Staphylococcus aureus TCH1516 response to sub-inhibitory concentrations of Nafcillin in different media conditions

Methicillin resistant S.aureus (MRSA) resistance to beta-lactam is dependent on environmental conditions. In physiologically relevant conditions present in RPMI (supplemented with 10% LB for proper growth) the MIC of beta lactam Nafcillin drops more than 20 fold when compared to MIC in bateriological Cation Adjusted Mueller Hinton Broth(CAMHB). In order to elucidate the underlying mechanism behind this difference, MRSA isolate TCH1516 was grown in each media in presence of varying levels of nafcillin. At 2.5 hour timepoint cells were harvested and expression profile determined with RNA sequencing. S.aureus was grown in two different bacterial conditions CAMHB/ RPMI + 10% LB (R10LB) with varying sub-inhibitory concentrations of Nafcillin – 0.0625 ug/mL and/or 0.5 ug/mL. SRPSRP127172. PRJNA422941