Methods Identifying Unknown Bacteria?

[damm182]

Hi can anyone give me a list of experiements that I can do to find out an unknown bacteria sample? thanks

[canalon]

16S DNA sequencing...

[MrMistery]

short and efficient list there canalon

[kolean]

Isn't the first thing to do is a Gram stain? And then find out if it is anaerobic, aerobic, or facultative? then look at it under a microscope for its shape? what about the media that it can grow on? put different antibiotics in the media and see if it still can grow on it?

[canalon]

Of course kolean, you are right this is a good way. Although I would disagree with the use of antibiotics as they are not species specific. Although the microscopic observation (gram, shape, capsule...) is usually done after the bacteria has been grown so you should know by then if it is aerobic or not. Then a group of selective media either prepared by hand or in a kit (Biomerieux API, BD crystal...) selected on the basis of the first observations.

But my method works well too. I f you have the right equipment. Might be faster too.

[stochastic]

Gram's stain is certainly useful in classification but not always truthful. Some organisms, Acinetobacter in particular, can readily stain gram-positive in fresh clinical material, yet stains gram-negative after growth on plated media.

[zami'87.]

There's also API method for biochemical characteristics http://en.wikipedia.org/wiki/Analytical_Profile_Index

[JackBean]

Isn't the first thing to do is a Gram stain? And then find out if it is anaerobic, aerobic, or facultative? then look at it under a microscope for its shape? what about the media that it can grow on? put different antibiotics in the media and see if it still can grow on it?

Might be, but this takes lot of time, you need to be skillfull and often you get only the genus.
Basically, many PCR methods might be usefull and as wrote canalon, 16S sequencing is used, as it is specific and you do not need to cultivate the bacteria (so you do not risk the contaminaton or that the bacteria won't grow)