(A) Comparison of PFGE patterns from historically early
MSSA and MRSA isolates from Denmark and the U.K. and representatives of
the Iberian, Pediatric, and New York clones of MRSA. Lanes 2–12 show
early MSSA strains (Table 1). Lanes 13 and 15–22 show early MRSA
strains (Table 2). Lanes 23–25 show contemporary MRSA (Table 3).
Strains used in A are underlined in Tables 1, 2, and 3.
Lane 2, E213; lane 3, E228; lane 4, E306; lane 5, E803; lane 6, E1215;
lane 7, E1907; lane 8, E2104; lane 9, E1410; lane 10, E3008; lane 11,
E2260; lane 12, E2251; lane 13, E2672; lane 15, E2125; lane 16, E2213;
lane 17, E3015; lane 18, E3150; lane 19, E3520; lane 20, E4278; lane
21, ST61/6219; lane 22, ST63/458; lane 23, Iberian clone HPV107
(19); lane 24, Pediatric clone HDE288 (23); lane 25, New York clone
BK2464 (24). Lanes 1, 14, and 26 show strain NCTC8325 used as molecular
weight standard. (B) Computer-generated dendrogram of
the PFGE patterns shown in A. Results are from analysis
of similarity by Jacquard's coefficient; clustering was done by the
minimum linkage method.