Need Microbiology help- unknown bacteria

[Hamm]

I am hoping someone here can help. I have a problem. Either I did my SIM wrong (likely) or my capsule stain wrong (pretty unlikely).

What happened with the SIM was that I read the directions wrong. I stab inoculated it 3 times instead of once. I am not sure if I throw out the results completely or what. If I do, I know I have Citrobacter. If I don't, I would know I have Klebsiella. Only problem is that would mean my capsule stain was wrong because it was negative. I am not sure how I could have screwed that up.

Here's what I have:

Gram negative rod

MacConkey neg or undetermined (colony was cream/slightly pink)

Citrate positive

SIM negative, all of it. Possibly screwed this up

Deaminase negative

Glucose positive +CO2

Lactose positive +CO2

Capsule stain negative (again, could have messed it up, not sure how)

Possible unknowns:

Serratia

Streptococcus faecalis

Shigella

Salmonella

Klebsiella

Staphylococcus aureus

Enterobacter

Proteus vulgaris

Citrobacter

E. coli

Staphylococcus epidermis

Any insight appreciated

[mommajoz]

I would do the SIM test again. You may have fried your bacteria if you didnt wait long enough for the stabbing needle to cool. That happened to many people in my class.

You might run your stain again too. My class did two separate stains because of the high risk of messing it up. Your stain could have been messed up during the decolorizing step, or when you heat fixed your slide before the staining process.

We just finished the unknown bacteria in my micro class. I loved it!!

[Hamm]

That's the problem, we only had two lab days to do our tests. One day to do them and the next week was viewing the results. It wasn't possible to do the SIM test again and by the time I figured out I had a problem, after I was doing my report, doing any other tests was not an option.

[anonymousstudent]

if it's gram negative, you can rule out

serratia

streptococcus faecalis

shigella

salmonella

klebsiella

staphylococcus aureus

enterobacter

proteus vulgaris

citrobacter

e. coli

staphylococcus epidermis

if you had a positive on lactose + gas, r/o

serratia

shigella

salmonella

klebsiella

enterobacter

proteus vulgaris

citrobacter

e. coli

if simmon's citrate was positive, you can r/o

serratia

shigella

salmonella

klebsiella

enterobacter

proteus vulgaris again!

citrobacter

e. coli

that's as far down as i can get you...

serratia

shigella

salmonella

klebsiella

enterobacter

citrobacter

would they really give you klebsiella?!

[Hamm]

Yeah they gave us Klebsiella to do other tests in the lab. The list they gave was the list of unknowns they used.

[mangopeach]

My unknown was Citrobacter freundii, it was negative for indole,positive for motility and sulfur so if you have Citrobacter it should not have been negative for everything in the SIM. Acid in Sucrose,Lactose and Glucose but gas produced only in Sucrose and Glucose. No gas in the lactose.

[Hamm]

I was thinking I messed up the SIM but there was gas in the lactose so perhaps not. Thanks :)