Impact of Bicarbonate on PBP2a Production, Maturation, and Functionality in Methicillin-Resistant (MRSA).

Certain methicillin-resistant (MRSA) strains exhibit β-lactam-susceptibility , and in the presence of NaHCO (NaHCO-responsive MRSA). Herein, we investigate the impact of NaHCO on factors required for PBP2a functionality. Prototype NaHCO-responsive and -nonresponsive MRSA strains (as defined ) were assessed for the impact of NaHCO on: expression of genes involved in PBP2a production-maturation pathways (, , , , , , and ); membrane PBP2a and PrsA protein content; and membrane carotenoid content. Following NaHCO exposure in NaHCO-responsive (vs - nonresponsive) MRSA, there was significantly reduced expression of: ) and ; ) the gene axis; and ) Carotenoid production was reduced, while expression was increased by NaHCO exposure in all MRSA strains. This work underscores the distinct regulatory impact of NaHCO on a cadre of genes encoding factors required for maintenance of the MRSA phenotype through PBP2a functionality and maturation.