Resistance to antibiotics arose very shortly after these "wonder drugs" were first introduced.  This case study examines resistance to the most commonly used antibiotics, penicillin and its derivatives.  In particular, it examines a recent study that shows potential for restoring susceptibility to these antibiotics in MRSA (methicillin-resistant Staphylococcus aureus).  The case provides students with opportunities to collect and analyze data as well as interpret data from the new study.  The case was designed for use in an introductory college level biology or microbiology course.  Measuring, calculating means and standard errors, and graphing techniques are included, and this case can be used to introduce them or serve as practice.  The case can also be used in upper-level courses for the purpose of practicing data collection and analysis.