Anyone have experience with a toddler and recurring staph infections?

My 19 month had what turned out to be a staph infection across her bottom, tummy, and upper legs. It started mainly as blister-ish bumps in her diaper area and spread. Her pediatrician prescribed an antibiotic (keflex, I think?), which seemed to help. We finished the 10 day course and the blisters across her skin faded. However, the day after her last dose, a few new blisters appeared again...so we went back to the doctor, they confirmed the infection was back (or hadn't really cleared?) and prescribed a new antibiotic. We finished that round of antibiotics on Monday last week. I noticed a new spot on her bottom on Wednesday, but it seemed to start fading the next day, so I didn't think as much of it. Today I've noticed about ten new blisters through her diaper area though, so I'm thinking it's back again and will make her an appointment in the morning. Has anyone else dealt with staph infections with their toddlers/babies like this? What finally cleared it? Any advice?