Surface-anchored Staphylococcus aureus-binding
proteins which can bind to exposed human matrix
molecules improve the nasal colonization of MRSA.
Clumping factor B and Staphylococcus aureus surface
proteins G and X (SasG, SasX) have been shown to
combine to nasal epithelial cells (58-60). Among them,
SasX lately has attracted more attention because it was
found to play an important role in an MRSA epidemic
(60). SasX existed in a MGE mainly belonging to the
ST239 MRSA strain which was a major ringleader
of MRSA infections in Asia areas. It was discovered
that SasX played a wide role in nasal colonization,
biofilm generation, immune evasion and virulence in
animal infection models. Thus, SasX may be a critical
element promoting ST239 spread in Asia. The way
SasX functions may providereference for doctors and
researchers to understand how the spread of colonization
and virulence elements through HGT drives an MRSA
epidemic. Teichoic acids, a kind of surface polymer of
Staphylococcus aureus, helped make MRSA able to
colonize the human nose (54). Moreover, MRSA has
some mechanisms resistant to antibacterial peptides
which cause the subsequent innate immune reaction (61).