Figure 3.
Pulsed-field gel electrophoresis banding patterns of PVL-positive Staphylococcus aureus isolates. Antibiotic susceptibility profiles and D-test results, as measured by standard disk-diffusion techniques, are shown to the right of each gel lane. Lanes 1–5 and 7 represent PVL-positive MSSA isolates with representative antibiotic susceptibility patterns. Lane 6, shown for comparison, is a PVL-positive CA-MRSA isolate. The bracket indicates a DNA fragment thought to include the SCCmec cassette, and the arrow its location in CA-MRSA USA300. The dendrogram to the left of the gel shows the genetic relatedness among the strains; as a group, the seven isolates are > 87% similar. Ox, oxacillin; Pen, penicillin; Ery, erythromycin; Clin, clindamycin; Tet, tetracycline; Neg, negative; R, resistant; S, susceptible; ND, not done.