title: Staphylococcus aureus skin/soft-tissue infections: the impact of SCCmec type and Panton-Valentine leukocidin.
abstract: We assessed the role of Panton-Valentine leukocidin (PVL) and SCCmec type in community associated (CA) and healthcare associated (HC) Staphylococcus aureus (SA) skin/soft-tissue infections (STI). We prospectively monitored microbiology results (11 January 2005 to 6 January 2006), screened inpatients with SA in tissue samples or blood, and selected adults with STI. We recorded clinical/microbiological characteristics, and tested saved isolates for PVL genes (real time PCR) and SCCmec type (conventional multiplex PCR). We encountered 204 patients. MRSA strains that accounted for 70.5% CA and 66.0% HC cases, caused more abscesses (55.7% vs 29.7%; p =0.001) and were often PVL-positive (68.9% vs 4.8%; p <0.001). PVL-positive isolates caused more abscesses (72.9% vs 26.5%; p <0.001) but similar bacteremia (7.3% vs 7.1%). SCCmec IVa made up 95.8% of PVL-positive strains and accounted for 69.8% of the abscesses. SCCmec II caused higher mortality (14.8% vs 0-3.1%; p = 0.02). PVL was a predictor of abscesses (p <0.001). Predictors of bacteremia were age > or = 65 y (p =0.004), necrotizing infection (p =0.014), and head/neck location (p =0.05). These findings suggest that SCCmec type and PVL status influence STI manifestations and contribute to MRSA-MSSA differences. PVL is implicated in abscess formation but not bacteremia. Bacteremia is likely related to host condition and/or other virulence factors that were not studied.
authors.affiliation: Department of Medicine, St. John Hospital and Medical Center, Grosse Pointe Woods, MI 48236, USA.
authors.forename: Houssein
authors.initials: H
authors.lastname: Jahamy
authors.forename: Roopa
authors.initials: R
authors.lastname: Ganga
authors.forename: Basel
authors.initials: B
authors.lastname: Al Raiy
authors.forename: Stephen
authors.initials: S
authors.lastname: Shemes
authors.forename: Vijayalakshmi
authors.initials: V
authors.lastname: Nagappan
authors.forename: Mamta
authors.initials: M
authors.lastname: Sharma
authors.forename: Kathleen
authors.initials: K
authors.lastname: Riederer
authors.forename: Riad
authors.initials: R
authors.lastname: Khatib
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism*; D017714:Community-Acquired Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D005098:Exotoxins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005798:Genes, Bacterial; D006801:Humans; D007841:Latex Fixation Tests; D007956:Leukocidins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012044:Regression Analysis; D018461:Soft Tissue Infections / Q000382:microbiology* / Q000473:pathology; D013203:Staphylococcal Infections / Q000382:microbiology* / Q000473:pathology; D013207:Staphylococcal Skin Infections / Q000382:microbiology* / Q000473:pathology; D013211:Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*
chemical_list: D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin