Cultures take about 2-5 days. Getting the report from the doctor may take longer.
Some years back, Medicare and Medicaid decided not to pay for treatment of hospital acquired infections and the hospital was not allowed to bill the patient for same. Some hospitals then started testing patients prior to admission to avoid getting stuck with that cost if the patient had an unknown infection before being admitted. There was talk around the hospital where I worked to require visitors to be tested before being allowed in. That didn't happen but you would be aghast at how many visitors came in sick! What are they thinking?!
One of the reasons I prefer van/RV travel is I always wonder just how clean is the hotel room. Many disinfectants require a contact time of 10 minutes to work. Do the housekeepers spray the sinks, bathtubs, door knobs, faucets, etc and keep those surfaces wet for that ten minutes to allow it to work? I doubt it.
I had a MRSA infection in a wound, caught from a patient in the hospital where I worked. Had to stay home until I had three negative cultures, each two weeks apart. I've been swabbed and cultured several times since then and always had negative results. Good news.
I'd rather take a sponge bath in my van than risk a public shower!