Virulence factor landscape of a Staphylococcus aureus sequence type 45 strain, MCRF184.

ABSTRACT: BACKGROUND:We describe the virulence factors of a methicillin-sensitive Staphylococcus aureus sequence type (ST) 45 strain, MCRF184, (spa type t917), that caused severe necrotizing fasciitis in a 72-year-old diabetic male. The genome of MCRF184 possesses three genomic islands: a relatively large type III ?Sa? with 42 open reading frames (ORFs) that includes superantigen- and lipoprotein-like genes, a truncated ?Sa? that consists mostly of the enterotoxin gene cluster (egc), and a ?Sa? island with 18 ORFs including ?-toxin. Additionally, the genome has two phage-related regions: phage ?Sa3 with three genes of the immune evasion cluster (IEC), and an incomplete phage that is distinct from other S. aureus phages. Finally, the region between orfX and orfY harbors a putative efflux pump, acetyltransferase, regulators, and mobilization genes instead of genes of SCCmec. RESULTS:Virulence factors included phenol soluble modulins (PSMs) ?1 through ?4 and PSMs ?1 and ?2. Ten ORFs identified in MCRF184 had not been reported in previously sequenced S. aureus strains. CONCLUSION:The dire clinical outcome in the patient and the described virulence factors all suggest that MCRF184, a ST45 strain is a highly virulent strain of S. aureus.

SUBMITTER: Aswani V 

PROVIDER: S-EPMC6368776 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature