PFGE gel with the following profiles; lane 1, λ size marker; lane 2, E profile from outbreak 1; lane 3, E profile from outbreak 10; lane 4, E profile from outbreak 2; lane 5, E profile from outbreak 3; lane 6, G profile from outbreak 7; lane 7, B profile from outbreak 5; lane 8, B profile from outbreak 9; lane 9, B profile from outbreak 6; lane 10, P profile from outbreak 8; lane 11, sporadic strain with V profile; lane 12, sporadic strain with N profile; lane 13, sporadic strain with O profile; lane 14, sporadic strain with C profile; lane 15, sporadic strain with L profile; lane 16, λ size marker.