511. The cefazolin (CZ) and piperacillin-tazobactam (TZP) inoculum effects (IEs) are persistent amongst serial isolates of methicillin-sensitive <i>Staphylococcus aureus</i> (MSSA) derived from the sputum of persons with cystic fibrosis (pwCF) despite variation in other phenotypes.
Open forum infectious diseases