Is it possible to have staph infection more than once in life time?

Yes, many times: While we usually only get certain infections once (for example, chickenpox), we can get many infections many times, having staph once does not do much to make us immune to it. Unfortunately it is possible to get staph infections time and time again. Even after treating sometimes it continues to live in our bodies (esp. Nasopharynx) and thus is prone to recur.