Phasevarions Mediate Epigenetic Regulation of Antimicrobial Susceptibility in Neisseria meningitidis

Phase variation is a common feature of host-adapted bacterial pathogens such as Neisseria meningitidis. Recently, we reported that this rapid on/off switching of gene expression occurs in DNA methyltransferases, altering expression in multiple genes via changes in global methylation. In the current study, we compared MIC values of strains with ModA11, ModA12, and ModD1 phasevarions, revealing MIC differences due to ModA11 and ModA12 switching, with a ModA11_OFF strain showing 4-fold reduced susceptibilities to ceftazidime and ciprofloxacin.