Stress adaptation within the host effects antibiotic tolerance and treatment outcome in Staphylococcus aureus infections
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ABSTRACT: Staphylococcus aureus can cause severe invasive infections that require prolonged antibiotic treatment. Although S. aureus can easily acquire antibiotic resistance, even fully susceptible bacteria can persist and survive antibiotic therapy, thus complicating treatment. These so-called persisters are phenotypic variants of bacteria characterized by an arrested-growth phenotype that can tolerate high concentrations of chemotherapeutics and are associated with chronic and recurrent infections. Here, we show that S. aureus recovered directly from infection sites, displayed an increased bacterial lag-phase heterogeneity, forming more non-stable small colonies, indicating the presence of dormant bacteria. Infection modelling showed that host-mediated stress, including acidic pH, neutrophil exposure and murine abscesses, as well as antibiotic treatment, promoted formation of persisters both in vitro and in vivo. Proteomics and RNA sequencing revealed stress-response reactions in bacteria leading to an overall more virulent population. However, after persister-enrichment, S. aureus displayed down-regulation of pathways involved in virulence, cell division, and DNA replication, while ribosomal proteins, nucleotide-, and amino acid- metabolic pathways were up-regulated, suggesting their requirement to fuel and maintain the persister phenotype. We demonstrate that decreased aconitase activity and ATP-levels as well as accumulation of insoluble proteins correlated with dormancy and growth reactivation cycles. Combination of antibiotics with retinoid derivatives, especially CD1530, significantly reduced both persisters and total bacterial load in a murine infection model. Our study provides an in-depth characterization of S. aureus persisters and shows that treatment failure due to antibiotic persistence could be addressed by using retinoid derivatives in combination with conventional antibiotics.
INSTRUMENT(S): Q Exactive
ORGANISM(S): Bacteria Staphylococcus Aureus
DISEASE(S): Epidural Abscess
SUBMITTER: Markus Huemer
LAB HEAD: Annelies S. Zinkernagel
PROVIDER: PXD018332 | Pride | 2021-02-12
REPOSITORIES: Pride
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