I'm sorry to hear of your problem as infections are very rare. Now that you have MRSA, you could do everything possible to make sure you're no longer a carrier or colonized by culturing your nostrils, And your surgeon should use the antibiotics used to battle MRSA in your procedure and you could even consider continuing oral doses if you desire this. In all likelihood, it should go well.
Infections following a breast augmentation are extremely rare and usually due to a resident bacteria like MRSS present prior to surgery so see an infectious disease MD to make sure you are clear after a comprehensive course of antibiotics and prior to future surgery
It certainly sounds like your surgeon did all the right things to get you to heal up. It is likely that he will put you on different antibiotics around the time of your surgery due to the prior infection that you had. There is an extensive protocol involved to try to clear your skin of MRSA but it takes several weeks/months and repeat skin testing to know if this contamination has been eliminated. You can check with your infectious disease specialist regarding the details. It is uncommon to have a repeat infection after a secondary BBA. Good luck.
The best way to reduce the risk of infection after a breast augmentation is to follow strict recovery rules. No exercising, lifting, getting in dirty water for 6 weeks after surgery. I always give my patients post-op antibiotics and IV antibiotics during the actual procedure.