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TSB growth problem - (Oct/27/2010 )

Hello all,

We have difficulties growing MRSA in our lab. We spike 75mL of TSB with MRSA and place it in shaking incubator set at 36C and 200RPM. In parallel, we spike a TSA with the same MRSA and it grows.
We've also tried with Nutrient Broth but with no success
We also have contamination problem in the shaking incubator with other bacteria.

We never had difficulty growing MRSA before.

Please help because I don't understand!

-Fatmax-

Fatmax on Wed Oct 27 20:36:08 2010 said:


Hello all,

We have difficulties growing MRSA in our lab. We spike 75mL of TSB with MRSA and place it in shaking incubator set at 36C and 200RPM. In parallel, we spike a TSA with the same MRSA and it grows.
We've also tried with Nutrient Broth but with no success
We also have contamination problem in the shaking incubator with other bacteria.

We never had difficulty growing MRSA before.

Please help because I don't understand!


My first impression was to re-confirm the strain, do a 16s or other PCR and sequencing work to confirm that it is MRSA and not other bacteria. Do antibiotics sensitivity test to reconfirm as well.
I suspect that your stock culture was contaminated.
Also, Try to grow in TSB with antibiotics.

And: this article might help
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2566123/

-adrian kohsf-

adrian kohsf on Wed Oct 27 20:59:36 2010 said:


Fatmax on Wed Oct 27 20:36:08 2010 said:


Hello all,

We have difficulties growing MRSA in our lab. We spike 75mL of TSB with MRSA and place it in shaking incubator set at 36C and 200RPM. In parallel, we spike a TSA with the same MRSA and it grows.
We've also tried with Nutrient Broth but with no success
We also have contamination problem in the shaking incubator with other bacteria.

We never had difficulty growing MRSA before.

Please help because I don't understand!


My first impression was to re-confirm the strain, do a 16s or other PCR and sequencing work to confirm that it is MRSA and not other bacteria. Do antibiotics sensitivity test to reconfirm as well.
I suspect that your stock culture was contaminated.
Also, Try to grow in TSB with antibiotics.

And: this article might help
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2566123/


Thanks for the info.
Since we don't have a PCR, we use the BBL crystal system to confirm the identification of our microorganism used in our lab
On the other hand, it might be time for us to re-order a culture from ATCC, we re-hydrate a strain every 3 months but we've been using the Cryobank beads for quite some time now (at least 4 years).

Thanks again
Max

-Fatmax-

You are welcome. Wish you all the best. Good luck.

Adrian

-adrian kohsf-