The msaABCR Operon Regulates the Response to Oxidative Stress in Staphylococcus aureus

• Published in: Journal of bacteriology 2019-11, Vol.201 (21)
• Main Authors: Pandey, Shanti, Sahukhal, Gyan S, Elasri, Mohamed O
• Format: Article
• Language: English
• Subjects: Antibiotic resistance; Antibiotics; Bacteriology; Clonal deletion; Defense mechanisms; Gene expression; Genes; Hydrogen peroxide; Ohr gene; Oxidation resistance; Oxidative stress; Staphylococcus aureus; Transcription; Virulence
• ISSN: 0021-9193; 1098-5530
• DOI: 10.1128/JB.00417-19

has evolved a complex regulatory network that controls a multitude of defense mechanisms against the deleterious effects of oxidative stress stimuli, subsequently leading to the pathogen's survival and persistence in the hosts. Previously, we characterized the operon as a regulator of virulence, antibiotic resistance, and the formation of persister cells in Deletion of the operon resulted in the downregulation of several genes involved in resistance against oxidative stress. Notably, those included carotenoid biosynthetic genes and the gene, which is involved in resistance against organic hydroperoxides. These findings led us to hypothesize that the operon is involved in resisting oxidative stress generated in the presence of both H O and organic hydroperoxides. Here, we report that a protein product of the operon (MsaB) transcriptionally regulates the expression of the operon and the gene to resist oxidative stresses. In addition to its direct regulation of the operon and gene, we also show that MsaB is the transcriptional repressor of (repressor of ). Taken together, these results suggest that the operon regulates an oxidative stress defense mechanism, which is required to facilitate persistent and recurrent staphylococcal infections. Moving forward, we plan to investigate the role of in the persistence of under conditions. This study shows the involvement of the operon in resisting oxidative stress by generated under and conditions. We show that MsaB regulates the expression and production of a carotenoid pigment, staphyloxanthin, which is a potent antioxidant in We also demonstrate that MsaB regulates the gene, which is involved in defending against oxidative stress generated by organic hydroperoxides. This study highlights the importance of in the survival of in the presence of various environmental stimuli that mainly exert oxidative stress. The findings from this study indicate the possibility that is involved in the persistence of staphylococcal infections and therefore could be a potential antimicrobial target to overcome recalcitrant staphylococcal infections.