Need help Identifying an unknown

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Joined: Sun Apr 22, 2012 8:21 pm

Need help Identifying an unknown

Post by stks7rafe » Sun Apr 22, 2012 8:22 pm

Hey guys, I have a to identify an unknown for my lab class and I have no idea how to figure this all out. Hopefully someone here can help.

Here is what I have so far:

Gram Negative short rod

Indole: +
Methyl Red: -
V-P: -
Nitrate Reduction: -
Urease: +

Spirit Blue agar: -
Milk agar?: -
Starch test: -

Pictures of my results (names of tests or written above):

The tests for each of the liquid cultures (from right to left)
MR-VP (methyl red test)
(There are some other vials but those belonged to my lab mate)

MAC (if it isnt working for you in the link)

Catylase: +
Oxidase: +

The microbe is one of the following:

Bacillus subtilis
Pseudomonas aeruginosa
Staphylococcus aureus
Proteus vulgaris
Enterococcus faecalis
Escherichia coli
Bacillus megaterium
Enterobacter aerogenes
Staphylococcus epidermidis

Keep in mind i'm just a lowly microbiology student so my results might be off (I know my streaking is pretty bad) so the results might not be truly indicative of my unknown

ANY help is welcome and greatly appreciated

Thanks guys!

Posts: 424
Joined: Mon Nov 17, 2008 12:12 am

Post by JorgeLobo » Mon Apr 23, 2012 12:01 pm

You're not reading descriptions or your instructions have failed entirely to provide hierarchy of testing.
Suggest you start by culling the names, eliminating those not meeting reported Gram stain and Oxidase reactions.
If you unknown is imited to those offered - there is only one that fits these 2 observations.

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