AUTHOR=Rollin Guillaume , Tan Xin , Tros Fabiola , Dupuis Marion , Nassif Xavier , Charbit Alain , Coureuil Mathieu 

TITLE=Intracellular Survival of Staphylococcus aureus in Endothelial Cells: A Matter of Growth or Persistence

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.01354

DOI=10.3389/fmicb.2017.01354

ISSN=1664-302X

ABSTRACT=<p>The Gram-positive human pathogen <italic>Staphylococcus aureus</italic> is a leading cause of severe bacterial infections. Recent studies have shown that various cell types could readily internalize <italic>S. aureus</italic> and infected cells have been proposed to serve as vehicle for the systemic dissemination of the pathogen. Here we focused on the intracellular behavior of the Community-Associated Methicillin-Resistant <italic>S. aureus</italic> strain USA300. Supporting earlier observations, we found that wild-type <italic>S. aureus</italic> strain USA300 persisted for longer period within endothelial cells than within macrophages and that a mutant displaying the small colony variant phenotype (Δ<italic>hemDBL</italic>) had increased intracellular persistence. Time-lapse microscopy revealed that initial persistence of wild-type bacteria in endothelial cells corresponded to distinct single cell events, ranging from active intracellular bacterial proliferation, leading to cell lysis, to non-replicating bacterial persistence even 1 week after infection. In sharp contrast, Δ<italic>hemDBL</italic> mutant bacteria were essentially non-replicating up to 10 days after infection. These findings suggest that internalization of <italic>S. aureus</italic> in endothelial cells triggers its persistence and support the notion that endothelial cells might constitute an intracellular persistence niche responsible for reported relapse of infection after antibiotic therapy.</p>