Anyone clued up on microorganisms? Cocci, gram negative bacteria?

Found 11th Oct 2010
Afternoon all, could do with a nudge in the right direction with my biology report on microorganisms.

Basically, what could cocci (round) gram negative bacteria be?

We left a petri dish containing agar out in our classroom and then left it in the fridge for one week.

After gram staining and viewing with an oil immersion lens, one of my samples had hundres of cocci, gram positive bacteria - but there were also about 5 cocci, gram NEGATIVE bacteria in the section I was viewing. I cannot find out what these could be and would like to find out some possibilites to put in my report.

Can anyone gimme an idea, please? I have tried to find out myself, but can only find bacilli gram negative.

Thank yous, would really appreciate some help x

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cocci - Neisseria spp (Neisseria meningitidis & Neisseria gonorrhoeae - a bit worrying!) and coccibacilli like B.pertussis, H.influenzae L.pneumophilia
Edited by: "moob" 11th Oct 2010

Original Poster

moob

cocci - Neisseria spp (Neisseria meningitidis & Neisseria gonorrhoeae - a … cocci - Neisseria spp (Neisseria meningitidis & Neisseria gonorrhoeae - a bit worrying!) and coccibacilli like B.pertussis, H.influenzae L.pneumophilia


Thanks very much - it can't be either of the first two because they are both diplococci bacteria and from looking at the others which are all coccibaccili, the ones I have were perfectly spherical oO
Quite glad it's none of those though!
Edited by: "Mrs.Z" 11th Oct 2010

They might not be cocci, sometimes viewing with oil immersion lenses can make things look different.

You could try using a selective media to isolate them further, but maybe the easiest way would be to 'forget' about them in your report if you're unsure!

Not that I've ever done such a thing, of course. X)

Paracoccus, Megasphaera ?

Original Poster

moob

They might not be cocci, sometimes viewing with oil immersion lenses can … They might not be cocci, sometimes viewing with oil immersion lenses can make things look different.You could try using a selective media to isolate them further, but maybe the easiest way would be to 'forget' about them in your report if you're unsure!Not that I've ever done such a thing, of course. X)


Think I will have to take another good look, I was in a bit of a rush by that time as class was already finished. How could I isolate these further? I really appreciate your help I guess I could 'forget' about them if I were the kind of person to make my own life easier but I love being 'extra' LOL!

Original Poster

dungavel

Paracoccus, Megasphaera ?


Thanks for replying, would either of these be likely to show up in an air sample, though?

As I said above, I think I will have to take another look and speak to my teacher - haven't got class till Wednesday now

Mrs.Z

Think I will have to take another good look, I was in a bit of a rush by … Think I will have to take another good look, I was in a bit of a rush by that time as class was already finished. How could I isolate these further? I really appreciate your help I guess I could 'forget' about them if I were the kind of person to make my own life easier but I love being 'extra' LOL!



You can isolate using a medium that's got specific nutrients for the species in question, but that might end up quite complicated. Why not approach the lecturer for some pointers? It's been ages since I've done Micro to be honest, used to love it though.

It's good to be inquisitive, but sometimes you've got to wing it in my experience, i.e. forget you ever found them!

Original Poster

moob

You can isolate using a medium that's got specific nutrients for the … You can isolate using a medium that's got specific nutrients for the species in question, but that might end up quite complicated. Why not approach the lecturer for some pointers? It's been ages since I've done Micro to be honest, used to love it though.It's good to be inquisitive, but sometimes you've got to wing it in my experience, i.e. forget you ever found them!


LOL! Thanks very much - I agree that it is interesting

I'm not implying anything here and it has been a long time since I did microbiology but Chlamydia is a gram negative coccoid bacteria..........sadly my days of streaking plates are long gone.

gari189

I'm not implying anything here and it has been a long time since I did … I'm not implying anything here and it has been a long time since I did microbiology but Chlamydia is a gram negative coccoid bacteria..........sadly my days of streaking plates are long gone.



Not a very nice bunch, the gram negative cocci!!

Re about 5 of them in the sample, I wouldn't pay them much attention. You wouldn't really expect the staining to be totally uniform. They could even be small fungal spores!

