AUTHOR=Sun Yajun , Liu Miaomiao , Niu Mingze , Zhao Xin 

TITLE=Phenotypic Switching of Staphylococcus aureus Mu50 Into a Large Colony Variant Enhances Heritable Resistance Against β-Lactam Antibiotics

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.709841

DOI=10.3389/fmicb.2021.709841

ISSN=1664-302X

ABSTRACT=<p>Phenotypic heterogeneity within a bacterial population may confer new functionality and allow microorganisms to adapt to fluctuating environments. Previous work has suggested that <italic>Staphylococcus aureus</italic> could form small colony variants to avoid elimination by therapeutic antibiotics and host immunity systems. Here we show that a reversible non-pigment large colony morphology (Mu50∆<italic>lcpA</italic>-LC) was observed in <italic>S. aureus</italic> Mu50 after knocking out <italic>lcpA,</italic> coding for the LytR-CpsA-Psr family A protein. Mu50∆<italic>lcpA</italic>-LC increased resistance to β-lactam antibiotics, in addition, the enlarged cell size, enhanced spreading ability on solid medium, and reduced biofilm formation, suggesting better abilities for bacterial expansion. Moreover, the expression of <italic>spa</italic> encoding protein A was significantly increased in Mu50∆<italic>lcpA</italic>-LC. This study shows that besides the small colony variants, <italic>S. aureus</italic> could fight against antibiotics and host immunity through phenotype switching into a large colony variant.</p>