MsaABCR Operon and TCA Cycle Genes Form Persister Cells in ATP Dependent Manner in Staphylococcus aureus
Bridget Boehm1, Shanti Pandey2, Mohamed O. Elasri2
1Mississippi INBRE Research Scholar, Mississippi Gulf Coast Community College, Gulfport, MS
2School of Biological, Environment and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS
Persister cell formation is a significant virulence factor to overcome when treating bacterial infections. Without going through genetic modification, this sub-group of the bacterial population shows extreme antibiotic resistance. The presence of persister cells during Staphylococcus aureus infection contributes to treatment failures by becoming dormant under environmental stress, making antibiotic treatment ineffective against them. When the stress is removed, they resume growth, causing recurring infections. Previously, we showed msaABCR operon regulation of virulence factors such as biofilm formation, capsule production, and persister cell formation against antibiotic stress in S. aureus. Furthermore, we found msaABCR mutant defective in persister formation in gentamycin stress. We observed that ATP content is higher in msaABCR mutant cells as compared to wild type USA300 LAC in stationary growth phase. In this study, we attempt to study the role of TCA cycle genes in formation of persister cells. We measured the growth pattern of mutants of TCA cycle genes with wild-type USA300 LAC strain and found similar growth patterns in tryptic-soy-broth medium. On inactivation of TCA cycle genes, we observed increased persister formation in the presence of gentamycin. Since persister cell formation is associated with the depletion of ATP, we further plan to study whether ATP content plays a role in persister formation in TCA genes mutants and the role of msaABCR in TCA cycle activity in persister formation.