TY - JOUR
T1 - Diverse enterotoxin gene profiles among clonal complexes of Staphylococcus aureus isolates from the Bronx, New York
AU - Varshney, Avanish K.
AU - Mediavilla, José R.
AU - Robiou, Natalie
AU - Guh, Alice
AU - Wang, Xiabo
AU - Gialanella, Philip
AU - Levi, Michael H.
AU - Kreiswirth, Barry N.
AU - Fries, Bettina C.
PY - 2009/11
Y1 - 2009/11
N2 - 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 methicillinresistant 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.
AB - 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 methicillinresistant 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.
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U2 - 10.1128/AEM.00272-09
DO - 10.1128/AEM.00272-09
M3 - Article
C2 - 19749060
AN - SCOPUS:70350518256
SN - 0099-2240
VL - 75
SP - 6839
EP - 6849
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
IS - 21
ER -