Glycerol uptake is important for L-form formation and persistence in Staphylococcus aureus

S. aureus is a significant human pathogen and has previously been shown to form cell wall deficient forms or L-forms in vitro and in vivo during infection. Despite many previous studies on S. aureus L-forms, the mechanisms of L-form formation in this organism remain unknown. Here we established the L-form model in S. aureus and constructed a transposon mutant library to identify genes involved in L-form formation. Screening of the library for mutants defective in L-form formation identified glpF involved in glycerol uptake being important for L-form formation in S. aureus. Consistent with this observation, glpF was found to be highly expressed in L-form S. aureus but hardly expressed in normal walled form. In addition, glpF mutant was found to be defective in antibiotic persistence. The defect in L-form formation and antibiotic persistence of the glpF mutant could be complemented by the wild type glpF gene. These findings provide new insight into the mechanisms of L-form formation and persistence in S. aureus and may have implications for development of new drugs targeting persisters for improved treatment.