Agr, having been long acknowledged as a regulator of
virulence, plays an important part in toxin production
(68). Recent research suggested that Agr may increase
surface protein expression in a strain-dependant way
(69). Based on official guidelines, methicillin resistance
of MRSA is generated by mecA but the mechanism is
poorly understood. Lately, some studies indicated that
core genome-encoded regulators and the mec locus both
can affect Agr (