RESUMO
lukF-PV was present in 36% of skin and soft tissue infection (SSTI)-derived methicillin-susceptible Staphylococcus aureus (MSSA) strains and comprised six distinct clones, which contained fewer enterotoxin genes than strains without lukF-PV. Clinical presentations and outcomes of lukF-PV(+) methicillin-resistant S. aureus (MRSA) and MSSA SSTIs were comparable. In multivariable analysis, the presence of lukF-PV remained a significant predictor for incision and drainage among MSSA strains.
Assuntos
Antibacterianos/farmacologia , Toxinas Bacterianas/genética , Exotoxinas/genética , Leucocidinas/genética , Meticilina/farmacologia , Dermatopatias Bacterianas/epidemiologia , Infecções dos Tecidos Moles/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , New York/epidemiologia , Prevalência , Dermatopatias Bacterianas/microbiologia , Dermatopatias Bacterianas/patologia , Infecções dos Tecidos Moles/microbiologia , Infecções dos Tecidos Moles/patologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Resultado do Tratamento , Adulto JovemRESUMO
Staphylococcal enterotoxins (SE) can cause toxin-mediated disease, and those that function as superantigens are implicated in the pathogenesis of allergic diseases. The prevalence of 19 enterotoxin genes was determined by PCR in clinical S. aureus strains derived from wounds (108) and blood (99). We performed spa typing and multilocus sequence typing (MLST) to determine clonal origin, and for selected strains staphylococcal enterotoxin B (SEB) production was measured by enzyme-linked immunosorbent assay. Strains carried a median of five SE genes. For most SE genes, the prevalence rates among methicillin-resistant and methicillin-sensitive S. aureus isolates, as well as wound- and blood-derived isolates, did not differ. At least one SE gene was detected in all except two S. aureus isolates (>99%). Complete egc clusters were found in only 11% of S. aureus isolates, whereas the combination of sed, sej, and ser was detected in 24% of clinical strains. S. aureus strains exhibited distinct combinations of SE genes, even if their pulsed-field gel electrophoresis and MLST patterns demonstrated clonality. USA300 strains also showed considerable variability in SE content, although they contained a lower number of SE genes (mean, 3). By contrast, SE content was unchanged in five pairs of serial isolates. SEB production by individual strains varied up to 200-fold, and even up to 15-fold in a pair of serial isolates. In conclusion, our results illustrate the genetic diversity of S. aureus strains with respect to enterotoxin genes and suggest that horizontal transfer of mobile genetic elements encoding virulence genes occurs frequently.