Separation of microbes

[xenologist]

Hi all!

 

I am an undergraduate student at a college in Albany. I am currently running a research experiment studying biofilm formations. However I have run into a roadblock which I hope you can all help me with..

 

I have cultured Streptococcus Epidermis and Staphylococcus Aureus from environmental samples i took. I used Manitol salt agar plates to culture them. However, the problem i am running into now is that my S. Aureus sample also contains some species of Cornyebacterium. I cannot manage to separate these two microbes. The great tragedy of all of this is that i will eventually have to culture these two microbes together later on in the experiment, but for right now i need to obtain pure cultures.

 

If anyone knows of a way to separate these two organisms i would be greatly appreciative ( + 100 win! to the answerer ) weather it be a special type of agar or broth, or some kind of external chemical that i could introduce....

 

=) Thank you! I can't get to wait to know you all better on the forums.

 

-Xenologist

[JorgeLobo]

Simple aseptic technique and streaking for isolation should allow you to isolate these bugs from each other. The colonial morphology should be distinct enough - but you could also perform Gram stain as cellular morphology is also distinctive.

 

 

I assume you meant Stephylococcus epidermidis -I'm not aware there is a "Streptococcus epidermidis."

[JorgeLobo]

Simple aseptic technique and streaking for isolation should allow you to isolate these bugs from each other. The colonial morphology should be distinct enough - but you could also perform Gram stain as cellular morphology is also distinctive.

 

 

I assume you meant Stephylococcus epidermidis -I'm not aware there is a "Streptococcus epidermidis."

 

 

Sorry - meant Staphylococcus epidermidis

[CharonY]

Separating Staphylococcus and corynebacteria can be done as described, but is often tricky. Very often you will find contaminants even after serial streaking. Manitol agar is generally already selective, but many corynebacteria (darn them and their hardy cell surface) are very resistant to a wide range of pH and osmotic challenges. Unless you know precisely which strains you have, I am not sure that there is a easy way with selective media.

[Magdalene]

hello

 

In my master thesis I was work over biofilm formation of S. aureus and S. epidermidis and interaction with another bacteria like f.e. Lacidophillus or another bacteria. We usually using a chromogenic medium from BIOMERIEUX to isolation. You should visit their website:) If You want to isolate only S. aureus there is a specific medium: S. aureus ID.

I think that will be good choice:)