Selective: LiCl, polymyxin, acriflavine and ceftazidime. Differential: esculin-ferric ammonium citrate and mannitol-phenol red combos. Hydrolysis of esculin by Lmono will change media color to black; mannitol fermenting bacteria (enterococci) turn media yellow.
WHat is TSA-Blood agar used for? What are ingredients in this agar? What types of microbes are grown in it?
It is used to grow fastidious micro-o like Listeria. It is made of 2% yeast extract (nonselecitve) and 5% sheep blood. Listeria produces B-hemolysis when exposed to this medium, with brown zones around inoculation points.
What is TSAYE agar used for in the Listeria test?
It is a nonselective medium that is used to grow the organism with a clear background so you can see the irridescent blue-green colonies
What are characteristics of Listeria?
Catalase +, Hydrolyze esculin, lack oxidase
How are species of Listeria told apart? How is L. mono told apart?
by carbo fermentation (xylose, rhamnose and mannitol) and blood hemolysis. listeria mono ferments rhamnose and B-hemolysis of blood
When is a CAMP test used for Listeria?
When the hemolysis stabs are questionable in the TSA-Blood agar. Confirmatory test. B-Hemolytic strains will show enhancement with one another (S.aureus and L.monocytogenes).
How does the VIP test work?
Antibodies specific for Listeria antigen-->bind-->antibodies specific for antigen bind in a sandwich style---> bind to nonspecific antibodes TWO LINES INDICATE POSITIVE
How does the ENVIROPATH turn black?
It has indicators that indicate the B-gluconidase enzyme produced by Listeria. Turns the medium from yellow to black.
How does GeneQuence work for Salmonella?
Mother cell is lysed and denatured through heating process. PolydT is stuck to wall of microwell. You add complimentary strands of RNA that bind with the polydT, called the dA-dT complex. The dA has a capture probe that is specific for the Salmonella sequence. If salmonella is there, then it will bind to the dA complex. You add a detector probe that will also bind to salmonella and then add a substrate to change the color of the medium.
What are characteristics of Salmonella?
gram -, oxidase negative, ferment glucose (not sucrose or lactose) and produce acid and gas, use citrate as energy, decarboxylate lysine and ornithine, produce H2S, do not hydrolyze urea.
What type of medium is BS agar what is it used for and what are selective/differential ingredients?
salmonella, selective-differential. used for isolation
selective: brilliant green, bismuth sulfite

differential: sulfite (produces black colonies from desulfhydrase enzyme)
What type of medium is Hektoen Enteric agar what is it used for and what are selective/differential ingredients?
salmonella, isolation, selective-differential

Selective: Bile salts, bromothymol blue, acid fucshin (inh gm+)

Differential: Acid fuschin, bromothymol blue (acid productin from fermentation of sugars)
What type of medium is Lactose broth what is it used for and what are selective/differential/nonselective ingredients?
salmonella, nonselective. lactose in medium recovers injured cells
What type of medium is Lysine Iron Agar what is it used for and what are selective/differential ingredients?
SALMONELLA, DIFFERENTIAL, BIOCHEM IDENT

DIFFERENTIAL: GLUCOSE (FERM PRODUCES ACID, CHGS COLOR OF MEDIUM), LYSINE (DECARBOXYLATION PRODUCES ALKALINE CONDITIONS), BROMCRESOL PURPLE, SODIUM THIOSULFATE (Black precip)
What type of medium is Selenite Cystine Broth what is it used for and what are selective/differential ingredients?
salmonella, selective, enrichment.

selective: sodium acid selenite
What type of medium is tetrathionate broth (TT) what is it used for and what are selective/differential ingredients?
salmonella, selective, enrichment.

selective: sodium thiosulfate (Iodine in medium catalyzes conversion of this to tetrathionate. Salmonella has enzyme tetra... reductase that detoxifies this substance)
What type of medium is triple sugar iron (TSI) agar what is it used for and what are selective/differential ingredients?
salmonella, differential, biochem ident.

differential: phenol red (detects acid production from glucose ferm), sodium thiosulfate (balck colonies)
What type of medium is Xylose Lysine Desoxycholate agar what is it used for and what are selective/differential ingredients?
salmonella, selective-differential, isolation.

selective: desoxycholate (inh nonenterics)

differential: ferric ammonium citrate, sodium thiosulfate, phenol red
What type of medium is mEC broth what is it used for and what are selective/differential ingredients?
ecoli, selective, enruchment.

selective: novobiocin
What type of medium is Sorbitol McConkey Agar (SMAC) agar what is it used for and what are selective/differential ingredients?
ecoli, selective, isolation

selective: cefixime, potassium tellurite