Questions about Staph infections are the most common questions on this board if you look at all the previous threads. I want to ask you something before I answer your question, but before coming to this board, what was your impression about what Staph really is?
On to your question: Staphylococcus species are a group of bacteria which NORMALLY live on the skin in healthy people. Yes, this bug has the propensity to cause skin and soft tissue infections, but for the most part it just lives on your skin and in your nose and causes no problem. Even before your girlfriend got that infection on her chin, you were being exposed to the bacteria, so that ship has already sailed!
HOWEVER, Staphylococcus does not have the tools necessary to live in the GI tract like other bacteria do. So "eating" Staphylococcus would cause its immediate destruction by your stomach acid. Finally, if someone gets ill from invasive Staph infections, you get VERY ill. Ill to the point where you are in the hospital admitted. It's not a subtle bug. I hop I was able to answer your question. Can you please answer mine?