Isolating them further? Not those 5 for sure - they have had their chips.
If you think that there really are gram negative cocci then you would need to plate lots of diluted samples, grow the colonies and stain the bacteria growing in each colony.
ID by the standard tests.

It's a long time since I did any proper microbiology, as well!

Maybe someone dipped their knob in her media, so to speak.

Or her loop was inadequately flamed.

Sorry; I am ashamed that I have written that.:3

chesso

Or her loop was inadequately flamed. Sorry; I am ashamed that I have … Or her loop was inadequately flamed. Sorry; I am ashamed that I have written that.:3



Yes. So you should be.

Original Poster

mumbojumbo

http://library.med.utah.edu/kw/derm/pages/in06_5.htm;)


You sir/madam are a star! That is exactly how mine looked so I now have an explanation - thank you sooooooo much, I would leave you rep if I could

Original Poster

gari189

I'm not implying anything here and it has been a long time since I did … I'm not implying anything here and it has been a long time since I did microbiology but Chlamydia is a gram negative coccoid bacteria..........sadly my days of streaking plates are long gone.


I was rather worried how to search for that - didn't know what might turn up!

Mrs.Z

You sir/madam are a star! That is exactly how mine looked so I now have … You sir/madam are a star! That is exactly how mine looked so I now have an explanation - thank you sooooooo much, I would leave you rep if I could



It's only going to be S aureus if you smeared one yellow colony.

What agar were you using?

Original Poster

chesso

It's only going to be S aureus if you smeared one yellow colony.What agar … It's only going to be S aureus if you smeared one yellow colony.What agar were you using?



Yes the colony was yellow
My teacher didn't tell us which agar it wad and the bottle was just labelled 'agar'
The agar was like this one below:
http://www.channel4.com/food/images/mb/Channel4/4Food/big-food-map/channel4-on-tour/andrew-places/may08/week-four/01_mushroom_spores_on_agar--gt_full_width_landscape.jpg
Edited by: "Mrs.Z" 11th Oct 2010

Original Poster

The other colony I had was orange and were gram postive rod-like

Nutrient agar I guess.

It doesn't matter now you have confirmed that the colony was yellow!!

Yellow colony plus the appearance under the microscope gives strong evidence for S aureus. *thumbs up*

Original Poster

chesso

Nutrient agar I guess. It doesn't matter now you have confirmed that the … Nutrient agar I guess. It doesn't matter now you have confirmed that the colony was yellow!! Yellow colony plus the appearance under the microscope gives strong evidence for S aureus. *thumbs up*



Thank you, do you have any opinion on the orange colony, gram positive rod-like? I think I found what it likely is but would love a more 'professional' deduction.

Mrs.Z

The other colony I had was orange and were gram postive rod-like



It was only a few posts ago that I realised that the original slide was of the one colony!
It all makes sense to me now.

Enjoy your lab work - I used to.

Original Poster

chesso

It was only a few posts ago that I realised that the original slide was … It was only a few posts ago that I realised that the original slide was of the one colony!It all makes sense to me now. Enjoy your lab work - I used to.



Yes, I left a petri dish containing agar out in the air for 30 minutes, and then grew whatever was on it!
Then took two samples to magnify - one from a yellow colony and one from and orange colony

Mrs.Z

Thank you, do you have any opinion on the orange colony, gram positive … Thank you, do you have any opinion on the orange colony, gram positive rod-like? I think I found what it likely is but would love a more 'professional' deduction.


I am definitely not a professional.:D

I would think a Bacillus sp. but I haven't got any of the ID sheets and keys from way back when - I binned them all years ago!

You could grow the colony up, then extract the DNA from the cells, run it in a PCR (using primers which will target the conserved region of gram negative bacteria, in which it will contain the hypervariable region) then send it off for sequencing with a 454. Then you can blast the results against a database of known micro-organisms.

Original Poster

Yes I was looking at bacillus too - but the colour of the colony doesn't look right when I was Googling the images.

My colony looked like this colour
http://homepage.ntlworld.com/steveoid/microbeyellowplatebacteria.jpg

Edit: Oh, it could be this colour - type 9 is this colour, but should have endospores whereas mine did not
Edited by: "Mrs.Z" 11th Oct 2010
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