Figure 2. . . Results of pulsed-field gel electrophoresis (PFGE) of Sphingomonas paucimobilis isolates obtained in November 2007. Lanes 1 and 10, molecular weight marker; lanes 2–7, bloodstream isolates from patients 1–6, respectively; lane 8, isolate from contaminated fentanyl; lane 9, unrelated control isolate. Patients 2 through 6 received intravenous fentanyl within 48 hours before S. paucimobilis bacteremia developed and had isolates with a PFGE pattern indistinguishable from that of fentanyl isolates. Patient 1 did not receive intravenous fentanyl and had S. paucimobilis bacteremia with a distinct PFGE pattern.