title: Potential associations between severity of infection and the presence of virulence-associated genes in clinical strains of Staphylococcus aureus.
abstract: BACKGROUND
  The clinical spectrum of Staphylococcus aureus infection ranges from asymptomatic nasal carriage to osteomyelitis, infective endocarditis (IE) and death. In this study, we evaluate potential association between the presence of specific genes in a collection of prospectively characterized S. aureus clinical isolates and clinical outcome.
  
  
  RESULTS
  Two hundred thirty-nine S. aureus isolates (121 methicillin-resistant S. aureus [MRSA] and 118 methicillin-susceptible S. aureus [MSSA]) were screened by array comparative genomic hybridization (aCGH) to identify genes implicated in complicated infections. After adjustment for multiple tests, 226 genes were significantly associated with severity of infection. Of these 226 genes, 185 were not in the SCCmec element. Within the 185 non-SCCmec genes, 171 were less common and 14 more common in the complicated infection group. Among the 41 genes in the SCCmec element, 37 were more common and 4 were less common in the complicated group. A total of 51 of the 2014 sequences evaluated, 14 non-SCCmec and 37 SCCmec, were identified as genes of interest.
  
  
  CONCLUSIONS
  Of the 171 genes less common in complicated infections, 152 are of unknown function and may contribute to attenuation of virulence. The 14 non-SCCmec genes more common in complicated infections include bacteriophage-encoded genes such as regulatory factors and autolysins with potential roles in tissue adhesion or biofilm formation.
authors.affiliation: Department of Oral Biology, University at Buffalo, Buffalo, New York, United States of America. steven_gill@urmc.rochester.edu
authors.forename: Steven R
authors.initials: SR
authors.lastname: Gill
authors.forename: Lauren M
authors.initials: LM
authors.lastname: McIntyre
authors.forename: Charlotte L
authors.initials: CL
authors.lastname: Nelson
authors.forename: Brian
authors.initials: B
authors.lastname: Remortel
authors.forename: Tom
authors.initials: T
authors.lastname: Rude
authors.forename: L Barth
authors.initials: LB
authors.lastname: Reller
authors.forename: Vance G
authors.initials: VG
authors.lastname: Fowler
mesh_terms: D002999:Clone Cells; D055028:Comparative Genomic Hybridization; D005798:Genes, Bacterial / Q000235:genetics*; D005838:Genotype; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D015203:Reproducibility of Results; D013203:Staphylococcal Infections / Q000235:genetics* / Q000382:microbiology / Q000473:pathology*; D013211:Staphylococcus aureus / Q000235:genetics* / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics