Ever woke up and noticed a small zit or pimple? Yep, that’s likely a staph infection, although there might be some streptococcus in there as well. They probably also entered your blood stream, but got quickly eliminated by your immune system. It’s all about the bacterial load.
Which is why you should not scratch wounds, even when they itch really bad. Here is a pic of my leg from almost a year ago, it got out of control because I kept scratching the wound and ignored the occasional flaring pain until it got so bad that I almost passed out when moving my leg. This is a combination of staph aureus and strep pyogenes when they really thrive in your wound. If those had been resistant strains, I would have been in a lot of trouble.