Our lab frequently reports organisms other than Group A Strep in throat cultures (Staph aureus, Group C Strep, etc). I generally ignore them as contaminants, and would only treat if the patient is not improving.
However, I have gotten a couple of reports of MRSA from routine (confirmatory after negative rapid strep tests) throat cultures, in kids for whom MRSA has not been previously seen.
Would you go ahead and treat with Bactrim or Clindamycin, and then check for nasal carriage of MRSA later, even if the kid was no longer symptomatic? Or would you let it go like you would for the Group C,G, etc?