title: Virulence gene expression in human community-acquired Staphylococcus aureus infection.
abstract: Isolates of methicillin-resistant Staphylococcus aureus (MRSA) were once linked uniformly with hospital-associated infections; however, community-acquired MRSA (CA-MRSA) now represents an emerging threat worldwide. To examine the association of differential virulence gene expression with outcomes of human infection, we measured transcript levels of target staphylococcal genes directly in clinical samples from children with active known or suspected CA-MRSA infections. Virulence genes encoding secreted toxins, including Panton-Valentine leukocidin, were highly expressed during superficial and invasive CA-MRSA infections. In contrast, increased expression of surface-associated protein A was linked only with invasive disease. Comparisons with laboratory-grown corresponding clinical isolates revealed that tissue-specific expression profiles reflect the activity of the staphylococcal accessory gene regulator during human infection. These results represent the first demonstration of staphylococcal gene expression and regulation directly in human tissue. Such analysis will help to unravel the complex interactions between CA-MRSA and its host environmental niches during disease development.
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri 63110-1093, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Loughman
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Fritz
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Storch
authors.forename: David A
authors.initials: DA
authors.lastname: Hunstad
mesh_terms: D000038:Abscess / Q000382:microbiology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D006801:Humans; D007223:Infant; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D009504:Neutrophils / Q000502:physiology; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins