Spontaneously Occurring Small-Colony Variants of Staphylococcus aureus Show Enhanced Clearance by THP-1 Macrophages.

Autor:	Stoneham SM; Department of Microbiology and Infection, Royal Sussex County Hospital, Brighton, United Kingdom.; Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom., Cantillon DM; Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom., Waddell SJ; Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom., Llewelyn MJ; Department of Microbiology and Infection, Royal Sussex County Hospital, Brighton, United Kingdom.; Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom.
Jazyk:	angličtina
Zdroj:	Frontiers in microbiology [Front Microbiol] 2020 Jun 12; Vol. 11, pp. 1300. Date of Electronic Publication: 2020 Jun 12 (Print Publication: 2020).
DOI:	10.3389/fmicb.2020.01300
Abstrakt:	Staphylococcus aureus is a common cause of chronic and relapsing infection, especially when the ability of the immune system to sterilize a focus of infection is compromised (e.g., because of a foreign body or in the cystic fibrosis lung). Chronic infections are associated with slow-growing colony phenotypes of S. aureus on solid media termed small-colony variants (SCVs). Stable SCVs show characteristic mutations in the electron transport chain that convey resistance to antibiotics, particularly aminoglycosides. This can be used to identify SCVs from within mixed-colony phenotype populations of S. aureus . More recently, populations of SCVs that rapidly revert to a "wild-type" (WT) colony phenotype, in the absence of selection pressure, have also been described. In laboratory studies, SCVs accumulate through prolonged infection of non-professional phagocytes and may represent an adaptation to the intracellular environment. However, data from phagocytic cells are lacking. In this study, we mapped SCV and WT colony populations in axenic growth of multiple well-characterized methicillin-sensitive and methicillin-resistant S. aureus strains. We identified SCVs populations on solid media both in the presence and absence of gentamicin. We generated stable SCVs from Newman strain S. aureus , and infected human macrophages with WT S. aureus (Newman, 8325-4) and their SCV counterparts (SCV3, I10) to examine intracellular formation and survival of SCVs. We show that SCVs arise spontaneously during axenic growth, and that the ratio of SCV:WT morphology differs between strains. Exposure to the intracellular environment of human macrophages did not increase formation of SCVs over 5 days and macrophages were able to clear stable SCV bacteria more effectively than their WT counterparts. (Copyright © 2020 Stoneham, Cantillon, Waddell and Llewelyn.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu