Laboratory Diagnosis of Enterobacteriaceae Flashcards
Yersinia spp. bipolar appearance, closed safety pin appearance.
Wayson stain or Methylene Blue stain
Blue rod with prominent polar granules, giving rise to the safety-pin appearance,surrounded by a large, pink capsule.
[microscopic examination]
Donovan Body
Used as enrichment for the isolation of Shigella and other Enterobacteriaceae.
[culture media]
Gram-negative broth (GN) or Selenite broth (SEL)
Medium specifically used for the isolation of Y. enterocolitica from gastrointestinal specimens.
[culture media]
Cefsulodin-irgasan-novobiocin (CIN) agar
It is used to differentiate sorbitolnegative E. coli O157:H7 from other strains of E. coli that are capable of fermenting this sugar alcohol.
[culture media]
MacConkeysorbitol agar (MAC-SOR)
Broth cultures of Y. pestis exhibit a characteristic ____ in which clumps of cells adhere to one side of the tube.
Stalactite pattern
Colonies of Y. pestis on 5% sheep blood agar are ____ at 24 hours but exhibit a ___, ____ appearance at 48 hours.
pinpoint, rough, cauliflower
Production of hydrogen sulfide (H2S); ferrous sulfate. Salmonella spp. Positive reactions appear as brown to black precipitate.
[isolation of salmonella spp. and shigella spp.]
Bismuth sulfite agar
Positive reactions of Bimuth Sulfite Agar.
[color]
brown to black
Salmonella spp. appear as white to pink or red colonies surrounded by a bright halo.
[isolation of salmonella spp. and shigella spp.]
Brilliant green agar
Appear colorless.
[shigella, salmonella]
Shigella spp.
Colorless with a black center.
[shigella, salmonella]
Salmonella spp.
Selective enrichment for the growth of Salmonella spp.
Selenite broth
Colorless to red with black center. (Xylose-lysinedeoxychocolate agar)
[shigella, salmonella]
Salmonella spp.
Colorless to red. (Xylose-lysinedeoxychocolate agar)
[shigella, salmonella]
Shigella spp.
Lactose fermenter, forms blueblack with a metallic green sheen.
[Eosin/Methylene blue agar (EMB]
Escherichia coli
form pink colonies.
[Eosin/Methylene blue agar (EMB]
Other coliform fermenters
Translucent, either amber or colorless.
[Eosin/Methylene blue agar (EMB]
Nonfermenters
TSI means
Triple Sugar Iron agar
[3] Sugar in TSI agar
Glucose
Lactose
Sucrose
acidic (yellow) resulting from the fermentation of glucose under anaerobic conditions.
[TSI]
Butt
lactose and/or sucrose are fermented:
[TSI]
Siant
[3] Quality Control
- A/A
- K/A H2S+
- K/NC
A/A
[quality control]
Escherichia coli