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* Is B. cereus oxidase positive?
  adair - 06/12/18 18:06
  Hi there!

Thank you in advance for your help.

I am trying to identify an unknown for a microbiology class, and have it narrowed down. But I need to know a few things before I can confirm. Is Bacillus cereus oxidase positive or negative? Also, what is its typical MR-VP result?

I don't know if I have B. cereus or P. aeroginosa. My lab partner did the gram-staining, and isn't confident in his skills. It looked gram negative. However, the colony morphology looks like B. cereus -- grey, feathery edges, wide-spreading, rough -- but, there was no B hemolysis.

No growth on mannitol, Pink on MacConkey (wouldn't P. aeroginosa be clear? It doesn't ferment lactose.). Or is the simple fact that it grew at all on MacConkey and EMB indicative of a gram-negative, and therefore P. aeroginosa?

Sorry if this is scattered...late night!

Thank you!
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* Re:Is B. cereus oxidase positive?
  raza2001 - 06/12/18 22:58
  hi Dr

Bacillus Cereus 1- catalase +ve 2-citrate +ve 3-gram staining +ve 4- growth in KCN +ve 4-hemolysis +

5-Motility+ve 6-spor+ve 7- VP(voges proskauer)+ve

1-Gelatin Hydrolysis-ve 2-indole-ve 3- MR(Methyl Red-ve 4-Oxidase-ve 5-Pigment-ve

nitrate Reduction Variable Fermentation of
Adonitol Negative (-ve)
Arabinose Negative (-ve)
Arabitol Negative (-ve)
Cellobiose Variable
Fructose Positive (+ve)
Galactose Negative (-ve)
Glucose Positive (+ve)
Glycerol Positive (+ve)
Glycogen Positive (+ve)
Inositol Negative (-ve)
Inulin Negative (-ve)
Lactose Negative (-ve)
Maltose Positive (+ve)
Mannitol Negative (-ve)
Mannose Negative (-ve)
Melibiose Negative (-ve)
Raffinose Negative (-ve)
Rhamnose Negative (-ve)
Ribose Positive (+ve)
Salicin Variable
Sorbitol Negative (-ve)
Starch Positive (+ve)
Sucrose Variable
Trehalose Positive (+ve)
Xylose Negative (-ve)
Enzymatic Reactions
Acetate Utilization Variable
Arginine Dehydrolase Variable
Casein Hydrolysis Positive (+ve)
Esculin Hydrolysis Positive (+ve)
Lecithinase Positive (+ve)
Lysine Negative (-ve)
Ornithine Decarboxylase Negative (-ve)
Phenylalanine Deaminase Negative (-ve)
Tyrosine Hydrolysis Positive (+ve)
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