Bacteria Agars and visual identification Flashcards
What medium / media can be used to isolate 0157, Shiga toxin producing E. coli (STEC) strain?
Sorbitol MacConkey agar
Doing campylobacter plates your manager forgets to order more plates. What alternative can you use instead of campylobacter blood agar?
Hektoen enteric (HE) agar or HEA
What media is used to isolate vibrio cholerae?
Bile salt agar or TCBS, thiosulphate citrate bile salts sucrose agar
What media is selective for enterococcus species?
Bile esculin agar - contains 40% bile
What media allows bacteria to demonstrate their hemolytic properties?
Blood agar
Staphylococcus aureus: ß-Hemolytic;
Streptococcus pneumonia and S viridans: a-Hemolytic;
Enterococcus: Non-Hemolytic
What media is used to isolate bordetella pertussis?
Bordet - Gengou Agar
Charcoal Blood Agar
Regan - Lowe Medium
Note: Charcoal important in these agars to neutralize fatty acids and peroxide which are toxic to bordetella
What media is used to isolate Legionella?
Buffered charcoal yeast agar (BCYA)
What media is used for isolate of clostridium difficile?
Cefoxitin cycloserine Fructose agar (CCFA) or Cefoxitin cycloserine Egg Yolk Agar
What media is used to isolate Yersinia?
CIN, Cefsulodin - Irgasan - Novobiocin medium
Note: It can be used to isolate Aeromonas too!
CNA, Columbia - Colistin Nalidixic acid agar will isolate what kind of bacterias?
Gram positive cocci
What media isolates streptococcus pyogenes?
Crystal violet blood agar
What media is used to detect lipase and lecithinase activity in a bacterias from the clostridium genus?
Egg yolk agar
Chocolate agar is useful for what kind of bacterias?
fastidious organisms such as hemophilus (X/V factor requirements), Neisseria gonorrhoeae, and S. pneumoniae
What media is used to grow corynebacterium?
Loeffler slant. It stimulates metachromatic granules in Corynebacterium diphtheriae
What two medias are selective for mycobacterium?
Lowenstein-Jensen medium, middlebrook 7H10 agar, and Petragnani agar
What media is useful for differentiating enterobacteriaceae?
MacConkey Agar -> Lactose fermenters and non-lactose fermenters. All members of the family ferment glucose.
List media that are useful for differentiating Salmonella and Shigella from stool specimens?
MacConkey Bile Salt Lactose Agar (Not sure if we need to know)
Hektoen Enteric (HE) agar -> (Shigella flexneri are green / transparent colonies. Salmonella will be black colonies)
Salmonella - Shigella (SS) agar
What media is selective and indicator for S. aureus?
Mannitol salt agar
What is the agar of choice for antimicrobial susceptibility for bacteria?
Mueller - Hinton Agar
What is the media of choice for isolating campylobacter?
Skirrow’s Campylobacter medium
Campy Blood Agar
HE agar (alternative)
Selenite F broth is useful for isolating what kind of bacterias from stool samples?
Shigella and Salmonella
What media is useful for isolating Neisseria gonorrhoeae and Neisseria meningitidis?
Thayer - Martin Medium. It contains vancomycin, colistin, and nystatin
What would vibrio cholerae colonies look like on TCBS agar?
Yellow colonies would be vibrio cholerae. Vibrio parahaemolyticus would be green colonies. V. cholerae is able to ferment sucrose turning bromthymol (dye) from blue to yellow.
What would lactose fermenters and nonfermenters look like on MacConkey agar?
Lactose fermenters would be pink while non lactose fermenters would be clear or yellow.
On Hektoen enteric agar, what would salmonella and shigella look like?
Salmonella - black colonies (made so by production of H2S)
Shigella - Green colonies b/c of peptone metabolism increasing the pH (media color turns blue)
Other bacterias will be orange colonies (not shigella or salmonella) due to lactose fermentation. These orange colonies could be E. coli, K. pneumonia, and yersinia enterocolitica.
What does calcofluor stain target in fungi?
Chitin and cellulose.
What media is used to grow Francisella tularensis?
Cystine - Glucose Agar
What bacteria is isolated with skirrow agar?
Helicobacter pylori
What bacteria is isolated with cystine tellurite blood (tinsdale) agar and loeffler’s medium?
Corynebacterium diphtheriae
What is the difference in bacteria culture between cystine tellurite blood (tinsdale) and loeffler’s medium?
Loeffler’s medium enhances metachromatic granule formation. On Cystine tellurite blood agar the C. diphtheriae colonies will be black. Not sure what colony growth is like on tinsdale agar.
What kind of bacteria is isolated from BBE agar?
Bacteroides fragilis group -> black colonies
KVLB agar is used to isolate what bacteria?
Bacteroides species. The agar enhances pigment production.
CCFA agar or cycloserine - cefoxitin fructose agar is used to isolate what bacteria?
Clostridium difficle
CDC anaerobic blood agar is enriched with what kind of nutrients for anaerobes?
Hemin, cystine, and vitamin K
