. Cellulitis is an infection of the deep subcutaneous tissue of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria. Whether MRSA is causing cellulites in your case or not depends on the blood culture sensitivity report. Blood culture sensitivity is often done to find out the causative pathogen and its sensitivity to various antibiotics. If it is MRSA, then antibiotics other than amoxycillin can be prescribed depending upon the blood culture report.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.